awesome-x402

Awesome X402 

⚡ The Ultimate x402 Resource Hub - Everythng you need to build internet-native payments using HTTP 402. Perfect for AI agents, APIs, and micropayments. Build paywalls, monetize services, and enable autonomous agent payments with crypto/USDC. Zero fees, 2-second settlement.


Contents

• 🎯 Quick Start - Become an x402 Champion
• 📚 Official Resources
• 📖 Protocol Documentation
• 🚀 Quickstart Guides
• ⚙️ Protocol Implementations
• 🏭 Production Implementatdions
• 🛠️ SDKs & Client Libraries
• 🔧 Server Frameworks & Middleware
• 🏗️ Facilitators
• 💡 Example Applications
• 🎨 Use Cases & Patterns
• 🤖 AI Agent Integration
• Octodamus — AI market-intelligence API for agents. 33 pay-per-call x402 endpoints on Base ($0.01–$0.02, USDC, no keys): cross-venue derivatives facts, prediction-market odds, congressional trades, macro reference numbers, and a tokenized-equity suite (24/7 fair value, on-chain basis, and Arcus perp facts for Robinhood Chain). Ed25519-signed responses, MCP server, all endpoints cataloged in the CDP x402 Bazaar. (llms.txt) (Discovery) (MCP)
• 🔨 Tools & Utilities
• 🧪 Testing & Development
• 📚 Tutorials & Learning Resources
• 🎥 Videos & Talks
• 📝 Articles & Blog Posts
• 👥 Community
• 🌟 Ecosystem Projects
• 📊 Ecosystem Market Data
• 🚀 Migration Guides
• 🔒 Security & Audits
• 🔗 Related Protocols
• 🤝 Contributing
• Awesome Lists

The x402 protocol enables instant Blockchain payments over HTTP using the 402 "Payment Required" status code. This is your complete guide to mastering x402 and building the future of agent payments.

🚀 Start building in 5 minutes | ⚡ 2-second settlement | 💰 USDC on Base

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🎯 Quick Start - Become an x402 Champion

New to x402? Follow this path to mastery:

1. 5-Minute Quickstart - Accept your first payment.
2. Choose Your Stack - Find your language/framework.
3. Copy an Example - Working code you can run immediately.
4. Join the Community - Get help from other builders.

For AI Agents: Start with MCP Integration to enable Claude/other agents to make autonomous payments.

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📚 Official Resources

Core resources from the x402 protocol maintainers.

• x402 Protocol Specification - Official open-source protocol implementation by Coinbase.
• x402 Foundation - Protocol foundation website with overview and documentation.
• x402 Whitepaper - Technical deep dive into protocol architecture.
• Coinbase Developer Platform Docs - Complete implementation guide and API reference.
• Protocol Specifications - Detailed technical specifications.
• Payment Schemes - Different payment flow types.
• EVM Implementation - Ethereum Virtual Machine specifics.

📖 Protocol Documentation

Essential documentation for understanding and implementing x402.

• How x402 Works - Complete payment flow explanation with diagrams.
• Payment Requirements Schema - JSON structure for payment requests.
• Payment Payload Format - Client payment submission format.
• Verification & Settlement - Payment validation process.
• EIP-3009 TransferWithAuthorization - Gasless transfer standard used by x402.
• HTTP 402 Status Code - The long-dormant HTTP status.

🚀 Quickstart Guides

Get started with x402 in minutes.

• 5-Minute Quickstart for Sellers - Accept your first payment.
• Buyer/Client Setup - Make automated payments.
• One-Line Integration - Add payment middleware in a single line of code.
• Base Sepolia Testnet Setup - Get test USDC and start testing.
• Production Deployment Checklist - Go live on Base mainnet.

⚙️ Protocol Implementations

Official and community implementations of the x402 protocol.

Go

• coinbase/x402 ⭐ Official - Complete Go implementation.
• Core protocol types and utilities
• Payment verification and settlement logic
• Multi-chain support (Base, Base Sepolia, Ethereum, Solana)

TypeScript/JavaScript

• x402-typescript ⭐ Official - Complete TypeScript implementation.
• Core protocol types and utilities
• Payment verification and settlement logic
• Multi-chain support (Base, Base Sepolia, Ethereum, Solana)
• x402-data-api - HTTP 402 micro-payment data API with Base chain USDC payments. 16 developer data tools including email validation, DNS lookup, WHOIS, SSL check, and IP geolocation with x402 payment integration.

• x402-express - Express.js middleware example.
• hive-rosetta ⭐ Community - Open EIP-3009 transferWithAuthorization signer. Zero ethers/web3 dependency, primitives-only EIP-712. Returns wire shape {scheme: 'exact', network: 'eip155:8453', payload: {authorization, signature}}. Same package name on PyPI. (GitHub)

Python

• x402 ⭐ Official - Python SDK on PyPI.
• FastAPI middleware integration
• Requests session with auto-payments
• Payment requirement generation

• ag402 ⭐ Community - Payment layer for AI agents using x402. Wrap any API or MCP server with a USDC paywall (ag402 serve), or let agents auto-pay (ag402 run). Solana USDC, ~0.5s settlement, non-custodial, 648+ tests. Glama

• x402-pay - Call any x402 API with one API key. Routes requests through a broker that handles on-chain payment. httpx-based, optional wallet mode for direct payments. (GitHub)
• hive-rosetta ⭐ Community - Direct port of the Node hive-rosetta signer. Byte-identical EIP-712 digest across both languages. Returns {scheme, network, payload} matching CDP /verify and /settle. (GitHub)

Rust

• x402-rs ⭐ Community - Production-grade Rust implementation.
• Axum middleware
• Reqwest client wrapper
• Self-hostable facilitator
• Multi-chain support
• x402-axum - Axum web framework integration.
• x402-reqwest - Reqwest HTTP client wrapper.

