eth2.0-specs/specs/deneb/light-client/p2p-interface.md

# Deneb Light Client -- Networking

**Notice**: This document is a work-in-progress for researchers and implementers.

## Table of contents

<!-- TOC -->
<!-- START doctoc generated TOC please keep comment here to allow auto update -->
<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->

- [Networking](#networking)
  - [The gossip domain: gossipsub](#the-gossip-domain-gossipsub)
    - [Topics and messages](#topics-and-messages)
      - [Global topics](#global-topics)
        - [`light_client_finality_update`](#light_client_finality_update)
        - [`light_client_optimistic_update`](#light_client_optimistic_update)
  - [The Req/Resp domain](#the-reqresp-domain)
    - [Messages](#messages)
      - [GetLightClientBootstrap](#getlightclientbootstrap)
      - [LightClientUpdatesByRange](#lightclientupdatesbyrange)
      - [GetLightClientFinalityUpdate](#getlightclientfinalityupdate)
      - [GetLightClientOptimisticUpdate](#getlightclientoptimisticupdate)

<!-- END doctoc generated TOC please keep comment here to allow auto update -->
<!-- /TOC -->

## Networking

The [Capella light client networking specification](../../capella/light-client/p2p-interface.md) is extended to exchange [Deneb light client data](./sync-protocol.md).

### The gossip domain: gossipsub

#### Topics and messages

##### Global topics

###### `light_client_finality_update`

[0]: # (eth2spec: skip)

| `fork_version`                                         | Message SSZ type                    |
|--------------------------------------------------------|-------------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                                 |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientFinalityUpdate`  |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientFinalityUpdate` |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientFinalityUpdate`   |

###### `light_client_optimistic_update`

[0]: # (eth2spec: skip)

| `fork_version`                                         | Message SSZ type                      |
|--------------------------------------------------------|---------------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                                   |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientOptimisticUpdate`  |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientOptimisticUpdate` |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientOptimisticUpdate`   |

### The Req/Resp domain

#### Messages

##### GetLightClientBootstrap

[0]: # (eth2spec: skip)

| `fork_version`                                         | Response SSZ type                  |
|--------------------------------------------------------|------------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                                |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientBootstrap`      |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientBootstrap`     |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientBootstrap`       |

##### LightClientUpdatesByRange

[0]: # (eth2spec: skip)

| `fork_version`                                         | Response chunk SSZ type          |
|--------------------------------------------------------|----------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                              |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientUpdate`       |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientUpdate`      |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientUpdate`        |

##### GetLightClientFinalityUpdate

[0]: # (eth2spec: skip)

| `fork_version`                                         | Response SSZ type                   |
|--------------------------------------------------------|-------------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                                 |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientFinalityUpdate`  |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientFinalityUpdate` |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientFinalityUpdate`   |

##### GetLightClientOptimisticUpdate

[0]: # (eth2spec: skip)

| `fork_version`                                         | Response SSZ type                     |
|--------------------------------------------------------|---------------------------------------|
| `GENESIS_FORK_VERSION`                                 | n/a                                   |
| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` | `altair.LightClientOptimisticUpdate`  |
| `CAPELLA_FORK_VERSION`                                 | `capella.LightClientOptimisticUpdate` |
| `DENEB_FORK_VERSION` and later                         | `deneb.LightClientOptimisticUpdate`   |
Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			`# Deneb Light Client -- Networking`
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`Notice: This document is a work-in-progress for researchers and implementers.`

			`## Table of contents`

			`<!-- TOC -->`
			`<!-- START doctoc generated TOC please keep comment here to allow auto update -->`
			`<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->`

			`- [Networking](#networking)`
			`- [The gossip domain: gossipsub](#the-gossip-domain-gossipsub)`
			`- [Topics and messages](#topics-and-messages)`
			`- [Global topics](#global-topics)`
			- [`light_client_finality_update`](#light_client_finality_update)
			- [`light_client_optimistic_update`](#light_client_optimistic_update)
			`- [The Req/Resp domain](#the-reqresp-domain)`
			`- [Messages](#messages)`
			`- [GetLightClientBootstrap](#getlightclientbootstrap)`
			`- [LightClientUpdatesByRange](#lightclientupdatesbyrange)`
			`- [GetLightClientFinalityUpdate](#getlightclientfinalityupdate)`
			`- [GetLightClientOptimisticUpdate](#getlightclientoptimisticupdate)`

			`<!-- END doctoc generated TOC please keep comment here to allow auto update -->`
			`<!-- /TOC -->`

			`## Networking`

Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			`The [Capella light client networking specification](../../capella/light-client/p2p-interface.md) is extended to exchange [Deneb light client data](./sync-protocol.md).`
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`### The gossip domain: gossipsub`

			`#### Topics and messages`

			`##### Global topics`

			###### `light_client_finality_update`

			`[0]: # (eth2spec: skip)`

Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `fork_version` \| Message SSZ type \|
			`\|--------------------------------------------------------\|-------------------------------------\|`
			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientFinalityUpdate` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientFinalityUpdate` \|
			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientFinalityUpdate` \|
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			###### `light_client_optimistic_update`

			`[0]: # (eth2spec: skip)`

			\| `fork_version` \| Message SSZ type \|
Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			`\|--------------------------------------------------------\|---------------------------------------\|`
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientOptimisticUpdate` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientOptimisticUpdate` \|
Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientOptimisticUpdate` \|
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`### The Req/Resp domain`

			`#### Messages`

			`##### GetLightClientBootstrap`

			`[0]: # (eth2spec: skip)`

Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `fork_version` \| Response SSZ type \|
			`\|--------------------------------------------------------\|------------------------------------\|`
			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientBootstrap` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientBootstrap` \|
			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientBootstrap` \|
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`##### LightClientUpdatesByRange`

			`[0]: # (eth2spec: skip)`

Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `fork_version` \| Response chunk SSZ type \|
			`\|--------------------------------------------------------\|----------------------------------\|`
			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientUpdate` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientUpdate` \|
			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientUpdate` \|
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`##### GetLightClientFinalityUpdate`

			`[0]: # (eth2spec: skip)`

Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `fork_version` \| Response SSZ type \|
			`\|--------------------------------------------------------\|-------------------------------------\|`
			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientFinalityUpdate` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientFinalityUpdate` \|
			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientFinalityUpdate` \|
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00
			`##### GetLightClientOptimisticUpdate`

			`[0]: # (eth2spec: skip)`

			\| `fork_version` \| Response SSZ type \|
Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			`\|--------------------------------------------------------\|---------------------------------------\|`
EIP4844 support (`excess_data_gas`), fork tests nyi 2022-12-12 12:11:49 +00:00			\| `GENESIS_FORK_VERSION` \| n/a \|
			\| `ALTAIR_FORK_VERSION` through `BELLATRIX_FORK_VERSION` \| `altair.LightClientOptimisticUpdate` \|
			\| `CAPELLA_FORK_VERSION` \| `capella.LightClientOptimisticUpdate` \|
Replaced EIP4844 references with Deneb Fixes #3207 2023-01-23 14:08:34 +00:00			\| `DENEB_FORK_VERSION` and later \| `deneb.LightClientOptimisticUpdate` \|