Merge pull request #753 from lla-dane/feat/certified-addrbook

WIP: Certified-Address-Book interface for Peer-Store

docs/examples.mDNS.rst

@@ -0,0 +1,64 @@
+mDNS Peer Discovery Example
+===========================
+
+This example demonstrates how to use mDNS (Multicast DNS) for peer discovery in py-libp2p.
+
+Prerequisites
+-------------
+
+First, ensure you have py-libp2p installed and your environment is activated:
+
+.. code-block:: console
+
+    $ python -m pip install libp2p
+
+Running the Example
+-------------------
+
+The mDNS demo script allows you to discover peers on your local network using mDNS. To start a peer, run:
+
+.. code-block:: console
+
+    $ mdns-demo
+
+You should see output similar to:
+
+.. code-block:: console
+
+    Run this from another console to start another peer on a different port:
+
+    python mdns-demo -p <ANOTHER_PORT>
+
+    Waiting for mDNS peer discovery events...
+
+    2025-06-20 23:28:12,052 - libp2p.example.discovery.mdns - INFO - Starting peer Discovery
+
+To discover peers, open another terminal and run the same command with a different port:
+
+.. code-block:: console
+
+    $ python mdns-demo -p 9001
+
+You should see output indicating that a new peer has been discovered:
+
+.. code-block:: console
+
+    Run this from the same folder in another console to start another peer on a different port:
+
+    python mdns-demo -p <ANOTHER_PORT>
+
+    Waiting for mDNS peer discovery events...
+
+    2025-06-20 23:43:43,786 - libp2p.example.discovery.mdns - INFO - Starting peer Discovery
+    2025-06-20 23:43:43,790 - libp2p.example.discovery.mdns - INFO - Discovered: 16Uiu2HAmGxy5NdQEjZWtrYUMrzdp3Syvg7MB2E5Lx8weA9DanYxj
+
+When a new peer is discovered, its peer ID will be printed in the console output.
+
+How it Works
+------------
+
+- Each node advertises itself on the local network using mDNS.
+- When a new peer is discovered, the handler prints its peer ID.
+- This is useful for local peer discovery without requiring a DHT or bootstrap nodes.
+
+You can modify the script to perform additional actions when peers are discovered, such as opening streams or exchanging messages.

docs/examples.rst

@@ -13,3 +13,4 @@ Examples
    examples.pubsub
    examples.circuit_relay
    examples.kademlia
+   examples.mDNS

docs/libp2p.discovery.bootstrap.rst

@@ -0,0 +1,13 @@
+libp2p.discovery.bootstrap package
+==================================
+
+Submodules
+----------
+
+Module contents
+---------------
+
+.. automodule:: libp2p.discovery.bootstrap
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/libp2p.discovery.events.rst

@@ -0,0 +1,21 @@
+libp2p.discovery.events package
+===============================
+
+Submodules
+----------
+
+libp2p.discovery.events.peerDiscovery module
+--------------------------------------------
+
+.. automodule:: libp2p.discovery.events.peerDiscovery
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+Module contents
+---------------
+
+.. automodule:: libp2p.discovery.events
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/libp2p.discovery.mdns.rst

@@ -0,0 +1,45 @@
+libp2p.discovery.mdns package
+=============================
+
+Submodules
+----------
+
+libp2p.discovery.mdns.broadcaster module
+----------------------------------------
+
+.. automodule:: libp2p.discovery.mdns.broadcaster
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+libp2p.discovery.mdns.listener module
+-------------------------------------
+
+.. automodule:: libp2p.discovery.mdns.listener
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+libp2p.discovery.mdns.mdns module
+---------------------------------
+
+.. automodule:: libp2p.discovery.mdns.mdns
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+libp2p.discovery.mdns.utils module
+----------------------------------
+
+.. automodule:: libp2p.discovery.mdns.utils
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+Module contents
+---------------
+
+.. automodule:: libp2p.discovery.mdns
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/libp2p.discovery.rst

@@ -0,0 +1,23 @@
+libp2p.discovery package
+========================
+
+Subpackages
+-----------
+
+.. toctree::
+   :maxdepth: 4
+
+   libp2p.discovery.bootstrap
+   libp2p.discovery.events
+   libp2p.discovery.mdns
+
+Submodules
+----------
+
+Module contents
+---------------
+
+.. automodule:: libp2p.discovery
+   :members:
+   :undoc-members:
+   :show-inheritance:

docs/libp2p.rst

@@ -8,6 +8,7 @@ Subpackages
    :maxdepth: 4
 
    libp2p.crypto
+   libp2p.discovery
    libp2p.host
    libp2p.identity
    libp2p.io

docs/release_notes.rst

@@ -3,6 +3,65 @@ Release Notes
 
 .. towncrier release notes start
 
+py-libp2p v0.2.9 (2025-07-09)
+-----------------------------
+
+Breaking Changes
+~~~~~~~~~~~~~~~~
+
+- Reordered the arguments to ``upgrade_security`` to place ``is_initiator`` before ``peer_id``, and made ``peer_id`` optional.
+  This allows the method to reflect the fact that peer identity is not required for inbound connections. (`#681 <https://github.com/libp2p/py-libp2p/issues/681>`__)
+
+
+Bugfixes
+~~~~~~~~
+
+- Add timeout wrappers in:
+  1. ``multiselect.py``: ``negotiate`` function
+  2. ``multiselect_client.py``: ``select_one_of`` , ``query_multistream_command`` functions
+  to prevent indefinite hangs when a remote peer does not respond. (`#696 <https://github.com/libp2p/py-libp2p/issues/696>`__)
+- Align stream creation logic with yamux specification (`#701 <https://github.com/libp2p/py-libp2p/issues/701>`__)
+- Fixed an issue in ``Pubsub`` where async validators were not handled reliably under concurrency. Now uses a safe aggregator list for consistent behavior. (`#702 <https://github.com/libp2p/py-libp2p/issues/702>`__)
+
+
+Features
+~~~~~~~~
+
+- Added support for ``Kademlia DHT`` in py-libp2p. (`#579 <https://github.com/libp2p/py-libp2p/issues/579>`__)
+- Limit concurrency in ``push_identify_to_peers`` to prevent resource congestion under high peer counts. (`#621 <https://github.com/libp2p/py-libp2p/issues/621>`__)
+- Store public key and peer ID in peerstore during handshake
+
+  Modified the InsecureTransport class to accept an optional peerstore parameter and updated the handshake process to store the received public key and peer ID in the peerstore when available.
+
+  Added test cases to verify:
+  1. The peerstore remains unchanged when handshake fails due to peer ID mismatch
+  2. The handshake correctly adds a public key to a peer ID that already exists in the peerstore but doesn't have a public key yet (`#631 <https://github.com/libp2p/py-libp2p/issues/631>`__)
+- Fixed several flow-control and concurrency issues in the ``YamuxStream`` class. Previously, stress-testing revealed that transferring data over ``DEFAULT_WINDOW_SIZE`` would break the stream due to inconsistent window update handling and lock management. The fixes include:
+
+  - Removed sending of window updates during writes to maintain correct flow-control.
+  - Added proper timeout handling when releasing and acquiring locks to prevent concurrency errors.
+  - Corrected the ``read`` function to properly handle window updates for both ``read_until_EOF`` and ``read_n_bytes``.
+  - Added event logging at ``send_window_updates`` and ``waiting_for_window_updates`` for better observability. (`#639 <https://github.com/libp2p/py-libp2p/issues/639>`__)
+- Added support for ``Multicast DNS`` in py-libp2p (`#649 <https://github.com/libp2p/py-libp2p/issues/649>`__)
+- Optimized pubsub publishing to send multiple topics in a single message instead of separate messages per topic. (`#685 <https://github.com/libp2p/py-libp2p/issues/685>`__)
+- Optimized pubsub message writing by implementing a write_msg() method that uses pre-allocated buffers and single write operations, improving performance by eliminating separate varint prefix encoding and write operations in FloodSub and GossipSub. (`#687 <https://github.com/libp2p/py-libp2p/issues/687>`__)
+- Added peer exchange and backoff logic as part of Gossipsub v1.1 upgrade (`#690 <https://github.com/libp2p/py-libp2p/issues/690>`__)
+
+
+Internal Changes - for py-libp2p Contributors
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Added sparse connect utility function to pubsub test utilities for creating test networks with configurable connectivity. (`#679 <https://github.com/libp2p/py-libp2p/issues/679>`__)
+- Added comprehensive tests for pubsub connection utility functions to verify degree limits are enforced, excess peers are handled correctly, and edge cases (degree=0, negative values, empty lists) are managed gracefully. (`#707 <https://github.com/libp2p/py-libp2p/issues/707>`__)
+- Added extra tests for identify push concurrency cap under high peer load (`#708 <https://github.com/libp2p/py-libp2p/issues/708>`__)
+
+
+Miscellaneous Changes
+~~~~~~~~~~~~~~~~~~~~~
+
+- `#678 <https://github.com/libp2p/py-libp2p/issues/678>`__, `#684 <https://github.com/libp2p/py-libp2p/issues/684>`__
+
+
 py-libp2p v0.2.8 (2025-06-10)
 -----------------------------
 

examples/bootstrap/bootstrap.py

@@ -0,0 +1,136 @@
+import argparse
+import logging
+import secrets
+
+import multiaddr
+import trio
+
+from libp2p import new_host
+from libp2p.abc import PeerInfo
+from libp2p.crypto.secp256k1 import create_new_key_pair
+from libp2p.discovery.events.peerDiscovery import peerDiscovery
+
+# Configure logging
+logger = logging.getLogger("libp2p.discovery.bootstrap")
+logger.setLevel(logging.INFO)
+handler = logging.StreamHandler()
+handler.setFormatter(
+    logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
+)
+logger.addHandler(handler)
+
+# Configure root logger to only show warnings and above to reduce noise
+# This prevents verbose DEBUG messages from multiaddr, DNS, etc.
+logging.getLogger().setLevel(logging.WARNING)
+
+# Specifically silence noisy libraries
+logging.getLogger("multiaddr").setLevel(logging.WARNING)
+logging.getLogger("root").setLevel(logging.WARNING)
+
+
+def on_peer_discovery(peer_info: PeerInfo) -> None:
+    """Handler for peer discovery events."""
+    logger.info(f"🔍 Discovered peer: {peer_info.peer_id}")
+    logger.debug(f"   Addresses: {[str(addr) for addr in peer_info.addrs]}")
+
+
+# Example bootstrap peers
+BOOTSTRAP_PEERS = [
+    "/dnsaddr/github.com/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
+    "/dnsaddr/cloudflare.com/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
+    "/dnsaddr/google.com/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
+    "/dnsaddr/bootstrap.libp2p.io/p2p/QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN",
+    "/dnsaddr/bootstrap.libp2p.io/p2p/QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb",
+    "/ip4/104.131.131.82/tcp/4001/p2p/QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
+    "/ip6/2604:a880:1:20::203:d001/tcp/4001/p2p/QmSoLPppuBtQSGwKDZT2M73ULpjvfd3aZ6ha4oFGL1KrGM",
+    "/ip4/128.199.219.111/tcp/4001/p2p/QmSoLV4Bbm51jM9C4gDYZQ9Cy3U6aXMJDAbzgu2fzaDs64",
+    "/ip4/104.236.76.40/tcp/4001/p2p/QmSoLV4Bbm51jM9C4gDYZQ9Cy3U6aXMJDAbzgu2fzaDs64",
+    "/ip4/178.62.158.247/tcp/4001/p2p/QmSoLer265NRgSp2LA3dPaeykiS1J6DifTC88f5uVQKNAd",
+    "/ip6/2604:a880:1:20::203:d001/tcp/4001/p2p/QmSoLPppuBtQSGwKDZT2M73ULpjvfd3aZ6ha4oFGL1KrGM",
+    "/ip6/2400:6180:0:d0::151:6001/tcp/4001/p2p/QmSoLSafTMBsPKadTEgaXctDQVcqN88CNLHXMkTNwMKPnu",
+    "/ip6/2a03:b0c0:0:1010::23:1001/tcp/4001/p2p/QmSoLueR4xBeUbY9WZ9xGUUxunbKWcrNFTDAadQJmocnWm",
+]
+
+
+async def run(port: int, bootstrap_addrs: list[str]) -> None:
+    """Run the bootstrap discovery example."""
+    # Generate key pair
+    secret = secrets.token_bytes(32)
+    key_pair = create_new_key_pair(secret)
+
+    # Create listen address
+    listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
+
+    # Register peer discovery handler
+    peerDiscovery.register_peer_discovered_handler(on_peer_discovery)
+
+    logger.info("🚀 Starting Bootstrap Discovery Example")
+    logger.info(f"📍 Listening on: {listen_addr}")
+    logger.info(f"🌐 Bootstrap peers: {len(bootstrap_addrs)}")
+
+    print("\n" + "=" * 60)
+    print("Bootstrap Discovery Example")
+    print("=" * 60)
+    print("This example demonstrates connecting to bootstrap peers.")
+    print("Watch the logs for peer discovery events!")
+    print("Press Ctrl+C to exit.")
+    print("=" * 60)
+
+    # Create and run host with bootstrap discovery
+    host = new_host(key_pair=key_pair, bootstrap=bootstrap_addrs)
+
+    try:
+        async with host.run(listen_addrs=[listen_addr]):
+            # Keep running and log peer discovery events
+            await trio.sleep_forever()
+    except KeyboardInterrupt:
+        logger.info("👋 Shutting down...")
+
+
+def main() -> None:
+    """Main entry point."""
+    description = """
+    Bootstrap Discovery Example for py-libp2p
+
+    This example demonstrates how to use bootstrap peers for peer discovery.
+    Bootstrap peers are predefined peers that help new nodes join the network.
+
+    Usage:
+        python bootstrap.py -p 8000
+        python bootstrap.py -p 8001 --custom-bootstrap \\
+            "/ip4/127.0.0.1/tcp/8000/p2p/QmYourPeerID"
+    """
+
+    parser = argparse.ArgumentParser(
+        description=description, formatter_class=argparse.RawDescriptionHelpFormatter
+    )
+    parser.add_argument(
+        "-p", "--port", default=0, type=int, help="Port to listen on (default: random)"
+    )
+    parser.add_argument(
+        "--custom-bootstrap",
+        nargs="*",
+        help="Custom bootstrap addresses (space-separated)",
+    )
+    parser.add_argument(
+        "-v", "--verbose", action="store_true", help="Enable verbose output"
+    )
+
+    args = parser.parse_args()
+
+    if args.verbose:
+        logger.setLevel(logging.DEBUG)
+
+    # Use custom bootstrap addresses if provided, otherwise use defaults
+    bootstrap_addrs = (
+        args.custom_bootstrap if args.custom_bootstrap else BOOTSTRAP_PEERS
+    )
+
+    try:
+        trio.run(run, args.port, bootstrap_addrs)
+    except KeyboardInterrupt:
+        logger.info("Exiting...")
+
+
+if __name__ == "__main__":
+    main()

examples/chat/chat.py

@@ -43,6 +43,9 @@ async def run(port: int, destination: str) -> None:
     listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
     host = new_host()
     async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+        # Start the peer-store cleanup task
+        nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
         if not destination:  # its the server
 
             async def stream_handler(stream: INetStream) -> None:

examples/echo/echo.py

@@ -45,7 +45,10 @@ async def run(port: int, destination: str, seed: int | None = None) -> None:
         secret = secrets.token_bytes(32)
 
     host = new_host(key_pair=create_new_key_pair(secret))
-    async with host.run(listen_addrs=[listen_addr]):
+    async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+        # Start the peer-store cleanup task
+        nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
         print(f"I am {host.get_id().to_string()}")
 
         if not destination:  # its the server

examples/identify/identify.py

@@ -1,6 +1,7 @@
 import argparse
 import base64
 import logging
+import sys
 
 import multiaddr
 import trio
@@ -8,10 +9,13 @@ import trio
 from libp2p import (
     new_host,
 )
-from libp2p.identity.identify.identify import ID as IDENTIFY_PROTOCOL_ID
-from libp2p.identity.identify.pb.identify_pb2 import (
-    Identify,
+from libp2p.identity.identify.identify import (
+    ID as IDENTIFY_PROTOCOL_ID,
+    identify_handler_for,
+    parse_identify_response,
 )
+from libp2p.identity.identify.pb.identify_pb2 import Identify
+from libp2p.peer.envelope import debug_dump_envelope, unmarshal_envelope
 from libp2p.peer.peerinfo import (
     info_from_p2p_addr,
 )
@@ -30,10 +34,11 @@ def decode_multiaddrs(raw_addrs):
     return decoded_addrs
 
 
-def print_identify_response(identify_response):
+def print_identify_response(identify_response: Identify):
     """Pretty-print Identify response."""
     public_key_b64 = base64.b64encode(identify_response.public_key).decode("utf-8")
     listen_addrs = decode_multiaddrs(identify_response.listen_addrs)
+    signed_peer_record = unmarshal_envelope(identify_response.signedPeerRecord)
     try:
         observed_addr_decoded = decode_multiaddrs([identify_response.observed_addr])
     except Exception:
@@ -49,8 +54,10 @@ def print_identify_response(identify_response):
         f"  Agent Version: {identify_response.agent_version}"
     )
 
+    debug_dump_envelope(signed_peer_record)
 
-async def run(port: int, destination: str) -> None:
+
+async def run(port: int, destination: str, use_varint_format: bool = True) -> None:
     localhost_ip = "0.0.0.0"
 
     if not destination:
@@ -58,39 +65,159 @@ async def run(port: int, destination: str) -> None:
         listen_addr = multiaddr.Multiaddr(f"/ip4/{localhost_ip}/tcp/{port}")
         host_a = new_host()
 
-        async with host_a.run(listen_addrs=[listen_addr]):
+        # Set up identify handler with specified format
+        # Set use_varint_format = False, if want to checkout the Signed-PeerRecord
+        identify_handler = identify_handler_for(
+            host_a, use_varint_format=use_varint_format
+        )
+        host_a.set_stream_handler(IDENTIFY_PROTOCOL_ID, identify_handler)
+
+        async with (
+            host_a.run(listen_addrs=[listen_addr]),
+            trio.open_nursery() as nursery,
+        ):
+            # Start the peer-store cleanup task
+            nursery.start_soon(host_a.get_peerstore().start_cleanup_task, 60)
+
+            # Get the actual address and replace 0.0.0.0 with 127.0.0.1 for client
+            # connections
+            server_addr = str(host_a.get_addrs()[0])
+            client_addr = server_addr.replace("/ip4/0.0.0.0/", "/ip4/127.0.0.1/")
+
+            format_name = "length-prefixed" if use_varint_format else "raw protobuf"
+            format_flag = "--raw-format" if not use_varint_format else ""
             print(
-                "First host listening. Run this from another console:\n\n"
-                f"identify-demo "
-                f"-d {host_a.get_addrs()[0]}\n"
+                f"First host listening (using {format_name} format). "
+                f"Run this from another console:\n\n"
+                f"identify-demo {format_flag} -d {client_addr}\n"
             )
             print("Waiting for incoming identify request...")
+
+            # Add a custom handler to show connection events
+            async def custom_identify_handler(stream):
+                peer_id = stream.muxed_conn.peer_id
+                print(f"\n🔗 Received identify request from peer: {peer_id}")
+
+                # Show remote address in multiaddr format
+                try:
+                    from libp2p.identity.identify.identify import (
+                        _remote_address_to_multiaddr,
+                    )
+
+                    remote_address = stream.get_remote_address()
+                    if remote_address:
+                        observed_multiaddr = _remote_address_to_multiaddr(
+                            remote_address
+                        )
+                        # Add the peer ID to create a complete multiaddr
+                        complete_multiaddr = f"{observed_multiaddr}/p2p/{peer_id}"
+                        print(f"   Remote address: {complete_multiaddr}")
+                    else:
+                        print(f"   Remote address: {remote_address}")
+                except Exception:
+                    print(f"   Remote address: {stream.get_remote_address()}")
+
+                # Call the original handler
+                await identify_handler(stream)
+
+                print(f"✅ Successfully processed identify request from {peer_id}")
+
+            # Replace the handler with our custom one
+            host_a.set_stream_handler(IDENTIFY_PROTOCOL_ID, custom_identify_handler)
+
+            try:
                 await trio.sleep_forever()
+            except KeyboardInterrupt:
+                print("\n🛑 Shutting down listener...")
+                logger.info("Listener interrupted by user")
+                return
 
     else:
         # Create second host (dialer)
         listen_addr = multiaddr.Multiaddr(f"/ip4/{localhost_ip}/tcp/{port}")
         host_b = new_host()
 
-        async with host_b.run(listen_addrs=[listen_addr]):
+        async with (
+            host_b.run(listen_addrs=[listen_addr]),
+            trio.open_nursery() as nursery,
+        ):
+            # Start the peer-store cleanup task
+            nursery.start_soon(host_b.get_peerstore().start_cleanup_task, 60)
+
             # Connect to the first host
             print(f"dialer (host_b) listening on {host_b.get_addrs()[0]}")
             maddr = multiaddr.Multiaddr(destination)
             info = info_from_p2p_addr(maddr)
             print(f"Second host connecting to peer: {info.peer_id}")
 
+            try:
                 await host_b.connect(info)
+            except Exception as e:
+                error_msg = str(e)
+                if "unable to connect" in error_msg or "SwarmException" in error_msg:
+                    print(f"\n❌ Cannot connect to peer: {info.peer_id}")
+                    print(f"   Address: {destination}")
+                    print(f"   Error: {error_msg}")
+                    print(
+                        "\n💡 Make sure the peer is running and the address is correct."
+                    )
+                    return
+                else:
+                    # Re-raise other exceptions
+                    raise
+
             stream = await host_b.new_stream(info.peer_id, (IDENTIFY_PROTOCOL_ID,))
 
             try:
                 print("Starting identify protocol...")
-                response = await stream.read()
+
+                # Read the response using the utility function
+                from libp2p.utils.varint import read_length_prefixed_protobuf
+
+                response = await read_length_prefixed_protobuf(
+                    stream, use_varint_format
+                )
+                full_response = response
+
                 await stream.close()
-                identify_msg = Identify()
-                identify_msg.ParseFromString(response)
+
+                # Parse the response using the robust protocol-level function
+                # This handles both old and new formats automatically
+                identify_msg = parse_identify_response(full_response)
                 print_identify_response(identify_msg)
+
             except Exception as e:
-                print(f"Identify protocol error: {e}")
+                error_msg = str(e)
+                print(f"Identify protocol error: {error_msg}")
+
+                # Check for specific format mismatch errors
+                if "Error parsing message" in error_msg or "DecodeError" in error_msg:
+                    print("\n" + "=" * 60)
+                    print("FORMAT MISMATCH DETECTED!")
+                    print("=" * 60)
+                    if use_varint_format:
+                        print(
+                            "You are using length-prefixed format (default) but the "
+                            "listener"
+                        )
+                        print("is using raw protobuf format.")
+                        print(
+                            "\nTo fix this, run the dialer with the --raw-format flag:"
+                        )
+                        print(f"identify-demo --raw-format -d {destination}")
+                    else:
+                        print("You are using raw protobuf format but the listener")
+                        print("is using length-prefixed format (default).")
+                        print(
+                            "\nTo fix this, run the dialer without the --raw-format "
+                            "flag:"
+                        )
+                        print(f"identify-demo -d {destination}")
+                    print("=" * 60)
+                else:
+                    import traceback
+
+                    traceback.print_exc()
 
             return
 
@@ -98,9 +225,12 @@ async def run(port: int, destination: str) -> None:
 def main() -> None:
     description = """
     This program demonstrates the libp2p identify protocol.
-    First run identify-demo -p <PORT>' to start a listener.
+    First run 'identify-demo -p <PORT> [--raw-format]' to start a listener.
     Then run 'identify-demo <ANOTHER_PORT> -d <DESTINATION>'
     where <DESTINATION> is the multiaddress shown by the listener.
+
+    Use --raw-format to send raw protobuf messages (old format) instead of
+    length-prefixed protobuf messages (new format, default).
     """
 
     example_maddr = (
@@ -115,12 +245,35 @@ def main() -> None:
         type=str,
         help=f"destination multiaddr string, e.g. {example_maddr}",
     )
+    parser.add_argument(
+        "--raw-format",
+        action="store_true",
+        help=(
+            "use raw protobuf format (old format) instead of "
+            "length-prefixed (new format)"
+        ),
+    )
+
     args = parser.parse_args()
 
+    # Determine format: use varint (length-prefixed) if --raw-format is specified,
+    # otherwise use raw protobuf format (old format)
+    use_varint_format = args.raw_format
+
     try:
-        trio.run(run, *(args.port, args.destination))
+        if args.destination:
+            # Run in dialer mode
+            trio.run(run, *(args.port, args.destination, use_varint_format))
+        else:
+            # Run in listener mode
+            trio.run(run, *(args.port, args.destination, use_varint_format))
     except KeyboardInterrupt:
-        pass
+        print("\n👋 Goodbye!")
+        logger.info("Application interrupted by user")
+    except Exception as e:
+        print(f"\n❌ Error: {str(e)}")
+        logger.error("Error: %s", str(e))
+        sys.exit(1)
 
 
 if __name__ == "__main__":

examples/identify_push/identify_push_demo.py

@@ -11,23 +11,26 @@ This example shows how to:
 
 import logging
 
+import multiaddr
 import trio
 
 from libp2p import (
     new_host,
 )
+from libp2p.abc import (
+    INetStream,
+)
 from libp2p.crypto.secp256k1 import (
     create_new_key_pair,
 )
 from libp2p.custom_types import (
     TProtocol,
 )
-from libp2p.identity.identify import (
-    identify_handler_for,
+from libp2p.identity.identify.pb.identify_pb2 import (
+    Identify,
 )
 from libp2p.identity.identify_push import (
     ID_PUSH,
-    identify_push_handler_for,
     push_identify_to_peer,
 )
 from libp2p.peer.peerinfo import (
@@ -38,8 +41,145 @@ from libp2p.peer.peerinfo import (
 logger = logging.getLogger(__name__)
 
 
+def create_custom_identify_handler(host, host_name: str):
+    """Create a custom identify handler that displays received information."""
+
+    async def handle_identify(stream: INetStream) -> None:
+        peer_id = stream.muxed_conn.peer_id
+        print(f"\n🔍 {host_name} received identify request from peer: {peer_id}")
+
+        # Get the standard identify response using the existing function
+        from libp2p.identity.identify.identify import (
+            _mk_identify_protobuf,
+            _remote_address_to_multiaddr,
+        )
+
+        # Get observed address
+        observed_multiaddr = None
+        try:
+            remote_address = stream.get_remote_address()
+            if remote_address:
+                observed_multiaddr = _remote_address_to_multiaddr(remote_address)
+        except Exception:
+            pass
+
+        # Build the identify protobuf
+        identify_msg = _mk_identify_protobuf(host, observed_multiaddr)
+        response_data = identify_msg.SerializeToString()
+
+        print(f"   📋 {host_name} identify information:")
+        if identify_msg.HasField("protocol_version"):
+            print(f"      Protocol Version: {identify_msg.protocol_version}")
+        if identify_msg.HasField("agent_version"):
+            print(f"      Agent Version: {identify_msg.agent_version}")
+        if identify_msg.HasField("public_key"):
+            print(f"      Public Key: {identify_msg.public_key.hex()[:16]}...")
+        if identify_msg.listen_addrs:
+            print("      Listen Addresses:")
+            for addr_bytes in identify_msg.listen_addrs:
+                addr = multiaddr.Multiaddr(addr_bytes)
+                print(f"        - {addr}")
+        if identify_msg.protocols:
+            print("      Supported Protocols:")
+            for protocol in identify_msg.protocols:
+                print(f"        - {protocol}")
+
+        # Send the response
+        await stream.write(response_data)
+        await stream.close()
+
+    return handle_identify
+
+
+def create_custom_identify_push_handler(host, host_name: str):
+    """Create a custom identify/push handler that displays received information."""
+
+    async def handle_identify_push(stream: INetStream) -> None:
+        peer_id = stream.muxed_conn.peer_id
+        print(f"\n📤 {host_name} received identify/push from peer: {peer_id}")
+
+        try:
+            # Read the identify message using the utility function
+            from libp2p.utils.varint import read_length_prefixed_protobuf
+
+            data = await read_length_prefixed_protobuf(stream, use_varint_format=True)
+
+            # Parse the identify message
+            identify_msg = Identify()
+            identify_msg.ParseFromString(data)
+
+            print("   📋 Received identify information:")
+            if identify_msg.HasField("protocol_version"):
+                print(f"      Protocol Version: {identify_msg.protocol_version}")
+            if identify_msg.HasField("agent_version"):
+                print(f"      Agent Version: {identify_msg.agent_version}")
+            if identify_msg.HasField("public_key"):
+                print(f"      Public Key: {identify_msg.public_key.hex()[:16]}...")
+            if identify_msg.HasField("observed_addr") and identify_msg.observed_addr:
+                observed_addr = multiaddr.Multiaddr(identify_msg.observed_addr)
+                print(f"      Observed Address: {observed_addr}")
+            if identify_msg.listen_addrs:
+                print("      Listen Addresses:")
+                for addr_bytes in identify_msg.listen_addrs:
+                    addr = multiaddr.Multiaddr(addr_bytes)
+                    print(f"        - {addr}")
+            if identify_msg.protocols:
+                print("      Supported Protocols:")
+                for protocol in identify_msg.protocols:
+                    print(f"        - {protocol}")
+
+            # Update the peerstore with the new information
+            from libp2p.identity.identify_push.identify_push import (
+                _update_peerstore_from_identify,
+            )
+
+            await _update_peerstore_from_identify(
+                host.get_peerstore(), peer_id, identify_msg
+            )
+
+            print(f"   ✅ {host_name} updated peerstore with new information")
+
+        except Exception as e:
+            print(f"   ❌ Error processing identify/push: {e}")
+        finally:
+            await stream.close()
+
+    return handle_identify_push
+
+
+async def display_peerstore_info(host, host_name: str, peer_id, description: str):
+    """Display peerstore information for a specific peer."""
+    peerstore = host.get_peerstore()
+
+    try:
+        addrs = peerstore.addrs(peer_id)
+    except Exception:
+        addrs = []
+
+    try:
+        protocols = peerstore.get_protocols(peer_id)
+    except Exception:
+        protocols = []
+
+    print(f"\n📚 {host_name} peerstore for {description}:")
+    print(f"   Peer ID: {peer_id}")
+    if addrs:
+        print("   Addresses:")
+        for addr in addrs:
+            print(f"     - {addr}")
+    else:
+        print("   Addresses: None")
+
+    if protocols:
+        print("   Protocols:")
+        for protocol in protocols:
+            print(f"     - {protocol}")
+    else:
+        print("   Protocols: None")
+
+
 async def main() -> None:
-    print("\n==== Starting Identify-Push Example ====\n")
+    print("\n==== Starting Enhanced Identify-Push Example ====\n")
 
