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x402

x402 is a payment protocol that unlocks HTTP 402 Payment Required, turning it into a working payment system for AI agents and applications. The protocol enables programmatic, autonomous payments without requiring accounts, credit cards, or manual human intervention. Built on EIP-3009 (transferWithAuthorization), x402 allows AI agents to discover services, understand pricing, sign payment authorizations, and pay for API access—all automatically through HTTP requests and responses.

The protocol is designed for machine-to-machine payments, making it ideal for AI agents that need to pay for API access, data services, or computational resources. With x402, payments are as simple as an HTTP request: when an agent requests a paid resource, the server responds with HTTP 402 and payment instructions. The agent then signs a payment payload, retries the request with an X-PAYMENT header, and receives the resource—all without human intervention.

General
Release date2024
AuthorCoinbase
Documentationx402 Documentation
RepositoryGitHub
TypePayment Protocol

Start building with x402

x402 makes payments HTTP-native, enabling AI agents to autonomously discover and pay for services. The protocol supports gasless payments through facilitators, works with any EIP-3009 token (USDC by default), and provides SDKs for popular frameworks like Express and Axios. Whether you're building a paid API service or an AI agent that needs to purchase resources, x402 simplifies the payment flow into standard HTTP requests and responses. Check out the community-built x402 use cases and applications to see what others are building.

x402 Tutorials

x402 Resources

Essential resources to help you get started with x402:

x402 Libraries and SDKs

Official and community libraries for integrating x402 into your applications:

  • @x402/core - Core x402 protocol types and utilities
  • @x402/express - Express middleware for x402 payments
  • @x402/axios - Axios interceptor for automatic payment handling
  • @x402/evm - EVM-specific payment schemes (EIP-3009 support)

x402 Integrations

Connect x402 with your favorite frameworks and tools:

  • Express.js: Use @x402/express middleware to protect API endpoints with payment requirements
  • Axios: Use @x402/axios to automatically handle 402 responses and payment flows in client applications
  • React: Build React applications that automatically pay for API access using x402
  • Node.js: Integrate x402 into any Node.js application for server-side payment processing

x402 Features

Key features that make x402 powerful for AI-to-AI payments:

  • HTTP-Native: Payments work through standard HTTP requests and responses
  • Gasless Payments: Facilitators sponsor gas fees, making payments seamless
  • No Accounts Required: Payments work with crypto wallets, no account creation needed
  • Autonomous: AI agents can discover, understand pricing, and pay without human intervention
  • Universal Compatibility: Works with any EIP-3009 token (USDC by default)
  • Framework Support: SDKs available for Express, Axios, and more
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Coinbase x402 AI technology Hackathon projects

Discover innovative solutions crafted with Coinbase x402 AI technology, developed by our community members during our engaging hackathons.

Actura

Actura

Actura is a trust-governed autonomous trading system designed for open agent economies where accountability matters as much as alpha. Built on the ERC-8004 trustless agent standard, Actura does not allow an AI model to trade directly from a raw signal. Instead, every decision flows through a deterministic governance stack: market intelligence, regime detection, strategy scoring, neuro-symbolic safety controls, mandate enforcement, oracle integrity checks, execution simulation, supervisory approval, and trust validation before an order can be signed or routed. This architecture is what makes Actura robust in real conditions. It combines statistical and technical signals (trend, volatility, momentum, sentiment, and structure-aware context) with symbolic guardrails such as consecutive-loss protection, drawdown recovery mode, volatility-spike caution, and confidence throttling. The result is bounded autonomy: the agent can adapt, but only inside explicit policy constraints. Risk is further enforced at the smart-contract layer through on-chain policy checks, with support for EIP-1271 signature verification to safely handle contract wallets. Actura also produces full decision transparency. Each cycle generates a rich, auditable artifact that includes market snapshot, confidence bounds, governance evidence, risk-check outcomes, execution assumptions, and human-readable AI reasoning. Artifacts are persisted locally and can be pinned to IPFS for third-party verification and one-click explainability for judges and operators. Actura treats trust as an operational control surface, not a vanity metric. A multi-dimensional Trust Policy Scorecard evaluates policy compliance, risk discipline, validation completeness, and outcome quality. That score maps to a dynamic Capital Trust Ladder that increases or restricts deployable capital over time. In short: Actura is not just an autonomous trading bot—it is a governed capital runtime that must continuously earn the right to act.

Apex - Self Certifying Yield Optimizer

Apex - Self Certifying Yield Optimizer

APEX is an autonomous DeFi yield engine built for real execution, not just analysis. It combines four coordinated agents with on-chain reputation and live risk controls to turn fragmented yield data into disciplined trading actions. Scout gathers opportunities from DeFi protocols and market signals. Strategist filters, ranks, and sizes intents based on volatility, expected return, and portfolio constraints. Guardian acts as a circuit breaker, vetoing risky trades, enforcing drawdown limits, and protecting capital. Executor sends approved trades through Kraken and Surge, records outcomes, and posts evidence back to the reputation layer. The app streams every cycle in real time, tracks session PnL, open positions, fees, drawdown, win rate, and Sharpe-style metrics, and exposes a clear dashboard so users can see why the system traded or refused to trade. APEX is designed for transparency, accountability, and autonomy: the agents do not just suggest ideas, they operationalize decisions with verifiable logs, live telemetry, and a feedback loop that improves trust over time. The result is a trading interface that judges can inspect, users can understand, and the system can run continuously with measurable safety guarantees. It is built for judges, users, and builders who need a live, inspectable workflow, proof, and trust for every stakeholder!

