v1.0.0 MetaPay402 Initial Launch

MetaPay402 v1.0.0 marks the official launch of our Meta-native implementation of the X402 payment standard, enabling autonomous, real-time blockchain payments between APIs, AI agents, and web services.

This release introduces full cross-language SDKs in Python and TypeScript, designed for seamless integration across FastAPI, Express.js, LangChain, and LangGraph.

The system uses the HTTP 402 Payment Required response to facilitate on-chain micropayments on Solana allowing APIs to monetize on a per-request basis and agents to transact autonomously.

Highlights

Instant payments with Solana’s 200ms finality

Micropayments down to $0.001 per API call

No API keys or accounts pay-per-use access

AI-native architecture for LangChain & LangGraph

Cross-chain ready (Solana-first, modular for Ethereum/Base)

SDK parity across Python and TypeScript

What’s Included

Core protocol libraries (@metapay402/core, openlibx402-core)

Server middleware for Express.js and FastAPI

Auto-paying clients for both languages

Example integrations and test utilities

Security and Reliability

On-chain verification and nonce protection

Private key isolation keys never leave the client

Environment-based configuration for production safety

Next Steps

CLI utilities for quick payment setup

Next.js and Django integrations

Analytics and on-chain transaction dashboard

Multi-chain expansion roadmap