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MicroAI Paygate
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MicroAI Paygate docs

Build against the paygate.
Developer documentation for the SDK, gateway API, custom x402-style flow, operations, and current production limits.

Architecture

MicroAI Paygate is split into small services so each trust boundary is visible.

Service Map

  • web/: Next.js browser app on port 3001.
  • sdk/typescript/: local TypeScript SDK for AI API builders.
  • gateway/: Go/Gin public API gateway on port 3000.
  • verifier/: Rust/Axum EIP-712 verifier on port 3002.
  • Redis: receipt storage by default and optional response cache.
  • AI provider: OpenRouter or Ollama depending on configuration.

Data Flow

  1. Browser or SDK sends an unsigned request to the gateway.
  2. Gateway returns a payment context.
  3. Browser wallet or SDK signer signs the context.
  4. Signed retry reaches the gateway.
  5. Gateway calls the verifier.
  6. Verifier recovers and validates the wallet signature.
  7. Gateway calls the AI provider.
  8. Gateway signs and stores the receipt.
  9. Browser or SDK verifies the receipt locally.

Boundaries

The gateway owns orchestration, rate limiting, timeouts, AI provider calls, receipt signing, receipt storage, and public error mapping.

The verifier owns EIP-712 parity, signer recovery, chain ID enforcement, timestamp freshness, and nonce replay protection for the verifier instance.

The web app owns wallet UX, chain switching, user-facing errors, receipt display, and browser-local receipt history.

The SDK owns programmatic client integration: challenge handling, EIP-712 signing, signed retry headers, receipt decoding, and receipt verification.

Deployment Shape

The deployed demo uses Render for backend services, Vercel for the Next.js web app, and Upstash for Redis. Local development runs the same logical services on ports 3000, 3001, and 3002.