# Kadena header API

**Canonical:** https://apis.io/apis/kadena/kadena-header-api/  
**Provider:** Kadena — https://apis.io/providers/kadena/  
**Base URL:** https://api.chainweb.com/chainweb/0.0/mainnet01  
**Documentation:** https://docs.kadena.io/api/chainweb-api

Kadena header API is one of 16 APIs that [Kadena](https://apis.io/providers/kadena/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. Tagged areas include header. The published artifact set on APIs.io includes an OpenAPI specification and an API reference.

These endpoints return block headers from the chain database. Similar to the block endpoints, block headers are generally returned in ascending order and include headers of orphaned blocks. For only querying block headers that are included in the winning branch of the chain the `branch` endpoints can be used, which return block headers in descending order starting from the leafs of branches of the block chain. Block headers are returned in three different formats specified in the `accept` header of the request: * `application/json`, returns block headers in base64Url (without padding) encoded binary. * `application/json;blockheader-encoding=object`, returns block headers in JSON encoding. * `application/octet-stream`, when supported by the endpoint, returns block headers as binary.

## Machine-readable artifacts (2)

- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/kadena/refs/heads/main/openapi/kadena-header-api-openapi.yml
- **APIReference** — https://kadena-io.github.io/chainweb-openapi/

## Other Kadena APIs (12)

- [Kadena block API](https://apis.io/apis/kadena/kadena-block-api/)
- [Kadena blockhash API](https://apis.io/apis/kadena/kadena-blockhash-api/)
- [Kadena config API](https://apis.io/apis/kadena/kadena-config-api/)
- [Kadena cut API](https://apis.io/apis/kadena/kadena-cut-api/)
- [Kadena endpoint-listen API](https://apis.io/apis/kadena/kadena-endpoint-listen-api/)
- [Kadena endpoint-local API](https://apis.io/apis/kadena/kadena-endpoint-local-api/)
- [Kadena endpoint-poll API](https://apis.io/apis/kadena/kadena-endpoint-poll-api/)
- [Kadena endpoint-private API](https://apis.io/apis/kadena/kadena-endpoint-private-api/)
- [Kadena endpoint-send API](https://apis.io/apis/kadena/kadena-endpoint-send-api/)
- [Kadena endpoint-spv API](https://apis.io/apis/kadena/kadena-endpoint-spv-api/)
- [Kadena mempool API](https://apis.io/apis/kadena/kadena-mempool-api/)
- [Kadena mining API](https://apis.io/apis/kadena/kadena-mining-api/)

## Tags

header

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/kadena/kadena-header-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/kadena/.