Build paid APIs with HTTP 402. Test with fake money in sandbox, graduate to real USDC on Base, and get discovered by agents that pay automatically.
WWW-Authenticate: Payment challenge="ch_a1b2c3d4", method="x402", amount="0.01", currency="USDC", expires="…"
X-Payment: eyJzY2hlbWUiOiJleGFjdCIsInNpZ25hdHVyZSI6Ii4uLiJ9
Payment-Receipt: rcpt_9x8y7z6w
<3ms
Challenge issued
12+
Payment networks
x402 + MPP
Dual protocol
$0.001
Min. transaction
How it works
Every paid API goes through the same loop. The only thing that changes is the money.
Register any API. Get a studio proxy endpoint instantly. Fire real HTTP 402 flows without touching a blockchain. Validate your contract, latency, and error handling before a single cent moves.
POST /api/v1/provider/services → studioSlug: "my-api" → 402 proxy ready in < 2s
Graduate to Base Sepolia. Claim 20 free USDC from the Circle faucet. Run real EIP-712 signed micropayments verified by the Coinbase CDP facilitator. Same code, real chain.
GET /api/v1/faucet/testnet-info → Circle faucet: 20 USDC / 2h → Network: base-sepolia
Promote to live. Your service appears in the discovery registry. Agents find it, negotiate 402, pay in USDC or Stripe, and call autonomously. Revenue flows to your wallet with each receipt.
GET /api/v1/discovery?env=live → Listed. Agents can call. → Payment-Receipt: rcpt_…
Built for the protocol
The proxy generates a signed challenge in under 3ms. No webhook latency, no blockchain round-trip at issuance.
Full 402 flow — challenge, credential, receipt — all with fake USDC. No wallet, no gas, no real money required.
Accept the Coinbase/Cloudflare x402 standard and the broader MPP protocol simultaneously. Any compliant client works.
Every service exposes pricing, endpoints, and invocation hints in structured JSON. Agents know what they're buying before they call.
See every 402 challenge issued, solved, and converted. Track latency, success rate, and revenue per service in real time.
Accept USDC on Base (x402), Tempo stablecoin rails, or Stripe for fiat. Swap rails without touching your API code.
From the ecosystem
HTTP 402 was designed for this — a native payment layer for the programmable internet. We're just making it real.
The next phase of the internet won't be browse-and-click. Machines will negotiate, pay, and interact autonomously.
The hardest part of building paid APIs isn't the payment — it's the testing. Once testing is easy, everything else follows.
Register your API, get a sandbox proxy endpoint, and run your first 402 payment flow in under five minutes. No credit card, no blockchain wallet required to start.