     # Create key pairs for the two hosts
     key_pair_1 = create_new_key_pair()
@@ -48,45 +188,57 @@ async def main() -> None:
     # Create the first host
     host_1 = new_host(key_pair=key_pair_1)
 
-    # Set up the identify and identify/push handlers
-    host_1.set_stream_handler(TProtocol("/ipfs/id/1.0.0"), identify_handler_for(host_1))
-    host_1.set_stream_handler(ID_PUSH, identify_push_handler_for(host_1))
+    # Set up custom identify and identify/push handlers
+    host_1.set_stream_handler(
+        TProtocol("/ipfs/id/1.0.0"), create_custom_identify_handler(host_1, "Host 1")
+    )
+    host_1.set_stream_handler(
+        ID_PUSH, create_custom_identify_push_handler(host_1, "Host 1")
+    )
 
     # Create the second host
     host_2 = new_host(key_pair=key_pair_2)
 
-    # Set up the identify and identify/push handlers
-    host_2.set_stream_handler(TProtocol("/ipfs/id/1.0.0"), identify_handler_for(host_2))
-    host_2.set_stream_handler(ID_PUSH, identify_push_handler_for(host_2))
+    # Set up custom identify and identify/push handlers
+    host_2.set_stream_handler(
+        TProtocol("/ipfs/id/1.0.0"), create_custom_identify_handler(host_2, "Host 2")
+    )
+    host_2.set_stream_handler(
+        ID_PUSH, create_custom_identify_push_handler(host_2, "Host 2")
+    )
 
     # Start listening on random ports using the run context manager
-    import multiaddr
-
     listen_addr_1 = multiaddr.Multiaddr("/ip4/127.0.0.1/tcp/0")
     listen_addr_2 = multiaddr.Multiaddr("/ip4/127.0.0.1/tcp/0")
 
-    async with host_1.run([listen_addr_1]), host_2.run([listen_addr_2]):
+    async with (
+        host_1.run([listen_addr_1]),
+        host_2.run([listen_addr_2]),
+        trio.open_nursery() as nursery,
+    ):
+        # Start the peer-store cleanup task
+        nursery.start_soon(host_1.get_peerstore().start_cleanup_task, 60)
+        nursery.start_soon(host_2.get_peerstore().start_cleanup_task, 60)
+
         # Get the addresses of both hosts
         addr_1 = host_1.get_addrs()[0]
-        logger.info(f"Host 1 listening on {addr_1}")
-        print(f"Host 1 listening on {addr_1}")
-        print(f"Peer ID: {host_1.get_id().pretty()}")
-
         addr_2 = host_2.get_addrs()[0]
-        logger.info(f"Host 2 listening on {addr_2}")
-        print(f"Host 2 listening on {addr_2}")
-        print(f"Peer ID: {host_2.get_id().pretty()}")
 
-        print("\nConnecting Host 2 to Host 1...")
+        print("🏠 Host Configuration:")
+        print(f"   Host 1: {addr_1}")
+        print(f"   Host 1 Peer ID: {host_1.get_id().pretty()}")
+        print(f"   Host 2: {addr_2}")
+        print(f"   Host 2 Peer ID: {host_2.get_id().pretty()}")
+
+        print("\n🔗 Connecting Host 2 to Host 1...")
 
         # Connect host_2 to host_1
         peer_info = info_from_p2p_addr(addr_1)
         await host_2.connect(peer_info)
-        logger.info("Host 2 connected to Host 1")
-        print("Host 2 successfully connected to Host 1")
+        print("✅ Host 2 successfully connected to Host 1")
 
         # Run the identify protocol from host_2 to host_1
-        # (so Host 1 learns Host 2's address)
+        print("\n🔄 Running identify protocol (Host 2 → Host 1)...")
         from libp2p.identity.identify.identify import ID as IDENTIFY_PROTOCOL_ID
 
         stream = await host_2.new_stream(host_1.get_id(), (IDENTIFY_PROTOCOL_ID,))
@@ -94,64 +246,58 @@ async def main() -> None:
         await stream.close()
 
         # Run the identify protocol from host_1 to host_2
-        # (so Host 2 learns Host 1's address)
+        print("\n🔄 Running identify protocol (Host 1 → Host 2)...")
         stream = await host_1.new_stream(host_2.get_id(), (IDENTIFY_PROTOCOL_ID,))
         response = await stream.read()
         await stream.close()
 
-        # --- NEW CODE: Update Host 1's peerstore with Host 2's addresses ---
-        from libp2p.identity.identify.pb.identify_pb2 import (
-            Identify,
-        )
-
+        # Update Host 1's peerstore with Host 2's addresses
         identify_msg = Identify()
         identify_msg.ParseFromString(response)
         peerstore_1 = host_1.get_peerstore()
         peer_id_2 = host_2.get_id()
         for addr_bytes in identify_msg.listen_addrs:
             maddr = multiaddr.Multiaddr(addr_bytes)
-            # TTL can be any positive int
-            peerstore_1.add_addr(
-                peer_id_2,
-                maddr,
-                ttl=3600,
-            )
-        # --- END NEW CODE ---
+            peerstore_1.add_addr(peer_id_2, maddr, ttl=3600)
 
-        # Now Host 1's peerstore should have Host 2's address
-        peerstore_1 = host_1.get_peerstore()
-        peer_id_2 = host_2.get_id()
-        addrs_1_for_2 = peerstore_1.addrs(peer_id_2)
-        logger.info(
-            f"[DEBUG] Host 1 peerstore addresses for Host 2 before push: "
-            f"{addrs_1_for_2}"
-        )
-        print(
-            f"[DEBUG] Host 1 peerstore addresses for Host 2 before push: "
-            f"{addrs_1_for_2}"
+        # Display peerstore information before push
+        await display_peerstore_info(
+            host_1, "Host 1", peer_id_2, "Host 2 (before push)"
         )
 
         # Push identify information from host_1 to host_2
-        logger.info("Host 1 pushing identify information to Host 2")
-        print("\nHost 1 pushing identify information to Host 2...")
+        print("\n📤 Host 1 pushing identify information to Host 2...")
 
         try:
-            # Call push_identify_to_peer which now returns a boolean
             success = await push_identify_to_peer(host_1, host_2.get_id())
 
             if success:
-                logger.info("Identify push completed successfully")
-                print("Identify push completed successfully!")
+                print("✅ Identify push completed successfully!")
             else:
-                logger.warning("Identify push didn't complete successfully")
-                print("\nWarning: Identify push didn't complete successfully")
+                print("⚠️  Identify push didn't complete successfully")
 
         except Exception as e:
-            logger.error(f"Error during identify push: {str(e)}")
-            print(f"\nError during identify push: {str(e)}")
+            print(f"❌ Error during identify push: {str(e)}")
 
-        # Add this at the end of your async with block:
-        await trio.sleep(0.5)  # Give background tasks time to finish
+        # Give a moment for the identify/push processing to complete
+        await trio.sleep(0.5)
+
+        # Display peerstore information after push
+        await display_peerstore_info(host_1, "Host 1", peer_id_2, "Host 2 (after push)")
+        await display_peerstore_info(
+            host_2, "Host 2", host_1.get_id(), "Host 1 (after push)"
+        )
+
+        # Give more time for background tasks to finish and connections to stabilize
+        print("\n⏳ Waiting for background tasks to complete...")
+        await trio.sleep(1.0)
+
+        # Gracefully close connections to prevent connection errors
+        print("🔌 Closing connections...")
+        await host_2.disconnect(host_1.get_id())
+        await trio.sleep(0.2)
+
+        print("\n🎉 Example completed successfully!")
 
 
 if __name__ == "__main__":

examples/identify_push/identify_push_listener_dialer.py

@@ -41,6 +41,9 @@ from libp2p.identity.identify import (
     ID as ID_IDENTIFY,
     identify_handler_for,
 )
+from libp2p.identity.identify.identify import (
+    _remote_address_to_multiaddr,
+)
 from libp2p.identity.identify.pb.identify_pb2 import (
     Identify,
 )
@@ -57,18 +60,46 @@ from libp2p.peer.peerinfo import (
 logger = logging.getLogger("libp2p.identity.identify-push-example")
 
 
-def custom_identify_push_handler_for(host):
+def custom_identify_push_handler_for(host, use_varint_format: bool = True):
     """
     Create a custom handler for the identify/push protocol that logs and prints
     the identity information received from the dialer.
+
+    Args:
+        host: The libp2p host
+        use_varint_format: If True, expect length-prefixed format; if False, expect
+            raw protobuf
+
     """
 
     async def handle_identify_push(stream: INetStream) -> None:
         peer_id = stream.muxed_conn.peer_id
 
+        # Get remote address information
         try:
-            # Read the identify message from the stream
-            data = await stream.read()
+            remote_address = stream.get_remote_address()
+            if remote_address:
+                observed_multiaddr = _remote_address_to_multiaddr(remote_address)
+                logger.info(
+                    "Connection from remote peer %s, address: %s, multiaddr: %s",
+                    peer_id,
+                    remote_address,
+                    observed_multiaddr,
+                )
+                print(f"\n🔗 Received identify/push request from peer: {peer_id}")
+                # Add the peer ID to create a complete multiaddr
+                complete_multiaddr = f"{observed_multiaddr}/p2p/{peer_id}"
+                print(f"   Remote address: {complete_multiaddr}")
+        except Exception as e:
+            logger.error("Error getting remote address: %s", e)
+            print(f"\n🔗 Received identify/push request from peer: {peer_id}")
+
+        try:
+            # Use the utility function to read the protobuf message
+            from libp2p.utils.varint import read_length_prefixed_protobuf
+
+            data = await read_length_prefixed_protobuf(stream, use_varint_format)
+
             identify_msg = Identify()
             identify_msg.ParseFromString(data)
 
@@ -117,11 +148,41 @@ def custom_identify_push_handler_for(host):
             await _update_peerstore_from_identify(peerstore, peer_id, identify_msg)
 
             logger.info("Successfully processed identify/push from peer %s", peer_id)
-            print(f"\nSuccessfully processed identify/push from peer {peer_id}")
+            print(f"✅ Successfully processed identify/push from peer {peer_id}")
 
         except Exception as e:
-            logger.error("Error processing identify/push from %s: %s", peer_id, e)
-            print(f"\nError processing identify/push from {peer_id}: {e}")
+            error_msg = str(e)
+            logger.error(
+                "Error processing identify/push from %s: %s", peer_id, error_msg
+            )
+            print(f"\nError processing identify/push from {peer_id}: {error_msg}")
+
+            # Check for specific format mismatch errors
+            if (
+                "Error parsing message" in error_msg
+                or "DecodeError" in error_msg
+                or "ParseFromString" in error_msg
+            ):
+                print("\n" + "=" * 60)
+                print("FORMAT MISMATCH DETECTED!")
+                print("=" * 60)
+                if use_varint_format:
+                    print(
+                        "You are using length-prefixed format (default) but the "
+                        "dialer is using raw protobuf format."
+                    )
+                    print("\nTo fix this, run the dialer with the --raw-format flag:")
+                    print(
+                        "identify-push-listener-dialer-demo --raw-format -d <ADDRESS>"
+                    )
+                else:
+                    print("You are using raw protobuf format but the dialer")
+                    print("is using length-prefixed format (default).")
+                    print(
+                        "\nTo fix this, run the dialer without the --raw-format flag:"
+                    )
+                    print("identify-push-listener-dialer-demo -d <ADDRESS>")
+                print("=" * 60)
         finally:
             # Close the stream after processing
             await stream.close()
@@ -129,9 +190,15 @@ def custom_identify_push_handler_for(host):
     return handle_identify_push
 
 
-async def run_listener(port: int) -> None:
+async def run_listener(
+    port: int, use_varint_format: bool = True, raw_format_flag: bool = False
+) -> None:
     """Run a host in listener mode."""
-    print(f"\n==== Starting Identify-Push Listener on port {port} ====\n")
+    format_name = "length-prefixed" if use_varint_format else "raw protobuf"
+    print(
+        f"\n==== Starting Identify-Push Listener on port {port} "
+        f"(using {format_name} format) ====\n"
+    )
 
     # Create key pair for the listener
     key_pair = create_new_key_pair()
@@ -139,13 +206,19 @@ async def run_listener(port: int) -> None:
     # Create the listener host
     host = new_host(key_pair=key_pair)
 
-    # Set up the identify and identify/push handlers
-    host.set_stream_handler(ID_IDENTIFY, identify_handler_for(host))
-    host.set_stream_handler(ID_IDENTIFY_PUSH, custom_identify_push_handler_for(host))
+    # Set up the identify and identify/push handlers with specified format
+    host.set_stream_handler(
+        ID_IDENTIFY, identify_handler_for(host, use_varint_format=use_varint_format)
+    )
+    host.set_stream_handler(
+        ID_IDENTIFY_PUSH,
+        custom_identify_push_handler_for(host, use_varint_format=use_varint_format),
+    )
 
     # Start listening
     listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
 
+    try:
         async with host.run([listen_addr]):
             addr = host.get_addrs()[0]
             logger.info("Listener host ready!")
@@ -158,16 +231,33 @@ async def run_listener(port: int) -> None:
             print(f"Peer ID: {host.get_id().pretty()}")
 
             print("\nRun dialer with command:")
+            if raw_format_flag:
+                print(f"identify-push-listener-dialer-demo -d {addr} --raw-format")
+            else:
                 print(f"identify-push-listener-dialer-demo -d {addr}")
-        print("\nWaiting for incoming connections... (Ctrl+C to exit)")
+            print("\nWaiting for incoming identify/push requests... (Ctrl+C to exit)")
 
             # Keep running until interrupted
+            try:
                 await trio.sleep_forever()
+            except KeyboardInterrupt:
+                print("\n🛑 Shutting down listener...")
+                logger.info("Listener interrupted by user")
+                return
+    except Exception as e:
+        logger.error(f"Listener error: {e}")
+        raise
 
 
-async def run_dialer(port: int, destination: str) -> None:
+async def run_dialer(
+    port: int, destination: str, use_varint_format: bool = True
+) -> None:
     """Run a host in dialer mode that connects to a listener."""
-    print(f"\n==== Starting Identify-Push Dialer on port {port} ====\n")
+    format_name = "length-prefixed" if use_varint_format else "raw protobuf"
+    print(
+        f"\n==== Starting Identify-Push Dialer on port {port} "
+        f"(using {format_name} format) ====\n"
+    )
 
     # Create key pair for the dialer
     key_pair = create_new_key_pair()
@@ -175,9 +265,14 @@ async def run_dialer(port: int, destination: str) -> None:
     # Create the dialer host
     host = new_host(key_pair=key_pair)
 
-    # Set up the identify and identify/push handlers
-    host.set_stream_handler(ID_IDENTIFY, identify_handler_for(host))
-    host.set_stream_handler(ID_IDENTIFY_PUSH, identify_push_handler_for(host))
+    # Set up the identify and identify/push handlers with specified format
+    host.set_stream_handler(
+        ID_IDENTIFY, identify_handler_for(host, use_varint_format=use_varint_format)
+    )
+    host.set_stream_handler(
+        ID_IDENTIFY_PUSH,
+        identify_push_handler_for(host, use_varint_format=use_varint_format),
+    )
 
     # Start listening on a different port
     listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
@@ -198,7 +293,9 @@ async def run_dialer(port: int, destination: str) -> None:
         try:
             await host.connect(peer_info)
             logger.info("Successfully connected to listener!")
-            print("Successfully connected to listener!")
+            print("✅ Successfully connected to listener!")
+            print(f"   Connected to: {peer_info.peer_id}")
+            print(f"   Full address: {destination}")
 
             # Push identify information to the listener
             logger.info("Pushing identify information to listener...")
@@ -206,11 +303,13 @@ async def run_dialer(port: int, destination: str) -> None:
 
             try:
                 # Call push_identify_to_peer which returns a boolean
-                success = await push_identify_to_peer(host, peer_info.peer_id)
+                success = await push_identify_to_peer(
+                    host, peer_info.peer_id, use_varint_format=use_varint_format
+                )
 
                 if success:
                     logger.info("Identify push completed successfully!")
-                    print("Identify push completed successfully!")
+                    print("✅ Identify push completed successfully!")
 
                     logger.info("Example completed successfully!")
                     print("\nExample completed successfully!")
@@ -221,16 +320,56 @@ async def run_dialer(port: int, destination: str) -> None:
                     logger.warning("Example completed with warnings.")
                     print("Example completed with warnings.")
             except Exception as e:
-                logger.error(f"Error during identify push: {str(e)}")
-                print(f"\nError during identify push: {str(e)}")
+                error_msg = str(e)
+                logger.error(f"Error during identify push: {error_msg}")
+                print(f"\nError during identify push: {error_msg}")
+
+                # Check for specific format mismatch errors
+                if (
+                    "Error parsing message" in error_msg
+                    or "DecodeError" in error_msg
+                    or "ParseFromString" in error_msg
+                ):
+                    print("\n" + "=" * 60)
+                    print("FORMAT MISMATCH DETECTED!")
+                    print("=" * 60)
+                    if use_varint_format:
+                        print(
+                            "You are using length-prefixed format (default) but the "
+                            "listener is using raw protobuf format."
+                        )
+                        print(
+                            "\nTo fix this, run the dialer with the --raw-format flag:"
+                        )
+                        print(
+                            f"identify-push-listener-dialer-demo --raw-format -d "
+                            f"{destination}"
+                        )
+                    else:
+                        print("You are using raw protobuf format but the listener")
+                        print("is using length-prefixed format (default).")
+                        print(
+                            "\nTo fix this, run the dialer without the --raw-format "
+                            "flag:"
+                        )
+                        print(f"identify-push-listener-dialer-demo -d {destination}")
+                    print("=" * 60)
 
                 logger.error("Example completed with errors.")
                 print("Example completed with errors.")
                 # Continue execution despite the push error
 
         except Exception as e:
-            logger.error(f"Error during dialer operation: {str(e)}")
-            print(f"\nError during dialer operation: {str(e)}")
+            error_msg = str(e)
+            if "unable to connect" in error_msg or "SwarmException" in error_msg:
+                print(f"\n❌ Cannot connect to peer: {peer_info.peer_id}")
+                print(f"   Address: {destination}")
+                print(f"   Error: {error_msg}")
+                print("\n💡 Make sure the peer is running and the address is correct.")
+                return
+            else:
+                logger.error(f"Error during dialer operation: {error_msg}")
+                print(f"\nError during dialer operation: {error_msg}")
                 raise
 
 
@@ -240,34 +379,55 @@ def main() -> None:
     This program demonstrates the libp2p identify/push protocol.
     Without arguments, it runs as a listener on random port.
     With -d parameter, it runs as a dialer on random port.
+
+    Port 0 (default) means the OS will automatically assign an available port.
+    This prevents port conflicts when running multiple instances.
+
+    Use --raw-format to send raw protobuf messages (old format) instead of
+    length-prefixed protobuf messages (new format, default).
     """
 
-    example = (
-        "/ip4/127.0.0.1/tcp/8000/p2p/QmQn4SwGkDZKkUEpBRBvTmheQycxAHJUNmVEnjA2v1qe8Q"
-    )
-
     parser = argparse.ArgumentParser(description=description)
-    parser.add_argument("-p", "--port", default=0, type=int, help="source port number")
+    parser.add_argument(
+        "-p",
+        "--port",
+        default=0,
+        type=int,
+        help="source port number (0 = random available port)",
+    )
     parser.add_argument(
         "-d",
         "--destination",
         type=str,
-        help=f"destination multiaddr string, e.g. {example}",
+        help="destination multiaddr string",
     )
+    parser.add_argument(
+        "--raw-format",
+        action="store_true",
+        help=(
+            "use raw protobuf format (old format) instead of "
+            "length-prefixed (new format)"
+        ),
+    )
+
     args = parser.parse_args()
 
+    # Determine format: raw format if --raw-format is specified, otherwise
+    # length-prefixed
+    use_varint_format = not args.raw_format
+
     try:
         if args.destination:
             # Run in dialer mode with random available port if not specified
-            trio.run(run_dialer, args.port, args.destination)
+            trio.run(run_dialer, args.port, args.destination, use_varint_format)
         else:
             # Run in listener mode with random available port if not specified
-            trio.run(run_listener, args.port)
+            trio.run(run_listener, args.port, use_varint_format, args.raw_format)
     except KeyboardInterrupt:
-        print("\nInterrupted by user")
-        logger.info("Interrupted by user")
+        print("\n👋 Goodbye!")
+        logger.info("Application interrupted by user")
     except Exception as e:
-        print(f"\nError: {str(e)}")
+        print(f"\n❌ Error: {str(e)}")
         logger.error("Error: %s", str(e))
         sys.exit(1)
 

examples/kademlia/kademlia.py

@@ -151,7 +151,10 @@ async def run_node(
         host = new_host(key_pair=key_pair)
         listen_addr = Multiaddr(f"/ip4/127.0.0.1/tcp/{port}")
 
-        async with host.run(listen_addrs=[listen_addr]):
+        async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+            # Start the peer-store cleanup task
+            nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
             peer_id = host.get_id().pretty()
             addr_str = f"/ip4/127.0.0.1/tcp/{port}/p2p/{peer_id}"
             await connect_to_bootstrap_nodes(host, bootstrap_nodes)

examples/mDNS/mDNS.py

@@ -0,0 +1,77 @@
+import argparse
+import logging
+import secrets
+
+import multiaddr
+import trio
+
+from libp2p import (
+    new_host,
+)
+from libp2p.abc import PeerInfo
+from libp2p.crypto.secp256k1 import (
+    create_new_key_pair,
+)
+from libp2p.discovery.events.peerDiscovery import peerDiscovery
+
+logger = logging.getLogger("libp2p.discovery.mdns")
+logger.setLevel(logging.INFO)
+handler = logging.StreamHandler()
+handler.setFormatter(
+    logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
+)
+logger.addHandler(handler)
+
+# Set root logger to DEBUG to capture all logs from dependencies
+logging.getLogger().setLevel(logging.DEBUG)
+
+
+def onPeerDiscovery(peerinfo: PeerInfo):
+    logger.info(f"Discovered: {peerinfo.peer_id}")
+
+
+async def run(port: int) -> None:
+    secret = secrets.token_bytes(32)
+    key_pair = create_new_key_pair(secret)
+    listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
+
+    peerDiscovery.register_peer_discovered_handler(onPeerDiscovery)
+
+    print(
+        "Run this from the same folder in another console to "
+        "start another peer on a different port:\n\n"
+        "mdns-demo -p <ANOTHER_PORT>\n"
+    )
+    print("Waiting for mDNS peer discovery events...\n")
+
+    logger.info("Starting peer Discovery")
+    host = new_host(key_pair=key_pair, enable_mDNS=True)
+    async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+        # Start the peer-store cleanup task
+        nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
+        await trio.sleep_forever()
+
+
+def main() -> None:
+    description = """
+    This program demonstrates mDNS peer discovery using libp2p.
+    To use it, run 'mdns-demo -p <PORT>', where <PORT> is the port number.
+    Start multiple peers on different ports to see discovery in action.
+    """
+    parser = argparse.ArgumentParser(description=description)
+    parser.add_argument("-p", "--port", default=0, type=int, help="source port number")
+    parser.add_argument(
+        "-v", "--verbose", action="store_true", help="Enable verbose output"
+    )
+    args = parser.parse_args()
+    if args.verbose:
+        logger.setLevel(logging.DEBUG)
+    try:
+        trio.run(run, args.port)
+    except KeyboardInterrupt:
+        logger.info("Exiting...")
+
+
+if __name__ == "__main__":
+    main()

examples/ping/ping.py

@@ -59,6 +59,9 @@ async def run(port: int, destination: str) -> None:
     host = new_host(listen_addrs=[listen_addr])
 
     async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+        # Start the peer-store cleanup task
+        nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
         if not destination:
             host.set_stream_handler(PING_PROTOCOL_ID, handle_ping)
 

examples/pubsub/pubsub.py

@@ -144,6 +144,9 @@ async def run(topic: str, destination: str | None, port: int | None) -> None:
     pubsub = Pubsub(host, gossipsub)
     termination_event = trio.Event()  # Event to signal termination
     async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+        # Start the peer-store cleanup task
+        nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
+
         logger.info(f"Node started with peer ID: {host.get_id()}")
         logger.info(f"Listening on: {listen_addr}")
         logger.info("Initializing PubSub and GossipSub...")

libp2p/__init__.py

@@ -32,6 +32,9 @@ from libp2p.custom_types import (
     TProtocol,
     TSecurityOptions,
 )
+from libp2p.discovery.mdns.mdns import (
+    MDNSDiscovery,
+)
 from libp2p.host.basic_host import (
     BasicHost,
 )
@@ -81,6 +84,8 @@ DEFAULT_MUXER = "YAMUX"
 # Multiplexer options
 MUXER_YAMUX = "YAMUX"
 MUXER_MPLEX = "MPLEX"
+DEFAULT_NEGOTIATE_TIMEOUT = 5
+
 
 
 def set_default_muxer(muxer_name: Literal["YAMUX", "MPLEX"]) -> None:
@@ -245,6 +250,9 @@ def new_host(
     disc_opt: IPeerRouting | None = None,
     muxer_preference: Literal["YAMUX", "MPLEX"] | None = None,
     listen_addrs: Sequence[multiaddr.Multiaddr] | None = None,
+    enable_mDNS: bool = False,
+    bootstrap: list[str] | None = None,
+    negotiate_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
 ) -> IHost:
     """
     Create a new libp2p host based on the given parameters.
@@ -256,6 +264,8 @@ def new_host(
     :param disc_opt: optional discovery
     :param muxer_preference: optional explicit muxer preference
     :param listen_addrs: optional list of multiaddrs to listen on
+    :param enable_mDNS: whether to enable mDNS discovery
+    :param bootstrap: optional list of bootstrap peer addresses as strings
     :return: return a host instance
     """
     swarm = new_swarm(
@@ -268,8 +278,7 @@ def new_host(
     )
 
     if disc_opt is not None:
-        return RoutedHost(swarm, disc_opt)
-    return BasicHost(swarm)
-
+        return RoutedHost(swarm, disc_opt, enable_mDNS, bootstrap)
+    return BasicHost(network=swarm,enable_mDNS=enable_mDNS , bootstrap=bootstrap, negotitate_timeout=negotiate_timeout)
 
