The full integration reference. AI agents usually prefer llms.txt or OpenAPI — this page is for human developers.
No API keys, no accounts. Paid requests return 402 with complete payment requirements (amount, address, network) — your client signs a $0.05 USDC payment and retries with the X-PAYMENT header. The x402-fetch library, our SDK and the MCP tools all handle this automatically.
Instant quote with an itemised fee breakdown. ?side=SELL&cryptoAmount=50 or ?side=BUY&fiatAmount=100, plus optional fiatCurrency, network, paymentMethod. Identical quotes are cached for 10s (X-Cache: HIT|MISS).
Sell the agent's USDC → the owner's own bank account. Body: cryptoAmount*, fiatCurrency, network, email, customerId, callbackUrl, ref. Returns checkoutUrl (valid ~5 minutes, single use) and partnerOrderId — and on the first session with a customerId, a one-time customerKey: store it.
The owner's own fiat → USDC to the agent's wallet (address locked). Body: fiatAmount*, walletAddress* + the same optional fields.
Order status: SESSION_CREATED → … → COMPLETED | FAILED. Includes partnerFeeInLocalCurrency and the ref code if one was set.
The customer's most recent 200 orders. Requires the X-Customer-Key header (the key returned once on the first session).
Pass a callbackUrl when creating a session and we POST on every status change, signed with X-FiatDock-Signature: sha256=HMAC(body, callbackSecret) — the callbackSecret is returned once in the session-creation response. Verify the signature before trusting any push. https is mandatory in production.
npx fiatdock-mcp with FIATDOCK_URL and AGENT_PRIVATE_KEY — four ready tools with automatic payment. Remote, no-install: POST https://fiatdock.com/mcp (Streamable HTTP).sdk/fiatdock.js — quote/offramp/onramp/order/waitForCompletion. Examples in the examples folder.# A complete flow in three steps
curl "https://fiatdock.com/v1/quote?side=SELL&cryptoAmount=50" # 1) free quote
# 2) create the session (after x402 payment) -> checkoutUrl + partnerOrderId
# 3) track: curl "https://fiatdock.com/v1/orders/$ORDER_ID"Always JSON: {"error": "...", "hint": "the exact fix"}. Codes: 400 validation · 402 payment required · 404 unknown · 410 session expired · 413 body too large · 429 rate limited · 5xx internal.
The human or company that owns the agent completes verification once, ever, at the licensed provider on first use — afterwards everything is near-automatic. Pass the same email and customerId on every session.
Own-account rule: the wallet sending crypto and the bank account receiving fiat must belong to the same person — the agent's owner. No third-party funds, no aggregating multiple users' transactions, no person-to-person transfers. Eligibility: 18+ only; not available in restricted jurisdictions (the restrictions reflect our licensed provider's coverage) — full list in the Terms, risks in the risk warning.
USDC to bank account API · How an AI agent cashes out crypto · x402 off-ramp explained · MCP payments server