---
title: "GetBeaconHeadersByBlockId"
method: GET
path: "/{apiKey}/eth/v1/beacon/headers/{blockId}"
---

# GetBeaconHeadersByBlockId

`GET /{apiKey}/eth/v1/beacon/headers/{blockId}`

Get block header. Retrieves block header for given block id.

## 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>.
- `blockId` string, required

## Response `200`

A block header

- object
  - `execution_optimistic` boolean, required — True if the response references an unverified execution payload. Optimistic information may be invalidated at a later time. If the field is not present, assume the False value.
  - `finalized` boolean, required — True if the response references the finalized history of the chain, as determined by fork choice. If the field is not present, additional calls are necessary to compare the epoch of the requested information with the finalized checkpoint.
  - `data` object, required
    - `root` string, hex, required
    - `canonical` boolean, required
    - `header` object, required — The [`SignedBeaconBlockHeader`](https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/phase0/beacon-chain.md#signedbeaconblockheader) object envelope from the CL spec.
      - `message` object, required — The [`BeaconBlockHeader`](https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/phase0/beacon-chain.md#beaconblockheader) object from the CL spec.
        - `slot` string, required — The slot to which this block corresponds.
        - `proposer_index` string, required — Index of validator in validator registry.
        - `parent_root` string, hex, required — The signing merkle root of the parent `BeaconBlock`.
        - `state_root` string, hex, required — The tree hash merkle root of the `BeaconState` for the `BeaconBlock`.
        - `body_root` string, hex, required — The tree hash merkle root of the `BeaconBlockBody` for the `BeaconBlock`
      - `signature` string, hex, required

---

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