Alive402

Demo

About

Alive402 makes AI free trials fair and turns the moment after a trial into a native agent-payment flow. AI APIs commonly offer free credits, but email addresses, browser cookies, and wallet addresses are easy to rotate. Alive402 gives a person one promotional API call after they complete World Selfie Check. The backend verifies the World proof, uses its scoped nullifier as a privacy-preserving continuity signal, and atomically records the entitlement for that provider campaign. The next request reaches the same protected inference endpoint and receives a real HTTP 402 Payment Required response. A budgeted agent reads the x402 payment requirements, pays 0.001 test USDC on Hedera through Blocky402, retries the original request, and unlocks the AI response. The app then shows the execution receipt and Hedera transaction. The result is a reusable access pattern for AI inference, data APIs, developer tools, and other metered HTTP services: let a real person try once, then let humans or agents pay per request without subscriptions or API keys.

How it's made

Alive402 is built with TanStack Start, React, TypeScript, Vite, and Tailwind. The application uses Supabase Postgres for persistent provider campaigns, World enrollment records, one-time proof-signal hashes, opaque server sessions, access decisions, and sanitized payment receipts. For World, we use the IDKit Selfie Check legacy preset. The browser never receives the RP signing key. Instead, the server creates a short-lived random signal, stores only its hash, signs the RP context server-side, and sends the completed IDKit result unchanged to World’s backend verification API. After verification, Alive402 normalizes the scoped nullifier and grants one promotional entitlement per provider campaign. Selfie images are never stored. For paid access, the protected OpenRouter inference endpoint uses x402 v2 with canonical PAYMENT-REQUIRED, PAYMENT-SIGNATURE, and PAYMENT-RESPONSE headers. We use @x402/core, @x402/hedera, @x402/fetch, and the Blocky402 facilitator to build, verify, and settle an exact payment in test USDC on Hedera Testnet. The demo agent is server-side and constrained to one network, one USDC asset, one merchant account, a maximum payment amount, and a daily spend limit. A HashScan-linked receipt proves the settlement. Vercel hosts the application and Vercel Analytics measures real product traffic.