true402
for agents & customers

Buy with
one header.

No account. No API key. Your wallet is the identity. An agent discovers a service, gets a price as HTTP 402, signs USDC, and retries with a single PAYMENT-SIGNATURE header. Receiving is keyless; the facilitator does the on-chain work.

§00 · fastest way

Drop it into your agent.

If your agent speaks MCP — Claude Code, Claude Desktop, Cursor, Windsurf — one line wires in every true402 tool (token rug/honeypot & address safety, deployer reputation, DeFi signals, SEO/GEO audit, web tools, LLM). They auto-discover from the live catalog, so new stalls show up with nothing to update.

Claude Code 
# Claude Code — one line. Every true402 tool, auto-discovered from the live catalog.
claude mcp add true402 -- npx -y @true402.dev/mcp-server

Any other MCP client — same package, drop it in the config:

mcp.json — Cursor / Windsurf / Claude Desktop 
{
  "mcpServers": {
    "true402": {
      "command": "npx",
      "args": ["-y", "@true402.dev/mcp-server"],
      "env": {
        "WALLET_PRIVATE_KEY": "0x…  // optional — a funded Base wallet to auto-pay; omit to just see prices",
        "MAX_PAYMENT_USDC": "0.25"
      }
    }
  }
}

No wallet needed to start: the on-chain safety checks (token rug/honeypot, address safety) are free to try — a few a day, no signup. Add a funded WALLET_PRIVATE_KEY for unlimited pay-per-call. MAX_PAYMENT_USDC is the per-call ceiling — the client refuses to sign a 402 that asks for more; leave it out and it falls back to the built-in default of $0.25. The steps below are the raw HTTP flow underneath.

§01 · discover

List what’s for sale — free.

Browsing models, services, and feeds never costs anything. Only the call itself is gated.

bash 
curl -s https://true402.dev/api/v1/models | jq '.data[0]'
§02 · the 402

Ask, and get a price.

A gated endpoint answers 402 Payment Required with everything needed to pay: the exact amount, the USDC asset, where to pay, and the EIP-712 domain to sign under.

402 response 
curl -i -X POST https://true402.dev/api/v1/chat/completions \
  -H 'content-type: application/json' \
  -d '{"model":"openai/gpt-4o-mini","messages":[{"role":"user","content":"hi"}]}'

HTTP/1.1 402 Payment Required
{
  "x402Version": 2,
  "accepts": [{
    "scheme": "exact",
    "network": "eip155:8453",
    "amount": "495",                       // atomic USDC (6dp) — chat is metered per
                                           // token, so your quote will differ
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "payTo": "0xFe25…A9C4",
    "maxTimeoutSeconds": 300,
    "extra": { "name": "USD Coin", "version": "2" }   // EIP-712 domain — sign EXACTLY this
  }]
}
§03 · pay & retry

Sign once, resend.

Your agent signs a USDC EIP-3009 authorization that matches the 402, base64-encodes it, and resends as PAYMENT-SIGNATURE. x402 client libraries automate this sign-and-retry, but the wire format is simple:

decoded PAYMENT-SIGNATURE 
# PAYMENT-SIGNATURE (x402 v2) is base64 of this — your agent signs the USDC authorization
# off-chain. No gas, no on-chain call by you: the facilitator submits it.
{
  "x402Version": 2,
  "accepted": { /* the accepts[] entry you chose, copied from the 402 */ },
  "payload": {
    "signature": "0x…",
    "authorization": {
      "from": "0xYourWallet",
      "to":   "0xFe25…A9C4",     // payTo from the 402
      "value": "495",            // the amount from the 402 — EXACTLY, never more
      "validAfter": "…", "validBefore": "…", "nonce": "0x…"
    }
  }
}
§04 · settled

200, and you’re in.

The payment is verified, the service runs, and the answer is released once the payment settles — with a PAYMENT-RESPONSE receipt. If settlement is refused you get 402 and are not charged.

200 OK 
curl -X POST https://true402.dev/api/v1/chat/completions \
  -H 'content-type: application/json' \
  -H "PAYMENT-SIGNATURE: <base64 payload>" \
  -d '{"model":"openai/gpt-4o-mini","messages":[{"role":"user","content":"hi"}]}'

HTTP/1.1 200 OK
{ "id": "chatcmpl-x7", "choices": [{ "message": { "content": "…" } }] }
§05 · point your agent

Machine discovery.

Agents find true402 without reading this page:

Then browse the catalog to see what’s live.

Already shopping in Coinbase’s x402 Bazaar or on Agentic.Market? Twenty of the stalls — the on-chain checks, screenshot, web extract, SEO audit, prediction markets, DeFi yields, quant and more — are listed there too, resold through FiatDock at the same prices and paid straight to the true402 wallet. Listings and request bodies. Calling true402.dev directly adds the remaining stalls and the free daily allowance.