🏭 Production Implementations

Real companies using x402 in production with proven scale and transaction volumes.

• AfaAgent x402 API Suite - 43 production-grade x402 APIs (DeFi, wallet security, AI/ML, developer tools, SEO) with pay-per-call USDC micropayments on Base. Includes MCP server with 43 tools (Streamable HTTP), OpenAPI 3.0 spec, llms.txt, and agents.json for AI-agent discovery. Premium services up to .99/call. (Discovery | MCP | GitHub)
• Langston Search - Autonomous AI agent's pay-per-query web search API (Brave, falls back to SerpAPI), live on Solana mainnet. 0.02 USDC per query via x402 exact scheme. (Discovery)

High-Volume Production Deployments

• Kaisha — Japan Company Registry API - Official-registry data for all 5.76M Japanese corporations + 5.05M invoice registrations from National Tax Agency open data: resolve company names / corporate numbers (法人番号) to registry records, verify Japan invoice registration numbers (適格請求書/T+13-digit) against the NTA dataset, and compute Japanese business days & national holidays. $0.002–$0.01 USDC per call on Base & Solana via CDP facilitator. No API keys. MCP: npx -y kaisha-mcp. (OpenAPI | llms.txt | Discovery | x402scan | npm | GitHub)
• MoneyMachine x402 Suite - Agent-payable APIs on Base USDC: GigRadar (Superteam/r/forhire/HN/Freelancer gigs $0.15), LightHouse-lite web vitals ($0.12), DocClerk PDF field extract ($0.25), CrawlJudge ($0.03), Axe-lite a11y ($0.08), HTML scrape ($0.05). Self-facilitator, open source. PayTo 0x5Cc3c4E5020Ec3D81E392658eFe7b27966872CE7.

• J-sey Data API - Pay-per-call data API on Base with 18 endpoints for wallet lookups, web scraping, crypto prices, and DeFi yields; $0.002 per call via x402.
• Fleet x402 Microservices - Two agent-payable AI services on Base: SEO Audit ($0.05 USDC) and Competitive Intel Pack ($0.50 USDC). Instant response, zero auth required, machine-readable JSON. (Discovery)
• Arch Tools - 58 production API tools for AI agents with x402 payments built in. Web scraping, AI generation, crypto data, OCR, browser automation, MCP compatible. Patent-pending agent auth. 15+ chains supported. (GitHub)
• Bounty API - Agent-native API marketplace with x402 micropayments. 7 live endpoints. Free + paid ($0.005-0.01 USDC on Base). MCP: npx bountyapi-mcp. Verified on-chain. (GitHub: vncent786/bounty-api)
• PayAPI Market - First marketplace for x402-powered APIs. 10 APIs, 65 endpoints: UK property data, email verification, company enrichment, postcode lookup, currency/crypto rates, screenshots, DNS intelligence, web scraping, IP geolocation, QR codes. $0.001–$0.01 USDC on Base per request. MCP server discovery. (GitHub)
• LogicNodes - Live A2A marketplace with 619 deterministic microservices payable per-call in USDC. No signup — agents pay via x402, results include SHA-256 trust hashes. 8 chains: Base, Solana, Arc, Arbitrum, Optimism, Polygon, Ethereum, World Chain. Tiers: Micro $0.001 · Basic $0.05 · Standard $0.15 · Premium $0.50 USDC. MCP: npx @logicnodez/mcp-bridge | Python: pip install logicnodes-m2m. (npm) | (PyPI) | (Agent Guide) | (llms.txt)
• JarvisClaw - x402 payment gateway bridging 200+ LLM providers (OpenAI, Anthropic, Google, DeepSeek, etc.) to on-chain USDC micropayments on Base. HD wallet per-user isolation, real-time exchange-rate pricing, three-tier caching marketplace, circuit breaker fault tolerance, and multi-chain fallback. Pay-per-token with sub-cent granularity — no API keys, no subscriptions. MCP-native with intent resolution for autonomous agents. (Docs) | (SDK: Python) | (SDK: Go)
• Superhighway - Web search API for AI agents, live in production on Base mainnet. Five tools: search, news, images, scrape, and one-call deep research. $0.001 USDC per call. MCP-compatible: npx -y superhighway-mcp. Free API key available.
• Rug Munch Intelligence - 117 MCP tools + 19 REST API endpoints for crypto data: DexScreener, Birdeye, GMGN, Arkham, Nansen, Dune, Jupiter, DeFiLlama, and more. $0.001-$0.02 USDC per call. Multi-chain (Base + Solana), free trial (1 call/IP), OpenAPI spec, no API keys, no signup. (Discovery | OpenAPI | MCP Catalog | Solana | GitHub)
• AIsa - Leading x402 payment processor with 10.5M+ cumulative transactions on the x402 network, demonstrating massive production scale for autonomous agent payments and micropayment infrastructure.
• Bitget - Major cryptocurrency exchange integrating x402 for seamless payment flows, enabling instant settlements and gasless transfers for trading operations.
• AI Rook — Trading Intelligence + General Agent APIs — 22 endpoints across 4 categories: trading intelligence (market pulse, trade signals, order flow, liquidation heatmap, AI chart analysis, backtests, smart money), web utilities (web-fetch, search, screenshot, IP lookup, email validate, QR, PDF extract, domain lookup), AI inference (summarize, extract-data, classify via Queen MiniMax M2.7 456B MoE), image generation (FLUX.2-klein). Pay-per-call $0.002–$2.00 USDC on Base via x402-atm v3.0. No API keys. No signup. EscrowV2 onchain settlement. (OpenAPI | x402 manifest | MCP tools)
• Stratalize — 100+ attested financial, healthcare, real estate, and governance intelligence tools with x402 micropayments on Base. Ed25519-signed outputs on every synthesis. $0.02–$1.00 USDC per tool call. MCP registry: com.stratalize. (x402.json)
• Coinbase Developer Platform - Official CDP implementation processing hundreds of thousands of transactions weekly with enterprise-grade reliability and 2-second settlement times.
• Cloudflare Workers - Edge computing platform with x402 integration serving global distributed payment verification at scale across 300+ data centers.
• GigSoul AI Research Agent - 23-endpoint AI research API for consultants: SEC filings, earnings calls, competitor analysis, market research, and document intelligence. - Cloudflare Workers - Edge computing platform with x402 integration serving global distributed payment verification at scale across 300+ data centers..01 USDC per call on Base mainnet. Wallet: x2b6c16fb557291b98222a570526ff2430848b723. (OpenAPI | .well-known/x402.json)
• Zuluworks AI — Sovereign Shaka PQC-Shield Factory - Autonomous A2A factory on Cloudflare Workers selling 5 post-quantum-hardened agent services via x402 USDC on Base L2: quantum-shield ($0.10, ML-KEM-768 PQC tunnel — NIST FIPS 203), kya ($0.01, agent trust scoring), browser-rendering ($0.03, headless browser extraction), memory ($0.05, semantic recall on a PQC knowledge index), workers-ai ($0.02, Llama 3.1 inference). All settlement routed through Coinbase CDP facilitator for Bazaar indexing. (Agent Card | Bazaar Manifest | MCP | Sitemap)
• Suede Agent Studio - Visual agent-flow builder that publishes flows as pay-per-call x402 endpoints (USDC on Base). Machine-readable catalog at /api/catalog; each agent exposes /.well-known/x402, /.well-known/agent-card, and /a2a. Two live agents: Daily Lyric Drop ($0.10 USDC) and The Ownership Loop ($0.25 USDC).
• Satelink RPC - Pay-per-call blockchain RPC for agents: one $0.10 USDC settlement on Base buys a 1,000-call Polygon JSON-RPC bundle — no signup, no subscription. HTTP 402-native with spec-compliant payment requirements past the free tier (500 calls/day/IP); wallet-signature registration for prepaid credits at $0.00003/call. Machine-readable manifest, live pricing, market comparison and capability APIs. (Manifest | Pricing | Compare)
• Agent402 - Open-source, self-hostable x402 + MCP server with ~1,100 deterministic web tools: browser rendering, web search, PDF/image/OCR/audio, geo, live data (FX, weather, USGS, gov-data), network truth (DNS/TLS/WHOIS), crypto/x402 helpers, ~1,040 pure-CPU utilities. Dual-rail: free via proof-of-work, paid via USDC on Base/Polygon/Arbitrum (x402 v2 with Bazaar discovery). No LLM in the serving path — every tool re-tested against its own example before each release. Ships a hosted MCP connector (/mcp), an open x402 index (Find · Route · Leaderboard — the first public on-chain ranking of x402 sellers by settled USDC volume), and the agent402-tollbooth pay-per-crawl gate for the publisher side. MIT. (MCP) (OpenAPI) (Discovery) (GitHub)
• Asset Forge - Vercel-serverless micro-API for AI agents that returns SVG OG cards, robots.txt + sitemap.xml + llms.txt bundles, initials avatars, and shields-style status badges. Six endpoints including /api/payment-required that publishes an x402-spec at runtime. USDC paid on Base at $0.01 per call (recipient 0x833ca7dcdb6a681ddc0c15982ef0d609bceb3a5e). Free demo path with ?demo=1 (3,000/day shared quota). HMAC-signed mode for per-key quotas. (Docs | GitHub)

