xpaysh/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.

GitHub stars

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

---

🎯 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.

---

📚 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 [email protected] and @ledgerhq/[email protected] 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)

• 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) (Docs)

• AIServices - 16-endpoint crypto and market intelligence API for AI agents. 11 free endpoints (prices, trending, global market cap, gas tracker, predictions, news, social sentiment, swap quotes) plus 4 paid endpoints via x402: search ($0.01), technical indicators ($0.02), DeFi yields ($0.02), and URL metadata ($0.01). USDC on Base via Coinbase CDP facilitator. Remote MCP server at /mcp (8 tools, SSE transport). No API keys for free endpoints, no signup. (Discovery) (MCP) (GitHub)

• Intelica - Competitive intelligence API for autonomous AI agents. Analyzes any URL or company description and returns structured JSON with market positioning, competitors, pain points, and executable Market Score. 10 context modes including regulatory_compliance, venture_screening, crypto_protocol, and sales_enablement. Standard tier $0.05 USDC, Elite tier $1.00 USDC per call on Base and Solana mainnet. MCP server at /mcp. A2A protocol at /message/send. (OpenAPI) (Discovery)

• PulseNetwork - 75 pay-per-call intelligence APIs (930+ endpoints) for AI agents under one federated catalog: token-safety verdicts across 8 chains including Robinhood Chain (memecoin + EVM rug/honeypot analysis), macro & FRED-grade economic primitives, geopolitical risk, clinical-trials intel, US government spending, stablecoin/RWA monitors, sports data, prediction markets, immigration/tax/legal doc-prep, and more. $0.001–$2.00 per call — USDC on Base + Solana, native USDG on Robinhood Chain (eip155:4663). CDP-facilitated settlement, per-repo /.well-known/x402.json discovery on all 70+ hosts, no API keys or signup. (Hub & catalog) (llms.txt) (OpenAPI) (MCP)

• DevDrops - 22 pay-per-query data APIs for AI agents — prediction markets (Polymarket + Manifold), property intelligence, sports odds, regulatory filings, FX rates, weather, IP geolocation, academic papers, document summarisation (Claude), and more. $0.001–$0.10 USDC per query on Base. No API keys or subscriptions. (OpenAPI) (Catalog)

• Verification Oracle - Independent verification of agent work products — citation-support checks and data/schema validation returning wallet-signed attestations (EIP-191) — plus cited coding research that ships pre-verified with a signed attestation. $0.10/research call, $0.25/verification, USDC on Base mainnet via CDP facilitator. Free per-wallet quotas, free receipt-verification endpoint, Bazaar discovery extension, no API keys or signup. (llms.txt) (OpenAPI) (Discovery)

• Regression Incoming — NFL Fantasy Rankings - Model-driven 2026 NFL preseason fantasy football rankings for AI agents. 5 x402-protected endpoints on Base mainnet: GET /v1/rankings/preseason ($1.00, full 412-player preseason rankings with confidence scores), GET /v1/rankings/preseason/{player_id} ($0.10, single-player projection by player ID), GET /v1/draft-board/half-ppr ($1.00, 320-player VOR draft board with floor/ceiling/tier), GET /v1/draft-board/half-ppr/{player_id} ($0.10, single-player draft board row), POST /v1/bundle/purchase ($3.00, 7-day unlimited-access JWT). USDC on Base via CDP Facilitator. Bazaar discovery extension on all 402 responses. No API keys or signup. (Discovery) (Catalog)

• Darrylbots x402 Research - Agent-readable paid JSON research endpoints on Base USDC: stock-screen reports plus Polymarket/trading-agent analysis with structured rankings, risks, provenance, and disclaimers. $0.001 USDC per resource, no API key or account. (Catalog) (x402scan)

• agentdata-nl - European company screening for AI agents, straight from official public registers: company registers (UK, FR, NO, CH, CZ, FI, PL), insolvency checks (NL, FR), EU + UN sanctions screening, EU VAT (VIES), LEI, MiCA crypto-firm and token-registry checks, EURC peg monitoring and an x402 counterparty pre-payment trust check. 18 endpoints, $0.002–$0.18 per call, all-or-nothing billing — you are only charged when the task fully completed. x402 v2 with Bazaar discovery extension, USDC on Base via CDP facilitator. No API keys, no signup. (x402 manifest) (OpenAPI) (llms.txt) (MCP) (GitHub)

• WebberSites x402 Data API - 41 pay-per-call endpoints for AI agents, all $0.001–$0.009 USDC on Base via CDP facilitator: web scraping, document extraction (PDF/DOCX/CSV), single-page and whole-site SEO/accessibility audits, brand-kit/logo/icon/social-card generation, multi-page website building, DNS & email intelligence, geolocation, crypto data, a free machine message board, and a wallet-owned persistent Agent Datastore — give your agent a memory. Free 402 previews on page-check endpoints. No API keys, no signup. (Discovery) (OpenAPI) (MCP Server) (npm) (GitHub)

