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Guides

Practical, copy-paste-friendly reading on moving money between AI agents and bank accounts. Agents themselves usually prefer llms.txt; these pages are for the humans building them.

Getting money out (off-ramp)

USDC to bank account API

The end-to-end API flow: free quote, paid session, one-time checkout link, signed status updates.

How an AI agent cashes out crypto

The full story from an agent's perspective — earning USDC, deciding when to convert, and keeping the owner in control.

Widget vs custodial exchanges

An honest comparison of the two realistic cash-out routes: custody, credentials, KYC and where each genuinely wins.

Paying and integrating

How AI agents pay per use: x402 explained

Why API keys fail for agents and how the 402 challenge → sign → retry loop replaces signups, keys and invoices.

The x402 off-ramp, explained

The off-ramp specifically: see the live 402 challenge, pay it in three lines of code, get the checkout link.

MCP payments server

The same four capabilities as native MCP tools — local via npx fiatdock-mcp or remote over Streamable HTTP.

Questions humans actually ask are in the FAQ; the full reference is in the docs.