• Tollbooth - 37 paid x402 MCP tools: OSINT feeds (SEC 8-K, FRED, GDELT, flights, quakes, air quality, GitHub trending, HN), prediction market scans (Polymarket, Kalshi cross-platform arbitrage), web intel (scrape, stack detection, lead scoring), and agent security (threat intel, supply chain IOCs). $0.01–$0.10 USDC on Base. No account required. (agent.json | x402 | OpenAPI)
• GoldBean API — 146+ AI endpoints including Baidu OCR, Translation, TTS, LLM Chat with x402 micropayments on Base. From ### Production Success Metrics.01/call for premium AI. MCP server at mcpize.com/mcp/goldbean. (GitHub)
• Signal Oracle - 360 agent-payable change-intelligence feeds on Base: DepWatch (breaking-change verdicts for any npm/PyPI/Maven/crates/RubyGems package), RegWatch (55 regulatory verticals — data privacy, AI governance, securities, tariffs, PFAS, and more), TariffWatch (US import-duty changes + combined §301/§232/IEEPA effective rates), CVEWatch/KEVWatch (new and actively-exploited vulnerabilities), SanctionsWatch (OFAC SDN), SEC EDGAR event watches (M&A, bankruptcy, going-concern, cyber incidents), Treasury/macro indicators, plus premium one-call verdict endpoints (DepAudit, PackageHealth, TariffAudit, ComplianceAudit, VendorRisk). $0.01–$1.00 USDC per call, free samples, machine-readable JSON. (Discovery | MCP)
• Tollbooth - 56 verified financial, tax & legal calculators for AI agents (net-pay, federal/state income tax, self-employment & estimated tax, capital-gains, LLC & entity comparison, mortgage/loan/refinance, retirement/RMD/Social-Security, HSA/FSA, crypto/DeFi, sales tax, plus $1 bundled tax-estimate reports). Every answer ships its 2026 primary source (IRS/SSA), a formula trace, and a reproducible SHA-256 hash — plus a free golden-vector self-check (/v1/golden/:id) so an agent can re-verify the math without trusting the server. $0.02–$1.00 USDC on Base mainnet (x402 v2 + CDP Bazaar discovery). No API keys, no signup. MCP: npx tollbooth-x402. (OpenAPI | Catalog | Agent Card | llms.txt | Verify | npm)
• MIDAX402 - Pay-per-query semantic search over 300+ curated x402 ecosystem entries: protocol mechanics, facilitators, ERC-8004, and MCP/A2A integrations. Four tiers from $0.03 to $0.25 in USDC on Base Mainnet via the CDP Facilitator, no signup or API key required. (OpenAPI | Agent Card)
• Yield.xyz AgentKit - MCP server for DeFi yield discovery & execution across 80+ networks (staking, lending, vaults, RWAs); 2,988+ opportunities. Free discovery tier; paid tools (wallet balances, unsigned enter/exit/manage tx building) at $0.001 USDC per call on Base. No signup — agents pay via x402. (Discovery)
• ToolSnap MCP — 28 context-efficient MCP tools for AI agents: web extraction, data processing, SEO, image processing. Flagship fetch_extract benchmarked at 98.1% token reduction (53,820 → 2,001 tokens, saving ~$0.156/call at Sonnet pricing). x402 v2 on Base with EIP-3009 transferWithAuthorization. Dual payment: pay-per-call $0.02 USDC or prepaid ($0.50 deposit → $0.01/call off-chain, no per-call gas, no 402 round-trip). 27 tools free, no API keys. Cloudflare Workers edge-native, 0ms cold start. Glama A rated. (GitHub | Glama)