• StillOS Notary - Signed, fail-closed trust & verification primitives for agent-to-agent commerce. agent-clearance is the counterparty credit-check before one agent pays another: OFAC SDN + live on-chain wallet screen → CLEAR/REVIEW/BLOCK. Plus claim-verdict (grade any claim vs external ground truth), grade-strategy (REAL_EDGE/REGIME_LUCK/NEGATIVE_EV), screen-entity (OFAC SDN), insider-conviction/smart-money (proprietary EDGAR scoring), and distress-score (single-ticker distress vs a backtested modified-Altman-Z model). Every response Ed25519-signed and independently verifiable, no account. Free tiers, then $0.02–$0.75 x402 USDC on Base via a self-hosted facilitator (no CDP dependency). Paid MCP server (edge-gate) listed in the official MCP Registry. (llms.txt) (agent.json) (OpenAPI) (MCP Registry)

• Anicca Compute Primitives - 31 pay-per-call tools for AI agents spanning financial calculators, trading and risk signals, data utilities, and web research, plus Franklin1's autonomous v2 storefront and three wallet-isolated POST /image storefronts that generate 1024×1024 images for $0.05. $0.001–$0.05 USDC on Base via x402, with no API keys or signup; the open-source Anicca earn framework routes revenue directly to each serving agent's own wallet. (Anicca discovery) (Franklin1 image) (Franklin2 image) (Claude-P image) (GitHub)

• Social Intel — Instagram influencer search API for AI agents. Search by niche, country, demographics, or follower count → returns usernames, bios, follower counts, business categories, and public business emails. Single-profile lookup at $0.01; full search $0.50–$1.30 (100 leads). USDC on Base, Solana, Polygon, Arbitrum. No signup. (OpenAPI) (MCP Server) (Demo)

• GlobalAPI - Compliance and macro-economics API hub for AI agents across 43 endpoints. Crypto wallet sanctions screening checks any EVM, BTC, Solana, TRX, or XRP address against OFAC SDN, UK FCDO, and UN SC lists in <200ms ($0.002/check); unified DeFi counterparty check bundles sanctions + Tornado Cash labels + wallet age into a PASS/WARN/BLOCK verdict ($0.01). Economic indicators from official statistical agencies — BLS and FRED (US), ONS (UK), Eurostat (EU), Statistics Canada, ABS (AU), e-Stat (JP), IMF DataMapper (190 countries), World Bank (200 countries) — with AI commentary. Company registry lookups for Norway, Singapore, Ireland, France, Canada, and Denmark. No API key — x402 USDC on Base mainnet, $0.002–$0.10/call. (OpenAPI | Discovery)

• The Bot Wire - Real-time news wire for AI agents: 40 curated sources (markets, crypto, tech, world, business, energy) refreshed every 5 minutes, full-text searched in ~1ms with per-article freshness timestamps. GET /news (ranked search with summaries) and GET /headlines (by category) at $0.005 USDC on Base via x402 v2; free preview tier, no API keys, no signup. (Discovery | OpenAPI | llms.txt | MCP on npm)

• Sivut Public x402 Data APIs - Public page markdown conversion and x402 seller intelligence endpoints for AI agents, paid in USDC on Base via x402. Prices range from $0.003 to $1.00 per call; no signup or API key. (OpenAPI) (llms.txt) (GitHub)

• LoneStarOracle - 39 x402-gated AI data services on Base: token forensics (TokenScope), smart contract audits (RattlerAI/CottonmouthAI/CopperheadAI), weather consensus, oil & gas (CrownBlock), on-chain intel (ChainScout), macroeconomics (MacroPulse), real estate, commodities, stablecoin risk, and more. $0.02-$2.00 USDC per call. No API keys. MCP server at mcp.lonestaroracle.xyz (38 tools, xyz.lonestaroracle/mcp-server v1.1.0). (Discovery | MCP | Status)

• TOUGH LOVE SECURITY ImageGen - Pay-per-image AI generation powered by Cloudflare Workers AI (Stable Diffusion XL Lightning + Flux-1-Schnell). Three tiers: $0.50 single, $1.99 12-pack, $7.99 100-bundle. Stripe Checkout for humans, x402 for agents at $0.04/image. No accounts, no expiring credits. (Launch post)

• QueryLines - Surplus lines market data, per query. U.S. excess & surplus (E&S) insurance premium and policy-count statistics from state stamping office publications: time series, YoY summaries, and cross-state comparison by state, coverage line, and month/quarter/year. $0.10 single-state query, $0.50 cross-state compare, USDC on Base via CDP facilitator with Bazaar discovery. Free discovery endpoints, no API keys or signup; every response cites its source report. (OpenAPI) (MCP Server) (llms.txt)

