Quick Start Guide

This guide will help you quickly set up and start using Shield for submitting private Bitcoin transactions.

Prerequisites

Before using Shield, you should have:

• Basic understanding of Bitcoin transactions

• The ability to create and sign raw Bitcoin transactions

• A tool or library capable of making HTTP requests (curl, request, axios, etc.)

Quick Start

1. Get Shield Fee Information

First, query Shield to get the current payment address and fee rates:

curl -XGET 'https://shield.rebarlabs.io/v1/info'

You'll receive a response like:

{
    "height": 886512,
    "payment": {
        "p2wpkh": "bc1q..."
    },
    "fees": [
        {
            "estimated_hashrate": 0.12,
            "feerate": 18.0
        },
        {
            "estimated_hashrate": 0.27,
            "feerate": 24.0
        }
    ]
}

2. Create a Transaction with Shield Fee

When creating your Bitcoin transaction, add an output that pays the Shield service:

1. Choose a fee tier from the response above based on your confirmation needs. The estimated_hashrate represents an estimate of the cumulative % hashrate of the network's hashrate available at a given fee, and the corresponding fee rate (in sats/vbyte)

2. Create an additional transaction output for Rebar (the value doesn't matter yet).

3. Calculate the total fee (including the new transaction output): Transaction Size (vbytes) × Fee Rate (sats/vbyte)

4. Modify the output to your transaction to pay this amount to the Shield payment address

3. Submit the Transaction

Submit your signed transaction to Shield:

curl -XPOST 'https://shield.rebarlabs.io/v1/rpc' \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": "1",
    "method": "sendrawtransaction",
    "params": ["YOUR_SIGNED_TRANSACTION_HEX"]
  }'

On success, you'll receive the transaction ID:

{
    "result": "txid_hex_string",
    "error": null,
    "id": "1"
}

Code Examples

JavaScript (Node.js with axios)

const axios = require('axios');

async function submitTransaction(txHex) {
  try {
    // Get fee information
    const infoResponse = await axios.get('https://shield.rebarlabs.io/v1/info');
    console.log('Payment address:', infoResponse.data.payment.p2wpkh);
    console.log('Fee options:', infoResponse.data.fee_tiers);
    
    // Submit transaction
    const response = await axios.post('https://shield.rebarlabs.io/v1/rpc', {
      jsonrpc: '1.0',
      id: 'shield',
      method: 'sendrawtransaction',
      params: [txHex]
    });
    
    console.log('Transaction submitted:', response.data.result);
    return response.data.result;
  } catch (error) {
    console.error('Error:', error.response?.data || error.message);
    throw error;
  }
}

// Usage
// submitTransaction('YOUR_SIGNED_TRANSACTION_HEX');

Next Steps

• Read the Developer Guide for more detailed instructions

• Check the API Reference for comprehensive API documentation

• See the FAQ for answers to common questions