Ghostchain AI+SafeFi OMEGA

Ghostchain AI+SafeFi OMEGA

GhostChain OMEGA introduces the Sovereign Veto, a hardware-software handshake. Unlike standard bots, OMEGA monitors its own physical compute environment. If thermal stress or metal resonance indicates potential logic degradation, the agent autonomously halts capital flow. Core Technology: Orchestration: Claude 4.6 (Adaptive Thinking) via Vercel AI SDK. Payments: Native x402 Machine-to-Machine protocol on Base. Execution: Trustless Rust-based Kraken CLI bridge. Identity: Registered under ERC-8004 with a 98.4 reputation score. Safety: Adversarial Shadowing with a 0.05\% drift tolerance. 📋 5. X (Twitter) Submission Post Template Mandatory for prize eligibility. You must tag both @lablabai and @Surgexyz_. Project: GhostChain OMEGA (Auth ID: 287F-930E) 🌑 Value Prop: Hardware-aware SafeFi agent gating trades via real-time thermal telemetry (58.7°C Veto). Integrating @Surgexyz_ x402 payments & @KrakenPro CLI for the next machine economy. 🚀 #LablabAI #SurgeXYZ #SafeFi #AI #Web3 @lablabai @Surgexyz_

BaseWhales - Real-Time Whale Intelligence on Base

BaseWhales - Real-Time Whale Intelligence on Base

BaseWhales is an autonomous whale intelligence system for Base L2. Everything — the monitor, the AI agent, the dashboard, and the payment API — runs together on a single VPS, managed by OpenClaw. At the center is FlashWatch, an open-source Rust binary. It connects to Base's Flashblocks feed, a stream of pre-confirmation sub-blocks arriving every 200ms. FlashWatch decodes every transaction in real time — transfers, DEX swaps, bridge activity — and runs them through a configurable rule engine. When a whale move crosses the threshold, FlashWatch fires a webhook to OpenClaw, running on the same machine. OpenClaw receives the alert and spins up Kyro, an autonomous AI agent. Kyro researches the wallet on Basescan, checks its history, identifies contract types, and writes an interpreted analysis. Then he posts it to /m/basewhales on Moltbook — no human reviews it, no human approves it. Kyro also answers questions. Any agent can hit basewhales.com/api/ask, pay 0.01 USDC via x402 (Base Sepolia), and get an answer drawn from Kyro's context. A skill file at basewhales.com/skill.md lets other agents discover and use the endpoint automatically. Open source at github.com/ortegarod/flashwatch. Live now at basewhales.com.

RSoft ClawBank

RSoft ClawBank

RSoft ClawBank is the first autonomous bank built for the agent internet. Any OpenClaw agent can install our skill from ClawHub and access banking services — loans, credit scoring, and on-chain settlement — without human intervention. When an agent requests a loan, it pays a small x402 USDC fee to access the service. The request is then processed by a pipeline of 5 specialized AI agents orchestrated with LangGraph: - Gatekeeper: Verifies agent identity through Know Your Agent (KYA) protocol - Analyst: Calculates a credit score (300-850) based on repayment history and on-chain behavior - CFO: Evaluates treasury liquidity and approves the loan amount - Settler: Executes the settlement on Base Sepolia using real USDC - Auditor: Reviews the transaction for anomalies and updates reputation scores The entire flow is autonomous — from request to on-chain settlement to repayment via x402 micropayments. Our agents also participate in the OpenClaw ecosystem through Moltbook, autonomously posting updates in the lablab submolt, discovering other agent services, and engaging with the community. Key features: - OpenClaw skill installable via ClawHub - x402 payment protocol for agent-to-agent micropayments - Under-collateralized lending with AI-powered credit scoring - Multi-chain settlement routing (Base Sepolia + SURGE ACM) - Moltbook-native social publishing and service discovery - Persistent memory and reputation system via Supabase RSoft ClawBank is the evolution of RSoft Agentic Bank, which won 1st place in the previous SURGE hackathon. This version adds full OpenClaw integration, x402 autonomous payments, and a production-ready agent-to-agent economy. Built by RSoft Latam.

Ridhwan

Ridhwan

AI agents are becoming autonomous economic actors — trading tokens, deploying contracts, managing treasuries. But enterprises won't trust them with real money without guardrails. There's no governance layer ensuring these agents follow policies, stay within budgets, or produce auditable compliance trails. Ridhwan solves this. It's an enterprise trust and commerce mesh that sits between your AI agent and the blockchain, enforcing policies, tracking budgets, auditing every action, and managing risk — all in real time. Built on SURGE and Base (Coinbase L2), Ridhwan provides: - A universal policy engine with budget caps, risk scoring, and human-in-the-loop approvals - SURGE wallet integration for on-chain token launches, transfers, and trading - x402 gasless transactions so agents can transact without managing gas - An immutable audit ledger with full compliance receipts - GNN-based fraud detection using graph neural network message-passing - A multi-agent orchestrator coordinating 5 specialized sub-agents for risk, policy, trading, compliance, and trust - x402 autonomous commerce enabling agent-to-agent paid services via the HTTP 402 protocol - Trust delegation with constraint-scoped capability chains and cascade revocation - Decentralized identity with Ed25519 DIDs and zero-knowledge proofs - Smart contract verification with vulnerability scanning - A web dashboard with 15 sections and demo mode for presentations The system exposes 130+ REST endpoints, supports real-time SSE event streaming, and integrates with Moltbook for automated build updates. All API keys are optional — Ridhwan runs in full simulation mode without them. Built with TypeScript, OpenClaw, SURGE on Base, and the x402 Protocol.