• TOUGH LOVE SECURITY ClawWork - Instant AI labor marketplace with three tiers: $5 quick polish (90s turnaround), $25 deep brief (1.5K-3K word structured deliverable), $99 full deliverable (pitch decks, RFPs, content calendars). Stripe + x402 ($0.05/call on bulk). Powered by Claude 4.7 Sonnet. (Launch post)

• TOUGH LOVE SECURITY Contract Risk Score - Smart contract risk scoring API for DeFi devs. Scores Ethereum / Base / Arbitrum / Optimism contracts across 10 risk categories (admin-key centralization, oracle exposure, honeypot indicators, known exploit signatures). $1.25 per 5-pack via Stripe, $0.25/call via x402. Triage layer between "free Etherscan glance" and "$50K formal audit." (Launch post)

• GLHFDD - AI-powered text analysis, code analysis, and data transformation APIs built by a self-hosted AI agent. Pay-per-call via x402 protocol on Base mainnet. POST /analyze/text ($0.01), POST /analyze/code ($0.02), POST /transform/data ($0.005). No API keys, no signup. Auto-discovery via bazaar.json.

• Deepnets - Solana token intelligence: safety analysis, deep wallet-funding-network mapping, holder breakdowns, social/Twitter research, trending feed, streamflow/staking lockup data. 13+ pay-per-request endpoints on Solana mainnet: /api/token-safety/{mint}, /api/token-details/{mint} (full holder + network breakdown), /api/holder-analysis/{mint}, /api/social_research/{mint}, /api/wallet-details/{address}, /api/network-details/{networkAddress}, /api/trending, /api/watchlist, /api/flagged-tokens, and more. $0.01 basic / $0.15 holder analysis. USDC on Solana, gas sponsored by the facilitator — no SOL needed. v2 with Bazaar discovery extension. (OpenAPI) (Docs) (Marketing)

• OnChain Token Safety (wick.pics) - Multi-chain token-safety verdicts for AI agents: rug/honeypot verdict (0–100 + evidence), live sell-simulation, ownership/privilege checks, size-aware exit-safety, wallet drainer-approval + address-poisoning scans. One API covers PulseChain, Monad, Base & BSC — the free tools (GoPlus, Honeypot.is) don't cover PulseChain, and Monad safety coverage is rare anywhere. $0.01–$0.05 USDC per call on Base, self-hosted settlement. (Discovery) (OpenAPI) (MCP on npm)

• OpenPulsechain - PulseChain blockchain analytics API with 28 x402-paid endpoints: token safety scores (0-100), opportunity signals, whale alerts, pair analytics (price impact, volatility), deployer reputation, AML funding tree, smart money feed, gas price, OHLCV history. Covers 5,900+ tokens. $0.001–$0.03 USDC per call on Base. (x402 Discovery) (npm MCP) (GitHub)

• DataFood (TOUGH LOVE SECURITY) - Universal data hub for AI agents — 17 cross-niche sources (crypto prices, ETH gas, weather, news, HN, GitHub trending, DeFi yield, token risk via GoPlus, HHS healthcare-breach feed, geocoding, more) behind one POST /api/data/bundle call. Bundle micropayments save up to 92% vs per-API alternatives. Day pass $0.99 unlimited 24h, week pass $4.99. Payable via x402 USDC OR Stripe Checkout — same session_id works across every tool call. Free 1-row preview at /api/data/preview?type=…&q=…. (Live demo) (MCP server) (x402 descriptor) (catalog)

• x402 Trust Oracle - Pre-trade trust check for autonomous trading agents before paying market data, oracle, price signal, funding data, or execution-input endpoints. Endpoint https://api.x402oracle.com/v1/trade-check, route /v1/trade-check. Price: $0.002 / 2000 atomic USDC on Base mainnet eip155:8453. asset 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913. payTo 0x2DF1AEc598a104Fc15E80C0B60e50C497559A980.

• Askew - Security and DeFi intelligence for AI agents. 5 pay-per-call endpoints on Base mainnet: /yields ($0.002, live APY across 5 chains via DefiLlama), /staking/router ($0.003, SOL/ATOM native vs liquid staking routing), /research/query ($0.003, search agent-economy research and experiment corpus), /intel/threats ($0.002, Guardian security threat summary), /intel/feed ($0.005, combined research + threats + staking strategic feed). Free preview at /yields/preview and /health. Self-hosted facilitator (xpay.sh). Auto-discovery: (/.well-known/x402.json | llms.txt | /offers)

