/transaction/material - Polkadot

Example code for the /transaction/material REST method. Complete guide on how to use /transaction/material REST in GetBlock Web3 documentation.

This endpoint returns the data needed to construct and sign a transaction offline: the genesis hash, chain name, spec and transaction versions, and metadata.

On GetBlock's unified endpoint, Asset Hub is the default network. To call this endpoint against the Relaychain, add an /rc prefix to the path (for example, /rc/transaction/material).

Endpoint

GET /transaction/material

Query Parameters

Parameter	Type	Required	Description
noMeta	boolean	No	Omit the metadata field from the response
metadataVersion	integer	No	Metadata version to include

Request

cURL

curl --location 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/transaction/material'

JavaScript

example.js

const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/transaction/material');
const data = await response.json();
console.log(data);

Python

example.py

import requests

response = requests.get('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/transaction/material')
print(response.json())

Response

{
  "at": {
    "hash": "0x255bc00927df8d33d561792635cbc6bde480a0a505eef5ff28630ece3fc15b32",
    "height": "6754362"
  },
  "genesisHash": "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3",
  "chainName": "Polkadot",
  "specName": "polkadot",
  "specVersion": "1002000",
  "txVersion": "26",
  "metadata": "0x6d657461..."
}

Response Fields

Field	Type	Description
genesisHash	string	Genesis block hash
chainName	string	Chain name
specVersion	string	Runtime spec version
txVersion	string	Transaction format version
metadata	string	SCALE-encoded metadata, hex-encoded

Use Cases

• Offline Signing: Gather signing material for cold wallets

• Transaction Construction: Build extrinsics with correct versions

• Custody Systems: Prepare transactions for secure signing

• SDK Integration: Feed signing material to a client