Documentation

HTTP 402 on Solana for trustless, per-request billing.

About MetaPay402

MetaPay402 is a Meta-native framework built on the X402 protocol. It enables APIs, Meta services, and AI agents to complete autonomous crypto transactions using the HTTP 402 Payment Required standard, powered by Solana for secure and near-instant micropayments.

Core capabilities

  • Seamless integration: add pay-per-call to any endpoint
  • AI optimized: autonomous agents with auto-payment clients
  • Instant settlement: ~200ms on Solana
  • Micropayments: as small as $0.001
  • No credentials: no API keys or manual billing
  • Cross-language SDKs: Python and TypeScript

Supported languages and SDKs

  • Python: FastAPI, LangChain, LangGraph
  • TypeScript/Node.js: Express.js, LangChain.js, LangGraph.js

How MetaPay402 works

  1. Client requests a paid endpoint
  2. Server replies with HTTP 402 and payment instructions
  3. Client completes on-chain payment on Solana
  4. Server verifies the transaction
  5. Endpoint unlocks and returns data

Project layout

metapay402/
├── packages/
│   ├── python/
│   │   ├── metapay402-core
│   │   ├── metapay402-fastapi
│   │   ├── metapay402-client
│   │   ├── metapay402-langchain
│   │   └── metapay402-langgraph
│   └── typescript/
│       ├── metapay402-core
│       ├── metapay402-express
│       ├── metapay402-client
│       ├── metapay402-langchain
│       └── metapay402-langgraph
├── examples/
│   ├── fastapi-server
│   ├── express-server
│   ├── langchain-agent
│   └── langgraph-workflow
└── docs/

Where MetaPay402 fits in

MetaPay402 powers a new kind of economy inside Meta's ecosystem — where AI agents, tools, and APIs exchange value directly on-chain without human intervention. This replaces credit cards and subscriptions with verified, instant crypto payments.

Built for developers

  • Convert any endpoint into a revenue stream
  • Self-monetize APIs with per-call billing
  • Remove manual invoicing and authentication systems
  • Collect verified USDC instantly after each call

Built for agents

  • AI tools can pay for ads, analytics, or compute automatically
  • Transactions execute in under 300ms via Solana
  • No subscriptions, no stored credentials
  • Pay only when data/resources are consumed

Built for the Meta ecosystem

  • Connects with Meta Ads, Meta APIs, and future Meta services
  • Enables blockchain-native automation inside Meta environments
  • Works with Solana now; expansion to Base and Ethereum planned

Status

  • Core payment engine: Stable
  • SDKs: Complete (Python, TypeScript)
  • Agent toolkit: In progress
  • Dashboard: Planned
  • Multi-chain support: Planned

Learn more and track releases on the repository.

Repository