---
title: "PostValidatorPrepareBeaconProposer"
method: POST
path: "/{apiKey}/eth/v1/validator/prepare_beacon_proposer"
---

# PostValidatorPrepareBeaconProposer

`POST /{apiKey}/eth/v1/validator/prepare_beacon_proposer`

Publish multiple contribution and proofs. Publish multiple signed sync committee contribution and proofs.

## Path parameters

- `apiKey` string, required — <style> .custom-style { color: #048FF4; } </style> For higher throughput, please <span class="custom-style"><a href="../docs/quick-start-guide#-creating-your-api-key-on-the-zan-platform" target="_blank">create your own API key</a></span>.

## Request body

- object[]
  - `message` object, required
    - `aggregator_index` string, required — Index of validator in validator registry.
    - `selection_proof` string, hex, required
    - `contribution` object, required
      - `slot` string, required — The slot at which the validator is providing a sync committee contribution.
      - `beacon_block_root` string, hex, required — Block root for this contribution.
      - `subcommittee_index` string, required — The index of the subcommittee that the contribution pertains to.
      - `aggregation_bits` string, hex, required — A bit is set if a signature from the validator at the corresponding index in the subcommittee is present in the aggregate `signature`.
      - `signature` string, hex, required — Signature by the validator(s) over the block root of `slot`
  - `signature` string, hex, required

## Response `200`

Successful response

---

[API](https://skmtc.dev/zan/apis/zan-getnftmetadata.md) · [All operations](https://skmtc.dev/zan/apis/zan-getnftmetadata/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/zan/zan-getnftmetadata/revisions/be8fa2338895/schema)