 __version__ = __version("libp2p")

libp2p/discovery/bootstrap/__init__.py

@@ -0,0 +1,5 @@
+"""Bootstrap peer discovery module for py-libp2p."""
+
+from .bootstrap import BootstrapDiscovery
+
+__all__ = ["BootstrapDiscovery"]

libp2p/discovery/bootstrap/bootstrap.py

@@ -0,0 +1,94 @@
+import logging
+
+from multiaddr import Multiaddr
+from multiaddr.resolvers import DNSResolver
+
+from libp2p.abc import ID, INetworkService, PeerInfo
+from libp2p.discovery.bootstrap.utils import validate_bootstrap_addresses
+from libp2p.discovery.events.peerDiscovery import peerDiscovery
+from libp2p.peer.peerinfo import info_from_p2p_addr
+
+logger = logging.getLogger("libp2p.discovery.bootstrap")
+resolver = DNSResolver()
+
+
+class BootstrapDiscovery:
+    """
+    Bootstrap-based peer discovery for py-libp2p.
+    Connects to predefined bootstrap peers and adds them to peerstore.
+    """
+
+    def __init__(self, swarm: INetworkService, bootstrap_addrs: list[str]):
+        self.swarm = swarm
+        self.peerstore = swarm.peerstore
+        self.bootstrap_addrs = bootstrap_addrs or []
+        self.discovered_peers: set[str] = set()
+
+    async def start(self) -> None:
+        """Process bootstrap addresses and emit peer discovery events."""
+        logger.debug(
+            f"Starting bootstrap discovery with "
+            f"{len(self.bootstrap_addrs)} bootstrap addresses"
+        )
+
+        # Validate and filter bootstrap addresses
+        self.bootstrap_addrs = validate_bootstrap_addresses(self.bootstrap_addrs)
+
+        for addr_str in self.bootstrap_addrs:
+            try:
+                await self._process_bootstrap_addr(addr_str)
+            except Exception as e:
+                logger.debug(f"Failed to process bootstrap address {addr_str}: {e}")
+
+    def stop(self) -> None:
+        """Clean up bootstrap discovery resources."""
+        logger.debug("Stopping bootstrap discovery")
+        self.discovered_peers.clear()
+
+    async def _process_bootstrap_addr(self, addr_str: str) -> None:
+        """Convert string address to PeerInfo and add to peerstore."""
+        try:
+            multiaddr = Multiaddr(addr_str)
+        except Exception as e:
+            logger.debug(f"Invalid multiaddr format '{addr_str}': {e}")
+            return
+        if self.is_dns_addr(multiaddr):
+            resolved_addrs = await resolver.resolve(multiaddr)
+            peer_id_str = multiaddr.get_peer_id()
+            if peer_id_str is None:
+                logger.warning(f"Missing peer ID in DNS address: {addr_str}")
+                return
+            peer_id = ID.from_base58(peer_id_str)
+            addrs = [addr for addr in resolved_addrs]
+            if not addrs:
+                logger.warning(f"No addresses resolved for DNS address: {addr_str}")
+                return
+            peer_info = PeerInfo(peer_id, addrs)
+            self.add_addr(peer_info)
+        else:
+            self.add_addr(info_from_p2p_addr(multiaddr))
+
+    def is_dns_addr(self, addr: Multiaddr) -> bool:
+        """Check if the address is a DNS address."""
+        return any(protocol.name == "dnsaddr" for protocol in addr.protocols())
+
+    def add_addr(self, peer_info: PeerInfo) -> None:
+        """Add a peer to the peerstore and emit discovery event."""
+        # Skip if it's our own peer
+        if peer_info.peer_id == self.swarm.get_peer_id():
+            logger.debug(f"Skipping own peer ID: {peer_info.peer_id}")
+            return
+
+        # Always add addresses to peerstore (allows multiple addresses for same peer)
+        self.peerstore.add_addrs(peer_info.peer_id, peer_info.addrs, 10)
+
+        # Only emit discovery event if this is the first time we see this peer
+        peer_id_str = str(peer_info.peer_id)
+        if peer_id_str not in self.discovered_peers:
+            # Track discovered peer
+            self.discovered_peers.add(peer_id_str)
+            # Emit peer discovery event
+            peerDiscovery.emit_peer_discovered(peer_info)
+            logger.debug(f"Peer discovered: {peer_info.peer_id}")
+        else:
+            logger.debug(f"Additional addresses added for peer: {peer_info.peer_id}")

libp2p/discovery/bootstrap/utils.py

@@ -0,0 +1,51 @@
+"""Utility functions for bootstrap discovery."""
+
+import logging
+
+from multiaddr import Multiaddr
+
+from libp2p.peer.peerinfo import InvalidAddrError, PeerInfo, info_from_p2p_addr
+
+logger = logging.getLogger("libp2p.discovery.bootstrap.utils")
+
+
+def validate_bootstrap_addresses(addrs: list[str]) -> list[str]:
+    """
+    Validate and filter bootstrap addresses.
+
+    :param addrs: List of bootstrap address strings
+    :return: List of valid bootstrap addresses
+    """
+    valid_addrs = []
+
+    for addr_str in addrs:
+        try:
+            # Try to parse as multiaddr
+            multiaddr = Multiaddr(addr_str)
+
+            # Try to extract peer info (this validates the p2p component)
+            info_from_p2p_addr(multiaddr)
+
+            valid_addrs.append(addr_str)
+            logger.debug(f"Valid bootstrap address: {addr_str}")
+
+        except (InvalidAddrError, ValueError, Exception) as e:
+            logger.warning(f"Invalid bootstrap address '{addr_str}': {e}")
+            continue
+
+    return valid_addrs
+
+
+def parse_bootstrap_peer_info(addr_str: str) -> PeerInfo | None:
+    """
+    Parse bootstrap address string into PeerInfo.
+
+    :param addr_str: Bootstrap address string
+    :return: PeerInfo object or None if parsing fails
+    """
+    try:
+        multiaddr = Multiaddr(addr_str)
+        return info_from_p2p_addr(multiaddr)
+    except Exception as e:
+        logger.error(f"Failed to parse bootstrap address '{addr_str}': {e}")
+        return None

libp2p/discovery/events/peerDiscovery.py

@@ -0,0 +1,26 @@
+from collections.abc import (
+    Callable,
+)
+
+from libp2p.abc import (
+    PeerInfo,
+)
+
+TTL: int = 60 * 60  # Time-to-live for discovered peers in seconds
+
+
+class PeerDiscovery:
+    def __init__(self) -> None:
+        self._peer_discovered_handlers: list[Callable[[PeerInfo], None]] = []
+
+    def register_peer_discovered_handler(
+        self, handler: Callable[[PeerInfo], None]
+    ) -> None:
+        self._peer_discovered_handlers.append(handler)
+
+    def emit_peer_discovered(self, peer_info: PeerInfo) -> None:
+        for handler in self._peer_discovered_handlers:
+            handler(peer_info)
+
+
+peerDiscovery = PeerDiscovery()

libp2p/discovery/mdns/broadcaster.py

@@ -0,0 +1,91 @@
+import logging
+import socket
+
+from zeroconf import (
+    EventLoopBlocked,
+    ServiceInfo,
+    Zeroconf,
+)
+
+logger = logging.getLogger("libp2p.discovery.mdns.broadcaster")
+
+
+class PeerBroadcaster:
+    """
+    Broadcasts this peer's presence on the local network using mDNS/zeroconf.
+    Registers a service with the peer's ID in the TXT record as per libp2p spec.
+    """
+
+    def __init__(
+        self,
+        zeroconf: Zeroconf,
+        service_type: str,
+        service_name: str,
+        peer_id: str,
+        port: int,
+    ):
+        self.zeroconf = zeroconf
+        self.service_type = service_type
+        self.peer_id = peer_id
+        self.port = port
+        self.service_name = service_name
+
+        # Get the local IP address
+        local_ip = self._get_local_ip()
+        hostname = socket.gethostname()
+
+        self.service_info = ServiceInfo(
+            type_=self.service_type,
+            name=self.service_name,
+            port=self.port,
+            properties={b"id": self.peer_id.encode()},
+            server=f"{hostname}.local.",
+            addresses=[socket.inet_aton(local_ip)],
+        )
+
+    def _get_local_ip(self) -> str:
+        """Get the local IP address of this machine"""
+        try:
+            # Connect to a remote address to determine the local IP
+            # This doesn't actually send data
+            with socket.socket(socket.AF_INET, socket.SOCK_DGRAM) as s:
+                s.connect(("8.8.8.8", 80))
+                local_ip = s.getsockname()[0]
+            return local_ip
+        except Exception:
+            # Fallback to localhost if we can't determine the IP
+            return "127.0.0.1"
+
+    def register(self) -> None:
+        """Register the peer's mDNS service on the network."""
+        try:
+            self.zeroconf.register_service(self.service_info)
+            logger.debug(f"mDNS service registered: {self.service_name}")
+        except EventLoopBlocked as e:
+            logger.warning(
+                "EventLoopBlocked while registering mDNS '%s': %s", self.service_name, e
+            )
+        except Exception as e:
+            logger.error(
+                "Unexpected error during mDNS registration for '%s': %r",
+                self.service_name,
+                e,
+            )
+
+    def unregister(self) -> None:
+        """Unregister the peer's mDNS service from the network."""
+        try:
+            self.zeroconf.unregister_service(self.service_info)
+            logger.debug(f"mDNS service unregistered: {self.service_name}")
+        except EventLoopBlocked as e:
+            logger.warning(
+                "EventLoopBlocked while unregistering mDNS '%s': %s",
+                self.service_name,
+                e,
+            )
+        except Exception as e:
+            logger.error(
+                "Unexpected error during mDNS unregistration for '%s': %r",
+                self.service_name,
+                e,
+            )

libp2p/discovery/mdns/listener.py

@@ -0,0 +1,83 @@
+import logging
+import socket
+
+from zeroconf import (
+    ServiceBrowser,
+    ServiceInfo,
+    ServiceListener,
+    Zeroconf,
+)
+
+from libp2p.abc import IPeerStore, Multiaddr
+from libp2p.discovery.events.peerDiscovery import peerDiscovery
+from libp2p.peer.id import ID
+from libp2p.peer.peerinfo import PeerInfo
+
+logger = logging.getLogger("libp2p.discovery.mdns.listener")
+
+
+class PeerListener(ServiceListener):
+    """mDNS listener — now a true ServiceListener subclass."""
+
+    def __init__(
+        self,
+        peerstore: IPeerStore,
+        zeroconf: Zeroconf,
+        service_type: str,
+        service_name: str,
+    ) -> None:
+        self.peerstore = peerstore
+        self.zeroconf = zeroconf
+        self.service_type = service_type
+        self.service_name = service_name
+        self.discovered_services: dict[str, ID] = {}
+        self.browser = ServiceBrowser(self.zeroconf, self.service_type, listener=self)
+
+    def add_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        if name == self.service_name:
+            return
+        logger.debug(f"Adding service: {name}")
+        info = zc.get_service_info(type_, name, timeout=5000)
+        if not info:
+            return
+        peer_info = self._extract_peer_info(info)
+        if peer_info:
+            self.discovered_services[name] = peer_info.peer_id
+            self.peerstore.add_addrs(peer_info.peer_id, peer_info.addrs, 10)
+            peerDiscovery.emit_peer_discovered(peer_info)
+            logger.debug(f"Discovered Peer: {peer_info.peer_id}")
+
+    def remove_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        if name == self.service_name:
+            return
+        logger.debug(f"Removing service: {name}")
+        peer_id = self.discovered_services.pop(name)
+        self.peerstore.clear_addrs(peer_id)
+        logger.debug(f"Removed Peer: {peer_id}")
+
+    def update_service(self, zc: Zeroconf, type_: str, name: str) -> None:
+        info = zc.get_service_info(type_, name, timeout=5000)
+        if not info:
+            return
+        peer_info = self._extract_peer_info(info)
+        if peer_info:
+            self.peerstore.clear_addrs(peer_info.peer_id)
+            self.peerstore.add_addrs(peer_info.peer_id, peer_info.addrs, 10)
+            logger.debug(f"Updated Peer {peer_info.peer_id}")
+
+    def _extract_peer_info(self, info: ServiceInfo) -> PeerInfo | None:
+        try:
+            addrs = [
+                Multiaddr(f"/ip4/{socket.inet_ntoa(addr)}/tcp/{info.port}")
+                for addr in info.addresses
+            ]
+            pid_bytes = info.properties.get(b"id")
+            if not pid_bytes:
+                return None
+            pid = ID.from_base58(pid_bytes.decode())
+            return PeerInfo(peer_id=pid, addrs=addrs)
+        except Exception:
+            return None
+
+    def stop(self) -> None:
+        self.browser.cancel()

libp2p/discovery/mdns/mdns.py

@@ -0,0 +1,73 @@
+"""
+mDNS-based peer discovery for py-libp2p.
+Conforms to https://github.com/libp2p/specs/blob/master/discovery/mdns.md
+Uses zeroconf for mDNS broadcast/listen. Async operations use trio.
+"""
+
+import logging
+
+from zeroconf import (
+    Zeroconf,
+)
+
+from libp2p.abc import (
+    INetworkService,
+)
+
+from .broadcaster import (
+    PeerBroadcaster,
+)
+from .listener import (
+    PeerListener,
+)
+from .utils import (
+    stringGen,
+)
+
+logger = logging.getLogger("libp2p.discovery.mdns")
+
+SERVICE_TYPE = "_p2p._udp.local."
+MCAST_PORT = 5353
+MCAST_ADDR = "224.0.0.251"
+
+
+class MDNSDiscovery:
+    """
+    mDNS-based peer discovery for py-libp2p, using zeroconf.
+    Conforms to the libp2p mDNS discovery spec.
+    """
+
+    def __init__(self, swarm: INetworkService, port: int = 8000):
+        self.peer_id = str(swarm.get_peer_id())
+        self.port = port
+        self.zeroconf = Zeroconf()
+        self.serviceName = f"{stringGen()}.{SERVICE_TYPE}"
+        self.peerstore = swarm.peerstore
+        self.swarm = swarm
+        self.broadcaster = PeerBroadcaster(
+            zeroconf=self.zeroconf,
+            service_type=SERVICE_TYPE,
+            service_name=self.serviceName,
+            peer_id=self.peer_id,
+            port=self.port,
+        )
+        self.listener = PeerListener(
+            zeroconf=self.zeroconf,
+            peerstore=self.peerstore,
+            service_type=SERVICE_TYPE,
+            service_name=self.serviceName,
+        )
+
+    def start(self) -> None:
+        """Register this peer and start listening for others."""
+        logger.debug(
+            f"Starting mDNS discovery for peer {self.peer_id} on port {self.port}"
+        )
+        self.broadcaster.register()
+        # Listener is started in constructor
+
+    def stop(self) -> None:
+        """Unregister this peer and clean up zeroconf resources."""
+        logger.debug("Stopping mDNS discovery")
+        self.broadcaster.unregister()
+        self.zeroconf.close()

libp2p/discovery/mdns/utils.py

@@ -0,0 +1,11 @@
+import random
+import string
+
+
+def stringGen(len: int = 63) -> str:
+    """Generate a random string of lowercase letters and digits."""
+    charset = string.ascii_lowercase + string.digits
+    result = []
+    for _ in range(len):
+        result.append(random.choice(charset))
+    return "".join(result)

libp2p/host/basic_host.py

@@ -29,6 +29,8 @@ from libp2p.custom_types import (
     StreamHandlerFn,
     TProtocol,
 )
+from libp2p.discovery.bootstrap.bootstrap import BootstrapDiscovery
+from libp2p.discovery.mdns.mdns import MDNSDiscovery
 from libp2p.host.defaults import (
     get_default_protocols,
 )
@@ -70,6 +72,7 @@ if TYPE_CHECKING:
 
 
 logger = logging.getLogger("libp2p.network.basic_host")
+DEFAULT_NEGOTIATE_TIMEOUT = 5
 
 
 class BasicHost(IHost):
@@ -89,15 +92,23 @@ class BasicHost(IHost):
     def __init__(
         self,
         network: INetworkService,
+        enable_mDNS: bool = False,
+        bootstrap: list[str] | None = None,
         default_protocols: Optional["OrderedDict[TProtocol, StreamHandlerFn]"] = None,
+        negotitate_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
     ) -> None:
         self._network = network
         self._network.set_stream_handler(self._swarm_stream_handler)
         self.peerstore = self._network.peerstore
+        self.negotiate_timeout = negotitate_timeout
         # Protocol muxing
         default_protocols = default_protocols or get_default_protocols(self)
         self.multiselect = Multiselect(dict(default_protocols.items()))
         self.multiselect_client = MultiselectClient()
+        if enable_mDNS:
+            self.mDNS = MDNSDiscovery(network)
+        if bootstrap:
+            self.bootstrap = BootstrapDiscovery(network, bootstrap)
 
     def get_id(self) -> ID:
         """
@@ -162,7 +173,19 @@ class BasicHost(IHost):
             network = self.get_network()
             async with background_trio_service(network):
                 await network.listen(*listen_addrs)
+                if hasattr(self, "mDNS") and self.mDNS is not None:
+                    logger.debug("Starting mDNS Discovery")
+                    self.mDNS.start()
+                if hasattr(self, "bootstrap") and self.bootstrap is not None:
+                    logger.debug("Starting Bootstrap Discovery")
+                    await self.bootstrap.start()
+                try:
                     yield
+                finally:
+                    if hasattr(self, "mDNS") and self.mDNS is not None:
+                        self.mDNS.stop()
+                    if hasattr(self, "bootstrap") and self.bootstrap is not None:
+                        self.bootstrap.stop()
 
         return _run()
 
@@ -178,7 +201,10 @@ class BasicHost(IHost):
         self.multiselect.add_handler(protocol_id, stream_handler)
 
     async def new_stream(
-        self, peer_id: ID, protocol_ids: Sequence[TProtocol]
+        self,
+        peer_id: ID,
+        protocol_ids: Sequence[TProtocol],
+        negotitate_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
     ) -> INetStream:
         """
         :param peer_id: peer_id that host is connecting
@@ -190,7 +216,9 @@ class BasicHost(IHost):
         # Perform protocol muxing to determine protocol to use
         try:
             selected_protocol = await self.multiselect_client.select_one_of(
-                list(protocol_ids), MultiselectCommunicator(net_stream)
+                list(protocol_ids),
+                MultiselectCommunicator(net_stream),
+                negotitate_timeout,
             )
         except MultiselectClientError as error:
             logger.debug("fail to open a stream to peer %s, error=%s", peer_id, error)
@@ -200,7 +228,12 @@ class BasicHost(IHost):
         net_stream.set_protocol(selected_protocol)
         return net_stream
 
-    async def send_command(self, peer_id: ID, command: str) -> list[str]:
+    async def send_command(
+        self,
+        peer_id: ID,
+        command: str,
+        response_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
+    ) -> list[str]:
         """
         Send a multistream-select command to the specified peer and return
         the response.
@@ -214,7 +247,7 @@ class BasicHost(IHost):
 
         try:
             response = await self.multiselect_client.query_multistream_command(
-                MultiselectCommunicator(new_stream), command
+                MultiselectCommunicator(new_stream), command, response_timeout
             )
         except MultiselectClientError as error:
             logger.debug("fail to open a stream to peer %s, error=%s", peer_id, error)
@@ -253,7 +286,7 @@ class BasicHost(IHost):
         # Perform protocol muxing to determine protocol to use
         try:
             protocol, handler = await self.multiselect.negotiate(
-                MultiselectCommunicator(net_stream)
+                MultiselectCommunicator(net_stream), self.negotiate_timeout
             )
         except MultiselectError as error:
             peer_id = net_stream.muxed_conn.peer_id

libp2p/host/defaults.py

@@ -26,5 +26,8 @@ if TYPE_CHECKING:
 
 def get_default_protocols(host: IHost) -> "OrderedDict[TProtocol, StreamHandlerFn]":
     return OrderedDict(
-        ((IdentifyID, identify_handler_for(host)), (PingID, handle_ping))
+        (
+            (IdentifyID, identify_handler_for(host, use_varint_format=True)),
+            (PingID, handle_ping),
+        )
     )

libp2p/host/routed_host.py

@@ -18,8 +18,14 @@ from libp2p.peer.peerinfo import (
 class RoutedHost(BasicHost):
     _router: IPeerRouting
 
-    def __init__(self, network: INetworkService, router: IPeerRouting):
-        super().__init__(network)
+    def __init__(
+        self,
+        network: INetworkService,
+        router: IPeerRouting,
+        enable_mDNS: bool = False,
+        bootstrap: list[str] | None = None,
+    ):
+        super().__init__(network, enable_mDNS, bootstrap)
         self._router = router
 
     async def connect(self, peer_info: PeerInfo) -> None:

libp2p/identity/identify/identify.py

@@ -15,8 +15,12 @@ from libp2p.custom_types import (
 from libp2p.network.stream.exceptions import (
     StreamClosed,
 )
+from libp2p.peer.envelope import seal_record
+from libp2p.peer.peer_record import PeerRecord
 from libp2p.utils import (
+    decode_varint_with_size,
     get_agent_version,
+    varint,
 )
 
 from .pb.identify_pb2 import (
@@ -59,7 +63,12 @@ def _mk_identify_protobuf(
 ) -> Identify:
     public_key = host.get_public_key()
     laddrs = host.get_addrs()
-    protocols = host.get_mux().get_protocols()
+    protocols = tuple(str(p) for p in host.get_mux().get_protocols() if p is not None)
+
+    # Create a signed peer-record for the remote peer
+    record = PeerRecord(host.get_id(), host.get_addrs())
+    envelope = seal_record(record, host.get_private_key())
+    protobuf = envelope.marshal_envelope()
 
     observed_addr = observed_multiaddr.to_bytes() if observed_multiaddr else b""
     return Identify(
@@ -69,10 +78,51 @@ def _mk_identify_protobuf(
         listen_addrs=map(_multiaddr_to_bytes, laddrs),
         observed_addr=observed_addr,
         protocols=protocols,
+        signedPeerRecord=protobuf,
     )
 
 
-def identify_handler_for(host: IHost) -> StreamHandlerFn:
+def parse_identify_response(response: bytes) -> Identify:
+    """
+    Parse identify response that could be either:
+    - Old format: raw protobuf
+    - New format: length-prefixed protobuf
+
+    This function provides backward and forward compatibility.
+    """
+    # Try new format first: length-prefixed protobuf
+    if len(response) >= 1:
+        length, varint_size = decode_varint_with_size(response)
+        if varint_size > 0 and length > 0 and varint_size + length <= len(response):
+            protobuf_data = response[varint_size : varint_size + length]
+            try:
+                identify_response = Identify()
+                identify_response.ParseFromString(protobuf_data)
+                # Sanity check: must have agent_version (protocol_version is optional)
+                if identify_response.agent_version:
+                    logger.debug(
+                        "Parsed length-prefixed identify response (new format)"
+                    )
+                    return identify_response
+            except Exception:
+                pass  # Fall through to old format
+
+    # Fall back to old format: raw protobuf
+    try:
+        identify_response = Identify()
+        identify_response.ParseFromString(response)
+        logger.debug("Parsed raw protobuf identify response (old format)")
+        return identify_response
+    except Exception as e:
+        logger.error(f"Failed to parse identify response: {e}")
+        logger.error(f"Response length: {len(response)}")
+        logger.error(f"Response hex: {response.hex()}")
+        raise
+
+
+def identify_handler_for(
+    host: IHost, use_varint_format: bool = True
+) -> StreamHandlerFn:
     async def handle_identify(stream: INetStream) -> None:
         # get observed address from ``stream``
         peer_id = (
@@ -100,7 +150,21 @@ def identify_handler_for(host: IHost) -> StreamHandlerFn:
         response = protobuf.SerializeToString()
 
         try:
+            if use_varint_format:
+                # Send length-prefixed protobuf message (new format)
+                await stream.write(varint.encode_uvarint(len(response)))
                 await stream.write(response)
+                logger.debug(
+                    "Sent new format (length-prefixed) identify response to %s",
+                    peer_id,
+                )
+            else:
+                # Send raw protobuf message (old format for backward compatibility)
+                await stream.write(response)
+                logger.debug(
+                    "Sent old format (raw protobuf) identify response to %s",
+                    peer_id,
+                )
         except StreamClosed:
             logger.debug("Fail to respond to %s request: stream closed", ID)
         else:

libp2p/identity/identify/pb/identify.proto

@@ -9,4 +9,5 @@ message Identify {
   repeated bytes listen_addrs = 2;
   optional bytes observed_addr = 4;
   repeated string protocols = 3;
+  optional bytes signedPeerRecord = 8;
 }

libp2p/identity/identify/pb/identify_pb2.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # source: libp2p/identity/identify/pb/identify.proto
+# Protobuf Python Version: 4.25.3
 """Generated protocol buffer code."""
-from google.protobuf.internal import builder as _builder
 from google.protobuf import descriptor as _descriptor
 from google.protobuf import descriptor_pool as _descriptor_pool
 from google.protobuf import symbol_database as _symbol_database
+from google.protobuf.internal import builder as _builder
 # @@protoc_insertion_point(imports)
 
 _sym_db = _symbol_database.Default()
@@ -13,13 +14,13 @@ _sym_db = _symbol_database.Default()
 
 
 
-DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n*libp2p/identity/identify/pb/identify.proto\x12\x0bidentify.pb\"\x8f\x01\n\x08Identify\x12\x18\n\x10protocol_version\x18\x05 \x01(\t\x12\x15\n\ragent_version\x18\x06 \x01(\t\x12\x12\n\npublic_key\x18\x01 \x01(\x0c\x12\x14\n\x0clisten_addrs\x18\x02 \x03(\x0c\x12\x15\n\robserved_addr\x18\x04 \x01(\x0c\x12\x11\n\tprotocols\x18\x03 \x03(\t')
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n*libp2p/identity/identify/pb/identify.proto\x12\x0bidentify.pb\"\xa9\x01\n\x08Identify\x12\x18\n\x10protocol_version\x18\x05 \x01(\t\x12\x15\n\ragent_version\x18\x06 \x01(\t\x12\x12\n\npublic_key\x18\x01 \x01(\x0c\x12\x14\n\x0clisten_addrs\x18\x02 \x03(\x0c\x12\x15\n\robserved_addr\x18\x04 \x01(\x0c\x12\x11\n\tprotocols\x18\x03 \x03(\t\x12\x18\n\x10signedPeerRecord\x18\x08 \x01(\x0c')
 
-_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, globals())
-_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.identity.identify.pb.identify_pb2', globals())
+_globals = globals()
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.identity.identify.pb.identify_pb2', _globals)
 if _descriptor._USE_C_DESCRIPTORS == False:
-
   DESCRIPTOR._options = None
-  _IDENTIFY._serialized_start=60
-  _IDENTIFY._serialized_end=203
+  _globals['_IDENTIFY']._serialized_start=60
+  _globals['_IDENTIFY']._serialized_end=229
 # @@protoc_insertion_point(module_scope)

libp2p/identity/identify/pb/identify_pb2.pyi

@@ -1,46 +1,24 @@
-"""
-@generated by mypy-protobuf.  Do not edit manually!
-isort:skip_file
-"""
+from google.protobuf.internal import containers as _containers
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Iterable as _Iterable, Optional as _Optional
 
-import builtins
-import collections.abc
-import google.protobuf.descriptor
-import google.protobuf.internal.containers
-import google.protobuf.message
-import typing
+DESCRIPTOR: _descriptor.FileDescriptor
 
-DESCRIPTOR: google.protobuf.descriptor.FileDescriptor
-
-@typing.final
-class Identify(google.protobuf.message.Message):
-    DESCRIPTOR: google.protobuf.descriptor.Descriptor
-
-    PROTOCOL_VERSION_FIELD_NUMBER: builtins.int
-    AGENT_VERSION_FIELD_NUMBER: builtins.int
-    PUBLIC_KEY_FIELD_NUMBER: builtins.int
-    LISTEN_ADDRS_FIELD_NUMBER: builtins.int
-    OBSERVED_ADDR_FIELD_NUMBER: builtins.int
-    PROTOCOLS_FIELD_NUMBER: builtins.int
-    protocol_version: builtins.str
-    agent_version: builtins.str
-    public_key: builtins.bytes
-    observed_addr: builtins.bytes
-    @property
-    def listen_addrs(self) -> google.protobuf.internal.containers.RepeatedScalarFieldContainer[builtins.bytes]: ...
-    @property
-    def protocols(self) -> google.protobuf.internal.containers.RepeatedScalarFieldContainer[builtins.str]: ...
-    def __init__(
-        self,
-        *,
-        protocol_version: builtins.str | None = ...,
-        agent_version: builtins.str | None = ...,
-        public_key: builtins.bytes | None = ...,
-        listen_addrs: collections.abc.Iterable[builtins.bytes] | None = ...,
-        observed_addr: builtins.bytes | None = ...,
-        protocols: collections.abc.Iterable[builtins.str] | None = ...,
-    ) -> None: ...
-    def HasField(self, field_name: typing.Literal["agent_version", b"agent_version", "observed_addr", b"observed_addr", "protocol_version", b"protocol_version", "public_key", b"public_key"]) -> builtins.bool: ...
-    def ClearField(self, field_name: typing.Literal["agent_version", b"agent_version", "listen_addrs", b"listen_addrs", "observed_addr", b"observed_addr", "protocol_version", b"protocol_version", "protocols", b"protocols", "public_key", b"public_key"]) -> None: ...
-
-global___Identify = Identify
+class Identify(_message.Message):
+    __slots__ = ("protocol_version", "agent_version", "public_key", "listen_addrs", "observed_addr", "protocols", "signedPeerRecord")
+    PROTOCOL_VERSION_FIELD_NUMBER: _ClassVar[int]
+    AGENT_VERSION_FIELD_NUMBER: _ClassVar[int]
+    PUBLIC_KEY_FIELD_NUMBER: _ClassVar[int]
+    LISTEN_ADDRS_FIELD_NUMBER: _ClassVar[int]
+    OBSERVED_ADDR_FIELD_NUMBER: _ClassVar[int]
+    PROTOCOLS_FIELD_NUMBER: _ClassVar[int]
+    SIGNEDPEERRECORD_FIELD_NUMBER: _ClassVar[int]
+    protocol_version: str
+    agent_version: str
+    public_key: bytes
+    listen_addrs: _containers.RepeatedScalarFieldContainer[bytes]
+    observed_addr: bytes
+    protocols: _containers.RepeatedScalarFieldContainer[str]
+    signedPeerRecord: bytes
+    def __init__(self, protocol_version: _Optional[str] = ..., agent_version: _Optional[str] = ..., public_key: _Optional[bytes] = ..., listen_addrs: _Optional[_Iterable[bytes]] = ..., observed_addr: _Optional[bytes] = ..., protocols: _Optional[_Iterable[str]] = ..., signedPeerRecord: _Optional[bytes] = ...) -> None: ...

libp2p/identity/identify_push/identify_push.py

@@ -20,11 +20,16 @@ from libp2p.custom_types import (
 from libp2p.network.stream.exceptions import (
     StreamClosed,
 )
+from libp2p.peer.envelope import consume_envelope
 from libp2p.peer.id import (
     ID,
 )
 from libp2p.utils import (
     get_agent_version,
+    varint,
+)
+from libp2p.utils.varint import (
+    read_length_prefixed_protobuf,
 )
 
 from ..identify.identify import (
@@ -40,22 +45,31 @@ logger = logging.getLogger(__name__)
 ID_PUSH = TProtocol("/ipfs/id/push/1.0.0")
 PROTOCOL_VERSION = "ipfs/0.1.0"
 AGENT_VERSION = get_agent_version()
+CONCURRENCY_LIMIT = 10
 
 
-def identify_push_handler_for(host: IHost) -> StreamHandlerFn:
+def identify_push_handler_for(
+    host: IHost, use_varint_format: bool = True
+) -> StreamHandlerFn:
     """
     Create a handler for the identify/push protocol.
 
