GET v0/header

Gets the header of a block

This endpoint will return the block header from the designated Celestia network. A valid API key is required to access this endpoint. The header contains information about the block, such as its version, time, and hashes of various components.

Request

curl \
  -H 'Authorization: Bearer <YOUR API KEY>' \
  'https://t.tech/v0/header'

package main

import (
  "fmt"
  "io"
  "net/http"
)

func main() {
  url := "https://t.tech/v0/header"
  apiKey := "Your API Key" // Replace with your actual token

  req, err := http.NewRequest("GET", url, nil)
  if err != nil {
    fmt.Println("Error creating request:", err)
    return
  }

  req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", apiKey))

  client := &http.Client{}
  resp, err := client.Do(req)
  if err != nil {
    fmt.Println("Error sending request:", err)
    return
  }
  defer resp.Body.Close()

  body, err := io.ReadAll(resp.Body)
  if err != nil {
    fmt.Println("Error reading response body:", err)
    return
  }

  fmt.Println("Status:", resp.Status)
  fmt.Println("Response:", string(body))
}

// Cargo.toml dependencies:
// [dependencies]
// reqwest = { version = "0.12" }
// tokio = { version = "1.46", features = ["macros", "rt-multi-thread"] }
use reqwest::{Client, header};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();
    let url = "https://t.tech/v0/header";
    let api_key = "Your API Key"; // Replace with your actual token

    let res = client
        .get(url)
        .bearer_auth(api_key)
        .send()
        .await?;

    let status = res.status();
    let body = res.text().await?;
    println!("Status: {}", status);
    println!("Response: {}", body);

    Ok(())
}

Query Parameters

network

stringoptional

The Celestia network to which the data blob should be posted. Can be either mainnet or mocha-4. Defaults to mainnet if no value is specified. Read more about networks on the Celestia Docs here.

height

numberoptional

The height of the block for which to retrieve the header. If not specified, the latest block header will be returned.

Response

JSON object

dah — JSON object

Data Availability Header

columnRoots — array<base64 encoded string>

Commitments to all erasure-coded data

rowRoots — array<base64 encoded string>

Commitments to all erasure-coded data

header — JSON object

Top level object containing the block header information.

appHash — hexadecimal string

The hash of the application in the block.

chainId — string

The ID of the Celestia chain.

consensusHash — hexadecimal string

The hash of the consensus in the block.

dataHash — hexadecimal string

The hash of the data in the block.

evidenceHash — hexadecimal string

The hash of the evidence in the block.

height — string

The height of the block.

lastBlockId — JSON object

The ID of the last block.

hash — hexadecimal string

The hash of the last block.

parts — JSON object

The parts of the last block.

hash — hexadecimal string

The hash of the parts in the last block.

total — integer

The total number of parts in the last block.

lastCommitHash — hexadecimal string

The hash of the last commit.

lastResultsHash — hexadecimal string

The hash of the last results in the block.

nextValidatorsHash — hexadecimal string

The hash of the next validators in the block.

proposerAddress — hexadecimal string

The address of the proposer of the block.

time — string

The timestamp of the block in ISO 8601 format.

validatorsHash — hexadecimal string

The hash of the validators in the block.

version — JSON object

The version of the block and app.

app — string

The version of the application.

block — string

The version of the block.

Example Response

{
  "header": {
    "version": {
      "block": "11",
      "app": "3"
    },
    "chainId": "celestia",
    "height": "6344611",
    "time": "2025-07-08T15:33:26.747994942Z",
    "lastBlockId": {
      "hash": "C70D4A861A4C5B762628BD42C38261BBEC04F5228B23BA2F7173518563760931",
      "parts": {
        "total": 6,
        "hash": "C8420CE6E427A4612351A36FFD4746A68DCA9489380050121C76F16E3ED93413"
      }
    },
    "lastCommitHash": "F7F8D9835E5C3E97B01E1B12A562B3D694326FBDC8311A6DC7C86FBE846C0BB5",
    "dataHash": "694B04CB577E65545D75C27A1CDEE9E67288216D239AD81A33D2FD9220D91FFD",
    "validatorsHash": "2B85510ADE66F39FCA42A382E8CAAE609298ABEAD465AF6F7E52C43F624D6A3B",
    "nextValidatorsHash": "2B85510ADE66F39FCA42A382E8CAAE609298ABEAD465AF6F7E52C43F624D6A3B",
    "consensusHash": "D3A6C023D98608DD2614CCE2EA6BBD162662C383D890077372462FFE34141D1E",
    "appHash": "92F6347A823DFE9FB339DA3E2245DCF8F014FA41D23A17A96FE14FCAA8A1B93E",
    "lastResultsHash": "564C7F6939F939289BE10921472D8CC2445BA721470424BDD6AD35BAD2C05E2D",
    "evidenceHash": "E3B0C44298FC1C149AFBF4C8996FB92427AE41E4649B934CA495991B7852B855",
    "proposerAddress": "E65D72B89CBEF9A6F419C9BDE6C975AA0BF21A97"
  },
  "dah": {
    "rowRoots": [
      "//////////7//////////ql+/VFmJ8PWE9BcjrTDLrY/hzVeGdzFCpfEhiXDXZmt",
      "/////////////////////zHeGnUtPJn8QyPpePSYl4qRVrcUvG2fwptyoA85Myik"
    ],
    "columnRoots": [
      "//////////8//////////2mK8fXQ7RkpWN5Yn3BzLpD2qTgHw4FvMnEaZjYxPcKr",
      "/////////////////////4JbRmPvTQs9XzNmYw6Rh5KqDzNcPbGfUtVrWsXyLnMp"
    ]
  }
}