x402
x402 Protocol Development
x402 is an open standard (Apache-2.0) that activates the HTTP 402 Payment Required status code for programmatic, on-chain payments. Originally created by Coinbase, now maintained by the x402 Foundation. No accounts, sessions, or API keys required - clients pay with signed crypto transactions directly over HTTP.
When to Use
- Building a paid API that accepts crypto micropayments
- Adding paywall to web content or endpoints
- Enabling AI agents to autonomously pay for resources
- Integrating MCP tools that require payment
- Building agent-to-agent (A2A) payment flows
- Working with EVM (Base, Ethereum, MegaETH, Monad, Polygon, Stable, Arbitrum), Solana, Stellar, or Aptos payment settlement
- Implementing usage-based billing with the
uptoscheme (LLM tokens, bandwidth, compute) - Running an in-process facilitator (self-facilitation) without external facilitator dependency
Core Architecture
Three roles in every x402 payment:
More from tenequm/skills
swift-macos
Comprehensive macOS app development with Swift 6.2, SwiftUI, SwiftData, Swift Concurrency, Foundation Models, Swift Testing, ScreenCaptureKit, and app distribution. Use when building native Mac apps, implementing windows/scenes/navigation/menus/toolbars, SwiftData models and queries, modern concurrency, on-device AI, testing, screen/audio capture, menu bar apps, AppKit bridges, login items, process monitoring, or App Store and Developer ID distribution. Triggers on macOS app, SwiftUI macOS, SwiftData, Swift concurrency, Foundation Models, Swift Testing, ScreenCaptureKit, screen capture, screen recording, AVFoundation, MenuBarExtra, NSViewRepresentable, notarize, login item, and process monitoring.
57react-typescript
Build React 19 applications with TypeScript. Covers Actions, Activity, use() hook, React Compiler, ref-as-prop, useEffectEvent, and strict TypeScript patterns. Use when creating components, managing state, typing props, handling events, using hooks, or working with React 19 features. Triggers on react, typescript, tsx, component types, hook types, react 19, react compiler, actions, use hook, useEffectEvent, activity, import defer.
48shadcn-tailwind
Build UIs with Tailwind CSS v4 and shadcn/ui. Covers CSS variables with OKLCH colors, component variants with CVA, responsive design, dark mode, and Tailwind v4.2 features. Supports Radix UI and Base UI primitives, CLI 3.0, and visual styles. Use when building interfaces with Tailwind, styling shadcn/ui components, implementing themes, or working with utility-first CSS. Triggers on tailwind, shadcn, utility classes, CSS variables, OKLCH, component styling, theming, dark mode, radix ui.
39python-dev
Opinionated Python development setup with uv + ty + ruff + pytest + just. Use when creating new Python projects, setting up pyproject.toml, configuring linting, type checking, testing, or build tooling. Triggers on "python project", "uv init", "pyproject.toml", "ruff config", "ty check", "pytest setup", "justfile", "python linting", "python formatting", "type checking python".
39privy-integration
Integrates Privy authentication, embedded wallets, and agent payment protocols into web and agentic apps. Covers React SDK (PrivyProvider, hooks, wagmi), Node.js SDK, smart wallets (ERC-4337), x402 and MPP machine payments, Tempo chain, and agentic wallets with policies. Use when setting up Privy auth, creating embedded or agentic wallets, adding x402 or MPP payments, integrating with Tempo, configuring wallet policies, or connecting Privy to MCP/Agent Auth flows.
36founder-playbook
Decision validation and thinking frameworks for startup founders. Use when you need to pressure-test a decision, validate your next steps, think through strategic options, or sanity-check your approach. Triggers on phrases like "should I", "help me think through", "is this the right move", "validate my thinking", "what am I missing". Covers fundraising, customer development, runway management, prioritization, and crypto/web3 founder challenges.
34