Send Transaction API

Overview

The Send Transaction API provides two formats for submitting Solana transactions: standard JSON-RPC 2.0 format and custom REST API format.

Service Information

• Base URL: http://ams.flashblock.trade
• Authentication: Authorization Header required
• Protocol: HTTP/HTTPS

---

API Endpoints

1. JSON-RPC Transaction Submission

POST /

Submit transactions using JSON-RPC 2.0 specification.

Request Format:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "sendBundle",
  "params": [
    [
      "base64_encoded_transaction_1",
      "base64_encoded_transaction_2"
    ],
    {
      "encoding": "base64"
    }
  ]
}

Request Parameters:

• jsonrpc: Fixed value "2.0"
• id: Request ID for response matching
• method: Fixed value "sendBundle"
• params: Parameter array
  • params[0]: Array of base64-encoded transactions
  • params[1]: Encoding configuration object
    • encoding: Encoding format, fixed as "base64"

Request Headers:

Content-Type: application/json
Authorization: YOUR_API_KEY

Success Response:

{
  "jsonrpc": "2.0",
  "result": "5XHA7ofPAf3FaLUAY3kT52c...",
  "id": 1
}

Error Response:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -1009,
    "message": "Missing or invalid Authorization header",
    "data": null
  },
  "id": null
}

Error Codes:

• -1009: Missing or invalid Authorization header
• -1010: Transaction length too short or doesn't meet requirements
• -1013: Bundle method setting error, requires sendBundle

---

2. Custom REST API Transaction Submission

POST /api/v2/submit-batch

Submit transactions using custom REST API format.

Request Format:

{
  "transactions": [
    "base64_encoded_transaction_1",
    "base64_encoded_transaction_2"
  ]
}

Request Parameters:

• transactions: Array of base64-encoded transactions (optional, defaults to empty array)

Request Headers:

Content-Type: application/json
Authorization: YOUR_API_KEY

Success Response:

{
  "success": true,
  "code": 200,
  "message": "The transaction was submitted successfully, but the status of the transaction is pending.",
  "data": {
    "signatures": [
      "5XHA7ofPAf3FaLUAY3kT52c...",
      "4cmupyS9kyiEbfsW8kZkyEh..."
    ]
  }
}

Error Response:

{
  "success": false,
  "code": 1009,
  "message": "Missing or invalid Authorization header",
  "data": {
    "signatures": []
  }
}

Error Codes:

• 1009: Missing or invalid Authorization header
• 1010: Transaction length too short or doesn't meet requirements

---

Transaction Limits

• Maximum Transactions: 4 transactions per submission
• Transaction Format: All transactions must be valid base64 encoded
• Minimum Tip: Each transaction must include at least 0.001 SOL tip

Best Practices

Tip Integration Recommendation

It's recommended to include the tip directly in the original transaction rather than creating a separate tip transaction, regardless of the number of transactions. This approach:

• Reduces transaction count and complexity
• Improves transaction success rate
• Minimizes gas costs
• Provides better atomicity
• Ensures consistent transaction ordering

---

Example Code

JavaScript/Node.js

JSON-RPC Format

const axios = require('axios');

async function submitTransactionRPC(transactions, apiKey) {
  const payload = {
    jsonrpc: "2.0",
    id: 1,
    method: "sendBundle",
    params: [
      transactions,
      { encoding: "base64" }
    ]
  };

  const response = await axios.post('http://ams.flashblock.trade/', payload, {
    headers: {
      'Content-Type': 'application/json',
      'Authorization': apiKey
    }
  });

  return response.data;
}

Custom API Format

async function submitTransactionAPI(transactions, apiKey) {
  const payload = {
    transactions: transactions
  };

  const response = await axios.post('http://ams.flashblock.trade/api/v2/submit-batch', payload, {
    headers: {
      'Content-Type': 'application/json',
      'Authorization': apiKey
    }
  });

  return response.data;
}

Python

JSON-RPC Format

import requests

def submit_transaction_rpc(transactions, api_key):
    payload = {
        "jsonrpc": "2.0",
        "id": 1,
        "method": "sendBundle",
        "params": [
            transactions,
            {"encoding": "base64"}
        ]
    }
    
    headers = {
        'Content-Type': 'application/json',
        'Authorization': api_key
    }
    
    response = requests.post('http://ams.flashblock.trade/', 
                           json=payload, 
                           headers=headers)
    
    return response.json()

Custom API Format

def submit_transaction_api(transactions, api_key):
    payload = {
        "transactions": transactions
    }
    
    headers = {
        'Content-Type': 'application/json',
        'Authorization': api_key
    }
    
    response = requests.post('http://ams.flashblock.trade/api/v2/submit-batch', 
                           json=payload, 
                           headers=headers)
    
    return response.json()