> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt
> Use this file to discover all available pages before exploring further.

# Peer Exchange

## Channels

Pex has one channel. The channel identifier is listed below.

| Name       | Number |
| ---------- | ------ |
| PexChannel | 0      |

## Message Types

The current PEX service has two versions. The first uses IP/port pair but since the p2p stack is moving towards a transport agnostic approach,
node endpoints require a `Protocol` and `Path` hence the V2 version uses a [url](https://golang.org/pkg/net/url/#URL) instead.

### PexRequest

PexRequest is an empty message requesting a list of peers.

> EmptyRequest

### PexResponse

PexResponse is an list of net addresses provided to a peer to dial.

| Name      | Type                               | Description                              | Field Number |
| --------- | ---------------------------------- | ---------------------------------------- | ------------ |
| addresses | repeated [PexAddress](#pexaddress) | List of peer addresses available to dial | 1            |

### PexAddress

PexAddress provides needed information for a node to dial a peer.

| Name | Type   | Description      | Field Number |
| ---- | ------ | ---------------- | ------------ |
| id   | string | NodeID of a peer | 1            |
| ip   | string | The IP of a node | 2            |
| port | port   | Port of a peer   | 3            |

### PexRequestV2

PexRequest is an empty message requesting a list of peers.

> EmptyRequest

### PexResponseV2

PexResponse is an list of net addresses provided to a peer to dial.

| Name      | Type                                    | Description                              | Field Number |
| --------- | --------------------------------------- | ---------------------------------------- | ------------ |
| addresses | repeated [PexAddressV2](#pexresponsev2) | List of peer addresses available to dial | 1            |

### PexAddressV2

PexAddress provides needed information for a node to dial a peer.

| Name | Type   | Description                                           | Field Number |
| ---- | ------ | ----------------------------------------------------- | ------------ |
| url  | string | See [golang url](https://golang.org/pkg/net/url/#URL) | 1            |

### Message

Message is a [`oneof` protobuf type](https://developers.google.com/protocol-buffers/docs/proto#oneof). The one of consists of two messages.

| Name              | Type                            | Description                                          | Field Number |
| ----------------- | ------------------------------- | ---------------------------------------------------- | ------------ |
| pex\_request      | [PexRequest](#pexrequest)       | Empty request asking for a list of addresses to dial | 1            |
| pex\_response     | [PexResponse](#pexresponse)     | List of addresses to dial                            | 2            |
| pex\_request\_v2  | [PexRequestV2](#pexrequestv2)   | Empty request asking for a list of addresses to dial | 3            |
| pex\_response\_v2 | [PexRespinseV2](#pexresponsev2) | List of addresses to dial                            | 4            |