• Veles Finance Agent - Production FastAPI + LangGraph financial analysis service with x402 paywall on Base. Provides SEC 10-K extraction, stock due diligence, and Kelly Criterion at $0.01-$0.05 USDC per request. (Discovery)

• Denpyo — Japan Invoice & Receipt Reader - OCR Japanese invoices (請求書) and receipts (領収書) into structured JSON — vendor, line items, 8%/10% consumption-tax breakdown — with the qualified-invoice registration number (T+13 digits) verified against Japan's National Tax Agency registry in the same call. $0.01-$0.04 USDC on Base & Solana. Failed analyses are not charged. MCP: npx -y denpyo-mcp. (OpenAPI | llms.txt | GitHub)
• BridgeNode - DeepSeek V4 Flash v2 inference via x402 on Solana. No registration, no API keys. Per-call pricing at $0.001 USDC via prepaid deposit. MCP-compatible. (Discovery | OpenAPI)
• Appraxa IP Valuation - Standards-based patent valuation (DIN 77100 relief-from-royalty), calibrated on professional valuation cases. From $0.99 per valuation, USDC on Base.

• Venture NL Open-Data - Dutch government open-data API for AI agents: RDW vehicle records (kenteken lookup), BAG addresses and postcode bulk lookup, reverse geocoding, vehicle brand search, and APK expiry alerts. Free previews on every route; $0.001-$0.005 USDC per call on Base. CC0/CC BY licensed sources with attribution in every response. (OpenAPI | .well-known/x402 | pricing)
• mdapi - HTML-to-Markdown API for AI agents: POST a URL or raw HTML, get clean LLM-ready Markdown (Readability article extraction, tables preserved); POST /extract returns structured JSON (title, byline, links, images, meta). $0.005 USDC per call via x402 on Base, no signup, no API key. (OpenAPI)
• chainpulse - Real-time crypto market data API for AI agents: POST /price (aggregated USD spot prices with confidence score, incl. Base ERC-20s by address), POST /gas (live gas + USD transfer cost on Ethereum/Base/Arbitrum/Optimism/Polygon), POST /tvl (DeFi protocol TVL via DefiLlama slugs). $0.001 USDC per call via x402 on Base, no signup, no API key. (OpenAPI)
• Lazaretto - Pre-install security verification for AI agent skills, tools, and npm packages. Free, no-key lockfile check: POST a package-lock.json, yarn.lock, or pnpm-lock.yaml and every pinned version is matched against published malicious-package advisories in one call, catching compromised releases like chalk@5.6.1 and @ledgerhq/connect-kit@1.1.6 while leaving their clean releases alone. Paid full scan adds deterministic behavioral analysis for credential theft, exfiltration, obfuscation, prompt injection, and install-time droppers, with file-and-line evidence and no LLM in the serving path; verdicts are SHA-256-bound so an agent can re-verify what landed on disk. $0.03 USDC on Base (x402) or prepaid bundles down to $0.016/scan. Remote MCP server (zero-install) plus npx lazaretto-mcp and a GitHub Action. (OpenAPI | Discovery | Agent Card | MCP)
• Utilia Solana Preflight - Deterministic Solana transaction simulation, confirmed-transaction diagnostics, priority-fee, and SPL token-risk APIs plus bounded PDF and audio transforms, payable in USDC through x402 v2 at $0.002-$0.01 per call. No signup or API key; hosted MCP settles on Solana and explicit HTTP aliases support Base. Includes OpenAPI, x402 discovery, and an on-chain Solana agent identity. (Discovery | MCP | OpenAPI | On-chain identity)
• SuVerse Pay - Payment gateway + API catalog with ~490 paid endpoints on one origin: crypto market data, Polymarket smart-money verdicts, token-safety forensics (Base + Solana), macro/gov datasets, and an x402 endpoint liveness probe. $0.05–$0.75 USDC per call, multi-chain settlement (Base + Solana + Cosmos Noble) via a self-hosted facilitator, no API keys or signup. (OpenAPI | Catalog | MCP | Buyer SDK)

• Studio X - Production image and video generation API with 11 models, per-generation x402 pricing, and USDC settlement on Base. (OpenAPI | x402 discovery)

Production Success Metrics

Key Performance Indicators:

• 10.5M+ transactions - AIsa cumulative network volume
• 500K+ weekly transactions - Ecosystem-wide payment activity
• $180M+ market cap - Combined ecosystem valuation
• 2-second settlement - Average production payment finality
• 10,000%+ growth - Year-over-year transaction volume increase

