t402

• Name: t402
• URL: https://t402.io/
• Category: paid-request facilitator stack / multi-chain stablecoin middleware / agent-payments wrapper
• Tags: bitcoin-ecosystem ethereum-ecosystem solana-ecosystem
• Summary: t402 is facilitator-heavy paid-request packaging. It wraps the 402 -> sign -> verify -> settle path, ships chain modules and HTTP middleware, and leans on wallet tooling plus agent integrations to make the stack usable. Useful because the facilitator is the product here. Still not the canonical grammar.
• What it does:
  • Defines an HTTP-native paid-resource flow where servers advertise payment requirements, clients sign payment authorizations, and facilitators verify and settle the corresponding onchain payment before the resource server returns content
  • Ships chain- and scheme-specific packages spanning EVM, Solana, TON, TRON, NEAR, Aptos, Tezos, Polkadot, Stacks, Cosmos, Stellar, and Bitcoin/Lightning, with the docs emphasizing USDT coverage across many blockchain families
  • Provides server integrations for frameworks like Express, Next.js, Hono, and Fastify plus client wrappers for Fetch and Axios so developers can gate APIs and other HTTP resources behind programmable payments
  • Exposes a facilitator API and a documented self-hosting path for payment verification, settlement, metrics, rate limiting, wallet management, and production operations
  • Integrates with Tether WDK for wallet management and ERC-4337 gasless flows, and separately ships MCP tooling so AI agents can discover and pay for APIs autonomously with spending controls
  • Positions itself for API monetization, premium content, micropayments, and machine- or agent-driven paid access rather than only conventional human checkout
• Key claims:
  • The docs sell t402 as the open payment protocol for USDT with one HTTP header across many chain families. Fine marketing; the durable thing is the facilitator-operated verification and settlement layer sitting behind that pitch.
  • The monorepo layout matters more than the slogan. It includes core protocol types, many chain modules, HTTP integrations, WDK bindings, A2A transport, MCP tooling, and CLI utilities, which makes this an operator stack rather than one thin SDK.
  • The facilitator API is the real center of gravity: payment verification, settlement, supported-network discovery, API-key admission, and self-hosting all sit there.
  • The self-hosted facilitator guide is the strongest evidence that the note belongs above the small wrappers. Redis idempotency, Prometheus/Grafana monitoring, multi-chain RPC wiring, rate limits, and reverse-proxy deployment are real operations surfaces, not demo scaffolding.
  • The AI-agent-payments and WDK material matter because they show how t402 wants to become the default wallet-and-paywall package for agent environments, not because they make it a cleaner base protocol than x402 or MPP.
  • Keep the note blunt: t402 is serious facilitator middleware with broad packaging, but it is still more operator glue than canonical standard.
• Whitepaper: An official t402 whitepaper exists and was saved locally as ../whitepapers/t402-whitepaper.pdf; see also ../whitepapers/t402-primary-sources-2026-05-03.md.
• Sources:
  • https://t402.io/
  • https://docs.t402.io/
  • https://docs.t402.io/guides
  • https://docs.t402.io/guides/ai-agent-payments
  • https://docs.t402.io/guides/self-hosted-facilitator
  • https://docs.t402.io/reference/facilitator-api
  • https://raw.githubusercontent.com/t402-io/t402/main/README.md
  • https://t402.io/t402-whitepaper.pdf

Internal linkages

• Closest paid-request peers: x402 and machine-payments-protocol

Control surface

• The leverage sits in facilitator policy, supported chain modules, WDK wallet dependency, middleware defaults, and which paid-request flows get normalized for developers and agents.

• That makes t402 more substantial than a thin wrapper, but it is still a packaged control plane around stronger payment-auth ideas rather than the base rail itself.

• Last reviewed: 2026-06-12 UTC