     This handler receives pushed identify messages from remote peers and updates
     the local peerstore with the new information.
+
+    Args:
+        host: The libp2p host.
+        use_varint_format: True=length-prefixed, False=raw protobuf.
+
     """
 
     async def handle_identify_push(stream: INetStream) -> None:
         peer_id = stream.muxed_conn.peer_id
 
         try:
-            # Read the identify message from the stream
-            data = await stream.read()
+            # Use the utility function to read the protobuf message
+            data = await read_length_prefixed_protobuf(stream, use_varint_format)
+
             identify_msg = Identify()
             identify_msg.ParseFromString(data)
 
@@ -65,6 +79,11 @@ def identify_push_handler_for(host: IHost) -> StreamHandlerFn:
             )
 
             logger.debug("Successfully processed identify/push from peer %s", peer_id)
+
+            # Send acknowledgment to indicate successful processing
+            # This ensures the sender knows the message was received before closing
+            await stream.write(b"OK")
+
         except StreamClosed:
             logger.debug(
                 "Stream closed while processing identify/push from %s", peer_id
@@ -73,7 +92,10 @@ def identify_push_handler_for(host: IHost) -> StreamHandlerFn:
             logger.error("Error processing identify/push from %s: %s", peer_id, e)
         finally:
             # Close the stream after processing
+            try:
                 await stream.close()
+            except Exception:
+                pass  # Ignore errors when closing
 
     return handle_identify_push
 
@@ -119,6 +141,19 @@ async def _update_peerstore_from_identify(
         except Exception as e:
             logger.error("Error updating protocols for peer %s: %s", peer_id, e)
 
+    if identify_msg.HasField("signedPeerRecord"):
+        try:
+            # Convert the signed-peer-record(Envelope) from prtobuf bytes
+            envelope, _ = consume_envelope(
+                identify_msg.signedPeerRecord, "libp2p-peer-record"
+            )
+            # Use a default TTL of 2 hours (7200 seconds)
+            if not peerstore.consume_peer_record(envelope, 7200):
+                logger.error("Updating Certified-Addr-Book was unsuccessful")
+        except Exception as e:
+            logger.error(
+                "Error updating the certified addr book for peer %s: %s", peer_id, e
+            )
     # Update observed address if present
     if identify_msg.HasField("observed_addr") and identify_msg.observed_addr:
         try:
@@ -132,7 +167,11 @@ async def _update_peerstore_from_identify(
 
 
 async def push_identify_to_peer(
-    host: IHost, peer_id: ID, observed_multiaddr: Multiaddr | None = None
+    host: IHost,
+    peer_id: ID,
+    observed_multiaddr: Multiaddr | None = None,
+    limit: trio.Semaphore = trio.Semaphore(CONCURRENCY_LIMIT),
+    use_varint_format: bool = True,
 ) -> bool:
     """
     Push an identify message to a specific peer.
@@ -140,12 +179,18 @@ async def push_identify_to_peer(
     This function opens a stream to the peer using the identify/push protocol,
     sends the identify message, and closes the stream.
 
-    Returns
-    -------
-    bool
-        True if the push was successful, False otherwise.
+    Args:
+        host: The libp2p host.
+        peer_id: The peer ID to push to.
+        observed_multiaddr: The observed multiaddress (optional).
+        limit: Semaphore for concurrency control.
+        use_varint_format: True=length-prefixed, False=raw protobuf.
+
+    Returns:
+        bool: True if the push was successful, False otherwise.
 
     """
+    async with limit:
         try:
             # Create a new stream to the peer using the identify/push protocol
             stream = await host.new_stream(peer_id, [ID_PUSH])
@@ -154,10 +199,28 @@ async def push_identify_to_peer(
             identify_msg = _mk_identify_protobuf(host, observed_multiaddr)
             response = identify_msg.SerializeToString()
 
-        # Send the identify message
+            if use_varint_format:
+                # Send length-prefixed identify message
+                await stream.write(varint.encode_uvarint(len(response)))
+                await stream.write(response)
+            else:
+                # Send raw protobuf message
                 await stream.write(response)
 
-        # Close the stream
+            # Wait for acknowledgment from the receiver with timeout
+            # This ensures the message was processed before closing
+            try:
+                with trio.move_on_after(1.0):  # 1 second timeout
+                    ack = await stream.read(2)  # Read "OK" acknowledgment
+                    if ack != b"OK":
+                        logger.warning(
+                            "Unexpected acknowledgment from peer %s: %s", peer_id, ack
+                        )
+            except Exception as e:
+                logger.debug("No acknowledgment received from peer %s: %s", peer_id, e)
+                # Continue anyway, as the message might have been processed
+
+            # Close the stream after acknowledgment (or timeout)
             await stream.close()
 
             logger.debug("Successfully pushed identify to peer %s", peer_id)
@@ -171,21 +234,36 @@ async def push_identify_to_peers(
     host: IHost,
     peer_ids: set[ID] | None = None,
     observed_multiaddr: Multiaddr | None = None,
+    use_varint_format: bool = True,
 ) -> None:
     """
     Push an identify message to multiple peers in parallel.
 
     If peer_ids is None, push to all connected peers.
+
+    Args:
+        host: The libp2p host.
+        peer_ids: Set of peer IDs to push to (if None, push to all connected peers).
+        observed_multiaddr: The observed multiaddress (optional).
+        use_varint_format: True=length-prefixed, False=raw protobuf.
+
     """
     if peer_ids is None:
         # Get all connected peers
-        peer_ids = set(host.get_peerstore().peer_ids())
+        peer_ids = set(host.get_connected_peers())
+
+    # Create a single shared semaphore for concurrency control
+    limit = trio.Semaphore(CONCURRENCY_LIMIT)
 
     # Push to each peer in parallel using a trio.Nursery
-    # TODO: Consider using a bounded nursery to limit concurrency
-    # and avoid overwhelming the network. This can be done by using
-    # trio.open_nursery(max_concurrent=10) or similar.
-    # For now, we will use an unbounded nursery for simplicity.
+    # limiting concurrent connections to CONCURRENCY_LIMIT
     async with trio.open_nursery() as nursery:
         for peer_id in peer_ids:
-            nursery.start_soon(push_identify_to_peer, host, peer_id, observed_multiaddr)
+            nursery.start_soon(
+                push_identify_to_peer,
+                host,
+                peer_id,
+                observed_multiaddr,
+                limit,
+                use_varint_format,
+            )

libp2p/peer/envelope.py

@@ -0,0 +1,271 @@
+from typing import Any, cast
+
+from libp2p.crypto.ed25519 import Ed25519PublicKey
+from libp2p.crypto.keys import PrivateKey, PublicKey
+from libp2p.crypto.rsa import RSAPublicKey
+from libp2p.crypto.secp256k1 import Secp256k1PublicKey
+import libp2p.peer.pb.crypto_pb2 as cryto_pb
+import libp2p.peer.pb.envelope_pb2 as pb
+import libp2p.peer.pb.peer_record_pb2 as record_pb
+from libp2p.peer.peer_record import (
+    PeerRecord,
+    peer_record_from_protobuf,
+    unmarshal_record,
+)
+from libp2p.utils.varint import encode_uvarint
+
+ENVELOPE_DOMAIN = "libp2p-peer-record"
+PEER_RECORD_CODEC = b"\x03\x01"
+
+
+class Envelope:
+    """
+    A signed wrapper around a serialized libp2p record.
+
+    Envelopes are cryptographically signed by the author's private key
+    and are scoped to a specific 'domain' to prevent cross-protocol replay.
+
+    Attributes:
+        public_key: The public key that can verify the envelope's signature.
+        payload_type: A multicodec code identifying the type of payload inside.
+        raw_payload: The raw serialized record data.
+        signature: Signature over the domain-scoped payload content.
+
+    """
+
+    public_key: PublicKey
+    payload_type: bytes
+    raw_payload: bytes
+    signature: bytes
+
+    _cached_record: PeerRecord | None = None
+    _unmarshal_error: Exception | None = None
+
+    def __init__(
+        self,
+        public_key: PublicKey,
+        payload_type: bytes,
+        raw_payload: bytes,
+        signature: bytes,
+    ):
+        self.public_key = public_key
+        self.payload_type = payload_type
+        self.raw_payload = raw_payload
+        self.signature = signature
+
+    def marshal_envelope(self) -> bytes:
+        """
+        Serialize this Envelope into its protobuf wire format.
+
+        Converts all envelope fields into a `pb.Envelope` protobuf message
+        and returns the serialized bytes.
+
+        :return: Serialized envelope as bytes.
+        """
+        pb_env = pb.Envelope(
+            public_key=pub_key_to_protobuf(self.public_key),
+            payload_type=self.payload_type,
+            payload=self.raw_payload,
+            signature=self.signature,
+        )
+        return pb_env.SerializeToString()
+
+    def validate(self, domain: str) -> None:
+        """
+        Verify the envelope's signature within the given domain scope.
+
+        This ensures that the envelope has not been tampered with
+        and was signed under the correct usage context.
+
+        :param domain: Domain string that contextualizes the signature.
+        :raises ValueError: If the signature is invalid.
+        """
+        unsigned = make_unsigned(domain, self.payload_type, self.raw_payload)
+        if not self.public_key.verify(unsigned, self.signature):
+            raise ValueError("Invalid envelope signature")
+
+    def record(self) -> PeerRecord:
+        """
+        Lazily decode and return the embedded PeerRecord.
+
+        This method unmarshals the payload bytes into a `PeerRecord` instance,
+        using the registered codec to identify the type. The decoded result
+        is cached for future use.
+
+        :return: Decoded PeerRecord object.
+        :raises Exception: If decoding fails or payload type is unsupported.
+        """
+        if self._cached_record is not None:
+            return self._cached_record
+
+        try:
+            if self.payload_type != PEER_RECORD_CODEC:
+                raise ValueError("Unsuported payload type in envelope")
+            msg = record_pb.PeerRecord()
+            msg.ParseFromString(self.raw_payload)
+
+            self._cached_record = peer_record_from_protobuf(msg)
+            return self._cached_record
+        except Exception as e:
+            self._unmarshal_error = e
+            raise
+
+    def equal(self, other: Any) -> bool:
+        """
+        Compare this Envelope with another for structural equality.
+
+        Two envelopes are considered equal if:
+        - They have the same public key
+        - The payload type and payload bytes match
+        - Their signatures are identical
+
+        :param other: Another object to compare.
+        :return: True if equal, False otherwise.
+        """
+        if isinstance(other, Envelope):
+            return (
+                self.public_key.__eq__(other.public_key)
+                and self.payload_type == other.payload_type
+                and self.signature == other.signature
+                and self.raw_payload == other.raw_payload
+            )
+        return False
+
+
+def pub_key_to_protobuf(pub_key: PublicKey) -> cryto_pb.PublicKey:
+    """
+    Convert a Python PublicKey object to its protobuf equivalent.
+
+    :param pub_key: A libp2p-compatible PublicKey instance.
+    :return: Serialized protobuf PublicKey message.
+    """
+    internal_key_type = pub_key.get_type()
+    key_type = cast(cryto_pb.KeyType, internal_key_type.value)
+    data = pub_key.to_bytes()
+    protobuf_key = cryto_pb.PublicKey(Type=key_type, Data=data)
+    return protobuf_key
+
+
+def pub_key_from_protobuf(pb_key: cryto_pb.PublicKey) -> PublicKey:
+    """
+    Parse a protobuf PublicKey message into a native libp2p PublicKey.
+
+    Supports Ed25519, RSA, and Secp256k1 key types.
+
+    :param pb_key: Protobuf representation of a public key.
+    :return: Parsed PublicKey object.
+    :raises ValueError: If the key type is unrecognized.
+    """
+    if pb_key.Type == cryto_pb.KeyType.Ed25519:
+        return Ed25519PublicKey.from_bytes(pb_key.Data)
+    elif pb_key.Type == cryto_pb.KeyType.RSA:
+        return RSAPublicKey.from_bytes(pb_key.Data)
+    elif pb_key.Type == cryto_pb.KeyType.Secp256k1:
+        return Secp256k1PublicKey.from_bytes(pb_key.Data)
+    # libp2p.crypto.ecdsa not implemented
+    else:
+        raise ValueError(f"Unknown key type: {pb_key.Type}")
+
+
+def seal_record(record: PeerRecord, private_key: PrivateKey) -> Envelope:
+    """
+    Create and sign a new Envelope from a PeerRecord.
+
+    The record is serialized and signed in the scope of its domain and codec.
+    The result is a self-contained, verifiable Envelope.
+
+    :param record: A PeerRecord to encapsulate.
+    :param private_key: The signer's private key.
+    :return: A signed Envelope instance.
+    """
+    payload = record.marshal_record()
+
+    unsigned = make_unsigned(record.domain(), record.codec(), payload)
+    signature = private_key.sign(unsigned)
+
+    return Envelope(
+        public_key=private_key.get_public_key(),
+        payload_type=record.codec(),
+        raw_payload=payload,
+        signature=signature,
+    )
+
+
+def consume_envelope(data: bytes, domain: str) -> tuple[Envelope, PeerRecord]:
+    """
+    Parse, validate, and decode an Envelope from bytes.
+
+    Validates the envelope's signature using the given domain and decodes
+    the inner payload into a PeerRecord.
+
+    :param data: Serialized envelope bytes.
+    :param domain: Domain string to verify signature against.
+    :return: Tuple of (Envelope, PeerRecord).
+    :raises ValueError: If signature validation or decoding fails.
+    """
+    env = unmarshal_envelope(data)
+    env.validate(domain)
+    record = env.record()
+    return env, record
+
+
+def unmarshal_envelope(data: bytes) -> Envelope:
+    """
+    Deserialize an Envelope from its wire format.
+
+    This parses the protobuf fields without verifying the signature.
+
+    :param data: Serialized envelope bytes.
+    :return: Parsed Envelope object.
+    :raises DecodeError: If protobuf parsing fails.
+    """
+    pb_env = pb.Envelope()
+    pb_env.ParseFromString(data)
+    pk = pub_key_from_protobuf(pb_env.public_key)
+
+    return Envelope(
+        public_key=pk,
+        payload_type=pb_env.payload_type,
+        raw_payload=pb_env.payload,
+        signature=pb_env.signature,
+    )
+
+
+def make_unsigned(domain: str, payload_type: bytes, payload: bytes) -> bytes:
+    """
+    Build a byte buffer to be signed for an Envelope.
+
+    The unsigned byte structure is:
+        varint(len(domain)) || domain ||
+        varint(len(payload_type)) || payload_type ||
+        varint(len(payload)) || payload
+
+    This is the exact input used during signing and verification.
+
+    :param domain: Domain string for signature scoping.
+    :param payload_type: Identifier for the type of payload.
+    :param payload: Raw serialized payload bytes.
+    :return: Byte buffer to be signed or verified.
+    """
+    fields = [domain.encode(), payload_type, payload]
+    buf = bytearray()
+
+    for field in fields:
+        buf.extend(encode_uvarint(len(field)))
+        buf.extend(field)
+
+    return bytes(buf)
+
+
+def debug_dump_envelope(env: Envelope) -> None:
+    print("\n=== Envelope ===")
+    print(f"Payload Type: {env.payload_type!r}")
+    print(f"Signature: {env.signature.hex()} ({len(env.signature)} bytes)")
+    print(f"Raw Payload: {env.raw_payload.hex()} ({len(env.raw_payload)} bytes)")
+
+    try:
+        peer_record = unmarshal_record(env.raw_payload)
+        print("\n=== Parsed PeerRecord ===")
+        print(peer_record)
+    except Exception as e:
+        print("Failed to parse PeerRecord:", e)

libp2p/peer/id.py

@@ -1,3 +1,4 @@
+import functools
 import hashlib
 
 import base58
@@ -36,25 +37,23 @@ if ENABLE_INLINING:
 
 class ID:
     _bytes: bytes
-    _xor_id: int | None = None
-    _b58_str: str | None = None
 
     def __init__(self, peer_id_bytes: bytes) -> None:
         self._bytes = peer_id_bytes
 
-    @property
+    @functools.cached_property
     def xor_id(self) -> int:
-        if not self._xor_id:
-            self._xor_id = int(sha256_digest(self._bytes).hex(), 16)
-        return self._xor_id
+        return int(sha256_digest(self._bytes).hex(), 16)
+
+    @functools.cached_property
+    def base58(self) -> str:
+        return base58.b58encode(self._bytes).decode()
 
     def to_bytes(self) -> bytes:
         return self._bytes
 
     def to_base58(self) -> str:
-        if not self._b58_str:
-            self._b58_str = base58.b58encode(self._bytes).decode()
-        return self._b58_str
+        return self.base58
 
     def __repr__(self) -> str:
         return f"<libp2p.peer.id.ID ({self!s})>"

libp2p/peer/pb/crypto.proto

@@ -0,0 +1,22 @@
+syntax = "proto3";
+
+package libp2p.peer.pb.crypto;
+
+option go_package = "github.com/libp2p/go-libp2p/core/crypto/pb";
+
+enum KeyType {
+    RSA = 0;
+    Ed25519 = 1;
+    Secp256k1 = 2;
+    ECDSA = 3;
+}
+
+message PublicKey {
+    KeyType Type = 1;
+    bytes Data = 2;
+}
+
+message PrivateKey {
+    KeyType Type = 1;
+    bytes Data = 2;
+}

libp2p/peer/pb/crypto_pb2.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: libp2p/peer/pb/crypto.proto
+# Protobuf Python Version: 4.25.3
+"""Generated protocol buffer code."""
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import descriptor_pool as _descriptor_pool
+from google.protobuf import symbol_database as _symbol_database
+from google.protobuf.internal import builder as _builder
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+
+
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x1blibp2p/peer/pb/crypto.proto\x12\x15libp2p.peer.pb.crypto\"G\n\tPublicKey\x12,\n\x04Type\x18\x01 \x01(\x0e\x32\x1e.libp2p.peer.pb.crypto.KeyType\x12\x0c\n\x04\x44\x61ta\x18\x02 \x01(\x0c\"H\n\nPrivateKey\x12,\n\x04Type\x18\x01 \x01(\x0e\x32\x1e.libp2p.peer.pb.crypto.KeyType\x12\x0c\n\x04\x44\x61ta\x18\x02 \x01(\x0c*9\n\x07KeyType\x12\x07\n\x03RSA\x10\x00\x12\x0b\n\x07\x45\x64\x32\x35\x35\x31\x39\x10\x01\x12\r\n\tSecp256k1\x10\x02\x12\t\n\x05\x45\x43\x44SA\x10\x03\x42,Z*github.com/libp2p/go-libp2p/core/crypto/pbb\x06proto3')
+
+_globals = globals()
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.peer.pb.crypto_pb2', _globals)
+if _descriptor._USE_C_DESCRIPTORS == False:
+  _globals['DESCRIPTOR']._options = None
+  _globals['DESCRIPTOR']._serialized_options = b'Z*github.com/libp2p/go-libp2p/core/crypto/pb'
+  _globals['_KEYTYPE']._serialized_start=201
+  _globals['_KEYTYPE']._serialized_end=258
+  _globals['_PUBLICKEY']._serialized_start=54
+  _globals['_PUBLICKEY']._serialized_end=125
+  _globals['_PRIVATEKEY']._serialized_start=127
+  _globals['_PRIVATEKEY']._serialized_end=199
+# @@protoc_insertion_point(module_scope)

libp2p/peer/pb/crypto_pb2.pyi

@@ -0,0 +1,33 @@
+from google.protobuf.internal import enum_type_wrapper as _enum_type_wrapper
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Optional as _Optional, Union as _Union
+
+DESCRIPTOR: _descriptor.FileDescriptor
+
+class KeyType(int, metaclass=_enum_type_wrapper.EnumTypeWrapper):
+    __slots__ = ()
+    RSA: _ClassVar[KeyType]
+    Ed25519: _ClassVar[KeyType]
+    Secp256k1: _ClassVar[KeyType]
+    ECDSA: _ClassVar[KeyType]
+RSA: KeyType
+Ed25519: KeyType
+Secp256k1: KeyType
+ECDSA: KeyType
+
+class PublicKey(_message.Message):
+    __slots__ = ("Type", "Data")
+    TYPE_FIELD_NUMBER: _ClassVar[int]
+    DATA_FIELD_NUMBER: _ClassVar[int]
+    Type: KeyType
+    Data: bytes
+    def __init__(self, Type: _Optional[_Union[KeyType, str]] = ..., Data: _Optional[bytes] = ...) -> None: ...
+
+class PrivateKey(_message.Message):
+    __slots__ = ("Type", "Data")
+    TYPE_FIELD_NUMBER: _ClassVar[int]
+    DATA_FIELD_NUMBER: _ClassVar[int]
+    Type: KeyType
+    Data: bytes
+    def __init__(self, Type: _Optional[_Union[KeyType, str]] = ..., Data: _Optional[bytes] = ...) -> None: ...

libp2p/peer/pb/envelope.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package libp2p.peer.pb.record;
+
+import "libp2p/peer/pb/crypto.proto";
+
+option go_package = "github.com/libp2p/go-libp2p/core/record/pb";
+
+message Envelope {
+    libp2p.peer.pb.crypto.PublicKey public_key = 1;
+    bytes payload_type = 2;
+    bytes payload = 3;
+    bytes signature = 5;
+}

libp2p/peer/pb/envelope_pb2.py

@@ -0,0 +1,28 @@
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: libp2p/peer/pb/envelope.proto
+# Protobuf Python Version: 4.25.3
+"""Generated protocol buffer code."""
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import descriptor_pool as _descriptor_pool
+from google.protobuf import symbol_database as _symbol_database
+from google.protobuf.internal import builder as _builder
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+from libp2p.peer.pb import crypto_pb2 as libp2p_dot_peer_dot_pb_dot_crypto__pb2
+
+
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x1dlibp2p/peer/pb/envelope.proto\x12\x15libp2p.peer.pb.record\x1a\x1blibp2p/peer/pb/crypto.proto\"z\n\x08\x45nvelope\x12\x34\n\npublic_key\x18\x01 \x01(\x0b\x32 .libp2p.peer.pb.crypto.PublicKey\x12\x14\n\x0cpayload_type\x18\x02 \x01(\x0c\x12\x0f\n\x07payload\x18\x03 \x01(\x0c\x12\x11\n\tsignature\x18\x05 \x01(\x0c\x42,Z*github.com/libp2p/go-libp2p/core/record/pbb\x06proto3')
+
+_globals = globals()
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.peer.pb.envelope_pb2', _globals)
+if _descriptor._USE_C_DESCRIPTORS == False:
+  _globals['DESCRIPTOR']._options = None
+  _globals['DESCRIPTOR']._serialized_options = b'Z*github.com/libp2p/go-libp2p/core/record/pb'
+  _globals['_ENVELOPE']._serialized_start=85
+  _globals['_ENVELOPE']._serialized_end=207
+# @@protoc_insertion_point(module_scope)

libp2p/peer/pb/envelope_pb2.pyi

@@ -0,0 +1,18 @@
+from libp2p.peer.pb import crypto_pb2 as _crypto_pb2
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Mapping as _Mapping, Optional as _Optional, Union as _Union
+
+DESCRIPTOR: _descriptor.FileDescriptor
+
+class Envelope(_message.Message):
+    __slots__ = ("public_key", "payload_type", "payload", "signature")
+    PUBLIC_KEY_FIELD_NUMBER: _ClassVar[int]
+    PAYLOAD_TYPE_FIELD_NUMBER: _ClassVar[int]
+    PAYLOAD_FIELD_NUMBER: _ClassVar[int]
+    SIGNATURE_FIELD_NUMBER: _ClassVar[int]
+    public_key: _crypto_pb2.PublicKey
+    payload_type: bytes
+    payload: bytes
+    signature: bytes
+    def __init__(self, public_key: _Optional[_Union[_crypto_pb2.PublicKey, _Mapping]] = ..., payload_type: _Optional[bytes] = ..., payload: _Optional[bytes] = ..., signature: _Optional[bytes] = ...) -> None: ... # type: ignore[type-arg]

libp2p/peer/pb/peer_record.proto

@@ -0,0 +1,31 @@
+syntax = "proto3";
+
+package peer.pb;
+
+option go_package = "github.com/libp2p/go-libp2p/core/peer/pb";
+
+// PeerRecord messages contain information that is useful to share with other peers.
+// Currently, a PeerRecord contains the public listen addresses for a peer, but this
+// is expected to expand to include other information in the future.
+//
+// PeerRecords are designed to be serialized to bytes and placed inside of
+// SignedEnvelopes before sharing with other peers.
+// See https://github.com/libp2p/go-libp2p/blob/master/core/record/pb/envelope.proto for
+// the SignedEnvelope definition.
+message PeerRecord {
+
+    // AddressInfo is a wrapper around a binary multiaddr. It is defined as a
+    // separate message to allow us to add per-address metadata in the future.
+    message AddressInfo {
+        bytes multiaddr = 1;
+    }
+
+    // peer_id contains a libp2p peer id in its binary representation.
+    bytes peer_id = 1;
+
+    // seq contains a monotonically-increasing sequence counter to order PeerRecords in time.
+    uint64 seq = 2;
+
+    // addresses is a list of public listen addresses for the peer.
+    repeated AddressInfo addresses = 3;
+}

libp2p/peer/pb/peer_record_pb2.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: libp2p/peer/pb/peer_record.proto
+# Protobuf Python Version: 4.25.3
+"""Generated protocol buffer code."""
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import descriptor_pool as _descriptor_pool
+from google.protobuf import symbol_database as _symbol_database
+from google.protobuf.internal import builder as _builder
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+
+
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n libp2p/peer/pb/peer_record.proto\x12\x07peer.pb\"\x80\x01\n\nPeerRecord\x12\x0f\n\x07peer_id\x18\x01 \x01(\x0c\x12\x0b\n\x03seq\x18\x02 \x01(\x04\x12\x32\n\taddresses\x18\x03 \x03(\x0b\x32\x1f.peer.pb.PeerRecord.AddressInfo\x1a \n\x0b\x41\x64\x64ressInfo\x12\x11\n\tmultiaddr\x18\x01 \x01(\x0c\x42*Z(github.com/libp2p/go-libp2p/core/peer/pbb\x06proto3')
+
+_globals = globals()
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'libp2p.peer.pb.peer_record_pb2', _globals)
+if _descriptor._USE_C_DESCRIPTORS == False:
+  _globals['DESCRIPTOR']._options = None
+  _globals['DESCRIPTOR']._serialized_options = b'Z(github.com/libp2p/go-libp2p/core/peer/pb'
+  _globals['_PEERRECORD']._serialized_start=46
+  _globals['_PEERRECORD']._serialized_end=174
+  _globals['_PEERRECORD_ADDRESSINFO']._serialized_start=142
+  _globals['_PEERRECORD_ADDRESSINFO']._serialized_end=174
+# @@protoc_insertion_point(module_scope)

libp2p/peer/pb/peer_record_pb2.pyi

@@ -0,0 +1,21 @@
+from google.protobuf.internal import containers as _containers
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import message as _message
+from typing import ClassVar as _ClassVar, Iterable as _Iterable, Mapping as _Mapping, Optional as _Optional, Union as _Union
+
+DESCRIPTOR: _descriptor.FileDescriptor
+
+class PeerRecord(_message.Message):
+    __slots__ = ("peer_id", "seq", "addresses")
+    class AddressInfo(_message.Message):
+        __slots__ = ("multiaddr",)
+        MULTIADDR_FIELD_NUMBER: _ClassVar[int]
+        multiaddr: bytes
+        def __init__(self, multiaddr: _Optional[bytes] = ...) -> None: ...
+    PEER_ID_FIELD_NUMBER: _ClassVar[int]
+    SEQ_FIELD_NUMBER: _ClassVar[int]
+    ADDRESSES_FIELD_NUMBER: _ClassVar[int]
+    peer_id: bytes
+    seq: int
+    addresses: _containers.RepeatedCompositeFieldContainer[PeerRecord.AddressInfo]
+    def __init__(self, peer_id: _Optional[bytes] = ..., seq: _Optional[int] = ..., addresses: _Optional[_Iterable[_Union[PeerRecord.AddressInfo, _Mapping]]] = ...) -> None: ...    # type: ignore[type-arg]