Multi-Chain Production Support

| Chain | Status | Facilitators | Settlement | Production Examples | | ------------- | ----------- | -------------------------- | --------------- | ------------------------- | | Base | Production | Coinbase CDP, Cloudflare | Instant (2s) | AIsa, Bitget, thirdweb | | Base Sepolia | Testnet | Coinbase CDP | Instant (2s) | Development, Testing | | Ethereum | Production | Cloudflare | Deferred | Enterprise DApps | | Solana | Production | Community | Instant (<1s) | High-frequency trading | | BNB Chain | Production | Pieverse | Instant (2s) | Gaming, NFTs | | Radius | Production | Community | Instant (<1s) | Micropayments |

Data & Social APIs

• API Witchcraft (API_Dalla) — 19 hands-off pay-per-call APIs for AI agents, settling USDC on Base via Coinbase CDP Facilitator. Covers compliance (VAT/VIES validation, e-invoicing mandates, OFAC/EU/UN/UK sanctions + PEP screening, US export-control ECCN, FX rates, EPR fees), geo (IP lookup + VPN/Tor detection), crypto (prices, trending, collective arbitrage), agent-security (AgentDojo scenarios + SPAR scoring), web (scrape-permit check, BJJ lineage), lifestyle (digital-nomad visa index, weather micro-betting), and x402 seller tooling (reconcile, balance). $0.002 USDC/call, no API keys, no signup. (llms.txt | openapi.json | agent.json)
• KR-DART Events - Real-time Korean corporate disclosure (DART) events for AI agents. Korea's ~2,500 daily filings polled every 15s, classified into 31 categories with importance scores, English labels and English company names. Cursor-delta stream, material-only screen, per-company timelines. $0.002-$0.01 USDC on Base or Solana via x402 (Coinbase CDP facilitator, Bazaar discovery on every 402). No API keys, no signup. (llms.txt) (OpenAPI) (GitHub) (MCP)
• Tinstop Website Intelligence API - Pay-per-call domain security and performance audits on Base: DNS, SSL/TLS, HTTP security headers, SPF/DKIM/DMARC, and PageSpeed. $0.02–$0.10 USDC via x402 v2 (EIP-3009). (OpenAPI | Discovery | llms.txt)
• x402-seller - Decision-ready crypto market + on-chain intelligence for AI agents. 13 keyless pay-per-call endpoints on Base mainnet (no account, no API key): verdict-first ANSWER endpoints — /vet (one-call token due-diligence → clear/caution/avoid), /brief (market regime → risk_on/off), /screen (batch rug-check up to 8 tokens, sorted safest-first) — plus rug/honeypot safety with green+red flags, perp funding/OI, DEX pools, new launches, prices, and stocks. $0.001–$0.03 USDC. Redundant keyless facilitators (no CDP key needed). (OpenAPI | Discovery | llms.txt | GitHub)
• Sirenic - Official French & European company data for AI agents, from open government sources (INSEE/INPI, Etalab 2.0). Search 30M French companies, full profiles, KYB files with sanctions screening (5 official lists, scored matches), filed financials, BODACC legal alerts, sector benchmarks, failure-risk score, AI health summaries, PDF reports; European registers (BE/UK/NO/EE/LV) + worldwide GLEIF in one unified schema. $0.001–$0.50 USDC per call on Base mainnet via x402 v2 — no account, no API key; failed requests are never charged. MCP server with 25 tools. (llms.txt) (OpenAPI) (MCP) (Examples)
• Agent Utility API - 8 pay-per-call utility tools for AI agents in USDC on Base via x402 (CDP facilitator), served over both HTTP and MCP: company enrichment ($0.01), email verification ($0.01), Chainlink crypto/FX prices ($0.005), webpage-to-clean-text ($0.02), structured PDF extraction ($0.05), X/LinkedIn profile lookup ($0.05), Amazon/KDP market data ($0.05), and YouTube transcription ($0.10). Bazaar discovery extensions on all 402 responses; listed in the official MCP Registry. No API keys, no signup. (Discovery) (llms.txt) (MCP)
• afriref / latamref / asiaref / euroref / usaref / ausref - Verified government reference data for 58 countries across six continent-scoped brands on one engine: central-bank policy rates, VAT, minimum wages, CPI inflation, corporate & personal income-tax brackets and public holidays — 406 series, every value cited to its official gazette, central-bank or statistics-office source with effective dates and staleness flags. Africa 22 (incl. all 7 WAEMU members on one reconciled BCEAO rate and all 6 CEMAC members on one reconciled BEAC TIAO), Latin America 16, Asia 10, Europe 6, North America 2, Australasia 2. Honest structural nulls where no figure exists rather than a fabricated one — the US has no federal VAT, Malaysia levies SST and not a VAT at all, Italy and Bangladesh have no national statutory minimum wage, Singapore runs an S$NEER band instead of a policy rate, Argentina abolished its policy rate. From $0.005 USDC per series call (x402 v2, CDP-facilitated on Base, Bazaar discovery); free catalog and public-holiday endpoints; HMAC-signed change-alert webhooks; computed answers (VAT breakdown, minimum-wage compliance, working days, income tax, gross-to-net payroll); and cross-border VAT determination for digital-services sellers (EU, UK, South Africa), each rule cited to the statute. No API keys, no signup. (Discovery) (llms.txt)
• ZARONIA Verify - Independent, audit-grade recomputation of South African ZARONIA-linked FRN and money-market coupons against the SARB Compounded ZARONIA Index: full workings, a verdict at 0.05bp tolerance, and provenance; reproduces BESA/bank acceptance values to 4dp. From $0.005 USDC (index point) to $0.25 (FRN coupon verification), x402 v2 on Base; free conventions and latest-index endpoints. (Discovery) (llms.txt)
• WebIntel - EU/NL-focused web & business intelligence for AI agents on Base. 10 pay-per-call endpoints ($0.005–$0.25): page-to-markdown, page metadata, sitemap discovery, tech-stack detection, DNS & email-provider intel, EU company enrichment with live VIES VAT validation + Dutch KvK/BTW, standalone EU VAT validator, domain registration/age (RDAP), a 0–100 B2B lead score, and a full domain dossier. USDC on Base via Coinbase CDP facilitator, Bazaar discovery on every 402, no API keys or signup. (Catalog) (Discovery) (OpenAPI) (llms.txt)
