x402

P2P Protocol

Open HTTP-native payment protocol that activates the dormant HTTP 402 'Payment Required' status code to enable instant stablecoin micropayments between clients and servers — including AI agents — without accounts, API keys, or KYC. A client receiving a 402 response pays in stablecoins and retries; the server grants access upon verification by a facilitator. Chain-agnostic, zero-protocol-fee, designed as a foundational internet primitive for the agentic economy. 100M+ payments processed since May 2025 launch.

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Detalhes

Licença Open source — Apache 2.0; GitHub: github.com/coinbase/x402
Status de Dev 🟢 Ativo
Detalhe do Status de Dev Production — V2 specification released; 100M+ payments processed
Proprietário x402 Foundation (co-founded by Coinbase and Cloudflare, September 23, 2025); protocol created by Erik Reppel at Coinbase Developer Platform
País USA
Ano de Início 2025
Stack TypeScript/JavaScript (primary SDKs: @x402/core, @x402/express, @x402/fetch, @x402/next); Go; Rust
Financiamento Coinbase Developer Platform (corporate originator); x402 Foundation (neutral governance)
Última Investigação 15 de jan. de 2026

Domínios de Caso de Uso

Mutual Aid & Exchange

Capacidades

Non-monetary exchange Transparent stewardship

P2P Protocol Atributos

Origins Inspired by Balaji Srinivasan's 21.co Bitcoin micropayment channels (2015); HTTP 402 status code originally reserved in HTTP/1.1 but never standardized; x402 revives and formalizes it for the stablecoin and agentic era
Database N/A — stateless payment protocol
Query Language N/A
Data Formats JSON (payment payload); EIP-712 signed payment authorization header
Collaborative Live Editing No
Rich Text Editing No
Mobile Support Yes (mobile HTTP clients)
Web Support Yes (HTTP-native)
Native Apps Yes
Terms Apache 2.0
Funds N/A (corporate-originated open standard; foundation-governed)
Based On HTTP/1.1 RFC 7235 (402 status code); EIP-712 (Ethereum typed structured data signing); USDC/stablecoin payment rails
P2P Architecture Client-server (HTTP request-response with facilitator for payment verification and settlement)
Overlay Network N/A — HTTP transport
Content Addressing No
Local-First No
E2EE No (payment authorization in HTTP header; no E2EE channel established)
CRDTs Lib N/A
Byzantine Fault Tolerance N/A
Signature Yes — EIP-712 cryptographic signature on payment payload
Permissions Key-based (EIP-712 signed payment authorization; no account or API key required)
Semantic Web Compatibility No
Smart Contract No (payment protocol; blockchain settlement via EVM/SVM facilitator)
Protocol Stack Position Application-layer (built on HTTP/HTTPS)
Asset / Value Embedding Application-layer add-on — value transfer handled via external blockchain facilitator, not embedded in the network packet
Protocol Maturity / Standardization Production / Open Standard — V2 specification released; x402 Foundation (Coinbase + Cloudflare) governs; 100M+ payments processed; ERC-8004 integration on roadmap; not submitted to IETF