Architecture

A thin stack: a static frontend, an Express API, Postgres, and Solana for auth and settlement.

Components

• Frontend — static marketplace, account dashboard, and docs (Vercel).
• Backend API — Express service handling auth, keys, balances, top-ups, and the gateway proxy.
• Database — Supabase Postgres for users, API keys, balances, usage logs, and top-up records.
• Chain — Solana for wallet auth and USDC top-up settlement.

Auth

Sign-in uses a Solana message signature, not a password. A nonce endpoint returns a message; login verifies the signature and issues a JWT. Dashboard and top-up routes require that JWT.

wallet signature  →  JWT  →  dashboard / top-up routes
api key (hashed)  →  gateway proxy  →  upstream model

Settlement

Top-ups are real on-chain USDC transfers. Usage metering and balances are kept in Postgres for speed. We describe this as "USDC top-ups, metered off-chain" — accurate to how it runs.