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The transaction API is a WebSocket service.

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URL

wss://tx.launchblitz.ai?key=YOUR_API_KEY
key is required. The backend accepts either a LaunchBlitz session token or a user API key, but direct integrations should use an API key.

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Authentication

  • The socket reads the key query parameter during the WebSocket handshake.
  • Missing key values are rejected at handshake time.
  • Invalid keys do not receive the initial connected message.
  • An API key authenticates as the LaunchBlitz user that owns it, so requests run with that user’s wallets, tier, referral settings, and permissions.

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Initial message

After a successful connection, the server sends a plain text frame: 
connected
Wait for that message before you start sending transaction envelopes.

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Keepalives

The socket supports both text heartbeat messages and standard WebSocket ping/pong frames.
  • The server sends a text ping every 30 seconds.
  • Your client should reply with text pong.
  • If your client sends text ping, the server replies with text pong.
  • If your client sends a WebSocket ping frame, the server replies with a pong frame.
  • The server disconnects the client after 20 missed heartbeat intervals.
  • Reply to every incoming ping immediately.
  • Optionally send your own ping on a shorter interval to measure latency.
  • Reconnect on close and resubscribe your local request tracking state.

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JavaScript example

const apiKey = process.env.LAUNCHBLITZ_API_KEY;
const ws = new WebSocket(`wss://tx.launchblitz.ai?key=${encodeURIComponent(apiKey)}`);

ws.onopen = () => {
  console.log("socket open");
};

ws.onmessage = (event) => {
  if (event.data === "connected") {
    console.log("authenticated");
    return;
  }

  if (event.data === "ping") {
    ws.send("pong");
    return;
  }

  const message = JSON.parse(event.data);
  console.log(message.msg_type, message.body);
};

ws.onclose = () => {
  console.log("socket closed");
};

setInterval(() => {
  if (ws.readyState === WebSocket.OPEN) {
    ws.send("ping");
  }
}, 5000);

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Session identifiers in responses

Transaction responses include body.session_key, but that value is the server-side connection identifier for the authenticated session, not your raw API key. Use your own request identifier fields to correlate requests.