Complete app example.

Hono middleware for gating endpoints behind x402 payments with payment-agreement support for recurring agent-to-agent billing. ([npm](https://www.npmjs.com/package/@azeth/provider))

Brand-neutral Fastify payments engine: x402 USDC paywalls (auto-selects the Coinbase CDP facilitator when keys are present, Bazaar discovery on every route) **plus** Monero/Zcash view-key payment watching with webhooks and prepaid credit meters topped up via x402 or native XMR/ZEC. Ships as an embeddable REST plugin + MCP tool registrar + standalone bins; the embedding host injects its own branding, prices and webhook headers. MIT, production-extracted from seneschal.space. Built on [x402-server-kit](https://github.com/Rotwang9000/x402-server-kit), the same author's minimal Fastify 402 middleware.

Signed proof-of-delivery receipts for x402 sellers: verify settlement on-chain, merkle-batch and anchor receipt roots via EAS on Base, plus a notify layer that renders every sale as a human-readable alert (email HTML / Slack / Discord / Telegram / webhook). Zero deps beyond viem, 178 tests, Apache-2.0, running in production.

Per-second **streaming/metered** settlement for x402 — turns one-shot 402 calls into pay-as-you-consume billing (pay a tick, get the next chunk; stop paying, the gate shuts). One-line `createMeterRouter` Express adapter over a framework-free `StreamingMeter` core, plus an MCP server so agents open a session and pay tick-by-tick, and an EVM on-chain verifier that re-derives every settlement total straight from the token's Transfer ledger. MIT. ([GitHub](https://github.com/Risingtell/meter402))

Plugin marketplace primitive for x402. Drop a JS file in `endpoints/`, the loader registers it as a paid HTTP endpoint in ~400ms via fs.watch (no restart, no manifest edits). Generates Bazaar-shape 402 challenge with EIP-712 extras, `/.well-known/x402.json` manifest, agent-card, and OpenAPI spec automatically. Zero runtime dependencies. Production-extracted from api.autonomagic.org's 22 paid endpoints. ([npm](https://www.npmjs.com/package/autonomagic-marketplace)) ([GitHub](https://github.com/premsreelathasugeendran/autonomagic-marketplace))

Trust score middleware for x402 endpoints. One line: `app.use(requireScore({ minScore: 60 }))`. Extracts paying wallet from X-Payment header, looks up MolTrust trust score, blocks agents below threshold with 403 + registration link. Zero dependencies. ([npm](https://www.npmjs.com/package/@moltrust/x402)) ([GitHub](https://github.com/MoltyCel/moltrust-x402))

Authorization middleware for x402 endpoints. One line: `preflight(handler, { minScore: 40 })`. Gates by a 5-dimension trust score (wallet age, tx history, counterparties, funding source, ERC-8004), returns Ed25519-signed receipts verifiable with only the public key, supports block / warn / surcharge modes. Hono / Express / Next adapters. ([npm](https://www.npmjs.com/package/@larkinsh/x402)) ([GitHub](https://github.com/larkin-dev/larkin))

App Router middleware.

Pay-per-crawl gate for site owners. Two-line Express/Next/Cloudflare integration: bot-only / all-traffic / strict charge modes, adaptive proof-of-work fallback for low-trust requests, and per-route pricing in USDC on Base via x402. Ships `gate.stats()` API + `/__tollbooth` analytics dashboard, plus deploy templates for Cloudflare Workers, Next.js middleware, and Docker. Defaults preserve original site behavior — drop-in, no rewrite required. Also available as a managed service ([Tollbooth Cloud](https://agent402.tools/tollbooth/cloud)) and a [WordPress plugin](https://agent402.tools/tollbooth/wordpress). ([npm](https://www.npmjs.com/package/agent402-tollbooth)) ([GitHub](https://github.com/MikeyPetrillo/Agent402/tree/main/tollbooth))

One-line API monetization SDK. Wraps x402 setup into a single function call. Express, Next.js, and MCP support. Per-route pricing, Base/Arbitrum/Polygon, gas-free agent payments via EIP-3009. ([npm](https://www.npmjs.com/package/@monapi/sdk)) ([GitHub](https://github.com/DenisTheM/monapi))