state_call - JSON-RPC Method

Description

Invokes a runtime API exposed by the Enjin Matrix runtime. Calls are executed against the node's current state and return SCALE-encoded responses. Typical uses include querying the runtime metadata (Metadata_metadata), fetching session information, or invoking custom APIs without submitting extrinsics.

Parameters

Parameter	Type	Required	Description
method	string	Yes	Name of the runtime API function (e.g., Metadata_metadata)
data	string	Yes	Hex-encoded SCALE input payload
blockHash	string | null	No	Block hash for historical calls

Returns

Field	Type	Description
result	string	SCALE-encoded return value

Request Example

{
  "jsonrpc": "2.0",
  "method": "state_call",
  "params": [
    "Metadata_metadata",
    "0x",
    null
  ],
  "id": 1
}

Response Example (truncated)

{
  "jsonrpc": "2.0",
  "result": "0x526916006d6574610e610d000c1c73705f636f72651863727970746f2c4163636f756e7449643332...",
  "id": 1
}

The response is the same SCALE blob returned by state_getMetadata and can be decoded with the same tooling.

Code Examples

cURL

curl https://api-enjin-matrixchain.n.dwellir.com/YOUR_API_KEY \
  -X POST \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "method": "state_call",
    "params": ["Metadata_metadata", "0x", null],
    "id": 1
  }'

JavaScript (Polkadot.js)

import { ApiPromise, WsProvider } from '@polkadot/api';

const api = await ApiPromise.create({ provider: new WsProvider('wss://api-enjin-matrixchain.n.dwellir.com/YOUR_API_KEY') });
const metadataHex = await api.rpc.state.call('Metadata_metadata', '0x');
console.log(metadataHex.slice(0, 66));

Python (requests + scalecodec)

payload = {
    "jsonrpc": "2.0",
    "method": "state_call",
    "params": ["Metadata_metadata", "0x", None],
    "id": 1,
}

metadata_hex = requests.post(
    "https://api-enjin-matrixchain.n.dwellir.com/YOUR_API_KEY",
    headers={"Content-Type": "application/json"},
    data=json.dumps(payload),
    timeout=20,
).json()["result"]

# Decode with scalecodec.MetadataDecoder as shown in state_getMetadata

Tips

• Ensure inputs are SCALE-encoded. Many runtime APIs expect tuples or composites; consult metadata to build the payload.
• Blocking methods may be disabled on public RPC endpoints; run against a trusted node when invoking privileged APIs.
• Combine with state_callAt (via blockHash) to inspect past runtime behaviour.