get_transaction_proof - Nervos

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

Returns a Merkle proof that one or more transactions were included in a block. Used by light clients and cross-chain bridges to verify transaction inclusion without trusting the responder.

Parameters

Parameter	Type	Required	Description
tx_hashes	array of H256	Yes	Transaction hashes to prove
block_hash	H256	No	Optional block hash; if omitted, the node finds the block containing all the transactions

Request Example

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "get_transaction_proof",
    "params": [
        [
            "0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"
        ]
    ],
    "id": "getblock.io"
}'

JavaScript (Axios)

import axios from 'axios';

const data = JSON.stringify({
    "jsonrpc": "2.0",
    "method": "get_transaction_proof",
    "params": [
        [
            "0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"
        ]
    ],
    "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": "get_transaction_proof",
    "params": [
        [
            "0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"
        ]
    ],
    "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": "get_transaction_proof",
        "params": [
                [
                        "0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"
                ]
        ],
        "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": {
        "block_hash": "0x02530b25ad0ff677acc365cb73de3e8cc09c7ddd58272e879252e199d08df83b",
        "witnesses_root": "0x6a7e8d3f1c4b9a2e5d8b7c4f9a3e6b1d5c8a2f4e7b1d6c9a3e5b8d2f4a6c8e0b",
        "proof": {
            "indices": [
                "0x0"
            ],
            "lemmas": [
                "0x4a3e8d3f1c4b9a2e5d8b7c4f9a3e6b1d5c8a2f4e7b1d6c9a3e5b8d2f4a6c8e0b"
            ]
        }
    }
}

Response Parameters

Field	Type	Description
result.block_hash	H256	Block hash where the transactions are included
result.witnesses_root	H256	Root of the witnesses Merkle tree
result.proof.indices	array of Uint32	Indices of the transactions being proven within the block
result.proof.lemmas	array of H256	Merkle proof lemmas needed to reconstruct the root

Use Cases

• Light client transaction-inclusion proofs

• Cross-chain bridges proving CKB transactions on other chains

• SPV-style verification in mobile wallets

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

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('get_transaction_proof', [["0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"]]);
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': 'get_transaction_proof',
    'params': [["0xa0ef4eb5f4ceeb08a4c8524d84c5da95dce2f608e0ca2ec8091191b0f330c6e0"]]
}})
print(response.json())