Getting started with Amazon Managed Blockchain (AMB) Access Bitcoin

The following example shows how to get information about the 00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09 blockhash by using getBlock RPC. Replace the highlighted variables with your own inputs or choose one of the other RPC methods listed and enter the relevant inputs required.

Sign requests with your IAM user credentials by using Signature Version 4 (SigV4) in order to make Bitcoin JSON-RPC calls to the AMB Access Bitcoin endpoints. The awscurl command line tool can help you sign requests to AWS services using SigV4. For more information, see the awscurl README.md.

Install awscurl by using the method appropriate to your operating system. On macOS, HomeBrew is the recommended application:

brew install awscurl

If you have already installed and configured the AWS CLI, your IAM user credentials and default AWS Region are set in your environment and have access to awscurl. Using awscurl, submit a request to both the Bitcoin Mainnet and Testnet by invoking the getblock RPC. This call accepts a string parameter corresponding to the block hash for which you want to retrieve information.

The following command retrieves the block header data from the Bitcoin Mainnet by using the block hash in the params array to select the specific block for which to retrieve the headers. This example uses the us-east-1 endpoint. You can replace this with your preferred Bitcoin JSON-RPC and AWS Region that is supported by Amazon Managed Blockchain (AMB) Access Bitcoin. Furthermore, you can make a request against the Testnet network, rather than Mainnet, by replacing mainnet with testnet in the command.

awscurl -X POST -d '{ "jsonrpc": "1.0", "id": "getblockheader-curltest", "method": "getblockheader", "params": ["0000000000000000000105bebab2f9dd16234a30950d38ec6ddc24d466e750a0"] }' --service managedblockchain https://mainnet.bitcoin.managedblockchain.us-east-1.amazonaws.com  --region us-east-1 -k

The results include details from the block headers and a list of transaction hashes included in the requested block. See the following example:

{"result":{"hash":"0000000000000000000105bebab2f9dd16234a30950d38ec6ddc24d466e750a0",
      "confirmations":2,"height":799243,"version":664485888,"versionHex":"279b4000",
      "merkleroot":"568e79752e1921ecf40c961435abb41bc5700fe2833ecadc4abfc2f615ddc1b8",
      "time":1689684290,"mediantime":1689681317,"nonce":2091174943,"bits":"17053894",
      "difficulty":53911173001054.59,
      "chainwork":"00000000000000000000000000000000000000004f375cf72ff64e2404c1589c",
      "nTx":2135,
      "previousblockhash":"00000000000000000002ffe4efe07ae74ec8b92c7696f5e12b5da506f015ba6b",
      "nextblockhash":"000000000000000000038f05ddcf3f483fdcb74f4be606c022bcb673424fa4ca"},
      "error":null,"id":"curltest"}

To run this example Node.js script, apply the following prerequisites:

After you complete all prerequisites, copy the following package.json file and index.js script into your local environment by using your editor:

package.json

{
  "name": "bitcoin-rpc",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@aws-crypto/sha256-js": "^4.0.0",
    "@aws-sdk/credential-provider-node": "^3.360.0",
    "@aws-sdk/protocol-http": "^3.357.0",
    "@aws-sdk/signature-v4": "^3.357.0",
    "axios": "^1.4.0"
  }
}

index.js

const axios = require('axios');
const SHA256 = require('@aws-crypto/sha256-js').Sha256
const defaultProvider = require('@aws-sdk/credential-provider-node').defaultProvider
const HttpRequest = require('@aws-sdk/protocol-http').HttpRequest
const SignatureV4 = require('@aws-sdk/signature-v4').SignatureV4

// define a signer object with AWS service name, credentials, and region
const signer = new SignatureV4({
  credentials: defaultProvider(),
  service: 'managedblockchain',
  region: 'us-east-1',
  sha256: SHA256,
});


const rpcRequest = async () => {

  // create a remote procedure call (RPC) request object definig the method, input params
  let rpc = {
    jsonrpc: "1.0", 
    id: "1001", 
    method: 'getblock', 
    params: ["00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09"]
  }
  
  //bitcoin endpoint
  let bitcoinURL = 'https://mainnet.bitcoin.managedblockchain.us-east-1.amazonaws.com/';
  
  // parse the URL into its component parts (e.g. host, path)
  const url = new URL(bitcoinURL);
  
  // create an HTTP Request object
  const req = new HttpRequest({
    hostname: url.hostname.toString(),
    path: url.pathname.toString(),
    body: JSON.stringify(rpc),
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Accept-Encoding': 'gzip',
      host: url.hostname,
    }
  });

  
  // use AWS SignatureV4 utility to sign the request, extract headers and body
  const signedRequest = await signer.sign(req, { signingDate: new Date() });
  
  try {
    //make the request using axios
    const response = await axios({...signedRequest, url: bitcoinURL, data: req.body})

    console.log(response.data)
  } catch (error) {
    console.error('Something went wrong: ', error)
    throw error
  } 

 
}

rpcRequest();

The previous sample code uses Axios to make RPC requests to the Bitcoin endpoint, and it signs those requests with the appropriate Signature Version 4 (SigV4) headers by using the official AWS SDK v3 tools. To run the code, open a terminal in the same directory as your files and run the following:

npm i
node index.js

The result that is generated will resemble the following:

{"hash":"00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09","
    confirmations":784126,"height":1000, "version":1,"versionHex":"00000001",
    "merkleroot":"fe28050b93faea61fa88c4c630f0e1f0a1c24d0082dd0e10d369e13212128f33",
    "time":1232346882,
    "mediantime":1232344831,"nonce":2595206198,"bits":"1d00ffff","difficulty":1,
    "chainwork":"000000000000000000000000000000000000000000000000000003e903e903e9",
    "nTx":1,
    "previousblockhash":"0000000008e647742775a230787d66fdf92c46a48c896bfbc85cdc8acc67e87d",
    "nextblockhash":"00000000a2887344f8db859e372e7e4bc26b23b9de340f725afbf2edb265b4c6",
    "strippedsize":216,"size":216,"weight":864,
    "tx":["fe28050b93faea61fa88c4c630f0e1f0a1c24d0082dd0e10d369e13212128f33"]},
    "error":null,"id":"1001"}