How AI is applied across API Evangelist and APIs.io. Read my AI disclosure →
API Evangelist API Evangelist
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC
Discovery
Learnings
Guidance
Toolbox
Alignment
API Evangelist LLC

Need help?

Contact us
Kadena

Kadena header API

These endpoints return block headers from the chain database.Similar to the block endpoints, block headers are generally returned inascending order and include headers of orphaned blocks.For only querying block headers that are included in the winning branch ofthe chain the `branch` endpoints can be used, which return block headers indescending 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.

Documentation Provider Profile APIs.io OpenAPI GitHub

Kadena header API is one of 16 APIs that Kadena publishes on the 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.

This API exposes 3 operations across 3 paths, and defines 16 schemas. It is described by OpenAPI 3.2.0, at version 0.0.

Requests are made against 5 base URLs: https://api.chainweb.com/chainweb/{apiVersion}/mainnet01, https://api.testnet.chainweb.com/chainweb/{apiVersion}/testnet04, {schema}://{domain}:{port}/chainweb/{apiVersion}/{chainwebVersion}, https://{location}.chainweb.com/chainweb/{apiVersion}/mainnet01, https://{location}.testnet.chainweb.com/chainweb/{apiVersion}/testnet04.

3 operations 3 paths 16 schemas 2 GET1 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
0.0
Base URL
https://api.chainweb.com/chainweb/0.0/mainnet01
Resource Areas
1

Paths & Operations 3

Across 3 paths, the API surfaces 3 operations — 2 GET, 1 POST. Each is listed below with its method, path, parameters, and response codes.

header 3

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 orphan…

GET
/chain/{chain}/header
Get Block Headers
5 params → 200404
GET
/chain/{chain}/header/{blockHash}
Get Block Header by Hash
2 params → 200404406
POST
/chain/{chain}/header/branch
Get Block Header Branches
5 params body → 200400406404

Schemas 16

The contract defines 16 schemas that model the data the API accepts and returns. The most detailed are blockHeader (13 properties), page (3 properties). Each schema is shown below with its type and property counts.

sha256Hash
string
Base64Url (without padding) encoded SHA256 hash
target
string
The PoW target of a block represented as the base64Url (without padding) 256 bit little endian encoding of the numerical value.
hostAddress
string
Host address containing IPv4 and port
blockHeader
object
JSON Encoded Block Header
13 properties 13 required
base64Header
string
Base64Url (without padding) encoded binary block header
posixTimestamp
integer
Seconds since POSIX epoch
blockHeight
integer
The height of a block is the number of its predecessors in the block chain
binaryHeader
string
Binary representation of a block header
posixTimestampMicro
integer
Microseconds since POSIX epoch
blockHash
Base64Url (without padding) encoded block hash
blockWeight
string
The POW weight of a block is the sum of the difficulties of the block and of all of its ancestors. The difficulty of a block is the maximum difficulty divided…
nonce
string
PoW nonce of the block. This is computed by the miner such that the block hash is smaller than the target.
chainwebVersion
The version of the Chainweb network
payloadHash
Base64Url (without padding) encoded block payload hash
page
object
Page of a collection of items
3 properties 3 required
chainId
integer
A Chainweb chain ID. In Kadena Chainweb chains are named by numbers starting form 0. Valid values depend on the current graph at the respective block height of…

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

kadena-header-api-openapi.yml Raw ↑

Other APIs Kadena publishes across the network.

Kadena block API
AE Profile APIs.io
Kadena blockhash API
AE Profile APIs.io
Kadena config API
AE Profile APIs.io
Kadena cut API
AE Profile APIs.io
Kadena endpoint-listen API
AE Profile APIs.io
Kadena endpoint-local API
AE Profile APIs.io
Kadena endpoint-poll API
AE Profile APIs.io
Kadena endpoint-private API
AE Profile APIs.io
Kadena endpoint-send API
AE Profile APIs.io
Kadena endpoint-spv API
AE Profile APIs.io
Kadena mempool API
AE Profile APIs.io
Kadena mining API
AE Profile APIs.io
#Header
← Back to K APIs
API Details
ID
kadena:kadena-header-api
Base URL
https://api.chainweb.com/chainweb/0.0/mainnet01
Docs
https://docs.kadena.io/api/chainweb-api
Provider
Kadena
APIs.io →  GitHub →
Explore more
All APIs Providers APIs.io Network
Work with this as data

Every API here is available over the API and to AI agents over MCP. APIs is not yet its own endpoint on the v1 API. Reach this content through network search and the tag graph, or the MCP server below.

Installs https://mcp.apievangelist.com/mcp in Claude, Cursor, VS Code and the rest — one button, every client.

MCP tools for apis
4 tools reach this content
  • search_api_evangelistSearch every content type across the network at once.
  • find_relatedThe shared-tag relevance graph — what else covers this.
  • get_tagEverything one tag labels, across all content types.
  • guide_topicPRO — a curated bundle for a topic: area, guidance, rules, papers, stories, services.
All tools & prompts
Call it yourself
curl for this page
Search the network for this 
curl "https://api.apievangelist.com/v1/search?q=kadena-header-api&limit=10"
Everything under a tag 
curl "https://api.apievangelist.com/v1/tags/kadena-header-api"

Discovery needs no key. Full bodies and the synthesis endpoints are Pro.

Get an API key

Free tier, no email required. Sign in with whichever identity you already have.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have. Your account

Where this information came from

This is an independent, third-party profile of Kadena header API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.

Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.

info@apievangelist.com · Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.