• BitBooth - 6 utility, content, and security endpoints for AI agents on Base mainnet, settling via Coinbase CDP Facilitator. Tools: echo (x402 reference impl), json-repair (LLM tool-output cleanup with optional JSON Schema validation), faker (synthetic test data via @faker-js/faker), render-pro (full Playwright JS rendering + Mozilla Readability extraction for SPAs), web-diff (rendered URL change detection vs caller-supplied previous markdown), approval-safety (ERC-20 approve(spender, amount) pre-flight risk check — flags unlimited approvals to fresh contracts, EOA spenders, copycat tokens). $0.001 USDC per call for utility tier, $0.05 for premium tier. No API keys, no subscriptions. Self-hosted discovery at bazaar.json. (GitHub)

• EconDash - Global macroeconomic data API for AI agents: 753 indicators across 298 countries (World Bank, FRED, OECD). 15 x402-protected endpoints for GDP, inflation, employment, trade, country profiles, rankings, and metadata. $0.02 USDC/call on Base. Also supports MPP (Tempo + Solana). (Docs) (OpenAPI)

• ShadowQuant Intelligence - Validated equities/options market research for AI agents: volatility regime (VIX term structure, cross-asset ratios), options IV, seasonal bias with FDR-adjusted significance, Granger lead-lag map, correlation regime, and market context. Every response embeds provenance — generation timestamp, honest staleness flag, methodology, and a publicly graded track record. $0.005-$0.02 USDC per call on Base. No API keys, no signup. Research data, not investment advice. (Catalog) (Discovery) (Terms)

• anchor-x402 - 16 x402-paid services for AI agents on Base + Solana mainnet. 9 commodity primitives (OFAC sanctions screen, bundled wallet intel, dual-chain hash anchoring, signed attestations, mainnet tx + calldata decode, ENS + Bonfida SNS resolve, USD prices, datetime parse), 1 async due-diligence investigator ($7.77, 5–10 min, signed markdown report + dual-chain anchor proof), 1 verifiable signed RNG (/v1/roll, drop-in VRF for game studios), and 5 universal LLM endpoints (roast, oracle with on-chain anchored verdict, tldr, aura, grade). Plus a hosted chatbot at chat.anchor-x402.com — connect with passkey or any browser wallet, pay only when you approve. MCP server: anchor-x402-mcp. (GitHub) (Discovery) (Trust portal)

• romefeller.app - Document intelligence API: scrub PII (email, CPF, CNPJ, phones, API keys), verify document completeness, assess risk, and extract structured fields from invoices, NF-e, contracts, and receipts. Regex + Claude AI hybrid. 4 paid endpoints at $0.005–$0.15 USDC per call on Base mainnet via Coinbase CDP facilitator. Free regex preview at /preview (no payment required). No API keys, no signup. (/.well-known/x402.json | OpenAPI | llms.txt)

• QuantOracle - 73 deterministic quant finance endpoints for AI agents: Black-Scholes pricing with full Greeks, Kelly Criterion, Monte Carlo simulation, Sharpe/Sortino/Calmar/VaR/CVaR risk metrics, Hurst exponent, GARCH, drawdown analysis, plus 10 paid composites (full risk audit, hedge recommendations, options strategy optimizer, portfolio rebalance plan). Math verified against 120 published-textbook accuracy benchmarks (Hull, Lopez de Prado, Kelly, Parkinson). $0.002–$0.10 USDC per call on Base + Solana mainnets via Coinbase CDP facilitator. Free tier: 1,000 calls/IP/day, no signup, no API key. 15 free interactive calculators backed by the same engine at quantoracle.dev. (OpenAPI | x402 Discovery | AgentKit Integration | Calculators | GitHub)

• krewe - Decentralized AI inference network on Base. Each /v2/predict call is fanned out to 3 independent miner nodes; 2-of-3 byte-equal consensus is required before the result settles. 4 pay-per-call endpoints: text.structure ($0.005, entity/email/date extraction), text.embed ($0.01, sentence embeddings), web.scrape ($0.02, fetch + clean URL payload), text.complete ($0.05, quantized SLM completion via Qwen2.5-0.5B-Instruct). Settlement via EIP-3009 transferWithAuthorization, gas paid by the orchestrator (~$0.001 on Base) and recovered from the payment. No API keys, no signup. Live consensus events stream at /v2/live WebSocket. (SDK) (Orchestrator) (Miner)

• x402 inference gateway - OpenAI-compatible LLM chat completions for AI agents, paid per request in USDC on Base mainnet via the Coinbase CDP facilitator (Bazaar-indexed). x402 v2 upto scheme: authorize a ceiling derived from max_tokens, get billed actual token usage at upstream cost + 4% — from $0.001/call. 8 models (gpt-5.4-nano/mini, gpt-5.4, gpt-5.5, gpt-4o and gpt-4.1 families). No API key, no signup: point any OpenAI client at the URL. Billing transparency headers (X-Billed-Usd, X-Quoted-Ceiling-Usd) on every response; daily on-chain canary. Self-serve integration doc at GET /. (GitHub)

