send_transaction - Nervos

Example code for the send_transaction JSON-RPC method. Complete guide on how to use send_transaction JSON-RPC in GetBlock Web3 documentation.

Submits a new transaction to the tx pool. Returns the transaction hash. Uses passthrough (default) for outputs validator — pass well_known_scripts_only to enforce that all outputs use well-known lock scripts (a basic safety check).

Parameters

Parameter	Type	Required	Description
tx	Transaction	Yes	Signed transaction
outputs_validator	string	No	passthrough (default) or well_known_scripts_only

Request Example

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "send_transaction",
    "params": [
        {
            "version": "0x0",
            "cell_deps": [],
            "header_deps": [],
            "inputs": [],
            "outputs": [],
            "outputs_data": [],
            "witnesses": []
        },
        "passthrough"
    ],
    "id": "getblock.io"
}'

JavaScript (Axios)

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "send_transaction",
    "params": [
        {
            "version": "0x0",
            "cell_deps": [],
            "header_deps": [],
            "inputs": [],
            "outputs": [],
            "outputs_data": [],
            "witnesses": []
        },
        "passthrough"
    ],
    "id": "getblock.io"
});

const config = {
    method: 'post',
    url: 'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers: {
        'Content-Type': 'application/json'
    },
    data: data
};

axios(config)
    .then(response => console.log(JSON.stringify(response.data, null, 2)))
    .catch(error => console.log(error));

Python (Requests)

import requests
import json

url = "https://go.getblock.io/<ACCESS-TOKEN>/"

payload = json.dumps({
    "jsonrpc": "2.0",
    "method": "send_transaction",
    "params": [
        {
            "version": "0x0",
            "cell_deps": [],
            "header_deps": [],
            "inputs": [],
            "outputs": [],
            "outputs_data": [],
            "witnesses": []
        },
        "passthrough"
    ],
    "id": "getblock.io"
})

headers = {
    'Content-Type': 'application/json'
}

response = requests.post(url, headers=headers, data=payload)
print(response.text)

Rust (Reqwest)

use reqwest::Client;
use serde_json::json;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();

    let payload = json!({
        "jsonrpc": "2.0",
        "method": "send_transaction",
        "params": [
                {
                        "version": "0x0",
                        "cell_deps": [],
                        "header_deps": [],
                        "inputs": [],
                        "outputs": [],
                        "outputs_data": [],
                        "witnesses": []
                },
                "passthrough"
        ],
        "id": "getblock.io"
});

    let response = client
        .post("https://go.getblock.io/<ACCESS-TOKEN>/")
        .header("Content-Type", "application/json")
        .json(&payload)
        .send()
        .await?;

    let result: serde_json::Value = response.json().await?;
    println!("{:#?}", result);

    Ok(())
}

Response Example

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"
}

Response Parameters

Field	Type	Description
result	H256	Transaction hash — use get_transaction to track inclusion

Use Cases

• Wallet transaction submission

• DEX backends submitting orders

• Cross-chain bridge relayer transaction submission

Error Handling

Status Code	Error Message	Cause
403	Forbidden	Missing or invalid <ACCESS-TOKEN>
-32602	Invalid params	Request parameters are missing or malformed
-32601	Method not found	Method does not exist or is not enabled on this node
-32603	Internal error	Server-side error while processing the request
429	Too Many Requests	Rate limit exceeded for your plan
-1000 to -1099	PoolRejectedTransactionByOutputsValidator	Transaction rejected by output validator (use passthrough if you know what you're doing)
-1101	PoolRejectedTransactionByIllTransactionChecker	Transaction contains malformed components
-1102	PoolRejectedTransactionByMinFeeRate	Fee rate below the minimum
-1103	PoolRejectedTransactionByMaxAncestorsCountLimit	Transaction chain exceeds the ancestors limit
-1104	PoolIsFull	The mempool is full
-1105	PoolRejectedDuplicatedTransaction	Transaction is already in the pool

SDK Integration

@ckb-lumos/lumos

import { RPC } from '@ckb-lumos/rpc';

const rpc = new RPC('https://go.getblock.io/<ACCESS-TOKEN>/');

// Lumos provides typed methods on `rpc` (e.g. rpc.getTipHeader(), rpc.getBlock(hash)).
// For raw access to any CKB RPC method:
const result = await rpc.send('send_transaction', [{"version": "0x0", "cell_deps": [], "header_deps": [], "inputs": [], "outputs": [], "outputs_data": [], "witnesses": []}, "passthrough"]);
console.log(result);

ckb-sdk-python / requests

# Using the official CKB SDK Python (ckb-sdk-python).
# For methods not yet wrapped, fall back to raw requests.
import requests

response = requests.post('https://go.getblock.io/<ACCESS-TOKEN>/', json={
    'jsonrpc': '2.0',
    'id': 'getblock.io',
    'method': 'send_transaction',
    'params': [{"version": "0x0", "cell_deps": [], "header_deps": [], "inputs": [], "outputs": [], "outputs_data": [], "witnesses": []}, "passthrough"]
}})
print(response.json())