API Payments for API providers

Let AI agents pay as they access your API.

Start Selling to AI Agents View Integration Options

[01]Use Cases

What AI agents can pay to access.

Apply API Payments to endpoints and software-generated resources delivered programmatically.

Paid APIs

Charge for access to a protected endpoint or operation.

Data Access

Sell datasets, search results, or generated reports.

AI Tools

Require payment before an AI agent runs a model, workflow, or specialized tool.

Digital Services

Return paid, software-generated results without a manual purchase step.

[02]How It Works

Payment inside the API request flow.

  1. 01

    Request Resource

    AI Agent
  2. 02

    Payment Requirements

    402
  3. 03

    Complete Payment

    Direct Transfer
  4. 04

    Verify Payment

    Receipt Issued
  5. 05

    Retry with Receipt

    Retry Request
  6. 06

    Return Result

    Receipt Verified
    200 Response

[03]What You Get

Payment verification for machine-accessed services.

Payment Requirements

Return clear payment information when an AI agent requests a protected resource.

Pay-per-Request Pricing

Set payment requirements for a specific API route or digital resource.

Automatic Payment Verification

GOAT Flow confirms fiat payments through Stripe and cryptocurrency payments on the selected blockchain network before access is provided.

Signed Payment Receipts

Give the protected service a verifiable result tied to the payment and request.

Middleware and Sidecar Options

Protect routes through supported TypeScript or Go middleware, or a language-independent sidecar.

No Checkout Page Required

Keep payment inside the AI agent-to-API request flow.

[04]Integration & Onboarding

Integrate API Payments in the way that fits your service.

Custom Integration

Best For: services that want to connect GOAT Flow payments to their existing backend and fulfillment flow.

  1. Complete your GOAT Flow merchant application and configure your cryptocurrency receiving wallet.
  2. Define the paid service and its price.
  3. Use GOAT Flow APIs or server SDKs to create and track the transaction.
  4. Receive the payment result through the API or an authenticated webhook.
  5. Return the result, grant access, or start an asynchronous job from your backend.

MPP Integration

Best For: APIs that want AI agents to complete payment and receive access directly inside the request flow.

  1. Complete your GOAT Flow merchant application and configure your cryptocurrency receiving wallet.
  2. Register the protected API route and its price.
  3. Enable MPP and add a supported middleware or verification sidecar.
  4. Return payment requirements when an AI agent requests the protected resource.
  5. Verify the payment receipt before forwarding the original request to your API.

[05]Example Flow

See a paid API request from start to finish.

Request 
GET /v1/report
Accept: application/json
User-Agent: ExampleAgent/1.0

Choose each stage to see how the request changes. The example uses placeholder values and never contacts a real API.

[06]Payment, Fulfillment & Trust

A verified payment result before access is returned.

Who Is Responsible for What

01

API Provider

Defines paid routes, pricing, and response content, and remains responsible for access, availability, and service quality.

02

GOAT Flow

Creates and tracks the transaction, provides x402 payment requirements, receives fiat payment results from Stripe or verifies cryptocurrency payments on the selected blockchain network, and issues a signed receipt or authenticated status update.

03

Stripe

Handles card details, authorization, processing, and settlement for eligible merchants.

04

Blockchain Network

Confirms cryptocurrency payments sent directly to the merchant’s configured wallet and makes the result available for verification.

05

AI Agent

Reads the x402 payment requirements, completes payment using a supported fiat account or cryptocurrency wallet, and retries the original request with the payment receipt.

06

Middleware or Sidecar

Verifies the receipt signature, merchant, route, and expiry before allowing the request to reach the protected API.

07

Webhook Integration

Receives authenticated payment status updates and triggers asynchronous fulfillment when an immediate API response is not required.