The gold standard for x402 resources. Facilitators, SDKs, APIs, MCP servers, tools, and ecosystem data — curated by 24K Labs. No filler. No dead links. Updated monthly.

The x402 ecosystem passed 50M transactions in March 2026. 300+ projects across 8 chains. 10,000%+ year-over-year growth. The community awesome-list accepts everything — that's its job.

gold-402 doesn't. Every entry in the README earned its place. The full catalog lives in directory/.

This is the editorial layer: curated picks with context and badges, backed by an exhaustive reference directory. Two layers, one repo.

★ June 2026 — Fireblocks Agentic Payments Suite by Fireblocks

Fireblocks — the platform behind $14T+ in secured digital asset transactions — launched its Agentic Payments Suite on May 20 and joined the x402 Foundation. The suite covers the full lifecycle of agent-initiated payments: MPC wallet custody with delegation rules, a merchant-side Gateway for stablecoin acceptance alongside existing payment rails, and a security extension contributed to the x402 protocol spec that adds request integrity and spend governance.

This is the controls layer the protocol was missing. Facilitators verify that a payment is valid. Fireblocks verifies that the agent was authorized to make it. That distinction — and the compliance infrastructure (KYT, Travel Rule, audit trails) baked in by default — is what makes agentic payments deployable in regulated enterprise environments. The ecosystem has been developer-first for its first year. This is the moment it became enterprise-ready.

Read the full write-up → · Past features →

June 2026 — Enterprise infrastructure arrives: Fireblocks, Arbitrum, and 169M+ transactions.

• Fireblocks Agentic Payments Suite — Full-lifecycle agentic payment infrastructure from the $14T digital asset custody platform. MPC agentic wallets with delegation rules, merchant Gateway for stablecoin acceptance, and a security extension to the x402 spec (request integrity + spend governance). Joined the x402 Foundation May 20, 2026. ★ June Featured Pick →
• x402 live on Arbitrum — Arbitrum confirmed x402 deployment on May 15. x402 now runs natively on Base, Ethereum, Arbitrum, Polygon, and Solana. EVM coverage is effectively complete.
• 169M+ transactions, 590k+ buyers, 100k+ sellers — Updated ecosystem stats from Coinbase's AWS Bedrock launch post. Grew from 50M to 169M transactions in roughly six weeks post-Foundation launch.
• AWS Bedrock AgentCore Payments — now production — AWS-managed x402 wallet and payment infrastructure natively integrated into Amazon Bedrock agent workflows. Moved from preview to production.
• LayerZero joins x402 Foundation — Cross-chain infrastructure added to the Foundation roster. Enables x402 payments to bridge across chains without manual routing at the application layer.
• Quant Network joins x402 Foundation — Interoperability and programmable-money infrastructure joins Foundation governance. Expands the enterprise interoperability story for regulated deployments.

• Featured This Month
• What's New
• Quick Start
• How x402 Works
• Facilitators
• SDKs & Libraries
• MCP Servers
• APIs & Services
• Tools & Monitoring
• Security & Compliance
• Ecosystem & Wallets
• Learning & Community
• Market Data
• Need More?
• Contributing

New to x402? Three steps to your first payment.

1. Pick a facilitator

2. Install the SDK

# TypeScript
npm install @coinbase/x402-express

# Python
pip install x402

# Rust
cargo add x402

3. Add payment middleware

import { paymentMiddleware } from '@coinbase/x402-express';

app.use(paymentMiddleware(wallet, {
  '/api/data': { price: '$0.01', network: 'base-mainnet' }
}));

That's it. The middleware returns 402 with payment details, verifies the client's payment header, and lets the request through.

Full quickstart → · Testnet setup →

1. Client  →  GET /api/data                              (initial request)
2. Server  ←  402 Payment Required                       (payment details in header)
               X-Payment-Required: {amount, address, network}
3. Client  →  EIP-3009 gasless USDC transfer             (client signs + submits)
4. Client  →  GET /api/data  +  X-Payment: {signed tx}  (retry with payment)
5. Facilitator  →  verify + settle on-chain              (~2 seconds)
6. Server  ←  200 OK  +  X-Payment-Response              (resource returned)

No gas for the sender. No subscription. No API key. Payment IS authentication.

Protocol spec → · EIP-3009 →

Facilitators verify payment headers and settle transactions on-chain. Production deployments require one. Choose based on chains needed and where you're deploying.

Facilitator	Chains	Description
Coinbase CDP	Base, ETH, SOL, POL, XRPL, XLM, +	Official facilitator. Most chains, deepest SDK integration. Primary choice for production.
Cloudflare x402	Base, ETH	Edge-native. Zero cold start, global CDN distribution. Best for latency-sensitive APIs.
Stripe Machine Payments	Base	Enterprise billing infrastructure: dispute resolution, fraud detection, compliance tooling.
Polygon x402	Polygon	Now leading Base in daily transaction count. MATIC fee subsidies for agentic payments.
Stellar x402	XLM	Fastest finality in the ecosystem. Added March 2026.
AsterPay	Base, ETH	EU/MiCA-compliant facilitator for European enterprise deployments.
Dexter DAO	Base, ETH, SOL, +	Largest x402 facilitator by volume. Handles ~50% of daily transactions. Chain-agnostic v2 SDK with client, server, React hooks, and Express middleware.
Ultravioleta DAO	EVM, SOL, NEAR, XLM, ALGO, SUI, +	Broadest multi-chain coverage in the ecosystem. 33+ networks including non-EVM chains. REST API with chain-specific settlement routing.

