🔌 Already using @x402/express?
List your API in 30 seconds.

You wrote the service. You wired up the paymentMiddleware. Now put it where agents can find it — on minia2a.uk, the marketplace that handles discovery, trials, and payments so you don't have to.

You Have This

import { paymentMiddleware } from "@x402/express";

app.use(paymentMiddleware("0xYourAddress", {
  "/my-api": {
    price: "$0.05",
    network: "base",
    config: { description: "My x402 API" }
  }
}));

Now Add This

1 Register your endpoint

One curl command. Takes 30 seconds. Your listing goes into the review queue, then live in the minia2a directory.

# Sign  minia2a publish: <your-wallet>  with EIP-191 (personal_sign).
curl -X POST https://minia2a.uk/api/v1/publish-service \
  -H "Content-Type: application/json" \
  -d '{
    "name": "My API",
    "description": "What your API does — agents see this in search results",
    "endpoint": "https://your-api.com/my-endpoint",
    "price_cents": 5,
    "category": "data",
    "wallet": "0xYOUR_WALLET",
    "signature": "0xYOUR_SIGNATURE"
  }'
What happens next: minia2a probes that your endpoint is reachable over https, then queues the listing for review (reviewStatus: "pending", active: 0). Once approved it appears in the directory for agents searching your category. Callers get 5 free trial calls per signed wallet, then pay per call.

2 Verify (optional)

Check your listing is live and the x402 handshake works correctly.

curl -s -D - https://minia2a.uk/x402/find \
  -H "Content-Type: application/json" \
  -d '{"query":"your API name"}'

Why List on minia2a?

✅ Free to list No listing fee. 0% platform fee through 2026.
🔍 Agent discoverability 318+ agent developers searching x402 endpoints.
🎁 5 free trials Every listed endpoint gets 5 free trial calls. Lower barrier for first-time callers.
💰 Auto payments USDC on Base. x402 protocol handles the rest — no invoicing, no accounts receivable.
📊 Usage analytics Per-endpoint trial and transaction stats on your dashboard.
🌐 Ecosystem visibility Featured in x402 ecosystem, searchable by agents programmatically.

Already Listed? Here's What's Happening

📈 Active marketplace: 1,703 services, 42,983 free trials served, 357K+ total API requests. Agent developers are actively searching and testing x402 endpoints.

🔥 Top categories by trial usage: CAPTCHA solving (1,052 trials), knowledge retrieval (869), search (656), gas data (569) — agents are using these right now.

Why This Works

When you use @x402/express, your API already speaks the x402 protocol. You've done the hard part. minia2a handles everything else agents need to find and use your API:

v1 or v2?

Both work. Whether you're on x402-express (v1, deprecated) or @x402/express (v2), minia2a supports both. The x402 protocol handshake is backward-compatible — if your endpoint returns 402 Payment Required with a valid WWW-Authenticate header, you're good.

Recommendation: If you're still on v1, migrate to v2 for active support and new features. But your v1 endpoint lists on minia2a either way.

FAQ

Does minia2a take a cut?

5% on paid transactions. Free trials: zero fee. Payment goes directly to your wallet — minia2a never holds your funds.

Can I set my own price?

Yes. Any price in USDC. The maxAmountRequired from your x402 header is what agents pay. minia2a displays it, doesn't change it.

What if my endpoint goes down?

minia2a monitors uptime. Prolonged downtime removes the listing until it recovers. No penalty — just re-register when it's back.

Do I need to be on Base?

x402 currently uses Base (Ethereum L2). If your payment address is on Base, you're compatible. Multi-chain support is in development.