zkx402

Consumers (humans or AI agents) have different pricing tiers, with discount given to those that can verify their identities using zk credentials. Producers can prove the providence of their content by attaching zkproofs. e.g., confirmed authorship by a specific journalist, proof of human creation, IoT data with GPS/sensor details.

Whistleblowers get paid without ever revealing their identity. Journalists get cheaper access by proving they are human or work for reputable outlets. Journalist-controlled AI agents pay autonomously via x402 on Base to access private sensitive data.

The use case we are most excited about is for making private data saleable. Data owners would set a high price for data they are OK to lose control of. Or make it available at a discount for a verified organization who they are confident will not abuse the data, such as LLM model creators focused on creating transparent models.

We built the front-end with Next.js.

For the producers, the contents that they upload are verified for authenticity with vLayer prover. The sensitive private data uploaded by the whistleblowers are powered by vLayer's web prover server.

The human verification was conducted with Self.xyz for the consumers. On Self, users verify their passports or national ID on their Self mobile app with certain pieces of information that they want to selectively disclose: are over certain age, are citizens of certain countries, are on the list of OFAC or not. Self proof of humanity is recorded on Celo blockchain, and the proof is transported cross-chain to Base by Hyperlane.

For zkx402, we modify the existing x402 protocol to extend it with zk capabilities to make it more useful. We use Base's embedded wallet to create a new wallet from social login and re-use the majority of the x402 process, including the x402 facilitator.

Originally, we built 3 distinct working apps. We had trouble merging them at first, but eventually we came up with a creative way to merge the 3 apps together into one.

For the frontend app

• Frontend: Next.js + React + TypeScript + ShadCN UI + Tailwind CSS + React Router
• UI Components: Radix UI primitives (Dialog, Accordion, Dropdown, etc.)
• Forms: React Hook Form + Zod validation
• Data Fetching: TanStack Query (React Query)
• Charts: Recharts
• Icons: Lucide React

For the zkx402 payment

• Frontend: Next.js 14 + React + TypeScript
• Wallet & Auth: Coinbase CDP (Embedded Wallet with email/SMS/OAuth login)
• Payments:
  • Client → x402-fetch (HTTP 402 payment client)
  • Server → x402-express + @coinbase/x402 (payment middleware & facilitator)
  • Token → USDC on Base Sepolia
• APIs: CDP Faucet API + CDP Token Balances API
• Chain: Base Sepolia testnet (chainID: 84532)