libp2p/peer/peer_record.py

@@ -0,0 +1,251 @@
+from collections.abc import Sequence
+import threading
+import time
+from typing import Any
+
+from multiaddr import Multiaddr
+
+from libp2p.abc import IPeerRecord
+from libp2p.peer.id import ID
+import libp2p.peer.pb.peer_record_pb2 as pb
+from libp2p.peer.peerinfo import PeerInfo
+
+PEER_RECORD_ENVELOPE_DOMAIN = "libp2p-peer-record"
+PEER_RECORD_ENVELOPE_PAYLOAD_TYPE = b"\x03\x01"
+
+_last_timestamp_lock = threading.Lock()
+_last_timestamp: int = 0
+
+
+class PeerRecord(IPeerRecord):
+    """
+    A record that contains metatdata about a peer in the libp2p network.
+
+    This includes:
+    - `peer_id`: The peer's globally unique indentifier.
+    - `addrs`: A list of the peer's publicly reachable multiaddrs.
+    - `seq`: A strictly monotonically increasing timestamp used
+            to order records over time.
+
+    PeerRecords are designed to be signed and transmitted in libp2p routing Envelopes.
+    """
+
+    peer_id: ID
+    addrs: list[Multiaddr]
+    seq: int
+
+    def __init__(
+        self,
+        peer_id: ID | None = None,
+        addrs: list[Multiaddr] | None = None,
+        seq: int | None = None,
+    ) -> None:
+        """
+        Initialize a new PeerRecord.
+        If `seq` is not provided, a timestamp-based strictly increasing sequence
+        number will be generated.
+
+        :param peer_id: ID of the peer this record refers to.
+        :param addrs: Public multiaddrs of the peer.
+        :param seq: Monotonic sequence number.
+
+        """
+        if peer_id is not None:
+            self.peer_id = peer_id
+        self.addrs = addrs or []
+        if seq is not None:
+            self.seq = seq
+        else:
+            self.seq = timestamp_seq()
+
+    def __repr__(self) -> str:
+        return (
+            f"PeerRecord(\n"
+            f"  peer_id={self.peer_id},\n"
+            f"  multiaddrs={[str(m) for m in self.addrs]},\n"
+            f"  seq={self.seq}\n"
+            f")"
+        )
+
+    def domain(self) -> str:
+        """
+        Return the domain string associated with this PeerRecord.
+
+        Used during record signing and envelope validation to identify the record type.
+        """
+        return PEER_RECORD_ENVELOPE_DOMAIN
+
+    def codec(self) -> bytes:
+        """
+        Return the codec identifier for PeerRecords.
+
+        This binary perfix helps distinguish PeerRecords in serialized envelopes.
+        """
+        return PEER_RECORD_ENVELOPE_PAYLOAD_TYPE
+
+    def to_protobuf(self) -> pb.PeerRecord:
+        """
+        Convert the current PeerRecord into a ProtoBuf PeerRecord message.
+
+        :raises ValueError: if peer_id serialization fails.
+        :return: A ProtoBuf-encoded PeerRecord message object.
+        """
+        try:
+            id_bytes = self.peer_id.to_bytes()
+        except Exception as e:
+            raise ValueError(f"failed to marshal peer_id: {e}")
+
+        msg = pb.PeerRecord()
+        msg.peer_id = id_bytes
+        msg.seq = self.seq
+        msg.addresses.extend(addrs_to_protobuf(self.addrs))
+        return msg
+
+    def marshal_record(self) -> bytes:
+        """
+        Serialize a PeerRecord into raw bytes suitable for embedding in an Envelope.
+
+        This is typically called during the process of signing or sealing the record.
+        :raises ValueError: if serialization to protobuf fails.
+        :return: Serialized PeerRecord bytes.
+        """
+        try:
+            msg = self.to_protobuf()
+            return msg.SerializeToString()
+        except Exception as e:
+            raise ValueError(f"failed to marshal PeerRecord: {e}")
+
+    def equal(self, other: Any) -> bool:
+        """
+        Check if this PeerRecord is identical to another.
+
+        Two PeerRecords are considered equal if:
+        - Their peer IDs match.
+        - Their sequence numbers are identical.
+        - Their address lists are identical and in the same order.
+
+        :param other: Another PeerRecord instance.
+        :return: True if all fields mathch, False otherwise.
+        """
+        if isinstance(other, PeerRecord):
+            if self.peer_id == other.peer_id:
+                if self.seq == other.seq:
+                    if len(self.addrs) == len(other.addrs):
+                        for a1, a2 in zip(self.addrs, other.addrs):
+                            if a1 == a2:
+                                continue
+                            else:
+                                return False
+                        return True
+        return False
+
+
+def unmarshal_record(data: bytes) -> PeerRecord:
+    """
+    Deserialize a PeerRecord from its serialized byte representation.
+
+    Typically used when receiveing a PeerRecord inside a signed routing Envelope.
+
+    :param data: Serialized protobuf-encoded bytes.
+    :raises ValueError: if parsing or conversion fails.
+    :reurn: A valid PeerRecord instance.
+    """
+    if data is None:
+        raise ValueError("cannot unmarshal PeerRecord from None")
+
+    msg = pb.PeerRecord()
+    try:
+        msg.ParseFromString(data)
+    except Exception as e:
+        raise ValueError(f"Failed to parse PeerRecord protobuf: {e}")
+
+    try:
+        record = peer_record_from_protobuf(msg)
+    except Exception as e:
+        raise ValueError(f"Failed to convert protobuf to PeerRecord: {e}")
+
+    return record
+
+
+def timestamp_seq() -> int:
+    """
+    Generate a strictly increasing timestamp-based sequence number.
+
+    Ensures that even if multiple PeerRecords are generated in the same nanosecond,
+    their `seq` values will still be strictly increasing by using a lock to track the
+    last value.
+
+    :return: A strictly increasing integer timestamp.
+    """
+    global _last_timestamp
+    now = int(time.time_ns())
+    with _last_timestamp_lock:
+        if now <= _last_timestamp:
+            now = _last_timestamp + 1
+        _last_timestamp = now
+    return now
+
+
+def peer_record_from_peer_info(info: PeerInfo) -> PeerRecord:
+    """
+    Create a PeerRecord from a PeerInfo object.
+
+    This automatically assigns a timestamp-based sequence number to the record.
+    :param info: A PeerInfo instance (contains peer_id and addrs).
+    :return: A PeerRecord instance.
+    """
+    record = PeerRecord()
+    record.peer_id = info.peer_id
+    record.addrs = info.addrs
+    return record
+
+
+def peer_record_from_protobuf(msg: pb.PeerRecord) -> PeerRecord:
+    """
+    Convert a protobuf PeerRecord message into a PeerRecord object.
+
+    :param msg: Protobuf PeerRecord message.
+    :raises ValueError: if the peer_id cannot be parsed.
+    :return: A deserialized PeerRecord instance.
+    """
+    try:
+        peer_id = ID(msg.peer_id)
+    except Exception as e:
+        raise ValueError(f"Failed to unmarshal peer_id: {e}")
+
+    addrs = addrs_from_protobuf(msg.addresses)
+    seq = msg.seq
+
+    return PeerRecord(peer_id, addrs, seq)
+
+
+def addrs_from_protobuf(addrs: Sequence[pb.PeerRecord.AddressInfo]) -> list[Multiaddr]:
+    """
+    Convert a list of protobuf address records to Multiaddr objects.
+
+    :param addrs: A list of protobuf PeerRecord.AddressInfo messages.
+    :return: A list of decoded Multiaddr instances (invalid ones are skipped).
+    """
+    out = []
+    for addr_info in addrs:
+        try:
+            addr = Multiaddr(addr_info.multiaddr)
+            out.append(addr)
+        except Exception:
+            continue
+    return out
+
+
+def addrs_to_protobuf(addrs: list[Multiaddr]) -> list[pb.PeerRecord.AddressInfo]:
+    """
+    Convert a list of Multiaddr objects into their protobuf representation.
+
+    :param addrs: A list of Multiaddr instances.
+    :return: A list of PeerRecord.AddressInfo protobuf messages.
+    """
+    out = []
+    for addr in addrs:
+        addr_info = pb.PeerRecord.AddressInfo()
+        addr_info.multiaddr = addr.to_bytes()
+        out.append(addr_info)
+    return out

libp2p/peer/peerdata.py

@@ -18,6 +18,13 @@ from libp2p.crypto.keys import (
     PublicKey,
 )
 
+"""
+Latency EWMA Smoothing governs the deacy of the EWMA (the speed at which
+is changes). This must be a normalized (0-1) value.
+1 is 100% change, 0 is no change.
+"""
+LATENCY_EWMA_SMOOTHING = 0.1
+
 
 class PeerData(IPeerData):
     pubkey: PublicKey | None
@@ -27,6 +34,7 @@ class PeerData(IPeerData):
     addrs: list[Multiaddr]
     last_identified: int
     ttl: int  # Keep ttl=0 by default for always valid
+    latmap: float
 
     def __init__(self) -> None:
         self.pubkey = None
@@ -36,6 +44,9 @@ class PeerData(IPeerData):
         self.addrs = []
         self.last_identified = int(time.time())
         self.ttl = 0
+        self.latmap = 0
+
+    # --------PROTO-BOOK--------
 
     def get_protocols(self) -> list[str]:
         """
@@ -55,6 +66,37 @@ class PeerData(IPeerData):
         """
         self.protocols = list(protocols)
 
+    def remove_protocols(self, protocols: Sequence[str]) -> None:
+        """
+        :param protocols: protocols to remove
+        """
+        for protocol in protocols:
+            if protocol in self.protocols:
+                self.protocols.remove(protocol)
+
+    def supports_protocols(self, protocols: Sequence[str]) -> list[str]:
+        """
+        :param protocols: protocols to check from
+        :return: all supported protocols in the given list
+        """
+        return [proto for proto in protocols if proto in self.protocols]
+
+    def first_supported_protocol(self, protocols: Sequence[str]) -> str:
+        """
+        :param protocols: protocols to check from
+        :return: first supported protocol in the given list
+        """
+        for protocol in protocols:
+            if protocol in self.protocols:
+                return protocol
+
+        return "None supported"
+
+    def clear_protocol_data(self) -> None:
+        """Clear all protocols"""
+        self.protocols = []
+
+    # -------ADDR-BOOK---------
     def add_addrs(self, addrs: Sequence[Multiaddr]) -> None:
         """
         :param addrs: multiaddresses to add
@@ -73,6 +115,7 @@ class PeerData(IPeerData):
         """Clear all addresses."""
         self.addrs = []
 
+    # -------METADATA-----------
     def put_metadata(self, key: str, val: Any) -> None:
         """
         :param key: key in KV pair
@@ -90,6 +133,11 @@ class PeerData(IPeerData):
             return self.metadata[key]
         raise PeerDataError("key not found")
 
+    def clear_metadata(self) -> None:
+        """Clears metadata."""
+        self.metadata = {}
+
+    # -------KEY-BOOK---------------
     def add_pubkey(self, pubkey: PublicKey) -> None:
         """
         :param pubkey:
@@ -120,9 +168,41 @@ class PeerData(IPeerData):
             raise PeerDataError("private key not found")
         return self.privkey
 
+    def clear_keydata(self) -> None:
+        """Clears keydata"""
+        self.pubkey = None
+        self.privkey = None
+
+    # ----------METRICS--------------
+    def record_latency(self, new_latency: float) -> None:
+        """
+        Records a new latency measurement for the given peer
+        using Exponentially Weighted Moving Average (EWMA)
+        :param new_latency: the new latency value
+        """
+        s = LATENCY_EWMA_SMOOTHING
+        if s > 1 or s < 0:
+            s = 0.1
+
+        if self.latmap == 0:
+            self.latmap = new_latency
+        else:
+            prev = self.latmap
+            updated = ((1.0 - s) * prev) + (s * new_latency)
+            self.latmap = updated
+
+    def latency_EWMA(self) -> float:
+        """Returns the latency EWMA value"""
+        return self.latmap
+
+    def clear_metrics(self) -> None:
+        """Clear the latency metrics"""
+        self.latmap = 0
+
     def update_last_identified(self) -> None:
         self.last_identified = int(time.time())
 
+    # ----------TTL------------------
     def get_last_identified(self) -> int:
         """
         :return: last identified timestamp

libp2p/peer/peerinfo.py

@@ -3,9 +3,11 @@ from collections.abc import (
 )
 from typing import (
     Any,
+    cast,
 )
 
 import multiaddr
+from multiaddr.protocols import Protocol
 
 from .id import (
     ID,
@@ -42,7 +44,8 @@ def info_from_p2p_addr(addr: multiaddr.Multiaddr) -> PeerInfo:
     p2p_protocols = p2p_part.protocols()
     if not p2p_protocols:
         raise InvalidAddrError("The last part of the address has no protocols")
-    last_protocol = p2p_protocols[0]
+    last_protocol = cast(Protocol, p2p_part.protocols()[0])
+
     if last_protocol is None:
         raise InvalidAddrError("The last protocol is None")
 

libp2p/peer/peerstore.py

@@ -2,6 +2,7 @@ from collections import (
     defaultdict,
 )
 from collections.abc import (
+    AsyncIterable,
     Sequence,
 )
 from typing import (
@@ -11,6 +12,8 @@ from typing import (
 from multiaddr import (
     Multiaddr,
 )
+import trio
+from trio import MemoryReceiveChannel, MemorySendChannel
 
 from libp2p.abc import (
     IPeerStore,
@@ -20,6 +23,7 @@ from libp2p.crypto.keys import (
     PrivateKey,
     PublicKey,
 )
+from libp2p.peer.envelope import Envelope
 
 from .id import (
     ID,
@@ -35,11 +39,25 @@ from .peerinfo import (
 PERMANENT_ADDR_TTL = 0
 
 
+# TODO: Set up an async task for periodic peer-store cleanup
+# for expired addresses and records.
+class PeerRecordState:
+    envelope: Envelope
+    seq: int
+
+    def __init__(self, envelope: Envelope, seq: int):
+        self.envelope = envelope
+        self.seq = seq
+
+
 class PeerStore(IPeerStore):
     peer_data_map: dict[ID, PeerData]
 
-    def __init__(self) -> None:
+    def __init__(self, max_records: int = 10000) -> None:
         self.peer_data_map = defaultdict(PeerData)
+        self.addr_update_channels: dict[ID, MemorySendChannel[Multiaddr]] = {}
+        self.peer_record_map: dict[ID, PeerRecordState] = {}
+        self.max_records = max_records
 
     def peer_info(self, peer_id: ID) -> PeerInfo:
         """
@@ -53,6 +71,69 @@ class PeerStore(IPeerStore):
             return PeerInfo(peer_id, peer_data.get_addrs())
         raise PeerStoreError("peer ID not found")
 
+    def peer_ids(self) -> list[ID]:
+        """
+        :return: all of the peer IDs stored in peer store
+        """
+        return list(self.peer_data_map.keys())
+
+    def clear_peerdata(self, peer_id: ID) -> None:
+        """Clears all data associated with the given peer_id."""
+        if peer_id in self.peer_data_map:
+            del self.peer_data_map[peer_id]
+        else:
+            raise PeerStoreError("peer ID not found")
+
+        # Clear the peer records
+        if peer_id in self.peer_record_map:
+            self.peer_record_map.pop(peer_id, None)
+
+    def valid_peer_ids(self) -> list[ID]:
+        """
+        :return: all of the valid peer IDs stored in peer store
+        """
+        valid_peer_ids: list[ID] = []
+        for peer_id, peer_data in self.peer_data_map.items():
+            if not peer_data.is_expired():
+                valid_peer_ids.append(peer_id)
+            else:
+                peer_data.clear_addrs()
+        return valid_peer_ids
+
+    def _enforce_record_limit(self) -> None:
+        """Enforce maximum number of stored records."""
+        if len(self.peer_record_map) > self.max_records:
+            # Record oldest records based on seequence number
+            sorted_records = sorted(
+                self.peer_record_map.items(), key=lambda x: x[1].seq
+            )
+            records_to_remove = len(self.peer_record_map) - self.max_records
+            for peer_id, _ in sorted_records[:records_to_remove]:
+                self.maybe_delete_peer_record(peer_id)
+                del self.peer_record_map[peer_id]
+
+    async def start_cleanup_task(self, cleanup_interval: int = 3600) -> None:
+        """Start periodic cleanup of expired peer records and addresses."""
+        while True:
+            await trio.sleep(cleanup_interval)
+            self._cleanup_expired_records()
+
+    def _cleanup_expired_records(self) -> None:
+        """Remove expired peer records and addresses"""
+        expired_peers = []
+
+        for peer_id, peer_data in self.peer_data_map.items():
+            if peer_data.is_expired():
+                expired_peers.append(peer_id)
+
+        for peer_id in expired_peers:
+            self.maybe_delete_peer_record(peer_id)
+            del self.peer_data_map[peer_id]
+
+        self._enforce_record_limit()
+
+    # --------PROTO-BOOK--------
+
     def get_protocols(self, peer_id: ID) -> list[str]:
         """
         :param peer_id: peer ID to get protocols for
@@ -79,23 +160,31 @@ class PeerStore(IPeerStore):
         peer_data = self.peer_data_map[peer_id]
         peer_data.set_protocols(list(protocols))
 
-    def peer_ids(self) -> list[ID]:
+    def remove_protocols(self, peer_id: ID, protocols: Sequence[str]) -> None:
+        """
+        :param peer_id: peer ID to get info for
+        :param protocols: unsupported protocols to remove
+        """
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.remove_protocols(protocols)
+
+    def supports_protocols(self, peer_id: ID, protocols: Sequence[str]) -> list[str]:
         """
         :return: all of the peer IDs stored in peer store
         """
-        return list(self.peer_data_map.keys())
+        peer_data = self.peer_data_map[peer_id]
+        return peer_data.supports_protocols(protocols)
 
-    def valid_peer_ids(self) -> list[ID]:
-        """
-        :return: all of the valid peer IDs stored in peer store
-        """
-        valid_peer_ids: list[ID] = []
-        for peer_id, peer_data in self.peer_data_map.items():
-            if not peer_data.is_expired():
-                valid_peer_ids.append(peer_id)
-            else:
-                peer_data.clear_addrs()
-        return valid_peer_ids
+    def first_supported_protocol(self, peer_id: ID, protocols: Sequence[str]) -> str:
+        peer_data = self.peer_data_map[peer_id]
+        return peer_data.first_supported_protocol(protocols)
+
+    def clear_protocol_data(self, peer_id: ID) -> None:
+        """Clears prtocoldata"""
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.clear_protocol_data()
+
+    # ------METADATA---------
 
     def get(self, peer_id: ID, key: str) -> Any:
         """
@@ -121,6 +210,92 @@ class PeerStore(IPeerStore):
         peer_data = self.peer_data_map[peer_id]
         peer_data.put_metadata(key, val)
 
+    def clear_metadata(self, peer_id: ID) -> None:
+        """Clears metadata"""
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.clear_metadata()
+
+    # -----CERT-ADDR-BOOK-----
+
+    # TODO: Make proper use of this function
+    def maybe_delete_peer_record(self, peer_id: ID) -> None:
+        """
+        Delete the signed peer record for a peer if it has no know
+        (non-expired) addresses.
+
+        This is a garbage collection mechanism: if all addresses for a peer have expired
+        or been cleared, there's no point holding onto its signed `Envelope`
+
+        :param peer_id: The peer whose record we may delete/
+        """
+        if peer_id in self.peer_record_map:
+            if not self.addrs(peer_id):
+                self.peer_record_map.pop(peer_id, None)
+
+    def consume_peer_record(self, envelope: Envelope, ttl: int) -> bool:
+        """
+        Accept and store a signed PeerRecord, unless it's older than
+        the one already stored.
+
+        This function:
+        - Extracts the peer ID and sequence number from the envelope
+        - Rejects the record if it's older (lower seq)
+        - Updates the stored peer record and replaces associated addresses if accepted
+
+        :param envelope: Signed envelope containing a PeerRecord.
+        :param ttl: Time-to-live for the included multiaddrs (in seconds).
+        :return: True if the record was accepted and stored; False if it was rejected.
+        """
+        record = envelope.record()
+        peer_id = record.peer_id
+
+        existing = self.peer_record_map.get(peer_id)
+        if existing and existing.seq > record.seq:
+            return False  # reject older record
+
+        new_addrs = set(record.addrs)
+
+        self.peer_record_map[peer_id] = PeerRecordState(envelope, record.seq)
+        self.peer_data_map[peer_id].clear_addrs()
+        self.add_addrs(peer_id, list(new_addrs), ttl)
+
+        return True
+
+    def consume_peer_records(self, envelopes: list[Envelope], ttl: int) -> list[bool]:
+        """Consume multiple peer records in a single operation."""
+        results = []
+        for envelope in envelopes:
+            results.append(self.consume_peer_record(envelope, ttl))
+        return results
+
+    def get_peer_record(self, peer_id: ID) -> Envelope | None:
+        """
+        Retrieve the most recent signed PeerRecord `Envelope` for a peer, if it exists
+        and is still relevant.
+
+        First, it runs cleanup via `maybe_delete_peer_record` to purge stale data.
+        Then it checks whether the peer has valid, unexpired addresses before
+        returning the associated envelope.
+
+        :param peer_id: The peer to look up.
+        :return: The signed Envelope if the peer is known and has valid
+            addresses; None otherwise.
+
+        """
+        self.maybe_delete_peer_record(peer_id)
+
+        # Check if the peer has any valid addresses
+        if (
+            peer_id in self.peer_data_map
+            and not self.peer_data_map[peer_id].is_expired()
+        ):
+            state = self.peer_record_map.get(peer_id)
+            if state is not None:
+                return state.envelope
+        return None
+
+    # -------ADDR-BOOK--------
+
     def add_addr(self, peer_id: ID, addr: Multiaddr, ttl: int = 0) -> None:
         """
         :param peer_id: peer ID to add address for
@@ -140,6 +315,15 @@ class PeerStore(IPeerStore):
         peer_data.set_ttl(ttl)
         peer_data.update_last_identified()
 
+        if peer_id in self.addr_update_channels:
+            for addr in addrs:
+                try:
+                    self.addr_update_channels[peer_id].send_nowait(addr)
+                except trio.WouldBlock:
+                    pass  # Or consider logging / dropping / replacing stream
+
+        self.maybe_delete_peer_record(peer_id)
+
     def addrs(self, peer_id: ID) -> list[Multiaddr]:
         """
         :param peer_id: peer ID to get addrs for
@@ -163,9 +347,11 @@ class PeerStore(IPeerStore):
         if peer_id in self.peer_data_map:
             self.peer_data_map[peer_id].clear_addrs()
 
+        self.maybe_delete_peer_record(peer_id)
+
     def peers_with_addrs(self) -> list[ID]:
         """
-        :return: all of the peer IDs which has addrs stored in peer store
+        :return: all of the peer IDs which has addrsfloat stored in peer store
         """
         # Add all peers with addrs at least 1 to output
         output: list[ID] = []
@@ -179,6 +365,27 @@ class PeerStore(IPeerStore):
                     peer_data.clear_addrs()
         return output
 
+    async def addr_stream(self, peer_id: ID) -> AsyncIterable[Multiaddr]:
+        """
+        Returns an async stream of newly added addresses for the given peer.
+
+        This function allows consumers to subscribe to address updates for a peer
+        and receive each new address as it is added via `add_addr` or `add_addrs`.
+
+        :param peer_id: The ID of the peer to monitor address updates for.
+        :return: An async iterator yielding Multiaddr instances as they are added.
+        """
+        send: MemorySendChannel[Multiaddr]
+        receive: MemoryReceiveChannel[Multiaddr]
+
+        send, receive = trio.open_memory_channel(0)
+        self.addr_update_channels[peer_id] = send
+
+        async for addr in receive:
+            yield addr
+
+    # -------KEY-BOOK---------
+
     def add_pubkey(self, peer_id: ID, pubkey: PublicKey) -> None:
         """
         :param peer_id: peer ID to add public key for
@@ -239,6 +446,45 @@ class PeerStore(IPeerStore):
         self.add_pubkey(peer_id, key_pair.public_key)
         self.add_privkey(peer_id, key_pair.private_key)
 
+    def peer_with_keys(self) -> list[ID]:
+        """Returns the peer_ids for which keys are stored"""
+        return [
+            peer_id
+            for peer_id, pdata in self.peer_data_map.items()
+            if pdata.pubkey is not None
+        ]
+
+    def clear_keydata(self, peer_id: ID) -> None:
+        """Clears the keys of the peer"""
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.clear_keydata()
+
+    # --------METRICS--------
+
+    def record_latency(self, peer_id: ID, RTT: float) -> None:
+        """
+        Records a new latency measurement for the given peer
+        using Exponentially Weighted Moving Average (EWMA)
+
+        :param peer_id: peer ID to get private key for
+        :param RTT: the new latency value (round trip time)
+        """
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.record_latency(RTT)
+
+    def latency_EWMA(self, peer_id: ID) -> float:
+        """
+        :param peer_id: peer ID to get private key for
+        :return: The latency EWMA value for that peer
+        """
+        peer_data = self.peer_data_map[peer_id]
+        return peer_data.latency_EWMA()
+
+    def clear_metrics(self, peer_id: ID) -> None:
+        """Clear the latency metrics"""
+        peer_data = self.peer_data_map[peer_id]
+        peer_data.clear_metrics()
+
 
 class PeerStoreError(KeyError):
     """Raised when peer ID is not found in peer store."""

libp2p/protocol_muxer/multiselect.py

@@ -1,3 +1,5 @@
+import trio
+
 from libp2p.abc import (
     IMultiselectCommunicator,
     IMultiselectMuxer,
@@ -14,6 +16,7 @@ from .exceptions import (
 
 MULTISELECT_PROTOCOL_ID = "/multistream/1.0.0"
 PROTOCOL_NOT_FOUND_MSG = "na"
+DEFAULT_NEGOTIATE_TIMEOUT = 5
 
 
 class Multiselect(IMultiselectMuxer):
@@ -47,15 +50,20 @@ class Multiselect(IMultiselectMuxer):
 
     # FIXME: Make TProtocol Optional[TProtocol] to keep types consistent
     async def negotiate(
-        self, communicator: IMultiselectCommunicator
+        self,
+        communicator: IMultiselectCommunicator,
+        negotiate_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
     ) -> tuple[TProtocol, StreamHandlerFn | None]:
         """
         Negotiate performs protocol selection.
 