• SolProbe - Solana token risk scanner for AI agents with four pay-per-request endpoints settling USDC on Base or Solana mainnet at the same price (gas sponsored by the CDP facilitator — no SOL or ETH needed). Rug check / A–F safety grade ($0.02), market signal ($0.20), full due-diligence with wash-trading and bundled-launch detection ($0.50), and a bring-your-own-wallet Jupiter swap executor ($0.15); x402 v2 with the Bazaar discovery extension, no keys or signup. (llm.txt) (OpenAPI) (Discovery) (agentic.market)

• SolSigs ProofGuard - Post-payment trust and refund-evidence layer for AI agents using x402 endpoints. /proofguard/evaluate returns decision flags, receipt fields, trust scoring, and evidence links for Solana x402 calls. $0.003 USDC on Solana. (GitHub) (x402scan)

• Usenami - Multi-venue perp funding & RWA spread API for arb-aware AI agents. 6 pay-per-call endpoints on Base mainnet ($0.001–$0.010 USDC): per-venue funding rates across 30+ exchanges (/v1/funding/current, $0.001), cross-venue funding spread (/v1/perp/funding-spread?ticker=BTC, $0.001), oracle price-source family classification for basis-risk awareness (/v1/perp/oracle-families, $0.001), RWA perpetual coverage on Hyperliquid HIP-3 DEXes — stocks, metals, forex, commodities, pre-IPO synthetics (/v1/rwa/perp-coverage, $0.001), historical funding for backtesting (/v1/funding/historical?ticker=&from=&to=&aggr=1h|4h|1d, $0.005, 90d retention), and sized-depth quotes with precomputed slippage at $1K/$5K/$10K notional (/v1/orderbook/depth/aggregate/{venue}/{symbol}?size_usd=N, $0.010). Differentiated vs CoinGecko/CMC by perp-first focus + RWA inclusion + backtestable historical depth. x402 v2 with Bazaar discovery extension via Coinbase CDP Facilitator. MCP server with 6 paid + 2 free tools at namixai/usenami-mcp. (API base) (Provider)

• melis.ai x402 Tools - 23 audit-verified pay-per-call utility endpoints for AI agents, settling in USDC on Base via Coinbase CDP Facilitator. Production fleet at *.melis.ai. Covers: web scraping (ScrapePay $0.01, Playwright + robots.txt-aware), HTML-to-markdown token reduction (MarkdownOpt $0.005), cached fetch (CacheServe $0.001), structured HTML extraction (StructExtract $0.002), format conversion (DocConvert-Text $0.001, DocConvert-PDF $0.005), notifications (NotifyRelay /email $0.005, /notify (Telegram) $0.002, /webhook $0.001 HMAC-signed, SSRF-protected), JSON Schema validation (SchemaGate $0.001), prompt-injection screening (PromptGuard $0.002, MemScrub $0.001), URL safety (LinkRisk $0.005 lightweight, LinkSafe $0.01 Playwright+VirusTotal), embeddings + memory (EmbedPay $0.00005/1k tok, MemoryServe /write $0.001, /query $0.001), image moderation (ImageGuard $0.002), wallet trust scoring (KYA Oracle $0.005), response auditing (xAudit $0.002), multi-agent orchestration (IntentFlow $0.001, LoopWall /issue $0.001, /hop $0.0005). No API keys, no signup. (MCP Server) (GitHub) (Operator)

• Base Capital - Autonomous x402 on-chain risk-intelligence API for AI trading agents on Base. Token risk scores and risk-ranked trending signals at $0.01 USDC/call, backed by an on-chain RiskStake reputation contract (ERC-8004 agent identity, optimistic dispute resolution with bonded challenges, builder-code attribution). No API keys, no accounts. (manifest) (openapi)

• x402agent.no - Norway's AI agent API gateway — 7 live services, 23 endpoints covering Norwegian company registers (500K+ companies from Brønnøysundregistrene), SEO backlinks with Domain Rating, weather forecasts (MET Norway), 3,785 statistical tables (SSB), property/address data (Kartverket), IP search (Patentstyret), and public transport (Entur). $0.005–$0.10 USDC per query on Base via Coinbase CDP facilitator. No API keys, no accounts. (services.json) (llms.txt)

• dotrockets Agent Tools - Multi-tool x402 hub for AI agents (5 endpoints, $0.02–$0.10 USDC on Base mainnet, x402 v1+v2, no API keys or signup, gas-sponsored): cosmic live geophysics (KP-index with G1–G5 storms, Schumann resonance from Tomsk State University since 1997, solar wind, X-ray flux), ai-visibility score 0–100 for any domain (AI-crawler access, llms.txt, schema.org, SSR, + live LLM brand-knowledge check) with recommendations, screenshot (full-page Chromium PNG), scrape → clean Markdown (Mozilla Readability, optional JS render), and search (Brave + DuckDuckGo fallback). Machine-readable catalog, MCP server, and /.well-known discovery; Bazaar extension schema on every endpoint. (Catalog) (MCP) (.well-known/x402) (llms.txt)

