Auton

Agents that pay their own way.

A Next.js demo showing LLM agents that autonomously handle HTTP 402 Payment Required responses using real Solana transactions - no API keys, no billing, no humans in the loop.

Live at agent.mpptestkit.com

What it demos

1. Agent generates an ephemeral Solana keypair
2. Requests an airdrop from the devnet/testnet faucet
3. Hits a premium API endpoint → receives 402 Payment Required
4. Parses the Payment-Request header, sends a real SOL transfer on-chain
5. Retries the request with a Payment-Receipt header → receives 200 OK + data
6. Every step streams live to the terminal UI via SSE

The payment transaction is real - you can verify it on Solana Explorer.

Stack

• Next.js 14 (App Router)
• @solana/web3.js - real devnet/testnet transactions
• Tailwind CSS
• SSE (Server-Sent Events) for real-time streaming

Dev

npm install
npm run dev   # http://localhost:5174

How the agent API works

POST /api/agent accepts:

{ "query": "Get current SOL market data", "network": "devnet" }

It streams SSE events:

type	description
init	Keypair generation started
wallet	Keypair ready, public key included
fund	Airdrop request / confirmation
request	Initial GET to premium endpoint
payment_required	402 received, Payment-Request header parsed
payment	SOL transfer being built and sent
confirmed	On-chain confirmation + real tx signature
retry	Request retried with Payment-Receipt
success	200 OK received
result	Premium data payload
done	Stream complete
error	Agent error with message

Supported queries

Query	Endpoint
SOL market data	/premium/market/sol
Analytics report	/premium/analytics
ML inference	/premium/ml/inference
Research data	/premium/research

Networks

• devnet - default, fastest airdrop availability
• testnet - also supported, same flow