How is selling to AI agents different from selling to humans?

Agents don't fill in signup forms, store API keys, or pay invoices. They pay per call, in USDC, at the moment of the call, via the x402 protocol (an HTTP 402 'payment required' that the agent signs and retries). They discover services programmatically through MCP tools and llms.txt rather than via marketing pages. And they expect instant, on-chain settlement — not net-30 payout cycles. So selling to agents means: no onboarding friction, pay-per-call pricing, agent-native discovery, and direct on-chain payment.

Do I have to rewrite my API to sell to agents?

No rewrite of your business logic — you wrap it as an MCP server (a thin adapter exposing your endpoints as MCP tools) and point your FiatDock listing at it. FiatDock's gateway handles the x402 payment and forwards paid calls to your endpoint, signed, so you can accept only gateway traffic. Your raw endpoint stays private behind the gateway URL /s/{id}.

Is it non-custodial — do I get paid directly?

Yes. Each agent's payment settles on-chain directly to your wallet via x402; FiatDock takes 1% as an atomic on-chain split (0% for your first 30 days) and never holds, routes, or forwards your funds. You're paid per call, instantly.

How to sell an API to AI agents (2026) — pay-per-call via x402

Q: How do I sell an API to AI agents?

Expose your API as an MCP (Model Context Protocol) service and list it on an MCP marketplace with a per-call price. On FiatDock, AI agents discover your service (via the search_services MCP tool, /browse, or the JSON manifest) and pay per call in USDC over the x402 protocol — settled on-chain directly to your wallet, with no signup, API keys, or invoicing. You keep 100% for your first 30 days, then 99% (a 1% on-chain platform fee).

Aspect	Selling to humans	Selling to AI agents (FiatDock)
Onboarding	Signup, API key, dashboard	None — the agent just calls and pays
Payment	Card, invoice, subscription	USDC per call via x402, on-chain
Discovery	SEO, sales, marketing pages	MCP tools, llms.txt, JSON manifest — agents find you
Integration	REST docs to read	An MCP server (wrap your API once)
Getting paid	Net-30, payout cycles	Per call, instantly, to your wallet
Custody	Processor holds funds	Non-custodial — direct buyer→seller

Three steps to sell your API to agents

Wrap it as MCP

Expose your API as an MCP server (a thin adapter — tools that call your endpoints). No business-logic rewrite.

List it on FiatDock

Create an account, publish at /sell/new with a per-call price, set a payout wallet.

Agents pay per call

The gateway handles x402 + forwards paid calls (signed) to you; USDC settles to your wallet. 0% the first 30 days.

Why agents need x402 (not API keys)

An API key assumes a human signed up, stored a secret, and will be invoiced. An autonomous agent has none of that workflow — it has a wallet. x402 turns "payment required" into a protocol step: the agent calls, gets an HTTP 402 with the price, signs a USDC payment, and retries — all automatically. That's why selling to agents means pricing per call and being discoverable through MCP/llms.txt, not gating behind signups. FiatDock gives you both, non-custodially. Deeper dive: sell your MCP service · monetize an MCP server.

FAQ

How do I sell an API to AI agents?

Wrap it as an MCP service, list it on FiatDock with a per-call price, and agents pay in USDC via x402 — settled on-chain directly to your wallet, no signup or keys. Keep 100% for 30 days, then 99%.

How is it different from selling to humans?

No onboarding, pay-per-call pricing, agent-native discovery (MCP/llms.txt), and instant on-chain payment — see the table above.

Do I get paid directly?

Yes — non-custodial; each payment settles to your wallet via x402, FiatDock takes 1% (0% first 30 days) as an on-chain split.

How to sell an API to AI agents

Selling to humans vs selling to AI agents