• GoCreative AI - 145+ pay-per-call APIs for AI agents across social enrichment, OSINT lookups, web scraping, image generation, and document intelligence. USDC on Base via x402 (also Stripe). Free 5 calls/day per IP demo tier (no signup). Native MCP server, official GitHub Action, 7 npm + 4 PyPI SDKs, 20 HuggingFace Spaces. $0.001–$0.10 USDC per call. (MCP Server) (OpenAPI) (Discovery)

• fry.farm x402 Agentic Actions - 15 pay-per-call USDC endpoints on Algorand mainnet: DeFi/DePIN data + non-custodial transaction builders (staking, LP farming, NFT mint, P2P). Unsigned atomic groups — agents sign with their own wallet. (Catalog | MCP)

• 2s.io - Pay-per-call JSON API for AI agents. 35 endpoints: geo/IP, web extract + summarize + translate + screenshot, image compress + describe, barcodes (QR/Aztec/DataMatrix/PDF417), DNS + WHOIS, EVM gas oracle, US weather (NWS), climate stations + tides + sunrise (NOAA), live quakes + wildfires (USGS), Wikipedia, papers (arXiv/PubMed/Semantic Scholar), patents, federal court opinions + Federal Register + OFAC sanctions, US Census demographics, airport registry. Sub-cent to $0.03 USDC on Base via the Coinbase facilitator; bearer-account flow in preview. (Discovery | OpenAPI | .well-known/x402 | llms.txt)

• Seneschal - Monero & Zcash payment watching for AI agents: hand over a view key (read-only) and a webhook URL, get an HMAC-signed POST for every inbound XMR/ZEC payment — watches run on the operator's own full nodes, credit-metered at $0.02/day + $0.005/event, topped up via x402 USDC or natively in XMR/ZEC. Also: historical note scans, free Zcash UFVK derivation, live XMR/ZEC chain facts from $0.001, plus DeFi liquidation telemetry (Aave, Morpho, Spark, Compound at-risk borrowers) and Ethereum builder bid distributions. Settles via Coinbase CDP with Bazaar discovery on every route. REST + MCP, no API keys. (Discovery) (MCP Server) (GitHub)

• x402 Entity-ID Resolver - Canonical cross-registry entity-ID resolver for AI agents. One ambiguous company or crypto name/ticker ("Apple", "ETH", "Stripe") → ranked candidates with verified IDs fused across registries: SEC CIK + ticker, GLEIF LEI, Wikidata QID, CoinGecko slug, each tagged with the sources that agreed so every ID is checkable. The exact cross-registry lookup LLMs can't do reliably. $0.005 USDC per call on Base mainnet, gasless (EIP-3009), no API key. v2 with Bazaar discovery extension. (OpenAPI) (llms.txt) (.well-known/x402)

• HSH Data-on-Demand - Made-to-order B2B data for AI agents on Base mainnet. Describe any data need in plain language, receive a custom quote, pay per call in USDC via x402. Live company intelligence (hsh_company_intelligence at $0.02/call, free /v1/quote-smart discovery). Built for arbitrary data fulfillment — lead lists, contact enrichment, custom pulls — quoted by scope ($1-$50). No signup, no API keys. Both HTTP API and MCP Streamable HTTP transports. (Manifest) (Catalog) (MCP) (GitHub)

• img402 - Image hosting for AI agents. Upload an image, pay via x402, get a public CDN-backed URL. Three tiers: free (1MB, 7-day retention), $0.01 USDC (5MB, 1-year), $1 (5MB, permanent). USDC on Base and Solana via the Coinbase CDP facilitator; indexed in the CDP Bazaar. No API keys, no signup. Claude/agent skills available. (Docs | OpenAPI | llms.txt | Skills)

• Melvea — Citation-backed honey intelligence: structured varietal data and verifiable research provenance for 150+ honey varieties, including the obscure long tail foundation models get wrong. Every compositional datum resolvable to a real, published source (DOI/PMID). Endpoints: variety catalog, per-variety research citations, and grounded flavor/use recommendations — $0.02–$0.10 USDC per call on Base. (llms.txt) (ai-plugin.json)

• n0brains - Crypto intelligence with a live, auditable per-signal-type win-rate at /proof (forward returns vs BTC, 95% CI; underperforming types demoted in the open). 6 pay-per-call x402 endpoints on Base, $0.005/signal USDC, no account: signals, rotation, correlation, DEX liquidation map, S/R levels, macro. Also hosted MCP (23 tools) and pip install n0brains-cli. (Discovery)

• Qonoro Intelligence API - x402-native intelligence APIs for AI agents and business workflows on Base mainnet. Endpoints include /v1/company/research for company intelligence, /v1/competitors/analyze for business competitor analysis, and /v1/sales-signals/find for sales signal detection. Structured JSON outputs include source-backed evidence and confidence scores. Pricing by endpoint via /v1/pricing/{agent_id}; additional services are documented in the API docs.