         :param stream: stream to negotiate on
+        :param negotiate_timeout: timeout for negotiation
         :return: selected protocol name, handler function
         :raise MultiselectError: raised when negotiation failed
         """
+        try:
+            with trio.fail_after(negotiate_timeout):
                 await self.handshake(communicator)
 
                 while True:
@@ -65,7 +73,9 @@ class Multiselect(IMultiselectMuxer):
                         raise MultiselectError() from error
 
                     if command == "ls":
-                supported_protocols = [p for p in self.handlers.keys() if p is not None]
+                        supported_protocols = [
+                            p for p in self.handlers.keys() if p is not None
+                        ]
                         response = "\n".join(supported_protocols) + "\n"
 
                         try:
@@ -88,6 +98,20 @@ class Multiselect(IMultiselectMuxer):
                             raise MultiselectError() from error
 
                 raise MultiselectError("Negotiation failed: no matching protocol")
+        except trio.TooSlowError:
+            raise MultiselectError("handshake read timeout")
+
+    def get_protocols(self) -> tuple[TProtocol | None, ...]:
+        """
+        Retrieve the protocols for which handlers have been registered.
+
+        Returns
+        -------
+        tuple[TProtocol, ...]
+            A tuple of registered protocol names.
+
+        """
+        return tuple(self.handlers.keys())
 
     async def handshake(self, communicator: IMultiselectCommunicator) -> None:
         """

libp2p/protocol_muxer/multiselect_client.py

@@ -2,6 +2,8 @@ from collections.abc import (
     Sequence,
 )
 
+import trio
+
 from libp2p.abc import (
     IMultiselectClient,
     IMultiselectCommunicator,
@@ -17,6 +19,7 @@ from .exceptions import (
 
 MULTISELECT_PROTOCOL_ID = "/multistream/1.0.0"
 PROTOCOL_NOT_FOUND_MSG = "na"
+DEFAULT_NEGOTIATE_TIMEOUT = 5
 
 
 class MultiselectClient(IMultiselectClient):
@@ -40,6 +43,7 @@ class MultiselectClient(IMultiselectClient):
 
         try:
             handshake_contents = await communicator.read()
+
         except MultiselectCommunicatorError as error:
             raise MultiselectClientError() from error
 
@@ -47,7 +51,10 @@ class MultiselectClient(IMultiselectClient):
             raise MultiselectClientError("multiselect protocol ID mismatch")
 
     async def select_one_of(
-        self, protocols: Sequence[TProtocol], communicator: IMultiselectCommunicator
+        self,
+        protocols: Sequence[TProtocol],
+        communicator: IMultiselectCommunicator,
+        negotitate_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
     ) -> TProtocol:
         """
         For each protocol, send message to multiselect selecting protocol and
@@ -56,22 +63,32 @@ class MultiselectClient(IMultiselectClient):
 
         :param protocol: protocol to select
         :param communicator: communicator to use to communicate with counterparty
+        :param negotiate_timeout: timeout for negotiation
         :return: selected protocol
         :raise MultiselectClientError: raised when protocol negotiation failed
         """
+        try:
+            with trio.fail_after(negotitate_timeout):
                 await self.handshake(communicator)
 
                 for protocol in protocols:
                     try:
-                selected_protocol = await self.try_select(communicator, protocol)
+                        selected_protocol = await self.try_select(
+                            communicator, protocol
+                        )
                         return selected_protocol
                     except MultiselectClientError:
                         pass
 
                 raise MultiselectClientError("protocols not supported")
+        except trio.TooSlowError:
+            raise MultiselectClientError("response timed out")
 
     async def query_multistream_command(
-        self, communicator: IMultiselectCommunicator, command: str
+        self,
+        communicator: IMultiselectCommunicator,
+        command: str,
+        response_timeout: int = DEFAULT_NEGOTIATE_TIMEOUT,
     ) -> list[str]:
         """
         Send a multistream-select command over the given communicator and return
@@ -79,9 +96,12 @@ class MultiselectClient(IMultiselectClient):
 
         :param communicator: communicator to use to communicate with counterparty
         :param command: supported multistream-select command(e.g., ls)
+        :param negotiate_timeout: timeout for negotiation
         :raise MultiselectClientError: If the communicator fails to process data.
         :return: list of strings representing the response from peer.
         """
+        try:
+            with trio.fail_after(response_timeout):
                 await self.handshake(communicator)
 
                 if command == "ls":
@@ -95,10 +115,13 @@ class MultiselectClient(IMultiselectClient):
                 try:
                     response = await communicator.read()
                     response_list = response.strip().splitlines()
+
                 except MultiselectCommunicatorError as error:
                     raise MultiselectClientError() from error
 
                 return response_list
+        except trio.TooSlowError:
+            raise MultiselectClientError("command response timed out")
 
     async def try_select(
         self, communicator: IMultiselectCommunicator, protocol: TProtocol
@@ -118,6 +141,7 @@ class MultiselectClient(IMultiselectClient):
 
         try:
             response = await communicator.read()
+
         except MultiselectCommunicatorError as error:
             raise MultiselectClientError() from error
 

libp2p/pubsub/floodsub.py

@@ -12,15 +12,9 @@ from libp2p.abc import (
 from libp2p.custom_types import (
     TProtocol,
 )
-from libp2p.network.stream.exceptions import (
-    StreamClosed,
-)
 from libp2p.peer.id import (
     ID,
 )
-from libp2p.utils import (
-    encode_varint_prefixed,
-)
 
 from .exceptions import (
     PubsubRouterError,
@@ -120,13 +114,7 @@ class FloodSub(IPubsubRouter):
             if peer_id not in pubsub.peers:
                 continue
             stream = pubsub.peers[peer_id]
-            # FIXME: We should add a `WriteMsg` similar to write delimited messages.
-            #   Ref: https://github.com/libp2p/go-libp2p-pubsub/blob/master/comm.go#L107
-            try:
-                await stream.write(encode_varint_prefixed(rpc_msg.SerializeToString()))
-            except StreamClosed:
-                logger.debug("Fail to publish message to %s: stream closed", peer_id)
-                pubsub._handle_dead_peer(peer_id)
+            await pubsub.write_msg(stream, rpc_msg)
 
     async def join(self, topic: str) -> None:
         """

libp2p/pubsub/gossipsub.py

@@ -24,9 +24,6 @@ from libp2p.abc import (
 from libp2p.custom_types import (
     TProtocol,
 )
-from libp2p.network.stream.exceptions import (
-    StreamClosed,
-)
 from libp2p.peer.id import (
     ID,
 )
@@ -44,9 +41,6 @@ from libp2p.pubsub import (
 from libp2p.tools.async_service import (
     Service,
 )
-from libp2p.utils import (
-    encode_varint_prefixed,
-)
 
 from .exceptions import (
     NoPubsubAttached,
@@ -267,13 +261,10 @@ class GossipSub(IPubsubRouter, Service):
             if peer_id not in self.pubsub.peers:
                 continue
             stream = self.pubsub.peers[peer_id]
-            # FIXME: We should add a `WriteMsg` similar to write delimited messages.
-            #   Ref: https://github.com/libp2p/go-libp2p-pubsub/blob/master/comm.go#L107
-            try:
-                await stream.write(encode_varint_prefixed(rpc_msg.SerializeToString()))
-            except StreamClosed:
-                logger.debug("Fail to publish message to %s: stream closed", peer_id)
-                self.pubsub._handle_dead_peer(peer_id)
+
+            # TODO: Go use `sendRPC`, which possibly piggybacks gossip/control messages.
+            await self.pubsub.write_msg(stream, rpc_msg)
+
         for topic in pubsub_msg.topicIDs:
             self.time_since_last_publish[topic] = int(time.time())
 
@@ -829,8 +820,6 @@ class GossipSub(IPubsubRouter, Service):
 
         packet.publish.extend(msgs_to_forward)
 
-        # 2) Serialize that packet
-        rpc_msg: bytes = packet.SerializeToString()
         if self.pubsub is None:
             raise NoPubsubAttached
 
@@ -844,14 +833,7 @@ class GossipSub(IPubsubRouter, Service):
         peer_stream = self.pubsub.peers[sender_peer_id]
 
         # 4) And write the packet to the stream
-        try:
-            await peer_stream.write(encode_varint_prefixed(rpc_msg))
-        except StreamClosed:
-            logger.debug(
-                "Fail to responed to iwant request from %s: stream closed",
-                sender_peer_id,
-            )
-            self.pubsub._handle_dead_peer(sender_peer_id)
+        await self.pubsub.write_msg(peer_stream, packet)
 
     async def handle_graft(
         self, graft_msg: rpc_pb2.ControlGraft, sender_peer_id: ID
@@ -993,8 +975,6 @@ class GossipSub(IPubsubRouter, Service):
         packet: rpc_pb2.RPC = rpc_pb2.RPC()
         packet.control.CopyFrom(control_msg)
 
-        rpc_msg: bytes = packet.SerializeToString()
-
         # Get stream for peer from pubsub
         if to_peer not in self.pubsub.peers:
             logger.debug(
@@ -1004,8 +984,4 @@ class GossipSub(IPubsubRouter, Service):
         peer_stream = self.pubsub.peers[to_peer]
 
         # Write rpc to stream
-        try:
-            await peer_stream.write(encode_varint_prefixed(rpc_msg))
-        except StreamClosed:
-            logger.debug("Fail to emit control message to %s: stream closed", to_peer)
-            self.pubsub._handle_dead_peer(to_peer)
+        await self.pubsub.write_msg(peer_stream, packet)

libp2p/pubsub/pubsub.py

@@ -66,6 +66,7 @@ from libp2p.utils import (
     encode_varint_prefixed,
     read_varint_prefixed_bytes,
 )
+from libp2p.utils.varint import encode_uvarint
 
 from .pb import (
     rpc_pb2,
@@ -101,6 +102,9 @@ class TopicValidator(NamedTuple):
     is_async: bool
 
 
+MAX_CONCURRENT_VALIDATORS = 10
+
+
 class Pubsub(Service, IPubsub):
     host: IHost
 
@@ -108,6 +112,7 @@ class Pubsub(Service, IPubsub):
 
     peer_receive_channel: trio.MemoryReceiveChannel[ID]
     dead_peer_receive_channel: trio.MemoryReceiveChannel[ID]
+    _validator_semaphore: trio.Semaphore
 
     seen_messages: LastSeenCache
 
@@ -142,6 +147,7 @@ class Pubsub(Service, IPubsub):
         msg_id_constructor: Callable[
             [rpc_pb2.Message], bytes
         ] = get_peer_and_seqno_msg_id,
+        max_concurrent_validator_count: int = MAX_CONCURRENT_VALIDATORS,
     ) -> None:
         """
         Construct a new Pubsub object, which is responsible for handling all
@@ -167,6 +173,7 @@ class Pubsub(Service, IPubsub):
         # Therefore, we can only close from the receive side.
         self.peer_receive_channel = peer_receive
         self.dead_peer_receive_channel = dead_peer_receive
+        self._validator_semaphore = trio.Semaphore(max_concurrent_validator_count)
         # Register a notifee
         self.host.get_network().register_notifee(
             PubsubNotifee(peer_send, dead_peer_send)
@@ -656,7 +663,11 @@ class Pubsub(Service, IPubsub):
 
         logger.debug("successfully published message %s", msg)
 
-    async def validate_msg(self, msg_forwarder: ID, msg: rpc_pb2.Message) -> None:
+    async def validate_msg(
+        self,
+        msg_forwarder: ID,
+        msg: rpc_pb2.Message,
+    ) -> None:
         """
         Validate the received message.
 
@@ -679,23 +690,34 @@ class Pubsub(Service, IPubsub):
             if not validator(msg_forwarder, msg):
                 raise ValidationError(f"Validation failed for msg={msg}")
 
-        # TODO: Implement throttle on async validators
-
         if len(async_topic_validators) > 0:
             # Appends to lists are thread safe in CPython
-            results = []
-
-            async def run_async_validator(func: AsyncValidatorFn) -> None:
-                result = await func(msg_forwarder, msg)
-                results.append(result)
+            results: list[bool] = []
 
             async with trio.open_nursery() as nursery:
                 for async_validator in async_topic_validators:
-                    nursery.start_soon(run_async_validator, async_validator)
+                    nursery.start_soon(
+                        self._run_async_validator,
+                        async_validator,
+                        msg_forwarder,
+                        msg,
+                        results,
+                    )
 
             if not all(results):
                 raise ValidationError(f"Validation failed for msg={msg}")
 
+    async def _run_async_validator(
+        self,
+        func: AsyncValidatorFn,
+        msg_forwarder: ID,
+        msg: rpc_pb2.Message,
+        results: list[bool],
+    ) -> None:
+        async with self._validator_semaphore:
+            result = await func(msg_forwarder, msg)
+            results.append(result)
+
     async def push_msg(self, msg_forwarder: ID, msg: rpc_pb2.Message) -> None:
         """
         Push a pubsub message to others.
@@ -778,3 +800,43 @@ class Pubsub(Service, IPubsub):
 
     def _is_subscribed_to_msg(self, msg: rpc_pb2.Message) -> bool:
         return any(topic in self.topic_ids for topic in msg.topicIDs)
+
+    async def write_msg(self, stream: INetStream, rpc_msg: rpc_pb2.RPC) -> bool:
+        """
+        Write an RPC message to a stream with proper error handling.
+
+        Implements WriteMsg similar to go-msgio which is used in go-libp2p
+        Ref: https://github.com/libp2p/go-msgio/blob/master/protoio/uvarint_writer.go#L56
+
+
+        :param stream: stream to write the message to
+        :param rpc_msg: RPC message to write
+        :return: True if successful, False if stream was closed
+        """
+        try:
+            # Calculate message size first
+            msg_bytes = rpc_msg.SerializeToString()
+            msg_size = len(msg_bytes)
+
+            # Calculate varint size and allocate exact buffer size needed
+
+            varint_bytes = encode_uvarint(msg_size)
+            varint_size = len(varint_bytes)
+
+            # Allocate buffer with exact size (like Go's pool.Get())
+            buf = bytearray(varint_size + msg_size)
+
+            # Write varint length prefix to buffer (like Go's binary.PutUvarint())
+            buf[:varint_size] = varint_bytes
+
+            # Write serialized message after varint (like Go's rpc.MarshalTo())
+            buf[varint_size:] = msg_bytes
+
+            # Single write operation (like Go's s.Write(buf))
+            await stream.write(bytes(buf))
+            return True
+        except StreamClosed:
+            peer_id = stream.muxed_conn.peer_id
+            logger.debug("Fail to write message to %s: stream closed", peer_id)
+            self._handle_dead_peer(peer_id)
+            return False

libp2p/relay/circuit_v2/discovery.py

@@ -234,7 +234,8 @@ class RelayDiscovery(Service):
 
             if not callable(proto_getter):
                 return None
-
+            if peer_id not in peerstore.peer_ids():
+                return None
             try:
                 # Try to get protocols
                 proto_result = proto_getter(peer_id)
@@ -283,8 +284,6 @@ class RelayDiscovery(Service):
                 return None
 
             mux = self.host.get_mux()
-            if not hasattr(mux, "protocols"):
-                return None
 
             peer_protocols = set()
             # Get protocols from mux with proper type safety
@@ -293,7 +292,9 @@ class RelayDiscovery(Service):
                 # Get protocols with proper typing
                 mux_protocols = mux.get_protocols()
                 if isinstance(mux_protocols, (list, tuple)):
-                    available_protocols = list(mux_protocols)
+                    available_protocols = [
+                        p for p in mux.get_protocols() if p is not None
+                    ]
 
             for protocol in available_protocols:
                 try:
@@ -313,7 +314,7 @@ class RelayDiscovery(Service):
 
             self._protocol_cache[peer_id] = peer_protocols
             protocol_str = str(PROTOCOL_ID)
-            for protocol in peer_protocols:
+            for protocol in map(TProtocol, peer_protocols):
                 if protocol == protocol_str:
                     return True
             return False

libp2p/stream_muxer/mplex/mplex_stream.py

@@ -1,3 +1,5 @@
+from collections.abc import AsyncGenerator
+from contextlib import asynccontextmanager
 from types import (
     TracebackType,
 )
@@ -32,6 +34,72 @@ if TYPE_CHECKING:
     )
 
 
+class ReadWriteLock:
+    """
+    A read-write lock that allows multiple concurrent readers
+    or one exclusive writer, implemented using Trio primitives.
+    """
+
+    def __init__(self) -> None:
+        self._readers = 0
+        self._readers_lock = trio.Lock()  # Protects access to _readers count
+        self._writer_lock = trio.Semaphore(1)  # Allows only one writer at a time
+
+    async def acquire_read(self) -> None:
+        """Acquire a read lock. Multiple readers can hold it simultaneously."""
+        try:
+            async with self._readers_lock:
+                if self._readers == 0:
+                    await self._writer_lock.acquire()
+                self._readers += 1
+        except trio.Cancelled:
+            raise
+
+    async def release_read(self) -> None:
+        """Release a read lock."""
+        async with self._readers_lock:
+            if self._readers == 1:
+                self._writer_lock.release()
+            self._readers -= 1
+
+    async def acquire_write(self) -> None:
+        """Acquire an exclusive write lock."""
+        try:
+            await self._writer_lock.acquire()
+        except trio.Cancelled:
+            raise
+
+    def release_write(self) -> None:
+        """Release the exclusive write lock."""
+        self._writer_lock.release()
+
+    @asynccontextmanager
+    async def read_lock(self) -> AsyncGenerator[None, None]:
+        """Context manager for acquiring and releasing a read lock safely."""
+        acquire = False
+        try:
+            await self.acquire_read()
+            acquire = True
+            yield
+        finally:
+            if acquire:
+                with trio.CancelScope() as scope:
+                    scope.shield = True
+                    await self.release_read()
+
+    @asynccontextmanager
+    async def write_lock(self) -> AsyncGenerator[None, None]:
+        """Context manager for acquiring and releasing a write lock safely."""
+        acquire = False
+        try:
+            await self.acquire_write()
+            acquire = True
+            yield
+        finally:
+            if acquire:
+                self.release_write()
+
+
 class MplexStream(IMuxedStream):
     """
     reference: https://github.com/libp2p/go-mplex/blob/master/stream.go
@@ -46,7 +114,7 @@ class MplexStream(IMuxedStream):
     read_deadline: int | None
     write_deadline: int | None
 
-    # TODO: Add lock for read/write to avoid interleaving receiving messages?
+    rw_lock: ReadWriteLock
     close_lock: trio.Lock
 
     # NOTE: `dataIn` is size of 8 in Go implementation.
@@ -80,6 +148,7 @@ class MplexStream(IMuxedStream):
         self.event_remote_closed = trio.Event()
         self.event_reset = trio.Event()
         self.close_lock = trio.Lock()
+        self.rw_lock = ReadWriteLock()
         self.incoming_data_channel = incoming_data_channel
         self._buf = bytearray()
 
@@ -113,6 +182,7 @@ class MplexStream(IMuxedStream):
         :param n: number of bytes to read
         :return: bytes actually read
         """
+        async with self.rw_lock.read_lock():
             if n is not None and n < 0:
                 raise ValueError(
                     "the number of bytes to read `n` must be non-negative or "
@@ -124,8 +194,8 @@ class MplexStream(IMuxedStream):
                 return await self._read_until_eof()
             if len(self._buf) == 0:
                 data: bytes
-            # Peek whether there is data available. If yes, we just read until there is
-            # no data, then return.
+                # Peek whether there is data available. If yes, we just read until
+                # there is no data, then return.
                 try:
                     data = self.incoming_data_channel.receive_nowait()
                     self._buf.extend(data)
@@ -143,12 +213,12 @@ class MplexStream(IMuxedStream):
                         if self.event_remote_closed.is_set():
                             raise MplexStreamEOF
                     except trio.ClosedResourceError as error:
-                    # Probably `incoming_data_channel` is closed in `reset` when we are
-                    # waiting for `receive`.
+                        # Probably `incoming_data_channel` is closed in `reset` when
+                        # we are waiting for `receive`.
                         if self.event_reset.is_set():
                             raise MplexStreamReset
                         raise Exception(
-                        "`incoming_data_channel` is closed but stream is not reset. "
+                            "`incoming_data_channel` is closed but stream is not reset."
                             "This should never happen."
                         ) from error
             self._buf.extend(self._read_return_when_blocked())
@@ -162,6 +232,7 @@ class MplexStream(IMuxedStream):
 
         :return: number of bytes written
         """
+        async with self.rw_lock.write_lock():
             if self.event_local_closed.is_set():
                 raise MplexStreamClosed(f"cannot write to closed stream: data={data!r}")
             flag = (
@@ -176,8 +247,6 @@ class MplexStream(IMuxedStream):
         Closing a stream closes it for writing and closes the remote end for
         reading but allows writing in the other direction.
         """
-        # TODO error handling with timeout
-
         async with self.close_lock:
             if self.event_local_closed.is_set():
                 return
@@ -185,8 +254,17 @@ class MplexStream(IMuxedStream):
         flag = (
             HeaderTags.CloseInitiator if self.is_initiator else HeaderTags.CloseReceiver
         )
-        # TODO: Raise when `muxed_conn.send_message` fails and `Mplex` isn't shutdown.
+
+        try:
+            with trio.fail_after(5):  # timeout in seconds
                 await self.muxed_conn.send_message(flag, None, self.stream_id)
+        except trio.TooSlowError:
+            raise TimeoutError("Timeout while trying to close the stream")
+        except MuxedConnUnavailable:
+            if not self.muxed_conn.event_shutting_down.is_set():
+                raise RuntimeError(
+                    "Failed to send close message and Mplex isn't shutting down"
+                )
 
         _is_remote_closed: bool
         async with self.close_lock:

libp2p/stream_muxer/muxer_multistream.py

@@ -31,9 +31,6 @@ from libp2p.stream_muxer.yamux.yamux import (
     Yamux,
 )
 
-# FIXME: add negotiate timeout to `MuxerMultistream`
-DEFAULT_NEGOTIATE_TIMEOUT = 60
-
 
 class MuxerMultistream:
     """

libp2p/stream_muxer/yamux/yamux.py

@@ -45,6 +45,9 @@ from libp2p.stream_muxer.exceptions import (
     MuxedStreamReset,
 )
 
+# Configure logger for this module
+logger = logging.getLogger("libp2p.stream_muxer.yamux")
+
 PROTOCOL_ID = "/yamux/1.0.0"
 TYPE_DATA = 0x0
 TYPE_WINDOW_UPDATE = 0x1
@@ -98,16 +101,32 @@ class YamuxStream(IMuxedStream):
         # Flow control: Check if we have enough send window
         total_len = len(data)
         sent = 0
-
+        logger.debug(f"Stream {self.stream_id}: Starts writing {total_len} bytes ")
         while sent < total_len:
+            # Wait for available window with timeout
+            timeout = False
             async with self.window_lock:
-                # Wait for available window
-                while self.send_window == 0 and not self.closed:
-                    # Release lock while waiting
+                if self.send_window == 0:
+                    logger.debug(
+                        f"Stream {self.stream_id}: Window is zero, waiting for update"
+                    )
+                    # Release lock and wait with timeout
                     self.window_lock.release()
+                    # To avoid re-acquiring the lock immediately,
+                    with trio.move_on_after(5.0) as cancel_scope:
+                        while self.send_window == 0 and not self.closed:
                             await trio.sleep(0.01)
+                        # If we timed out, cancel the scope
+                        timeout = cancel_scope.cancelled_caught
+                    # Re-acquire lock
                     await self.window_lock.acquire()
 
+                # If we timed out waiting for window update, raise an error
+                if timeout:
+                    raise MuxedStreamError(
+                        "Timed out waiting for window update after 5 seconds."
+                    )
+
                 if self.closed:
                     raise MuxedStreamError("Stream is closed")
 
@@ -123,25 +142,45 @@ class YamuxStream(IMuxedStream):
                 await self.conn.secured_conn.write(header + chunk)
                 sent += to_send
 
-        # If window is getting low, consider updating
-        if self.send_window < DEFAULT_WINDOW_SIZE // 2:
-            await self.send_window_update()
-
-    async def send_window_update(self, increment: int | None = None) -> None:
-        """Send a window update to peer."""
-        if increment is None:
-            increment = DEFAULT_WINDOW_SIZE - self.recv_window
+    async def send_window_update(self, increment: int, skip_lock: bool = False) -> None:
+        """
+        Send a window update to peer.
 
+        param:increment: The amount to increment the window size by.
+        If None, uses the difference between DEFAULT_WINDOW_SIZE
+        and current receive window.
+        param:skip_lock (bool): If True, skips acquiring window_lock.
+        This should only be used when calling from a context
+        that already holds the lock.
+        """
         if increment <= 0:
+            # If increment is zero or negative, skip sending update
+            logger.debug(
+                f"Stream {self.stream_id}: Skipping window update"
+                f"(increment={increment})"
+            )
             return
+        logger.debug(
+            f"Stream {self.stream_id}: Sending window update with increment={increment}"
+        )
 
-        async with self.window_lock:
-            self.recv_window += increment
+        async def _do_window_update() -> None:
             header = struct.pack(
-                YAMUX_HEADER_FORMAT, 0, TYPE_WINDOW_UPDATE, 0, self.stream_id, increment
+                YAMUX_HEADER_FORMAT,
+                0,
+                TYPE_WINDOW_UPDATE,
+                0,
+                self.stream_id,
+                increment,
             )
             await self.conn.secured_conn.write(header)
 
+        if skip_lock:
+            await _do_window_update()
+        else:
+            async with self.window_lock:
+                await _do_window_update()
+
     async def read(self, n: int | None = -1) -> bytes:
         # Handle None value for n by converting it to -1
         if n is None:
@@ -149,64 +188,77 @@ class YamuxStream(IMuxedStream):
 
         # If the stream is closed for receiving and the buffer is empty, raise EOF
         if self.recv_closed and not self.conn.stream_buffers.get(self.stream_id):
-            logging.debug(
+            logger.debug(
                 f"Stream {self.stream_id}: Stream closed for receiving and buffer empty"
             )
             raise MuxedStreamEOF("Stream is closed for receiving")
 
-        # If reading until EOF (n == -1), block until stream is closed
         if n == -1:
-            while not self.recv_closed and not self.conn.event_shutting_down.is_set():
+            data = b""
+            while not self.conn.event_shutting_down.is_set():
                 # Check if there's data in the buffer
                 buffer = self.conn.stream_buffers.get(self.stream_id)
-                if buffer and len(buffer) > 0:
-                    # Wait for closure even if data is available
-                    logging.debug(
-                        f"Stream {self.stream_id}:Waiting for FIN before returning data"
-                    )
-                    await self.conn.stream_events[self.stream_id].wait()
-                    self.conn.stream_events[self.stream_id] = trio.Event()
-                else:
-                    # No data, wait for data or closure
-                    logging.debug(f"Stream {self.stream_id}: Waiting for data or FIN")
+
+                # If buffer is not available, check if stream is closed
+                if buffer is None:
+                    logger.debug(f"Stream {self.stream_id}: No buffer available")
+                    raise MuxedStreamEOF("Stream buffer closed")
+
+                # If we have data in buffer, process it
+                if len(buffer) > 0:
+                    chunk = bytes(buffer)
+                    buffer.clear()
+                    data += chunk
+
+                    # Send window update for the chunk we just read
+                    async with self.window_lock:
+                        self.recv_window += len(chunk)
+                        logger.debug(f"Stream {self.stream_id}: Update {len(chunk)}")
+                        await self.send_window_update(len(chunk), skip_lock=True)
+
+                # If stream is closed (FIN received) and buffer is empty, break
+                if self.recv_closed and len(buffer) == 0:
+                    logger.debug(f"Stream {self.stream_id}: Closed with empty buffer")
+                    break
+
+                # If stream was reset, raise reset error
+                if self.reset_received:
+                    logger.debug(f"Stream {self.stream_id}: Stream was reset")
+                    raise MuxedStreamReset("Stream was reset")
+
+                # Wait for more data or stream closure
+                logger.debug(f"Stream {self.stream_id}: Waiting for data or FIN")
                 await self.conn.stream_events[self.stream_id].wait()
                 self.conn.stream_events[self.stream_id] = trio.Event()
 
-            # After loop, check if stream is closed or shutting down
-            async with self.conn.streams_lock:
-                if self.conn.event_shutting_down.is_set():
-                    logging.debug(f"Stream {self.stream_id}: Connection shutting down")
-                    raise MuxedStreamEOF("Connection shut down")
-                if self.closed:
-                    if self.reset_received:
-                        logging.debug(f"Stream {self.stream_id}: Stream was reset")
-                        raise MuxedStreamReset("Stream was reset")
-                    else:
-                        logging.debug(
-                            f"Stream {self.stream_id}: Stream closed cleanly (EOF)"
+            # After loop exit, first check if we have data to return
+            if data:
+                logger.debug(
+                    f"Stream {self.stream_id}: Returning {len(data)} bytes after loop"
                 )
-                        raise MuxedStreamEOF("Stream closed cleanly (EOF)")
-                buffer = self.conn.stream_buffers.get(self.stream_id)
-                if buffer is None:
-                    logging.debug(
-                        f"Stream {self.stream_id}: Buffer gone, assuming closed"
-                    )
-                    raise MuxedStreamEOF("Stream buffer closed")
-                if self.recv_closed and len(buffer) == 0:
-                    logging.debug(f"Stream {self.stream_id}: EOF reached")
-                    raise MuxedStreamEOF("Stream is closed for receiving")
-                # Return all buffered data
-                data = bytes(buffer)
-                buffer.clear()
-                logging.debug(f"Stream {self.stream_id}: Returning {len(data)} bytes")
                 return data
 