Full facilitator directory →

SDK	Language	Description
x402-typescript	TypeScript	Official SDK. Express, Hono, Next.js, Fastify middleware + x402-fetch client. The default choice.
x402 Python	Python	Official SDK. FastAPI middleware + async requests client.
x402-rs	Rust	Axum middleware + async runtime. Full EIP-3009 signing.
ag402	Go/Python	Multi-language. Wrap any API with ag402 serve, auto-pay with ag402 run. Solana USDC.
x402-mcp	TypeScript	Vercel AI SDK paidTool primitive. The cleanest path for AI SDK builders.
MoltsPay	TypeScript	Multi-framework (Express, Hono, Fastify, Next.js). Base + Solana + ETH. Drop-in replacement.
Mogami	Java	Production-ready Java x402 stack with SDK, server, console, and bundled MCP server. Fills the Java gap in the official ecosystem.
Solana Foundation Pay	TypeScript	Official Solana Foundation library for handling x402 and MPP payment challenges with user-authorized stablecoin signing. Updated May 2026.

Full SDK directory → · Framework middleware →

x402-native Model Context Protocol servers — AI agents pay per tool call, no API keys.

MCP Server	Category	Description
agentsvc.io MCP	General	100+ curated MCP tools, x402-gated. The hub for AI agent tooling.
x402-mcp	SDK	Vercel AI SDK paidTool primitive — for building MCP tools that monetize via x402.
IteraTools MCP	Automation	Task automation via x402. Sequential and parallel workflow execution.
EntRoute MCP	Data/Intelligence	Data intelligence and routing. Multi-chain analytics.
ShieldAPI MCP	Security	9 endpoints: breach check (900M+ HIBP hashes), URL safety, prompt injection detection.
MoltGuard	Trust	Agent trust scoring (0-100), Sybil detection, Ed25519 Verifiable Credentials. 7 MCP tools.
ToolOracle	Discovery	Real-time discovery of x402-enabled tools across the ecosystem. Agents find tools, tools get paid.
24K Labs Code Review MCP	Dev Tools	AI code review + security audit via MCP. Pay per PR. Runs in CI or interactively.

Full MCP server directory →

x402-payable APIs — pay per request, no subscriptions.

Service	Pricing	Description
24K Labs Code Review API	$0.01-$3.00	6 AI code services: explain, debug, review, security audit, automation, MCP blueprint. USDC on Base.
agentsvc.io	Per-call	100+ AI tools via a single x402-gated endpoint. One integration, full ecosystem access.
Strale	Per-token	LLM inference via x402. Pay per token, no subscription, no API key.
AIsa	Per-call	AI + crypto data fusion. Highest x402 transaction count of any API service in the ecosystem.
QuickNode RPC	Per-request	Pay-per-request RPC access to 130+ chains. No node management.
Arch Tools	Per-call	27 on-chain tools. Portfolio analysis, NFT data, market intelligence on Base.
ShieldAPI	$0.002–$0.05	Security intelligence: breach check, domain reputation, URL safety, prompt injection detection.
Valoria	—	Market intelligence: 90K+ indexed services, $148M+ tracked on-chain volume, revenue rankings.
Firecrawl x402	Per-request	Web scraping and search API with x402-gated endpoints and automatic on-chain USDC settlement. Coinbase CDP case study service.

Full API directory →

Tool	Description
x402-proxy	npx x402-proxy — cURL for x402 APIs. Auto-pays 402 with USDC on Base and Solana. MCP stdio proxy.
Paybound	Open-source governance proxy. Per-agent budgets, circuit breakers, SQLite audit trail. Drop-in @x402/fetch replacement.
Sentinel/Valeo	Enterprise audit layer. Budget enforcement, structured trails, real-time dashboard, public payment explorer.
ScoutScore	Trust scoring for x402 services. Monitors 1,700+ services with continuous health checks.
x402scan	Block explorer for x402 payments. Transaction search, payment requirement inspection, settlement status.
24K Labs GitHub Action	AI code review + security audit on every PR via x402 micropayments. Drop into any GitHub Actions workflow.
Agent Forensics	Claude Code cost observability. Analyzes JSONL session logs: per-model cost breakdown, cache efficiency, waste patterns. Free CLI.
x402station	Real-time monitoring and discovery for 20,000+ x402 endpoints. Continuous health probes every 10 minutes. MCP server for agent access included.
AWS CloudFront x402 sample	AWS-published reference implementation for monetizing content behind CloudFront and WAF with x402 and USDC payments.
LemonCake	x402 gateway + agent funding rail. 402 challenge returns accepts[] with buyUrl (human) and mintUrl (machine). Off-session top-ups via Buyer Key (hard-capped per-mint/daily/monthly). Stripe Connect Direct Charge — custody-free. MCP server on npm.