• Stelar Digital x402 API (Algorand) - Pay-per-call market data and grid-trading params for AI agents, on Algorand mainnet via the GoPlausible facilitator. 3 endpoints: live P&L telemetry, price/signal check, and grid-parameter recommendation. $0.005-$0.05 USDC per call. (Discovery) (Catalog)

• TrustBoost PII Sanitizer — Context-aware PII sanitization for autonomous AI agent pipelines. Redacts emails, phone numbers, national IDs (RFC/CPF/CUIT/RRN), private keys, and financial data before text reaches LLMs. Every paid sanitization anchored on Solana via Helius — verifiable by any agent at /verify/{anchor_tx}. 8 languages: EN, ES-LATAM, PT-BR, DE, JA, FR, IT, KO. Privacy Budget per agent. TrustBoost Score M2M trust verification. 149 USDC on Solana → 10,000 sanitizations with on-chain proof. TRIAL: 50 free sanitizations with tx_hash=TRIAL. (Agent Card | MCP | Verify | Health | Demo)

• OpenClaw Research API — Pay-per-call research API for AI agents. Web search, content extraction, code analysis, and PDF processing endpoints. $0.01 USDC per call on Base and Solana via Dexter facilitator. Discovery: /.well-known/x402.

• Crypto Data Agent - Live crypto prices (up to 25 coins per call) and DeFi yield pools (APY/TVL with chain/stablecoin filters) for AI agents. -e.002 USDC per call, dual-rail payments on Base and Solana mainnet (gas sponsored by the facilitator — no ETH/SOL needed), Bazaar-listed, free live sample at /api/sample. (MCP Server) (Pricing)

• Kairos Lab x402 Workers - 8 pay-per-call endpoints for AI agents on Solana mainnet, accepting both USDC and USDT (multi-token paywall). Includes /audit-mcp ($0.05, MCP server compliance + security audit), /factcheck-fr ($0.02, French fact-checking via Wikipedia FR + Claude verdict), /translate-fr-pro ($0.03, professional FR translation with business/legal/tech glossaries + tu/vous register), /legal-fr-quickcheck ($0.10, French clause audit vs RGPD + Code civil + Code conso + Code travail with article-precise violations), /scrape-stealth ($0.01, rotating UA HTTP scraper with CSS selectors + SSRF protection), /agent-rep-check ($0.05, Moltbook agent reputation snapshot — karma, age, breadth, score), /submolt-recommend ($0.02, semantic submolt ranking for a topic), and /ai-act-mapping ($2.00, EU AI Act Article 50 risk-tier mapping for SaaS products + CGU/UI compliance hooks). Self-hosted facilitator, multi-token settlement, no API keys, no signup. (Discovery) (Docs) (Manifest) (Status)

• Kraken Crypto Signals - Pay-per-call crypto market-state signals (BUY/SELL/HOLD + confidence) for AI agents, from a live multi-timeframe Kraken strategy. Every response is ECDSA-signed (verifiable authenticity) plus a tamper-evident hash-chain track-record. Free preview endpoint, no API keys. $0.01 single pair / $0.10 market scan on Base via CDP Facilitator, x402 v2 with Bazaar discovery extension. (OpenAPI) (Discovery) (Preview) (GitHub)

• Agent Signals - Crypto market-intelligence for AI trading agents. 3 pay-per-call endpoints on Base mainnet: cross-exchange funding rate + crowding bias ($0.01), BTC->altcoin lead-lag signal ($0.02), and trend/chop market regime ($0.01). Computed live from free public exchange data (Binance/Bybit/OKX), settled in USDC via Coinbase CDP Facilitator. No API keys, no signup. (Catalog) (OpenAPI) (llms.txt) (x402scan)

• SYNTHORA md-extract - Western EN/EU web → clean markdown + token budget for AI agents. Every response ships an Ed25519 attestation receipt: the buyer verifies offline, with only the response in hand, that the output came from this mesh and was not tampered with — a cryptographic chain-of-custody the big scrapers don't provide. $0.005 USDC per call on Base, keyless facilitator (xpay.sh), no accounts, no signup.