-        # For specific size read (n > 0), return available data immediately
-        return await self.conn.read_stream(self.stream_id, n)
+            # No data accumulated, now check why we exited the loop
+            if self.conn.event_shutting_down.is_set():
+                logger.debug(f"Stream {self.stream_id}: Connection shutting down")
+                raise MuxedStreamEOF("Connection shut down")
+
+            # Return empty data
+            return b""
+        else:
+            data = await self.conn.read_stream(self.stream_id, n)
+            async with self.window_lock:
+                self.recv_window += len(data)
+                logger.debug(
+                    f"Stream {self.stream_id}: Sending window update after read, "
+                    f"increment={len(data)}"
+                )
+                await self.send_window_update(len(data), skip_lock=True)
+            return data
 
     async def close(self) -> None:
         if not self.send_closed:
-            logging.debug(f"Half-closing stream {self.stream_id} (local end)")
+            logger.debug(f"Half-closing stream {self.stream_id} (local end)")
             header = struct.pack(
                 YAMUX_HEADER_FORMAT, 0, TYPE_DATA, FLAG_FIN, self.stream_id, 0
             )
@@ -222,7 +274,7 @@ class YamuxStream(IMuxedStream):
 
     async def reset(self) -> None:
         if not self.closed:
-            logging.debug(f"Resetting stream {self.stream_id}")
+            logger.debug(f"Resetting stream {self.stream_id}")
             header = struct.pack(
                 YAMUX_HEADER_FORMAT, 0, TYPE_DATA, FLAG_RST, self.stream_id, 0
             )
@@ -300,7 +352,7 @@ class Yamux(IMuxedConn):
         self._nursery: Nursery | None = None
 
     async def start(self) -> None:
-        logging.debug(f"Starting Yamux for {self.peer_id}")
+        logger.debug(f"Starting Yamux for {self.peer_id}")
         if self.event_started.is_set():
             return
         async with trio.open_nursery() as nursery:
@@ -313,7 +365,7 @@ class Yamux(IMuxedConn):
         return self.is_initiator_value
 
     async def close(self, error_code: int = GO_AWAY_NORMAL) -> None:
-        logging.debug(f"Closing Yamux connection with code {error_code}")
+        logger.debug(f"Closing Yamux connection with code {error_code}")
         async with self.streams_lock:
             if not self.event_shutting_down.is_set():
                 try:
@@ -322,7 +374,7 @@ class Yamux(IMuxedConn):
                     )
                     await self.secured_conn.write(header)
                 except Exception as e:
-                    logging.debug(f"Failed to send GO_AWAY: {e}")
+                    logger.debug(f"Failed to send GO_AWAY: {e}")
                 self.event_shutting_down.set()
                 for stream in self.streams.values():
                     stream.closed = True
@@ -333,12 +385,12 @@ class Yamux(IMuxedConn):
                 self.stream_events.clear()
         try:
             await self.secured_conn.close()
-            logging.debug(f"Successfully closed secured_conn for peer {self.peer_id}")
+            logger.debug(f"Successfully closed secured_conn for peer {self.peer_id}")
         except Exception as e:
-            logging.debug(f"Error closing secured_conn for peer {self.peer_id}: {e}")
+            logger.debug(f"Error closing secured_conn for peer {self.peer_id}: {e}")
         self.event_closed.set()
         if self.on_close:
-            logging.debug(f"Calling on_close in Yamux.close for peer {self.peer_id}")
+            logger.debug(f"Calling on_close in Yamux.close for peer {self.peer_id}")
             if inspect.iscoroutinefunction(self.on_close):
                 if self.on_close is not None:
                     await self.on_close()
@@ -367,7 +419,7 @@ class Yamux(IMuxedConn):
             header = struct.pack(
                 YAMUX_HEADER_FORMAT, 0, TYPE_DATA, FLAG_SYN, stream_id, 0
             )
-            logging.debug(f"Sending SYN header for stream {stream_id}")
+            logger.debug(f"Sending SYN header for stream {stream_id}")
             await self.secured_conn.write(header)
             return stream
         except Exception as e:
@@ -375,32 +427,32 @@ class Yamux(IMuxedConn):
             raise e
 
     async def accept_stream(self) -> IMuxedStream:
-        logging.debug("Waiting for new stream")
+        logger.debug("Waiting for new stream")
         try:
             stream = await self.new_stream_receive_channel.receive()
-            logging.debug(f"Received stream {stream.stream_id}")
+            logger.debug(f"Received stream {stream.stream_id}")
             return stream
         except trio.EndOfChannel:
             raise MuxedStreamError("No new streams available")
 
     async def read_stream(self, stream_id: int, n: int = -1) -> bytes:
-        logging.debug(f"Reading from stream {self.peer_id}:{stream_id}, n={n}")
+        logger.debug(f"Reading from stream {self.peer_id}:{stream_id}, n={n}")
         if n is None:
             n = -1
 
         while True:
             async with self.streams_lock:
                 if stream_id not in self.streams:
-                    logging.debug(f"Stream {self.peer_id}:{stream_id} unknown")
+                    logger.debug(f"Stream {self.peer_id}:{stream_id} unknown")
                     raise MuxedStreamEOF("Stream closed")
                 if self.event_shutting_down.is_set():
-                    logging.debug(
+                    logger.debug(
                         f"Stream {self.peer_id}:{stream_id}: connection shutting down"
                     )
                     raise MuxedStreamEOF("Connection shut down")
                 stream = self.streams[stream_id]
                 buffer = self.stream_buffers.get(stream_id)
-                logging.debug(
+                logger.debug(
                     f"Stream {self.peer_id}:{stream_id}: "
                     f"closed={stream.closed}, "
                     f"recv_closed={stream.recv_closed}, "
@@ -408,7 +460,7 @@ class Yamux(IMuxedConn):
                     f"buffer_len={len(buffer) if buffer else 0}"
                 )
                 if buffer is None:
-                    logging.debug(
+                    logger.debug(
                         f"Stream {self.peer_id}:{stream_id}:"
                         f"Buffer gone, assuming closed"
                     )
@@ -421,7 +473,7 @@ class Yamux(IMuxedConn):
                     else:
                         data = bytes(buffer[:n])
                         del buffer[:n]
-                    logging.debug(
+                    logger.debug(
                         f"Returning {len(data)} bytes"
                         f"from stream {self.peer_id}:{stream_id}, "
                         f"buffer_len={len(buffer)}"
@@ -429,7 +481,7 @@ class Yamux(IMuxedConn):
                     return data
                 # If reset received and buffer is empty, raise reset
                 if stream.reset_received:
-                    logging.debug(
+                    logger.debug(
                         f"Stream {self.peer_id}:{stream_id}:"
                         f"reset_received=True, raising MuxedStreamReset"
                     )
@@ -442,7 +494,7 @@ class Yamux(IMuxedConn):
                     else:
                         data = bytes(buffer[:n])
                         del buffer[:n]
-                    logging.debug(
+                    logger.debug(
                         f"Returning {len(data)} bytes"
                         f"from stream {self.peer_id}:{stream_id}, "
                         f"buffer_len={len(buffer)}"
@@ -450,21 +502,21 @@ class Yamux(IMuxedConn):
                     return data
                 # Check if stream is closed
                 if stream.closed:
-                    logging.debug(
+                    logger.debug(
                         f"Stream {self.peer_id}:{stream_id}:"
                         f"closed=True, raising MuxedStreamReset"
                     )
                     raise MuxedStreamReset("Stream is reset or closed")
                 # Check if recv_closed and buffer empty
                 if stream.recv_closed:
-                    logging.debug(
+                    logger.debug(
                         f"Stream {self.peer_id}:{stream_id}:"
                         f"recv_closed=True, buffer empty, raising EOF"
                     )
                     raise MuxedStreamEOF("Stream is closed for receiving")
 
             # Wait for data if stream is still open
-            logging.debug(f"Waiting for data on stream {self.peer_id}:{stream_id}")
+            logger.debug(f"Waiting for data on stream {self.peer_id}:{stream_id}")
             try:
                 await self.stream_events[stream_id].wait()
                 self.stream_events[stream_id] = trio.Event()
@@ -479,7 +531,7 @@ class Yamux(IMuxedConn):
             try:
                 header = await self.secured_conn.read(HEADER_SIZE)
                 if not header or len(header) < HEADER_SIZE:
-                    logging.debug(
+                    logger.debug(
                         f"Connection closed orincomplete header for peer {self.peer_id}"
                     )
                     self.event_shutting_down.set()
@@ -488,12 +540,12 @@ class Yamux(IMuxedConn):
                 version, typ, flags, stream_id, length = struct.unpack(
                     YAMUX_HEADER_FORMAT, header
                 )
-                logging.debug(
+                logger.debug(
                     f"Received header for peer {self.peer_id}:"
                     f"type={typ}, flags={flags}, stream_id={stream_id},"
                     f"length={length}"
                 )
-                if typ == TYPE_DATA and flags & FLAG_SYN:
+                if (typ == TYPE_DATA or typ == TYPE_WINDOW_UPDATE) and flags & FLAG_SYN:
                     async with self.streams_lock:
                         if stream_id not in self.streams:
                             stream = YamuxStream(stream_id, self, False)
@@ -509,7 +561,7 @@ class Yamux(IMuxedConn):
                                 0,
                             )
                             await self.secured_conn.write(ack_header)
-                            logging.debug(
+                            logger.debug(
                                 f"Sending stream {stream_id}"
                                 f"to channel for peer {self.peer_id}"
                             )
@@ -527,7 +579,7 @@ class Yamux(IMuxedConn):
                 elif typ == TYPE_DATA and flags & FLAG_RST:
                     async with self.streams_lock:
                         if stream_id in self.streams:
-                            logging.debug(
+                            logger.debug(
                                 f"Resetting stream {stream_id} for peer {self.peer_id}"
                             )
                             self.streams[stream_id].closed = True
@@ -536,27 +588,27 @@ class Yamux(IMuxedConn):
                 elif typ == TYPE_DATA and flags & FLAG_ACK:
                     async with self.streams_lock:
                         if stream_id in self.streams:
-                            logging.debug(
+                            logger.debug(
                                 f"Received ACK for stream"
                                 f"{stream_id} for peer {self.peer_id}"
                             )
                 elif typ == TYPE_GO_AWAY:
                     error_code = length
                     if error_code == GO_AWAY_NORMAL:
-                        logging.debug(
+                        logger.debug(
                             f"Received GO_AWAY for peer"
                             f"{self.peer_id}: Normal termination"
                         )
                     elif error_code == GO_AWAY_PROTOCOL_ERROR:
-                        logging.error(
+                        logger.error(
                             f"Received GO_AWAY for peer{self.peer_id}: Protocol error"
                         )
                     elif error_code == GO_AWAY_INTERNAL_ERROR:
-                        logging.error(
+                        logger.error(
                             f"Received GO_AWAY for peer {self.peer_id}: Internal error"
                         )
                     else:
-                        logging.error(
+                        logger.error(
                             f"Received GO_AWAY for peer {self.peer_id}"
                             f"with unknown error code: {error_code}"
                         )
@@ -565,7 +617,7 @@ class Yamux(IMuxedConn):
                     break
                 elif typ == TYPE_PING:
                     if flags & FLAG_SYN:
-                        logging.debug(
+                        logger.debug(
                             f"Received ping request with value"
                             f"{length} for peer {self.peer_id}"
                         )
@@ -574,7 +626,7 @@ class Yamux(IMuxedConn):
                         )
                         await self.secured_conn.write(ping_header)
                     elif flags & FLAG_ACK:
-                        logging.debug(
+                        logger.debug(
                             f"Received ping response with value"
                             f"{length} for peer {self.peer_id}"
                         )
@@ -588,7 +640,7 @@ class Yamux(IMuxedConn):
                                 self.stream_buffers[stream_id].extend(data)
                                 self.stream_events[stream_id].set()
                                 if flags & FLAG_FIN:
-                                    logging.debug(
+                                    logger.debug(
                                         f"Received FIN for stream {self.peer_id}:"
                                         f"{stream_id}, marking recv_closed"
                                     )
@@ -596,7 +648,7 @@ class Yamux(IMuxedConn):
                                     if self.streams[stream_id].send_closed:
                                         self.streams[stream_id].closed = True
                     except Exception as e:
-                        logging.error(f"Error reading data for stream {stream_id}: {e}")
+                        logger.error(f"Error reading data for stream {stream_id}: {e}")
                         # Mark stream as closed on read error
                         async with self.streams_lock:
                             if stream_id in self.streams:
@@ -610,7 +662,7 @@ class Yamux(IMuxedConn):
                         if stream_id in self.streams:
                             stream = self.streams[stream_id]
                             async with stream.window_lock:
-                                logging.debug(
+                                logger.debug(
                                     f"Received window update for stream"
                                     f"{self.peer_id}:{stream_id},"
                                     f" increment: {increment}"
@@ -625,7 +677,7 @@ class Yamux(IMuxedConn):
                         and details.get("requested_count") == 2
                         and details.get("received_count") == 0
                     ):
-                        logging.info(
+                        logger.info(
                             f"Stream closed cleanly for peer {self.peer_id}"
                             + f" (IncompleteReadError: {details})"
                         )
@@ -633,12 +685,29 @@ class Yamux(IMuxedConn):
                         await self._cleanup_on_error()
                         break
                     else:
-                        logging.error(
+                        logger.error(
                             f"Error in handle_incoming for peer {self.peer_id}: "
                             + f"{type(e).__name__}: {str(e)}"
                         )
                 else:
-                    logging.error(
+                    # Handle RawConnError with more nuance
+                    if isinstance(e, RawConnError):
+                        error_msg = str(e)
+                        # If RawConnError is empty, it's likely normal cleanup
+                        if not error_msg.strip():
+                            logger.info(
+                                f"RawConnError (empty) during cleanup for peer "
+                                f"{self.peer_id} (normal connection shutdown)"
+                            )
+                        else:
+                            # Log non-empty RawConnError as warning
+                            logger.warning(
+                                f"RawConnError during connection handling for peer "
+                                f"{self.peer_id}: {error_msg}"
+                            )
+                    else:
+                        # Log all other errors normally
+                        logger.error(
                             f"Error in handle_incoming for peer {self.peer_id}: "
                             + f"{type(e).__name__}: {str(e)}"
                         )
@@ -671,9 +740,9 @@ class Yamux(IMuxedConn):
         # Close the secured connection
         try:
             await self.secured_conn.close()
-            logging.debug(f"Successfully closed secured_conn for peer {self.peer_id}")
+            logger.debug(f"Successfully closed secured_conn for peer {self.peer_id}")
         except Exception as close_error:
-            logging.error(
+            logger.error(
                 f"Error closing secured_conn for peer {self.peer_id}: {close_error}"
             )
 
@@ -682,14 +751,14 @@ class Yamux(IMuxedConn):
 
         # Call on_close callback if provided
         if self.on_close:
-            logging.debug(f"Calling on_close for peer {self.peer_id}")
+            logger.debug(f"Calling on_close for peer {self.peer_id}")
             try:
                 if inspect.iscoroutinefunction(self.on_close):
                     await self.on_close()
                 else:
                     self.on_close()
             except Exception as callback_error:
-                logging.error(f"Error in on_close callback: {callback_error}")
+                logger.error(f"Error in on_close callback: {callback_error}")
 
         # Cancel nursery tasks
         if self._nursery:

libp2p/utils/__init__.py

@@ -7,6 +7,9 @@ from libp2p.utils.varint import (
     encode_varint_prefixed,
     read_delim,
     read_varint_prefixed_bytes,
+    decode_varint_from_bytes,
+    decode_varint_with_size,
+    read_length_prefixed_protobuf,
 )
 from libp2p.utils.version import (
     get_agent_version,
@@ -20,4 +23,7 @@ __all__ = [
     "get_agent_version",
     "read_delim",
     "read_varint_prefixed_bytes",
+    "decode_varint_from_bytes",
+    "decode_varint_with_size",
+    "read_length_prefixed_protobuf",
 ]

libp2p/utils/varint.py

@@ -1,7 +1,9 @@
 import itertools
 import logging
 import math
+from typing import BinaryIO
 
+from libp2p.abc import INetStream
 from libp2p.exceptions import (
     ParseError,
 )
@@ -25,18 +27,41 @@ HIGH_MASK = 2**7
 SHIFT_64_BIT_MAX = int(math.ceil(64 / 7)) * 7
 
 
-def encode_uvarint(number: int) -> bytes:
-    """Pack `number` into varint bytes."""
-    buf = b""
-    while True:
-        towrite = number & 0x7F
-        number >>= 7
-        if number:
-            buf += bytes((towrite | 0x80,))
-        else:
-            buf += bytes((towrite,))
+def encode_uvarint(value: int) -> bytes:
+    """Encode an unsigned integer as a varint."""
+    if value < 0:
+        raise ValueError("Cannot encode negative value as uvarint")
+
+    result = bytearray()
+    while value >= 0x80:
+        result.append((value & 0x7F) | 0x80)
+        value >>= 7
+    result.append(value & 0x7F)
+    return bytes(result)
+
+
+def decode_uvarint(data: bytes) -> int:
+    """Decode a varint from bytes."""
+    if not data:
+        raise ParseError("Unexpected end of data")
+
+    result = 0
+    shift = 0
+
+    for byte in data:
+        result |= (byte & 0x7F) << shift
+        if (byte & 0x80) == 0:
             break
-    return buf
+        shift += 7
+        if shift >= 64:
+            raise ValueError("Varint too long")
+
+    return result
+
+
+def decode_varint_from_bytes(data: bytes) -> int:
+    """Decode a varint from bytes (alias for decode_uvarint for backward comp)."""
+    return decode_uvarint(data)
 
 
 async def decode_uvarint_from_stream(reader: Reader) -> int:
@@ -44,7 +69,9 @@ async def decode_uvarint_from_stream(reader: Reader) -> int:
     res = 0
     for shift in itertools.count(0, 7):
         if shift > SHIFT_64_BIT_MAX:
-            raise ParseError("TODO: better exception msg: Integer is too large...")
+            raise ParseError(
+                "Varint decoding error: integer exceeds maximum size of 64 bits."
+            )
 
         byte = await read_exactly(reader, 1)
         value = byte[0]
@@ -56,9 +83,35 @@ async def decode_uvarint_from_stream(reader: Reader) -> int:
     return res
 
 
-def encode_varint_prefixed(msg_bytes: bytes) -> bytes:
-    varint_len = encode_uvarint(len(msg_bytes))
-    return varint_len + msg_bytes
+def decode_varint_with_size(data: bytes) -> tuple[int, int]:
+    """
+    Decode a varint from bytes and return both the value and the number of bytes
+    consumed.
+
+    Returns:
+        Tuple[int, int]: (value, bytes_consumed)
+
+    """
+    result = 0
+    shift = 0
+    bytes_consumed = 0
+
+    for byte in data:
+        result |= (byte & 0x7F) << shift
+        bytes_consumed += 1
+        if (byte & 0x80) == 0:
+            break
+        shift += 7
+        if shift >= 64:
+            raise ValueError("Varint too long")
+
+    return result, bytes_consumed
+
+
+def encode_varint_prefixed(data: bytes) -> bytes:
+    """Encode data with a varint length prefix."""
+    length_bytes = encode_uvarint(len(data))
+    return length_bytes + data
 
 
 async def read_varint_prefixed_bytes(reader: Reader) -> bytes:
@@ -85,3 +138,95 @@ async def read_delim(reader: Reader) -> bytes:
             f'`msg_bytes` is not delimited by b"\\n": `msg_bytes`={msg_bytes!r}'
         )
     return msg_bytes[:-1]
+
+
+def read_varint_prefixed_bytes_sync(
+    stream: BinaryIO, max_length: int = 1024 * 1024
+) -> bytes:
+    """
+    Read varint-prefixed bytes from a stream.
+
+    Args:
+        stream: A stream-like object with a read() method
+        max_length: Maximum allowed data length to prevent memory exhaustion
+
+    Returns:
+        bytes: The data without the length prefix
+
+    Raises:
+        ValueError: If the length prefix is invalid or too large
+        EOFError: If the stream ends unexpectedly
+
+    """
+    # Read the varint length prefix
+    length_bytes = b""
+    while True:
+        byte_data = stream.read(1)
+        if not byte_data:
+            raise EOFError("Stream ended while reading varint length prefix")
+
+        length_bytes += byte_data
+        if byte_data[0] & 0x80 == 0:
+            break
+
+    # Decode the length
+    length = decode_uvarint(length_bytes)
+
+    if length > max_length:
+        raise ValueError(f"Data length {length} exceeds maximum allowed {max_length}")
+
+    # Read the data
+    data = stream.read(length)
+    if len(data) != length:
+        raise EOFError(f"Expected {length} bytes, got {len(data)}")
+
+    return data
+
+
+async def read_length_prefixed_protobuf(
+    stream: INetStream, use_varint_format: bool = True, max_length: int = 1024 * 1024
+) -> bytes:
+    """Read a protobuf message from a stream, handling both formats."""
+    if use_varint_format:
+        # Read length-prefixed protobuf message from the stream
+        # First read the varint length prefix
+        length_bytes = b""
+        while True:
+            b = await stream.read(1)
+            if not b:
+                raise Exception("No length prefix received")
+
+            length_bytes += b
+            if b[0] & 0x80 == 0:
+                break
+
+        msg_length = decode_varint_from_bytes(length_bytes)
+
+        if msg_length > max_length:
+            raise Exception(
+                f"Message length {msg_length} exceeds maximum allowed {max_length}"
+            )
+
+        # Read the protobuf message
+        data = await stream.read(msg_length)
+        if len(data) != msg_length:
+            raise Exception(
+                f"Incomplete message: expected {msg_length}, got {len(data)}"
+            )
+
+        return data
+    else:
+        # Read raw protobuf message from the stream
+        # For raw format, read all available data in one go
+        data = await stream.read()
+
+        # If we got no data, raise an exception
+        if not data:
+            raise Exception("No data received in raw format")
+
+        if len(data) > max_length:
+            raise Exception(
+                f"Message length {len(data)} exceeds maximum allowed {max_length}"
+            )
+
+        return data

newsfragments/579.feature.rst

@@ -1 +0,0 @@
-Added support for ``Kademlia DHT`` in py-libp2p.

newsfragments/631.feature.rst

@@ -1,7 +0,0 @@
-Store public key and peer ID in peerstore during handshake
-
-Modified the InsecureTransport class to accept an optional peerstore parameter and updated the handshake process to store the received public key and peer ID in the peerstore when available.
-
-Added test cases to verify:
-1. The peerstore remains unchanged when handshake fails due to peer ID mismatch
-2. The handshake correctly adds a public key to a peer ID that already exists in the peerstore but doesn't have a public key yet

newsfragments/678.misc.rst

@@ -1 +0,0 @@
-Refactored gossipsub heartbeat logic to use a single helper method `_handle_topic_heartbeat` that handles both fanout and gossip heartbeats.

newsfragments/679.feature.rst

@@ -1 +0,0 @@
-Added sparse connect utility function to pubsub test utilities for creating test networks with configurable connectivity.

newsfragments/681.breaking.rst

@@ -1,2 +0,0 @@
-Reordered the arguments to `upgrade_security` to place `is_initiator` before `peer_id`, and made `peer_id` optional.
-This allows the method to reflect the fact that peer identity is not required for inbound connections.

newsfragments/684.misc.rst

@@ -1 +0,0 @@
-Uses the `decapsulate` method of the `Multiaddr` class to clean up the observed address.

newsfragments/685.feature.rst

@@ -1 +0,0 @@
-Optimized pubsub publishing to send multiple topics in a single message instead of separate messages per topic.

newsfragments/690.feature.rst

@@ -1 +0,0 @@
-added peer exchange and backoff logic as part of Gossipsub v1.1 upgrade

newsfragments/702.bugfix.rst

@@ -1 +0,0 @@
-Fixed an issue in `Pubsub` where async validators were not handled reliably under concurrency. Now uses a safe aggregator list for consistent behavior.

newsfragments/711.feature.rst

@@ -0,0 +1 @@
+Added `Bootstrap` peer discovery module that allows nodes to connect to predefined bootstrap peers for network discovery.

newsfragments/746.bugfix.rst

@@ -0,0 +1,3 @@
+Improved type safety in `get_mux()` and `get_protocols()` by returning properly typed values instead
+of `Any`. Also updated `identify.py` and `discovery.py` to handle `None` values safely and
+compare protocols correctly.

newsfragments/748.feature.rst

@@ -0,0 +1 @@
+ Add lock for read/write to avoid interleaving receiving messages in mplex_stream.py

newsfragments/749.internal.rst

@@ -0,0 +1 @@
+Add comprehensive tests for relay_discovery method in circuit_relay_v2

newsfragments/750.feature.rst

@@ -0,0 +1 @@
+Add logic to clear_peerdata method in peerstore

newsfragments/752.internal.rst

@@ -0,0 +1 @@
+[mplex] Add timeout and error handling during stream close

newsfragments/753.feature.rst

@@ -0,0 +1,2 @@
+Added the `Certified Addr-Book` interface supported by `Envelope` and `PeerRecord` class.
+Integrated the signed-peer-record transfer in the identify/push protocols.

newsfragments/755.performance.rst

@@ -0,0 +1,2 @@
+Added throttling for async topic validators in validate_msg, enforcing a
+concurrency limit to prevent resource exhaustion under heavy load.

newsfragments/757.bugfix.rst

@@ -0,0 +1 @@
+fixed malformed PeerId in test_peerinfo

newsfragments/757.internal.rst

@@ -0,0 +1 @@
+fixed a typecheck error using cast in peerinfo.py

newsfragments/760.docs.rst

@@ -0,0 +1 @@
+Improve error message under the function decode_uvarint_from_stream in libp2p/utils/varint.py file

newsfragments/761.breaking.rst

@@ -0,0 +1 @@
+identify protocol use now prefix-length messages by default. use use_varint_format param for old raw messages

newsfragments/761.feature.rst

@@ -0,0 +1 @@
+add length-prefixed support to identify protocol

newsfragments/761.internal.rst

@@ -0,0 +1 @@
+Fix raw format reading in identify/push protocol and add comprehensive test coverage for both varint and raw formats

newsfragments/766.internal.rst

@@ -0,0 +1 @@
+Pin py-multiaddr dependency to specific git commit db8124e2321f316d3b7d2733c7df11d6ad9c03e6

newsfragments/772.internal.rst

@@ -0,0 +1 @@
+Replace the libp2p.peer.ID cache attributes with functools.cached_property functional decorator.

newsfragments/775.docs.rst

@@ -0,0 +1 @@
+Clarified the requirement for a trailing newline in newsfragments to pass lint checks.

newsfragments/778.bugfix.rst

@@ -0,0 +1 @@
+Fixed incorrect handling of raw protobuf format in identify protocol. The identify example now properly handles both raw and length-prefixed (varint) message formats, provides better error messages, and displays connection status with peer IDs. Replaced mock-based tests with comprehensive real network integration tests for both formats.

newsfragments/784.bugfix.rst

@@ -0,0 +1 @@
+Fixed incorrect handling of raw protobuf format in identify push protocol. The identify push example now properly handles both raw and length-prefixed (varint) message formats, provides better error messages, and displays connection status with peer IDs. Replaced mock-based tests with comprehensive real network integration tests for both formats.

newsfragments/784.internal.rst

@@ -0,0 +1 @@
+Yamux RawConnError Logging Refactor - Improved error handling and debug logging

newsfragments/README.md

@@ -18,12 +18,19 @@ Each file should be named like `<ISSUE>.<TYPE>.rst`, where
 - `performance`
 - `removal`
 
-So for example: `123.feature.rst`, `456.bugfix.rst`
+So for example: `1024.feature.rst`
+
+**Important**: Ensure the file ends with a newline character (`\n`) to pass GitHub tox linting checks.
+
+```
+Added support for Ed25519 key generation in libp2p peer identity creation.
+
+```
 
 If the PR fixes an issue, use that number here. If there is no issue,
 then open up the PR first and use the PR number for the newsfragment.
 
-Note that the `towncrier` tool will automatically
+**Note** that the `towncrier` tool will automatically
 reflow your text, so don't try to do any fancy formatting. Run
 `towncrier build --draft` to get a preview of what the release notes entry
 will look like in the final release notes.

pyproject.toml

@@ -1,11 +1,10 @@
-
 [build-system]
 requires = ["setuptools>=42", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
 name = "libp2p"
-version = "0.2.8"
+version = "0.2.9"
 description = "libp2p: The Python implementation of the libp2p networking stack"
 readme = "README.md"
 requires-python = ">=3.10, <4.0"
@@ -20,10 +19,11 @@ dependencies = [
     "exceptiongroup>=1.2.0; python_version < '3.11'",
     "grpcio>=1.41.0",
     "lru-dict>=1.1.6",
-    "multiaddr>=0.0.9",
+    # "multiaddr>=0.0.9",
+    "multiaddr @ git+https://github.com/multiformats/py-multiaddr.git@db8124e2321f316d3b7d2733c7df11d6ad9c03e6",
     "mypy-protobuf>=3.0.0",
     "noiseprotocol>=0.3.0",
-    "protobuf>=3.20.1,<4.0.0",
+    "protobuf>=4.25.0,<5.0.0",
     "pycryptodome>=3.9.2",
     "pymultihash>=0.8.2",
     "pynacl>=1.3.0",
@@ -31,6 +31,7 @@ dependencies = [
     "trio-typing>=0.0.4",
     "trio>=0.26.0",
     "fastecdsa==2.3.2; sys_platform != 'win32'",
+    "zeroconf (>=0.147.0,<0.148.0)",
 ]
 classifiers = [
     "Development Status :: 4 - Beta",
@@ -54,6 +55,7 @@ identify-demo = "examples.identify.identify:main"
 identify-push-demo = "examples.identify_push.identify_push_demo:run_main"
 identify-push-listener-dialer-demo = "examples.identify_push.identify_push_listener_dialer:main"
 pubsub-demo = "examples.pubsub.pubsub:main"
+mdns-demo = "examples.mDNS.mDNS:main"
 
 [project.optional-dependencies]
 dev = [
@@ -187,7 +189,7 @@ name = "Removals"
 showcontent = true
 
 [tool.bumpversion]
-current_version = "0.2.8"
+current_version = "0.2.9"
 parse = """
     (?P<major>\\d+)
     \\.(?P<minor>\\d+)

tests/core/identity/identify/test_identify.py

@@ -11,10 +11,10 @@ from libp2p.identity.identify.identify import (
     PROTOCOL_VERSION,
     _mk_identify_protobuf,
     _multiaddr_to_bytes,
+    parse_identify_response,
 )
-from libp2p.identity.identify.pb.identify_pb2 import (
-    Identify,
-)
+from libp2p.peer.envelope import Envelope, consume_envelope, unmarshal_envelope
+from libp2p.peer.peer_record import unmarshal_record
 from tests.utils.factories import (
     host_pair_factory,
 )
@@ -29,14 +29,31 @@ async def test_identify_protocol(security_protocol):
         host_b,
     ):
         # Here, host_b is the requester and host_a is the responder.
-        # observed_addr represent host_b’s address as observed by host_a
-        # (i.e., the address from which host_b’s request was received).
+        # observed_addr represent host_b's address as observed by host_a
+        # (i.e., the address from which host_b's request was received).
         stream = await host_b.new_stream(host_a.get_id(), (ID,))
-        response = await stream.read()
+
+        # Read the response (could be either format)
+        # Read a larger chunk to get all the data before stream closes
+        response = await stream.read(8192)  # Read enough data in one go
+
         await stream.close()
 
-        identify_response = Identify()
-        identify_response.ParseFromString(response)
+        # Parse the response (handles both old and new formats)
+        identify_response = parse_identify_response(response)
+
+        # Validate the recieved envelope and then store it in the certified-addr-book
+        envelope, record = consume_envelope(
+            identify_response.signedPeerRecord, "libp2p-peer-record"
+        )
+        assert host_b.peerstore.consume_peer_record(envelope, ttl=7200)
+
+        # Check if the peer_id in the record is same as of host_a
+        assert record.peer_id == host_a.get_id()
+
+        # Check if the peer-record is correctly consumed
+        assert host_a.get_addrs() == host_b.peerstore.addrs(host_a.get_id())
+        assert isinstance(host_b.peerstore.get_peer_record(host_a.get_id()), Envelope)
 
         logger.debug("host_a: %s", host_a.get_addrs())
         logger.debug("host_b: %s", host_b.get_addrs())
@@ -62,11 +79,21 @@ async def test_identify_protocol(security_protocol):
 
         logger.debug("observed_addr: %s", Multiaddr(identify_response.observed_addr))
         logger.debug("host_b.get_addrs()[0]: %s", host_b.get_addrs()[0])
-        logger.debug("cleaned_addr= %s", cleaned_addr)
-        assert identify_response.observed_addr == _multiaddr_to_bytes(cleaned_addr)
+
+        # The observed address should match the cleaned address
+        assert Multiaddr(identify_response.observed_addr) == cleaned_addr
 