• PARADIGMA Crypto Feed - 26 pay-per-call crypto data endpoints for AI agents: scored airdrop/quest opportunities (Galxe), trending tokens, spot prices for 25 coins, top stablecoin yields, chain TVL rankings, Fear & Greed index. $0.005-$0.01 USDC per call on Base mainnet via CDP facilitator (x402 v2, Bazaar discovery extension). No API keys.
• base-token-intel - Pay-per-call Base L2 token intelligence for trading agents: newly created DEX pools (Uniswap v2/v3, Aerodrome) with liquidity, ERC-20 risk reports (owner/renounce, bytecode red flags), and deployer intelligence (deployer wallet age, tx count, throwaway-wallet flags — a rug-pull signal not in free APIs). $0.01–$0.03 USDC on Base via Coinbase CDP facilitator, no API keys, no signup. (Discovery | OpenAPI)
• Voda Astro Data API - Astrology full charts, transit/mundane aspect time series, and global location data for AI agents. Flat $0.50 per request, x402 v2 USDC on Base mainnet plus MPP (Stripe/Tempo) on the same routes. No API keys, no signup. (OpenAPI) (llms.txt) (Agent Card)
• NIMATRON COT - CFTC Commitment of Traders positioning across all 438 futures markets (disaggregated + TFF): trader-category breakdowns, week-over-week changes, 52-week COT index, crowding-extremes screener, spec-flow rankings, and sector views. Live previews in every 402 response. $0.05–$1.00 USDC per call on Base via CDP facilitator, no API keys. Updated every Friday within hours of CFTC release. (Discovery) (llms.txt) (Catalog)
• enrich-gate - Pay-per-call gateway for AI agents: Google web search ($0.01), Exa neural search ($0.012), Firecrawl URL→markdown scraping ($0.015), and LLM inference ($0.005). USDC on Base via the Coinbase CDP facilitator — no accounts, no API keys, no subscriptions. MCP server included so any MCP agent can use it with just a funded wallet. (Catalog) (GitHub)
• GAUGE — Verifiable Environmental Signals - Flood-risk & river-anomaly checks for AI agents on Base. Real-time US river water level (gage height), streamflow & flood stage vs official USGS/NOAA thresholds, plus 5-year seasonal statistical anomaly (percentile/strata) and record_hash + OpenTimestamps verifiable provenance. Also air quality (US AQI/PM2.5) and precipitation (rainfall/drought). Skill $0.05; add-ons $0.01–$0.03; region $0.10; census $1. Free raw + sample, no API key. x402 USDC on Base. (agent.json | llms.txt | Sample)
• SNTL — Helium Intelligence - Live x402 agent for real-time Helium/Solana DePIN threat classification, anomaly scoring, wallet intelligence & forensic event chains over a 600K+ event datalake. 26 pay-per-call skills at $0.01 USDC (Solana mainnet, gasless via PayAI), first tier free, no signup. Agent-card: https://a2a.sntl.site/.well-known/agent-card.json · Source: github.com/substreambc/my-agent
• x402-endpoints - 40 pay-per-call x402 endpoints for AI agents on Base/USDC: official EU/global registries (GLEIF LEI, VIES VAT, UK Companies House, INSEE Sirene, EUR-Lex, ECB, BODACC, CVE, openFDA), crypto pre-trade safety (Solana rug/honeypot checks, perp funding/OI radar, DEX-CEX spread), and agent decision endpoints — due-diligence dossiers, structured analysis reports, action preflight clearance with a signed Ed25519 ClearancePacket, output QA + rewrite, prompt-injection/content-security scans, OFAC wallet screening, and x402 seller-trust. Every decision endpoint returns a structured machine-readable verdict + an offline-verifiable signed receipt. $0.005–$0.50 USDC via the Coinbase CDP facilitator, no API keys, no signup. (Discovery | Agent Card | llms.txt | MCP | GitHub)
• botsmith - Pay-per-call web and on-chain intelligence for AI agents, no API keys. read (any URL to clean, boilerplate-free markdown, $0.003), dossier (full domain intelligence in one call: DNS, SPF/DMARC, RDAP registration, live TLS cert, $0.004), and onchain (EVM address due-diligence: contract-or-wallet, scam and reputation flags, balances, verification, deployer, on Base/Ethereum/Optimism, $0.004). USDC on Base via the Coinbase CDP facilitator, x402 v2 with Bazaar discovery. (Discovery | Catalog | MCP)
• TerraDeed Scrape API - Pay-per-use web scraping and structured JSON extraction. $0.01/$0.05 USDC on Base mainnet. LLM-ready markdown, JS rendering, schema-driven extraction. (GitHub)
• EZ-Path — Best-execution pay-per-request DEX meta-router. Races 10+ venues (0x, ParaSwap, Aerodrome, Uniswap V3, Curve, Balancer, 1Inch, CoW Swap, Synthetix) concurrently on Base mainnet. Three tiers: basic ($0.03, 0x only), resilient ($0.10, dual-lane race), institutional ($0.50, all venues). Strict agent wallet drain protections with hardcoded toll address validation. x402 v2 USDC on Base. Supports ElizaOS plugin integration. (Discovery) (npm) (GitHub)
• Sentinel Intelligence API - Pay-per-brief fintech and AI governance intelligence. BNPL/embedded finance and AI compliance research briefs at $2 USDC; on-demand research on any topic at $10 USDC. CDP-facilitated settlement on Base mainnet. (Discovery) (GitHub)
• x402deploy - Two pay-per-call tools for AI agents on Base mainnet: web_search ($0.005, organic web results as JSON) and read_url ($0.005, fetches a page → cleaned main text). Keyless USDC settlement via the xpay facilitator — no API key, no accounts, no CDP. MCP server: npx -y github:minhthai1995/x402-search-mcp. (MCP) (serp) (read)
• CrowdPull public-data API - Capped public-data jobs for AI agents: marketplace leads, rental comps, product reviews, hiring signals, and row enrichment. USDC on Base via x402 with no separate account or API key. (OpenAPI | Discovery | Directory | MCP)
• Groundcheck - Claim grounding and delivery attestation for AI agents: machine-verified verdicts (supported/refuted/unverified) with confidence scores and cited sources, grounded against live web sources. Signed offline-verifiable receipts bind an x402 payment to what was actually delivered. Free single-claim tier; paid endpoints $0.005-$0.05 USDC on Base via the Coinbase CDP facilitator, x402 v1+v2 with Bazaar discovery on every 402. No API keys, no signup. (Discovery) (OpenAPI) (MCP on npm) (GitHub)

