author_submitExtrinsic

Description

Broadcasts a signed extrinsic to the node's transaction pool. The node validates the payload before gossiping it to peers.

Parameters

Position	Type	Description
0	string	SCALE-encoded, signed extrinsic hex

Returns

Type	Description
string	Extrinsic hash if accepted

Request Example

{
  "jsonrpc": "2.0",
  "method": "author_submitExtrinsic",
  "params": ["0x...signed extrinsic..."],
  "id": 1
}

Response Example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x1f6d…"
}

Code Examples

JavaScript (polkadot.js)

const tx = api.tx.balances.transferKeepAlive(dest, amount);
const hash = await tx.signAndSend(signer);
console.log('Submitted with hash', hash.toHex());

Python (py-substrate-interface)

substrate = SubstrateInterface(url="wss://api-astar.n.dwellir.com/YOUR_API_KEY", ss58_format=5)
keypair = Keypair.create_from_uri('//Alice')
call = substrate.compose_call(call_module='Balances', call_function='transfer_keep_alive', call_params={'dest': dest, 'value': amount})
extrinsic = substrate.create_signed_extrinsic(call=call, keypair=keypair)
receipt = substrate.submit_extrinsic(extrinsic, wait_for_inclusion=True)
print(receipt.extrinsic_hash)

Tip: For fee estimation before broadcasting, call payment_queryInfo with the same hex payload.