/runtime/metadata - Polkadot

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

This endpoint returns the runtime metadata as decoded JSON. The metadata version can be selected with the version query parameter.

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/runtime/metadata).

Endpoint

GET /runtime/metadata

Query Parameters

Parameter	Type	Required	Description
version	integer	No	Metadata version to return (for example, 14 or 15)
at	string	No	Block height or hash to query at

Request

cURL

curl --location 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/runtime/metadata?version=15'

JavaScript

example.js

const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/runtime/metadata?version=15');
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>/runtime/metadata?version=15')
print(response.json())

Response

{
  "magicNumber": 1635018093,
  "metadata": {
    "v15": {
      "pallets": [
        {
          "name": "System",
          "index": 0
        },
        {
          "name": "Balances",
          "index": 5
        }
      ]
    }
  }
}

Response Fields

Field	Type	Description
magicNumber	integer	Metadata magic number
metadata	object	Decoded runtime metadata, keyed by version

Use Cases

• SDK Bootstrapping: Load decoded metadata without SCALE parsing

• Pallet Discovery: Enumerate pallets, calls, and storage

• Type Registries: Build type registries from metadata

• Tooling: Generate typed bindings from metadata