• OSF — Open Source Filings - Provenance-stamped public-domain US government and scientific data for AI agents. SEC EDGAR, FRED, NOAA, openFDA, USGS, Crossref, and more — every record ships with a provenance URL back to its authoritative primary source. Pay-per-record x402 USDC on Base, $0.05–$0.50. Paid MCP server + listed in the official MCP Registry. No API keys, no subscriptions. (MCP | MCP Registry | Bazaar health)
• Touchstone - A deterministic-truth suite for AI agents: 14 pay-per-call endpoints whose answers reproduce a named public authority byte-for-byte, so an agent can re-run and verify an answer instead of trusting the seller. Physical truth — /sky (Sun/Moon/planet alt-az, rise/set/transit, twilight, phase; JPL DE421, ~1 arcsec) and /field (magnetic declination/inclination/intensity + secular variation; NOAA WMM2025, 100/100 on NOAA's published test values). Time — /time (IANA tzdata) and /prosody (CMUdict syllables/stress/meter). Trust primitives — /timestamp, /sealed (timelock encrypt-to-the-future), /random/proof (drand-backed provably-fair draws), /verify/sig (ecrecover, EIP-191/712). Text & code workbench — /unit (NIST SP 811 factors), /readability, /syntax, /proofread, /cite (APA/MLA/Chicago/BibTeX), /diff. Every answer is signed; same input → same bytes. USDC on Base via Coinbase CDP facilitator; x402 v2 with Bazaar discovery on every 402. No API keys, no signup; free schemas + samples at / and each /<route>/example. Prices $0.001–$0.003. (free library on PyPI) (GitHub)

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• AI Growth - Real-data feeds for AI agents, settling via Coinbase CDP Facilitator on Base mainnet. Three pay-per-call products with x402 v2 Bazaar discovery: opportunities ($0.01, Claude-scored AI revenue opportunities from real GitHub bounties), verification ($0.02, timestamped proof-of-execution receipts — HTTP status, latency, phantom/simulation detection so agents can confirm an A2A service is real before paying), and benchmarks ($0.02, real endpoint liveness & latency measurements for routing). All data sourced from verified live calls — no synthetic data. No API keys, no signup. Select product via ?product=<id>. (Discovery)
• MiroShark - Universal swarm-intelligence engine exposed as a paid API: POST a scenario to the /x402/run surface and hundreds of grounded LLM personas simulate Twitter, Reddit, and a prediction market hour-by-hour, returning an analytical report. USDC on Base via x402. (GitHub)
• wrapper-agency APIs - Suite of 8 pay-per-call utility APIs settled in USDC on Base via x402 (free tier + one key for all): historical FX rates, color conversion, timezone/DST, fake/mock data, cron explainer, QR codes, data-format conversion, and encode/hash. (FX) (Color) (Timezone) (Mock data) (Cron) (QR) (Data format) (Encode)
• Crest x402 Data - x402 agent profiling plus crypto market data. Profile any x402 buyer or EVM wallet (whale score, behavior cluster, x402 spend graph, risk), plus prices, gas, DeFi, derivatives, NFTs, and DEX pairs. $0.002-$0.90 USDC on Base via Coinbase CDP facilitator, no API keys. (Agent Card | llms.txt | l402-services)
• Pyrimid - Agent commerce protocol for x402-style USDC payments on Base. Includes on-chain vendor/product registry, payment router, affiliate attribution, MCP endpoint, and live catalog API for agent-discoverable paid services. Current mainnet proof: 3 vendors, 8 on-chain products, 4 routed test payments. (Catalog) (MCP) (Skill)
• Polybot Arb Intelligence — Real-time cross-platform prediction market arb data (Polymarket+Kalshi+Myriad). x402 USDC on Base. Live API

