On September 18, an agent at wallet 0xc9c7b38c paid $0.010 USDC to call GET /api/market/signal on my x402 endpoint. Then it came back twice more — POST /api/storage/pin ($0.008) and POST /api/agent/attest ($0.040). Total: $0.058 USDC settled on Base.
I didn't know this agent. It found my endpoints on the Coinbase Bazaar, decided they were worth paying for, and paid. No API key signup. No OAuth. No billing dashboard. Just HTTP 402 → pay → get data.
What is x402?
x402 is a protocol by Coinbase that lets AI agents pay for API calls with USDC on Base. When an agent hits an endpoint without paying, it gets back HTTP 402 (Payment Required) with a payment envelope. The agent settles on-chain and replays the request with a proof header. The server verifies and serves the response.
What I built
Enclave402 — a pay-per-call API gateway with these routes:
| Route | Price | What it does |
|---|---|---|
GET /api/market/signal |
$0.003 | Market data signals |
POST /api/agent/attest |
$0.040 | EIP-712 signed attestations |
POST /api/storage/pin |
$0.008 | IPFS pinning |
GET /api/compute/search |
$0.005 | Compute search |
GET /api/census/verdict |
$0.002 | Endpoint trust verdict |
The receipts
All three transactions are on-chain on Base:
-
0x6ae197...— market/signal, $0.010 -
0xd73c2c...— storage/pin, $0.008 -
0x4b06e2...— agent/attest, $0.040
What I learned
The first outside payer validates the whole model. Before 0xc9c7, every settlement was me testing my own endpoints. The moment a stranger's agent decided my data was worth $0.04, the economics became real.
x402 removes the signup barrier. No API key management, no billing portal, no "contact sales." The agent pays per call. If the data is bad, it stops paying. Market discipline at the HTTP layer.
The trust problem is unsolved. I also built a census oracle that probes 8,848 Bazaar endpoints. 33% get an "avoid" verdict — broken, unreachable, or non-compliant. An agent paying $0.04 per call needs to know if the seller will actually deliver. That's why every verdict is EIP-712 signed.
Source
Everything is open: gitlab.com/coachhype/x402-autonomous-api
If you're building x402 endpoints or have agents that pay for API calls, I'd like to hear what your settlement numbers look like.
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