---
title: "Subscribe to sync committee subnets"
method: POST
path: "/eth/v1/validator/sync_committee_subscriptions"
tags: ["ValidatorRequiredApi", "Validator"]
---

# Subscribe to sync committee subnets

`POST /eth/v1/validator/sync_committee_subscriptions`

## Request

- Base URL: `eth2-beacon-mainnet.nodereal.io/v1/api_key` (relative, and the document’s source URL is not known)
- URL: `eth2-beacon-mainnet.nodereal.io/v1/api_key/eth/v1/validator/sync_committee_subscriptions`
- Auth: none declared

Subscribe to a number of sync committee subnets

Sync committees are not present in phase0, but are required for Altair networks.

Subscribing to sync committee subnets is an action performed by VC to enable network participation in Altair networks, and only required if the VC has an active validator in an active sync committee.

## Request body

- object[]
  - `validator_index` string
  - `sync_committee_indices` string[]
  - `until_epoch` string: The final epoch (exclusive value) that the specified validator requires the subscription for.

## Response `200`

Successful response

## Other responses

- `400`: Invalid request syntax.
- `500`: Beacon node internal error.

---

[API](https://skmtc.dev/nodereal/apis/eth-beacon-node-api.md) - [All operations](https://skmtc.dev/nodereal/apis/eth-beacon-node-api/llms.txt) - [OpenAPI document](https://skmtc.dev/nodereal/apis/eth-beacon-node-api/revisions/1878ea8657a1?raw)