Sign In With Agent

import express from 'express';
import { SIWAServer } from '@siwa/server';

const app = express();
const siwa = new SIWAServer({
  domain: 'api.example.com',
  uri: 'https://api.example.com',
  statement: 'Sign in to Example API',
});

// Challenge endpoint
app.get('/siwa/challenge', async (req, res) => {
  const challenge = await siwa.createChallenge(req.query.pubkey);
  res.json(challenge);
});

// Verify endpoint
app.post('/siwa/verify', async (req, res) => {
  const session = await siwa.verifySignature(
    req.body.message, req.body.pubkey, req.body.signature
  );
  res.json(session);
});

// Protected route with middleware
app.get('/api/data', siwa.middleware(), (req, res) => {
  res.json({ agent: req.agentAddress });
});

import { Keypair } from '@solana/web3.js';
import { createMessage, serializeMessage, verify } from '@siwa/core';
import nacl from 'tweetnacl';
import bs58 from 'bs58';

// === AGENT SIDE ===

const keypair = Keypair.generate();
const pubkey = keypair.publicKey.toBase58();

// 1. Get challenge from service (fetch omitted for clarity)
const challenge = await getChallenge(pubkey);

// 2. Sign the challenge message
const msgBytes = new TextEncoder().encode(challenge.message);
const sig = nacl.sign.detached(msgBytes, keypair.secretKey);
const signature = bs58.encode(sig);

// === SERVICE SIDE ===

// 3. Verify the signature
const result = await verify(challenge.message, signature, pubkey, {
  domain: 'api.example.com',
});

if (result.success) {
  console.log('✓ Agent authenticated:', result.message.address);
  // Issue session token, grant access...
}