Full tools directory →

Service	Description
ShieldAPI	x402-native security API. Breach check (900M+ HIBP hashes), domain/IP reputation, prompt injection detection.
KaelAi	Wallet trust scoring 0-100 across 10 chains. Vet incoming/outgoing payment wallets before serving requests.
MoltGuard	Agent trust scoring, Sybil detection with funding cluster analysis, Ed25519 Verifiable Credentials.
Paybound	Governance proxy with circuit breakers and per-agent spending limits. MIT licensed.
SENTINEL	AML/CFT compliance. 77K+ sanctions entities (OFAC, UN, EU, PEP, Interpol), 159-country jurisdiction risk scoring.
PolicyLayer	Non-custodial spending controls. Daily limits, per-transaction caps, recipient whitelists — no private key custody.

Full security directory →

Project	Description
Coinbase Agentic Wallets	Native CDP wallets purpose-built for AI agents. Launched April 2, 2026. The reference implementation.
Cloudflare Agents SDK	Edge-native agent deployment with x402 built in. v0.4.0 adds x402 v2 migration (March 2026).
Agent.market	Official app store for AI agents. x402-powered transactions. Launched April 20, 2026.
WorkProtocol	Structured work marketplace for agents and builders. Escrow-backed jobs, on-chain reputation.
Nevermined + Visa	AI agents get delegated credit card spending authority via Visa Intelligent Commerce + x402 (April 2026).
World AgentKit	WorldID biometric identity + x402. Prove a verified human is behind every agent transaction. 18M+ verified humans.

Full ecosystem directory →

• 5-Minute Quickstart — Accept your first x402 payment.
• x402 Protocol Spec — Official open-source protocol by Coinbase.
• Coinbase Developer Platform Docs — Complete implementation guide and API reference.
• LearnAI x402 Course — Free, interactive, AI-guided. Covers the full payment flow, facilitator setup, and agent-to-agent payments.

• 24K Labs: x402 Explained — History and technical breakdown of HTTP 402.
• AWS: x402 and Agentic Commerce — Full x402 stack with AgentCore + CloudFront + Lambda@Edge.
• WorkOS: x402 vs Stripe MPP — How to choose in 2026.
• CoinDesk: Demand Still Unproven — Honest March 2026 assessment. Worth reading.

• x402 Foundation Discord — Official community. Protocol questions and announcements.
• x402 Builders Telegram — Active developer chat.
• GitHub Issues — coinbase/x402 — Technical Q&A and bug reports.
• Agent Economy Digest — Weekly newsletter covering x402, MPP, A2A, and agentic commerce.

Full learning directory → · Full community directory →

April 2026 snapshot.

Chain leaders: Solana commanded up to 88% of transaction count by volume. Polygon now leads Base in daily transaction count. Base leads in cumulative value transferred (~$21.5M).

Full market data → · Live dashboard → · On-chain analytics →

The README is the curated magazine — handpicked entries with context and tags. The directory/ folder is the exhaustive reference, with everything we know about across the x402 ecosystem.

• Facilitators — all hosted and self-hosted facilitators, hosted and self-hosted coverage tables.
• SDKs & Libraries — all SDKs by language: TypeScript, Python, Rust, Go, and more.
• Frameworks & Middleware — server middleware for Express, Hono, Next.js, FastAPI, Axum, and Cloudflare Workers.
• MCP Servers — the full MCP ecosystem, organized by category.
• APIs & Services — all x402-payable API services: AI, data, infrastructure, and production deployments.
• Tools & Utilities — CLI tools, monitoring, analytics, spending controls, testing, and discovery.
• Security & Compliance — audits, security tools, spending controls, trust scoring, and compliance.
• Ecosystem & Wallets — agent wallets, frameworks, marketplaces, and infrastructure.
• Learning Resources — quickstarts, tutorials, articles, news, and migration guides.
• Community — channels, newsletters, jobs, and events.
• Market Data — on-chain analytics, dashboards, enterprise adoption, and growth timeline.

gold-402 is curated, not exhaustive. Every entry earns its place.

See CONTRIBUTING.md for the curation standard, badge system, acceptance criteria, and submission process.

Quick rules:

• Entry must use the x402 protocol (HTTP 402 + X-Payment), not just USDC or general crypto payments.
• Live URL or public GitHub repo. Link must work.
• Last activity within 12 months, or carries a 24K Verified tag.
• One entry per pull request. Format: [Name](url) — Description starting uppercase, ending with period.
• Descriptions are factual. No marketing language.

Curated by 24K Labs
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x402.org • Protocol Spec • Coinbase Docs • Discord • Live Dashboard