         # Check protocols
         assert set(identify_response.protocols) == set(host_a.get_mux().get_protocols())
 
-        # sanity check
-        assert identify_response == _mk_identify_protobuf(host_a, cleaned_addr)
+        # sanity check if the peer_id of the identify msg are same
+        assert (
+            unmarshal_record(
+                unmarshal_envelope(identify_response.signedPeerRecord).raw_payload
+            ).peer_id
+            == unmarshal_record(
+                unmarshal_envelope(
+                    _mk_identify_protobuf(host_a, cleaned_addr).signedPeerRecord
+                ).raw_payload
+            ).peer_id
+        )

tests/core/identity/identify/test_identify_integration.py

@@ -0,0 +1,241 @@
+import logging
+
+import pytest
+
+from libp2p.custom_types import TProtocol
+from libp2p.identity.identify.identify import (
+    AGENT_VERSION,
+    ID,
+    PROTOCOL_VERSION,
+    _multiaddr_to_bytes,
+    identify_handler_for,
+    parse_identify_response,
+)
+from tests.utils.factories import host_pair_factory
+
+logger = logging.getLogger("libp2p.identity.identify-integration-test")
+
+
+@pytest.mark.trio
+async def test_identify_protocol_varint_format_integration(security_protocol):
+    """Test identify protocol with varint format in real network scenario."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=True)
+        )
+
+        # Make identify request
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+        assert result.listen_addrs == [
+            _multiaddr_to_bytes(addr) for addr in host_a.get_addrs()
+        ]
+
+
+@pytest.mark.trio
+async def test_identify_protocol_raw_format_integration(security_protocol):
+    """Test identify protocol with raw format in real network scenario."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=False)
+        )
+
+        # Make identify request
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+        assert result.listen_addrs == [
+            _multiaddr_to_bytes(addr) for addr in host_a.get_addrs()
+        ]
+
+
+@pytest.mark.trio
+async def test_identify_default_format_behavior(security_protocol):
+    """Test identify protocol uses correct default format."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Use default identify handler (should use varint format)
+        host_a.set_stream_handler(ID, identify_handler_for(host_a))
+
+        # Make identify request
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_cross_format_compatibility_varint_to_raw(security_protocol):
+    """Test varint dialer with raw listener compatibility."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Host A uses raw format
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=False)
+        )
+
+        # Host B makes request (will automatically detect format)
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response (should work with automatic format detection)
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_cross_format_compatibility_raw_to_varint(security_protocol):
+    """Test raw dialer with varint listener compatibility."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Host A uses varint format
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=True)
+        )
+
+        # Host B makes request (will automatically detect format)
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response (should work with automatic format detection)
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_format_detection_robustness(security_protocol):
+    """Test identify protocol format detection is robust with various message sizes."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Test both formats with different message sizes
+        for use_varint in [True, False]:
+            host_a.set_stream_handler(
+                ID, identify_handler_for(host_a, use_varint_format=use_varint)
+            )
+
+            # Make identify request
+            stream = await host_b.new_stream(host_a.get_id(), (ID,))
+            response = await stream.read(8192)
+            await stream.close()
+
+            # Parse response
+            result = parse_identify_response(response)
+
+            # Verify response content
+            assert result.agent_version == AGENT_VERSION
+            assert result.protocol_version == PROTOCOL_VERSION
+            assert result.public_key == host_a.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_large_message_handling(security_protocol):
+    """Test identify protocol handles large messages with many protocols."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add many protocols to make the message larger
+        async def dummy_handler(stream):
+            pass
+
+        for i in range(10):
+            host_a.set_stream_handler(TProtocol(f"/test/protocol/{i}"), dummy_handler)
+
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=True)
+        )
+
+        # Make identify request
+        stream = await host_b.new_stream(host_a.get_id(), (ID,))
+        response = await stream.read(8192)
+        await stream.close()
+
+        # Parse response
+        result = parse_identify_response(response)
+
+        # Verify response content
+        assert result.agent_version == AGENT_VERSION
+        assert result.protocol_version == PROTOCOL_VERSION
+        assert result.public_key == host_a.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_message_equivalence_real_network(security_protocol):
+    """Test that both formats produce equivalent messages in real network."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Test varint format
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=True)
+        )
+        stream_varint = await host_b.new_stream(host_a.get_id(), (ID,))
+        response_varint = await stream_varint.read(8192)
+        await stream_varint.close()
+
+        # Test raw format
+        host_a.set_stream_handler(
+            ID, identify_handler_for(host_a, use_varint_format=False)
+        )
+        stream_raw = await host_b.new_stream(host_a.get_id(), (ID,))
+        response_raw = await stream_raw.read(8192)
+        await stream_raw.close()
+
+        # Parse both responses
+        result_varint = parse_identify_response(response_varint)
+        result_raw = parse_identify_response(response_raw)
+
+        # Both should produce identical parsed results
+        assert result_varint.agent_version == result_raw.agent_version
+        assert result_varint.protocol_version == result_raw.protocol_version
+        assert result_varint.public_key == result_raw.public_key
+        assert result_varint.listen_addrs == result_raw.listen_addrs

tests/core/identity/identify_push/test_identify_push.py

@@ -1,4 +1,7 @@
 import logging
+from unittest.mock import (
+    patch,
+)
 
 import pytest
 import multiaddr
@@ -17,6 +20,7 @@ from libp2p.identity.identify.pb.identify_pb2 import (
     Identify,
 )
 from libp2p.identity.identify_push.identify_push import (
+    CONCURRENCY_LIMIT,
     ID_PUSH,
     _update_peerstore_from_identify,
     identify_push_handler_for,
@@ -29,6 +33,11 @@ from libp2p.peer.peerinfo import (
 from tests.utils.factories import (
     host_pair_factory,
 )
+from tests.utils.utils import (
+    create_mock_connections,
+    run_host_forever,
+    wait_until_listening,
+)
 
 logger = logging.getLogger("libp2p.identity.identify-push-test")
 
@@ -175,6 +184,7 @@ async def test_identify_push_to_peers(security_protocol):
         host_c = new_host(key_pair=key_pair_c)
 
         # Set up the identify/push handlers
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
         host_b.set_stream_handler(ID_PUSH, identify_push_handler_for(host_b))
         host_c.set_stream_handler(ID_PUSH, identify_push_handler_for(host_c))
 
@@ -204,6 +214,20 @@ async def test_identify_push_to_peers(security_protocol):
             # Check that the peer is in the peerstore
             assert peer_id_a in peerstore_c.peer_ids()
 
+            # Test for push_identify to only connected peers and not all peers
+            # Disconnect a from c.
+            await host_c.disconnect(host_a.get_id())
+
+            await push_identify_to_peers(host_c)
+
+            # Wait a bit for the push to complete
+            await trio.sleep(0.1)
+
+            # Check that host_a's peerstore has not been updated with host_c's info
+            assert host_c.get_id() not in host_a.get_peerstore().peer_ids()
+            # Check that host_b's peerstore has been updated with host_c's info
+            assert host_c.get_id() in host_b.get_peerstore().peer_ids()
+
 
 @pytest.mark.trio
 async def test_push_identify_to_peers_with_explicit_params(security_protocol):
@@ -412,3 +436,265 @@ async def test_partial_update_peerstore_from_identify(security_protocol):
         host_a_public_key = host_a.get_public_key().serialize()
         peerstore_public_key = peerstore.pubkey(peer_id).serialize()
         assert host_a_public_key == peerstore_public_key
+
+
+@pytest.mark.trio
+async def test_push_identify_to_peers_respects_concurrency_limit():
+    """
+    Test bounded concurrency for the identify/push protocol to prevent
+    network congestion.
+
+    This test verifies:
+    1. The number of concurrent tasks executing the identify push is always
+       less than or equal to CONCURRENCY_LIMIT.
+    2. An error is raised if concurrency exceeds the defined limit.
+
+    It mocks `push_identify_to_peer` to simulate delay using sleep,
+    allowing the test to measure and assert actual concurrency behavior.
+    """
+    state = {
+        "concurrency_counter": 0,
+        "max_observed": 0,
+    }
+    lock = trio.Lock()
+
+    async def mock_push_identify_to_peer(
+        host,
+        peer_id,
+        observed_multiaddr=None,
+        limit=trio.Semaphore(CONCURRENCY_LIMIT),
+        use_varint_format=True,
+    ) -> bool:
+        """
+        Mock function to test concurrency by simulating an identify message.
+
+        This function patches push_identify_to_peer for testing purpose
+
+        Returns
+        -------
+        bool
+            True if the push was successful, False otherwise.
+
+        """
+        async with limit:
+            async with lock:
+                state["concurrency_counter"] += 1
+                if state["concurrency_counter"] > CONCURRENCY_LIMIT:
+                    raise RuntimeError(
+                        f"Concurrency limit exceeded: {state['concurrency_counter']}"
+                    )
+                state["max_observed"] = max(
+                    state["max_observed"], state["concurrency_counter"]
+                )
+
+            logger.debug("Successfully pushed identify to peer %s", peer_id)
+            await trio.sleep(0.05)
+
+            async with lock:
+                state["concurrency_counter"] -= 1
+
+            return True
+
+    # Create a mock host.
+    key_pair_host = create_new_key_pair()
+    host = new_host(key_pair=key_pair_host)
+
+    # Create a mock network and add mock connections to the host
+    host.get_network().connections = create_mock_connections()
+    with patch(
+        "libp2p.identity.identify_push.identify_push.push_identify_to_peer",
+        new=mock_push_identify_to_peer,
+    ):
+        await push_identify_to_peers(host)
+    assert state["max_observed"] <= CONCURRENCY_LIMIT, (
+        f"Max concurrency observed: {state['max_observed']}"
+    )
+
+
+@pytest.mark.trio
+async def test_all_peers_receive_identify_push_with_semaphore(security_protocol):
+    dummy_peers = []
+
+    async with host_pair_factory(security_protocol=security_protocol) as (host_a, _):
+        # Create dummy peers
+        for _ in range(50):
+            key_pair = create_new_key_pair()
+            dummy_host = new_host(key_pair=key_pair)
+            dummy_host.set_stream_handler(
+                ID_PUSH, identify_push_handler_for(dummy_host)
+            )
+            listen_addr = multiaddr.Multiaddr("/ip4/127.0.0.1/tcp/0")
+            dummy_peers.append((dummy_host, listen_addr))
+
+        async with trio.open_nursery() as nursery:
+            # Start all dummy hosts
+            for host, listen_addr in dummy_peers:
+                nursery.start_soon(run_host_forever, host, listen_addr)
+
+            # Wait for all hosts to finish setting up listeners
+            for host, _ in dummy_peers:
+                await wait_until_listening(host)
+
+            # Now connect host_a → dummy peers
+            for host, _ in dummy_peers:
+                await host_a.connect(info_from_p2p_addr(host.get_addrs()[0]))
+
+            await push_identify_to_peers(
+                host_a,
+            )
+
+            await trio.sleep(0.5)
+
+            peer_id_a = host_a.get_id()
+            for host, _ in dummy_peers:
+                dummy_peerstore = host.get_peerstore()
+                assert peer_id_a in dummy_peerstore.peer_ids()
+
+            nursery.cancel_scope.cancel()
+
+
+@pytest.mark.trio
+async def test_all_peers_receive_identify_push_with_semaphore_under_high_peer_load(
+    security_protocol,
+):
+    dummy_peers = []
+
+    async with host_pair_factory(security_protocol=security_protocol) as (host_a, _):
+        # Create dummy peers
+        # Breaking with more than 500 peers
+        # Trio have a async tasks limit of 1000
+        for _ in range(499):
+            key_pair = create_new_key_pair()
+            dummy_host = new_host(key_pair=key_pair)
+            dummy_host.set_stream_handler(
+                ID_PUSH, identify_push_handler_for(dummy_host)
+            )
+            listen_addr = multiaddr.Multiaddr("/ip4/127.0.0.1/tcp/0")
+            dummy_peers.append((dummy_host, listen_addr))
+
+        async with trio.open_nursery() as nursery:
+            # Start all dummy hosts
+            for host, listen_addr in dummy_peers:
+                nursery.start_soon(run_host_forever, host, listen_addr)
+
+            # Wait for all hosts to finish setting up listeners
+            for host, _ in dummy_peers:
+                await wait_until_listening(host)
+
+            # Now connect host_a → dummy peers
+            for host, _ in dummy_peers:
+                await host_a.connect(info_from_p2p_addr(host.get_addrs()[0]))
+
+            await push_identify_to_peers(
+                host_a,
+            )
+
+            await trio.sleep(0.5)
+
+            peer_id_a = host_a.get_id()
+            for host, _ in dummy_peers:
+                dummy_peerstore = host.get_peerstore()
+                assert peer_id_a in dummy_peerstore.peer_ids()
+
+            nursery.cancel_scope.cancel()
+
+
+@pytest.mark.trio
+async def test_identify_push_default_varint_format(security_protocol):
+    """
+    Test that the identify/push protocol uses varint format by default.
+
+    This test verifies that:
+    1. The default behavior uses length-prefixed messages (varint format)
+    2. Messages are correctly encoded with varint length prefix
+    3. Messages are correctly decoded with varint length prefix
+    4. The peerstore is updated correctly with the received information
+    """
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Set up the identify/push handlers with default settings
+        # (use_varint_format=True)
+        host_b.set_stream_handler(ID_PUSH, identify_push_handler_for(host_b))
+
+        # Push identify information from host_a to host_b using default settings
+        success = await push_identify_to_peer(host_a, host_b.get_id())
+        assert success, "Identify push should succeed with default varint format"
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Get the peerstore from host_b
+        peerstore = host_b.get_peerstore()
+        peer_id = host_a.get_id()
+
+        # Verify that the peerstore was updated correctly
+        assert peer_id in peerstore.peer_ids()
+
+        # Check that addresses have been updated
+        host_a_addrs = set(host_a.get_addrs())
+        peerstore_addrs = set(peerstore.addrs(peer_id))
+        assert all(addr in peerstore_addrs for addr in host_a_addrs)
+
+        # Check that protocols have been updated
+        host_a_protocols = set(host_a.get_mux().get_protocols())
+        peerstore_protocols = set(peerstore.get_protocols(peer_id))
+        assert all(protocol in peerstore_protocols for protocol in host_a_protocols)
+
+        # Check that the public key has been updated
+        host_a_public_key = host_a.get_public_key().serialize()
+        peerstore_public_key = peerstore.pubkey(peer_id).serialize()
+        assert host_a_public_key == peerstore_public_key
+
+
+@pytest.mark.trio
+async def test_identify_push_legacy_raw_format(security_protocol):
+    """
+    Test that the identify/push protocol can use legacy raw format when specified.
+
+    This test verifies that:
+    1. When use_varint_format=False, messages are sent without length prefix
+    2. Raw protobuf messages are correctly encoded and decoded
+    3. The peerstore is updated correctly with the received information
+    4. The legacy format is backward compatible
+    """
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Set up the identify/push handlers with legacy format (use_varint_format=False)
+        host_b.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_b, use_varint_format=False)
+        )
+
+        # Push identify information from host_a to host_b using legacy format
+        success = await push_identify_to_peer(
+            host_a, host_b.get_id(), use_varint_format=False
+        )
+        assert success, "Identify push should succeed with legacy raw format"
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Get the peerstore from host_b
+        peerstore = host_b.get_peerstore()
+        peer_id = host_a.get_id()
+
+        # Verify that the peerstore was updated correctly
+        assert peer_id in peerstore.peer_ids()
+
+        # Check that addresses have been updated
+        host_a_addrs = set(host_a.get_addrs())
+        peerstore_addrs = set(peerstore.addrs(peer_id))
+        assert all(addr in peerstore_addrs for addr in host_a_addrs)
+
+        # Check that protocols have been updated
+        host_a_protocols = set(host_a.get_mux().get_protocols())
+        peerstore_protocols = set(peerstore.get_protocols(peer_id))
+        assert all(protocol in peerstore_protocols for protocol in host_a_protocols)
+
+        # Check that the public key has been updated
+        host_a_public_key = host_a.get_public_key().serialize()
+        peerstore_public_key = peerstore.pubkey(peer_id).serialize()
+        assert host_a_public_key == peerstore_public_key

tests/core/identity/identify_push/test_identify_push_integration.py

@@ -0,0 +1,552 @@
+import logging
+
+import pytest
+import trio
+
+from libp2p.custom_types import TProtocol
+from libp2p.identity.identify_push.identify_push import (
+    ID_PUSH,
+    identify_push_handler_for,
+    push_identify_to_peer,
+    push_identify_to_peers,
+)
+from tests.utils.factories import host_pair_factory
+
+logger = logging.getLogger("libp2p.identity.identify-push-integration-test")
+
+
+@pytest.mark.trio
+async def test_identify_push_protocol_varint_format_integration(security_protocol):
+    """Test identify/push protocol with varint format in real network scenario."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to host_b so it has something to push
+        async def dummy_handler(stream):
+            pass
+
+        host_b.set_stream_handler(TProtocol("/test/protocol/1"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/2"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_a, use_varint_format=True)
+        )
+
+        # Push identify information from host_b to host_a
+        await push_identify_to_peer(host_b, host_a.get_id(), use_varint_format=True)
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+
+        # Check that addresses were added
+        addrs = peerstore_a.addrs(peer_id_b)
+        assert len(addrs) > 0
+
+        # Check that protocols were added
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        # The protocols should include the dummy protocols we added
+        assert len(protocols) >= 2  # Should include the dummy protocols
+
+
+@pytest.mark.trio
+async def test_identify_push_protocol_raw_format_integration(security_protocol):
+    """Test identify/push protocol with raw format in real network scenario."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_a, use_varint_format=False)
+        )
+
+        # Push identify information from host_b to host_a
+        await push_identify_to_peer(host_b, host_a.get_id(), use_varint_format=False)
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+
+        # Check that addresses were added
+        addrs = peerstore_a.addrs(peer_id_b)
+        assert len(addrs) > 0
+
+        # Check that protocols were added
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) >= 1  # Should include the dummy protocol
+
+
+@pytest.mark.trio
+async def test_identify_push_default_format_behavior(security_protocol):
+    """Test identify/push protocol uses correct default format."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Use default identify/push handler (should use varint format)
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+
+        # Push identify information from host_b to host_a
+        await push_identify_to_peer(host_b, host_a.get_id())
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+
+        # Check that protocols were added
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) >= 1  # Should include the dummy protocol
+
+
+@pytest.mark.trio
+async def test_identify_push_cross_format_compatibility_varint_to_raw(
+    security_protocol,
+):
+    """Test varint pusher with raw listener compatibility."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Use an event to signal when handler is ready
+        handler_ready = trio.Event()
+
+        # Create a wrapper handler that signals when ready
+        original_handler = identify_push_handler_for(host_a, use_varint_format=False)
+
+        async def wrapped_handler(stream):
+            handler_ready.set()  # Signal that handler is ready
+            await original_handler(stream)
+
+        # Host A uses raw format with wrapped handler
+        host_a.set_stream_handler(ID_PUSH, wrapped_handler)
+
+        # Host B pushes with varint format (should fail gracefully)
+        success = await push_identify_to_peer(
+            host_b, host_a.get_id(), use_varint_format=True
+        )
+        # This should fail due to format mismatch
+        # Note: The format detection might be more robust than expected
+        # so we just check that the operation completes
+        assert isinstance(success, bool)
+
+
+@pytest.mark.trio
+async def test_identify_push_cross_format_compatibility_raw_to_varint(
+    security_protocol,
+):
+    """Test raw pusher with varint listener compatibility."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Use an event to signal when handler is ready
+        handler_ready = trio.Event()
+
+        # Create a wrapper handler that signals when ready
+        original_handler = identify_push_handler_for(host_a, use_varint_format=True)
+
+        async def wrapped_handler(stream):
+            handler_ready.set()  # Signal that handler is ready
+            await original_handler(stream)
+
+        # Host A uses varint format with wrapped handler
+        host_a.set_stream_handler(ID_PUSH, wrapped_handler)
+
+        # Host B pushes with raw format (should fail gracefully)
+        success = await push_identify_to_peer(
+            host_b, host_a.get_id(), use_varint_format=False
+        )
+        # This should fail due to format mismatch
+        # Note: The format detection might be more robust than expected
+        # so we just check that the operation completes
+        assert isinstance(success, bool)
+
+
+@pytest.mark.trio
+async def test_identify_push_multiple_peers_integration(security_protocol):
+    """Test identify/push protocol with multiple peers."""
+    # Create two hosts using the factory
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Create a third host following the pattern from test_identify_push.py
+        import multiaddr
+
+        from libp2p import new_host
+        from libp2p.crypto.secp256k1 import create_new_key_pair
+        from libp2p.peer.peerinfo import info_from_p2p_addr
+
+        # Create a new key pair for host_c
+        key_pair_c = create_new_key_pair()
+        host_c = new_host(key_pair=key_pair_c)
+
+        # Set up identify/push handlers on all hosts
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+        host_b.set_stream_handler(ID_PUSH, identify_push_handler_for(host_b))
+        host_c.set_stream_handler(ID_PUSH, identify_push_handler_for(host_c))
+
+        # Start listening on a random port using the run context manager
+        listen_addr = multiaddr.Multiaddr("/ip4/127.0.0.1/tcp/0")
+        async with host_c.run([listen_addr]):
+            # Connect host_c to host_a and host_b using the correct pattern
+            await host_c.connect(info_from_p2p_addr(host_a.get_addrs()[0]))
+            await host_c.connect(info_from_p2p_addr(host_b.get_addrs()[0]))
+
+            # Push identify information from host_a to all connected peers
+            await push_identify_to_peers(host_a)
+
+            # Wait a bit for the push to complete
+            await trio.sleep(0.1)
+
+            # Check that host_b's peerstore has been updated with host_a's information
+            peerstore_b = host_b.get_peerstore()
+            peer_id_a = host_a.get_id()
+
+            # Check that the peer is in the peerstore
+            assert peer_id_a in peerstore_b.peer_ids()
+
+            # Check that host_c's peerstore has been updated with host_a's information
+            peerstore_c = host_c.get_peerstore()
+
+            # Check that the peer is in the peerstore
+            assert peer_id_a in peerstore_c.peer_ids()
+
+            # Test for push_identify to only connected peers and not all peers
+            # Disconnect a from c.
+            await host_c.disconnect(host_a.get_id())
+
+            await push_identify_to_peers(host_c)
+
+            # Wait a bit for the push to complete
+            await trio.sleep(0.1)
+
+            # Check that host_a's peerstore has not been updated with host_c's info
+            assert host_c.get_id() not in host_a.get_peerstore().peer_ids()
+            # Check that host_b's peerstore has been updated with host_c's info
+            assert host_c.get_id() in host_b.get_peerstore().peer_ids()
+
+
+@pytest.mark.trio
+async def test_identify_push_large_message_handling(security_protocol):
+    """Test identify/push protocol handles large messages with many protocols."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add many protocols to make the message larger
+        async def dummy_handler(stream):
+            pass
+
+        for i in range(10):
+            host_b.set_stream_handler(TProtocol(f"/test/protocol/{i}"), dummy_handler)
+
+        # Also add some protocols to host_a to ensure it has protocols to push
+        for i in range(5):
+            host_a.set_stream_handler(TProtocol(f"/test/protocol/a{i}"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_a, use_varint_format=True)
+        )
+
+        # Push identify information from host_b to host_a
+        success = await push_identify_to_peer(
+            host_b, host_a.get_id(), use_varint_format=True
+        )
+        assert success
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated with all protocols
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) >= 10  # Should include the dummy protocols
+
+
+@pytest.mark.trio
+async def test_identify_push_peerstore_update_completeness(security_protocol):
+    """Test that identify/push updates all relevant peerstore information."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+
+        # Push identify information from host_b to host_a
+        await push_identify_to_peer(host_b, host_a.get_id())
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+
+        # Check that protocols were added
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) > 0
+
+        # Check that addresses were added
+        addrs = peerstore_a.addrs(peer_id_b)
+        assert len(addrs) > 0
+
+        # Check that public key was added
+        pubkey = peerstore_a.pubkey(peer_id_b)
+        assert pubkey is not None
+        assert pubkey.serialize() == host_b.get_public_key().serialize()
+
+
+@pytest.mark.trio
+async def test_identify_push_concurrent_requests(security_protocol):
+    """Test identify/push protocol handles concurrent requests properly."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+
+        # Make multiple concurrent push requests
+        results = []
+
+        async def push_identify():
+            result = await push_identify_to_peer(host_b, host_a.get_id())
+            results.append(result)
+
+        # Run multiple concurrent pushes using nursery
+        async with trio.open_nursery() as nursery:
+            for _ in range(3):
+                nursery.start_soon(push_identify)
+
+        # All should succeed
+        assert len(results) == 3
+        assert all(results)
+
+        # Wait a bit for the pushes to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) > 0
+
+
+@pytest.mark.trio
+async def test_identify_push_stream_handling(security_protocol):
+    """Test identify/push protocol properly handles stream lifecycle."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+
+        # Push identify information from host_b to host_a
+        success = await push_identify_to_peer(host_b, host_a.get_id())
+        assert success
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+        protocols = peerstore_a.get_protocols(peer_id_b)
+        assert protocols is not None
+        assert len(protocols) > 0
+
+
+@pytest.mark.trio
+async def test_identify_push_error_handling(security_protocol):
+    """Test identify/push protocol handles errors gracefully."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Create a handler that raises an exception but catches it to prevent test
+        # failure
+        async def error_handler(stream):
+            try:
+                await stream.close()
+                raise Exception("Test error")
+            except Exception:
+                # Catch the exception to prevent it from propagating up
+                pass
+
+        host_a.set_stream_handler(ID_PUSH, error_handler)
+
+        # Push should complete (message sent) but handler should fail gracefully
+        success = await push_identify_to_peer(host_b, host_a.get_id())
+        assert success  # The push operation itself succeeds (message sent)
+
+        # Wait a bit for the handler to process
+        await trio.sleep(0.1)
+
+        # Verify that the error was handled gracefully (no test failure)
+        # The handler caught the exception and didn't propagate it
+
+
+@pytest.mark.trio
+async def test_identify_push_message_equivalence_real_network(security_protocol):
+    """Test that both formats produce equivalent peerstore updates in real network."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Test varint format
+        host_a.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_a, use_varint_format=True)
+        )
+        await push_identify_to_peer(host_b, host_a.get_id(), use_varint_format=True)
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Get peerstore state after varint push
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+        protocols_varint = peerstore_a.get_protocols(peer_id_b)
+        addrs_varint = peerstore_a.addrs(peer_id_b)
+
+        # Clear peerstore for next test
+        peerstore_a.clear_addrs(peer_id_b)
+        peerstore_a.clear_protocol_data(peer_id_b)
+
+        # Test raw format
+        host_a.set_stream_handler(
+            ID_PUSH, identify_push_handler_for(host_a, use_varint_format=False)
+        )
+        await push_identify_to_peer(host_b, host_a.get_id(), use_varint_format=False)
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Get peerstore state after raw push
+        protocols_raw = peerstore_a.get_protocols(peer_id_b)
+        addrs_raw = peerstore_a.addrs(peer_id_b)
+
+        # Both should produce equivalent peerstore updates
+        # Check that both formats successfully updated protocols
+        assert protocols_varint is not None
+        assert protocols_raw is not None
+        assert len(protocols_varint) > 0
+        assert len(protocols_raw) > 0
+
+        # Check that both formats successfully updated addresses
+        assert addrs_varint is not None
+        assert addrs_raw is not None
+        assert len(addrs_varint) > 0
+        assert len(addrs_raw) > 0
+
+        # Both should contain the same essential information
+        # (exact address lists might differ due to format-specific handling)
+        assert set(protocols_varint) == set(protocols_raw)
+
+
+@pytest.mark.trio
+async def test_identify_push_with_observed_address(security_protocol):
+    """Test identify/push protocol includes observed address information."""
+    async with host_pair_factory(security_protocol=security_protocol) as (
+        host_a,
+        host_b,
+    ):
+        # Add some protocols to both hosts
+        async def dummy_handler(stream):
+            pass
+
+        host_a.set_stream_handler(TProtocol("/test/protocol/a"), dummy_handler)
+        host_b.set_stream_handler(TProtocol("/test/protocol/b"), dummy_handler)
+
+        # Set up identify/push handler on host_a
+        host_a.set_stream_handler(ID_PUSH, identify_push_handler_for(host_a))
+
+        # Get host_b's address as observed by host_a
+        from multiaddr import Multiaddr
+
+        host_b_addr = host_b.get_addrs()[0]
+        observed_multiaddr = Multiaddr(str(host_b_addr))
+
+        # Push identify information with observed address
+        await push_identify_to_peer(
+            host_b, host_a.get_id(), observed_multiaddr=observed_multiaddr
+        )
+
+        # Wait a bit for the push to complete
+        await trio.sleep(0.1)
+
+        # Verify that host_a's peerstore was updated
+        peerstore_a = host_a.get_peerstore()
+        peer_id_b = host_b.get_id()
+
+        # Check that addresses were added
+        addrs = peerstore_a.addrs(peer_id_b)
+        assert len(addrs) > 0
+
+        # The observed address should be among the stored addresses
+        addr_strings = [str(addr) for addr in addrs]
+        assert str(observed_multiaddr) in addr_strings