Identify v1.0.0

The identify protocol is used to query a peer about basic information and its capabilities.

The protocol works by opening a stream, using /ipfs/id/1.0.0 as the protocol string. The peer being identified responds by returning an Identify message and closes the stream.

The Identify Message

message Identify {
  optional string protocolVersion = 5;
  optional string agentVersion = 6;
  optional bytes publicKey = 1;
  repeated bytes listenAddrs = 2;
  optional bytes observedAddr = 4;
  repeated string protocols = 3;
}

protocolVersion

The protocol version identifies the family of protocols used by the peer. The current protocol version is ipfs/0.1.0; if the protocol major or minor version does not match the protocol used by the initiating peer, then the connection is considered unusable and the peer must close the connection.

agentVersion

This is a free-form string, identifying the implementation of the peer. The usual format is agent-name/version, where agent-name is the name of the program or library and version is its semantic version.

publicKey

This is the public key of the peer, marshalled in binary form as specicfied in peer-ids.

listenAddrs

These are the addresses on which the peer is listening as multi-addresses.

observedAddr

This is the connection source address of the stream initiating peer as observed by the peer being identified; it is a multi-address. The initiator can use this address to infer the existence of a NAT and its public address.

For example, in the case of a TCP/IP transport the observed addresses will be of the form /ip4/x.x.x.x/tcp/xx. In the case of a circuit relay connection, the observed address will be of the form /p2p/QmRelay/p2p-circuit. In the case of onion transport, there is no observable source address.

protocols

This is a list of protocols supported by the peer.