• Bismuth - Utility API suite for AI agents on x402. 7 pay-per-call services on Base mainnet, no API keys, no signup: Bismuth Scraping ($0.02 scrape / $0.10 BFS crawl — Playwright, SSRF-protected), Bismuth Screenshot ($0.01, Playwright PNG/JPEG), Bismuth PDF Extraction ($0.01, OCR + vision mode), Bismuth Email ($0.01, Resend + CC/BCC/attachments), Bismuth Search ($0.01, Tavily-ranked), Bismuth Conversion ($0.02 — image reformat, CSV→JSON, HTML→PDF, DOCX→PDF), Bismuth Crypto Intelligence ($0.01–$0.10, CoinGecko/DeFiLlama/CoinTelegraph/GitHub across 17 major coins). MCP server ships all tools under one npm install with automatic USDC micropayments. (MCP Server | Scraping Discovery | Screenshot Discovery | PDF Discovery | Email Discovery | Search Discovery | Conversion Discovery | Crypto Discovery)
• Aigregator - Structured data on 5,336+ AI tools via REST API and MCP server. Search, compare, and retrieve tool profiles. USDC micropayments on Base. (MCP Server)
• Xquik - Real-time X (Twitter) data API with 7 MPP/x402 pay-per-use endpoints — tweet lookup, tweet search, user lookup, follower check, article extraction, media download, and trends. No accounts or subscriptions required. (GitHub) (npm) (MCP Server)
• AgentBodega - Agent-ready paid API shelf with 51 x402-payable public-data, social-media, cloud/status, domain, artifact, launch-readiness, and x402-inspection endpoints. USDC on Base, no API keys or signup, full input/output contracts, examples, pricing, and payment metadata. (Catalog | OpenAPI | Discovery | MCP | GitHub)
• glim.sh - Live data from Twitter, Reddit, the web, GitHub, Amazon, and YouTube for AI agents. 11 MCP tools, $0.002-$0.015 USDC per call (Base/Solana/Monad). No API keys, no scraping stack. (MCP Server) (OpenAPI) (GitHub)
• agentsvc.io - 20 utility tools for AI agents via x402 USDC micropayments on Base. Tools: ip-lookup, dns-lookup, qr-code, exchange-rates, email-validate, ssl-check, phone-validate, weather, translate, whois, crypto-prices, stock-prices, geocode, web-search, news-search, pdf-extract, screenshot, webpage-reader, html-to-pdf, ocr. $0.001–$0.008 USDC per call. No API keys, no signup. Auto-discovery: /.well-known/agent-services.json | Catalog | OpenAPI | MCP Server | (GitHub)
• x402 Vending Machine - Base mainnet USDC bundler hub for AI agents (x402 V2 + Coinbase CDP): ~19 pay-per-call tools including multi-step packs (bundle-infra, bundle-outbound, domain-intel), DNS/TLS/WHOIS/HTTP utilities, email MX, FX, IP geo, CoinGecko spots, QR, page text extract, Base balances, and Kronos BTC/ETH candle research forecasts. Live data only; fail-closed (no settle on handler errors). CDP Bazaar indexed. (Discovery) (Agent catalog) (OpenAPI) (llms.txt) (GitHub)
• AgentData API - Real-time crypto market data for AI agents. 16 pay-per-request endpoints on Base Mainnet: prices, funding rates, volatility, liquidation levels, DeFi yields, cross-exchange arbitrage, technical indicators (RSI/MACD/BB/ATR), support/resistance, sentiment, stablecoin health, and historical OHLCV. Self-hosted facilitator, no accounts required. Supports x402 v2 with Bazaar discovery extension. (Discovery) (OpenAPI)
• x402 Finance API - Live crypto market data (BTC/ETH/SOL at $0.002 USDC) + Token Safety analysis (honeypot/liquidity/ownership at $0.05 USDC). Native x402 V2 on Base Mainnet with Coinbase CDP Facilitator. Includes discovery, llms.txt, and MCP tool definitions. (llms.txt)
• DripMetrics - Crypto market microstructure and options metrics for AI agents: VPIN, Kyle's lambda, roll spread, order-flow imbalance, BTC options (GEX, expected move, variance risk premium), Polymarket, Hyperliquid, and on-chain activity, plus an AI-written BTC market summary. $0.05–$0.25 USDC per call on Base via the Coinbase CDP facilitator; x402 v2 with Bazaar discovery on every 402. No API keys, no signup. (OpenAPI) (MCP Server) (GitHub)
• Stakao Agent Allocation Analysis - Informational Bittensor allocation analysis API for AI agents, paid with x402 v2 USDC on Base. Supports walletless model portfolio snapshots, wallet-specific preflight flows, OpenAPI, read-only MCP, and llms.txt discovery. (OpenAPI | Docs | llms.txt)
• GPT55 x402 Wallet Safety and Merchant Readiness - x402-paid agent gateway for AI buyers that need wallet signing safety, EIP-712/Permit2 risk decoding, EVM transaction risk decoding, approval-risk auditing, x402 prepay trust checks, merchant-readiness reports, and GPT55 chat on Base USDC. Prices start at $0.0001 for chat, $0.004 for prepay checks, and $0.01 for signing/approval checks. (Discovery) (OpenAPI) (Wallet Safety Kit) (MCP Config)
• Fly Labs Agentic Market - YouTube data APIs for AI agents, paid in USDC on Base. Two endpoints live: POST /api/agents/transcribe ($0.03) returns a stable v1.0 JSON payload with verbatim transcript, language, time-indexed paragraphs, creator chapters, and canonical metadata (captions when available, Whisper fallback otherwise, no LLM rewrites). POST /api/agents/engagement ($0.02) returns view/like/comment counts, derived ratios, a composite engagement score, channel info (subscribers included), and full video context (tags, categories, thumbnail, availability, live status). Transparent cache on every response (cache.hit, cachedAt, ageSec) — transcripts are permanent, engagement refreshes every 6 hours. Typed error codes, OpenAPI 3.1, no signup. (OpenAPI 3.1) (Manifest)
• NicheData KDP Intelligence - Niche demand and competition intelligence for Kindle Direct Publishing authors. AI agents query keyword-level data including demand scores, competition intensity, BSR ranges, revenue estimates, and pricing analytics. $0.03 USDC per query on Base via CDP Facilitator. Free discovery endpoint lists all available niches. ([OpenAPI](https://nichedata.