• SwapTitan - No-KYC cross-chain crypto swap API for AI agents — 1288+ assets aggregated across 3 providers (ChangeNOW, SimpleSwap, Heleket). H2H Privacy Routing automatically pipes any-to-any swaps through Monero so source and destination chains stay unlinkable on-chain. 10 MCP tools: swap_quote, swap_create, swap_status, get_prices, get_assets, ai_chat (Llama 3.3 70B), check_portfolio, rug_check, create_wallet, set_price_alert. $0.02 USDC on Base per MCP call (2 free/day per IP), $0.05 per swap_create, or €49.99/mo Agent Tier for unlimited via X-License-Key header. On-chain x402 verification with 10-min TX freshness + KV replay protection. (MCP Server) (Pricing) (GitHub) (Agent Card)

• BORT Inference - OpenAI-compatible LLM chat completions for AI agents on BNB Chain. deepseek-v4-flash at 0.02 $U per call via POST /v1/chat/completions, settled with EIP-3009 transferWithAuthorization (x402, scheme exact/eip3009 on eip155:56); the facilitator sponsors gas so the buyer needs only $U. No account, no API key. (Agent Card)

• BrazilMCP - Official-source Brazilian company data (KYB) for AI agents. Receita Federal registry lookup by CNPJ or company name ($0.005), sanctions screening across all 5 Brazilian federal lists ($0.02), and a full due-diligence dossier with government procurement history and compliance risk flags ($0.25). Own dataset rebuilt monthly from the full official publication (68M+ companies), not a wrapper. x402 v1+v2 USDC on Base via CDP facilitator, no API keys, no signup. Paid MCP server, listed in the official MCP Registry. (MCP) (MCP Registry) (Schemas)

• ProxyLLM LLM Cost Scout - Send a monthly OpenAI API bill, get back the flat ChatGPT/Codex subscription tier that absorbs it through the ProxyLLM gateway: exact new total, savings, live model catalog, and machine-readable agent signup steps (email OTP, no browser). $0.005 USDC on Base via Coinbase CDP facilitator, no API keys. (OpenAPI | auth.md | llms.txt)

• eurc402 - EURC-priced, EU-sovereign compliance data for autonomous agents. EU VAT validation (VIES, all 27 member states) and pan-EU company data across 7 official registers (🇳🇴 🇫🇷 🇫🇮 🇸🇰 🇬🇧 🇱🇻 🇷🇴), normalized to one JSON schema with per-record provenance + open-data licence. €0.01–0.02/call — priced and settled in EURC (primary) or USDC on Base via the CDP facilitator. No API keys, no signup; country auto-detected from the id. (Discovery | OpenAPI | Docs | llms.txt)

• Telemost - Telegram channel analytics and statistics for AI agents: subscriber growth, average views and reach, engagement (ER/ERR/ERR24), full-text post search across public channels, mention and brand tracking, sentiment, and similar-channel discovery. 19 pay-per-call tools plus a free catalog, USDC on Base and Solana via x402, no accounts or API keys. (MCP) (npm) (Catalog) (MCP Registry)

• scrape402 - 16 pay-per-call utility APIs for AI agents: web scraping (clean text, markdown, PDF-to-text, LLM structured extract), crypto market data (spot with batch pairs, OHLC candles with backtest ranges, order book, gas oracle), FX rates, weather (current + historical), RSS-to-JSON, and data utilities. $0.002-$0.015 USDC on Base via the CDP facilitator - no API keys, no signup. (OpenAPI) (Discovery) (llms.txt)

• Solana AI Agent API - OFAC-sanctions AML screening, program safety heuristics, rug-pull risk scan (free), plus wallet credit score and AI-powered wallet/smart-money/spending analysis (paid) for Solana. $0.001-$0.005 USDC on Base via PayAI facilitator, no API keys, no signup. (Discovery) (OpenAPI)

• Lazarus Long Healthspan ROI Advisor - Evidence-based longevity interventions ranked by ROI for older adults. POST a user profile (age cohort, health concerns, time, budget) and receive the top 5 interventions with evidence grades, expected benefits, and effort levels. $0.05 USDC per call on Base mainnet via Coinbase CDP facilitator. No API keys, no signup. (Discovery | Agents.txt)

• OmniNexu - Structured, traceable S&P 500 financial intelligence for AI agents. 8 x402-paywalled endpoints ($0.01–$0.05 USDC on Base): company fundamentals, SEC Form 4 insider trades, 13F institutional holdings, industry peer ranking, multi-year CAGR trends, and smart-money bundles. SEC EDGAR-sourced with cross-source confidence scoring. No API keys, no signup. Open source (Apache 2.0). (GitHub) (Discovery)

• SEC Reg CF Raise Tracker - Track US Regulation Crowdfunding (Form C) startup raises for AI agents: query live and historical offerings by issuer CIK, industry (SIC), state, security type, minimum size, or recency — returns parsed deal terms (amount sought, max, raised-so-far, deadline, funding portal, issuer financials) with honest open/closed/unknown statuses and index-freshness metadata. 1,200+ offerings indexed from SEC EDGAR (public domain). $0.02 USDC on Base via Coinbase CDP facilitator, no API key, no account.

• Sanctions Screening - Screen a person, company, or crypto wallet address against the OFAC SDN list (US Treasury) and the UN Security Council Consolidated List in one call: matches with source list, sanction programs, alias matched, and match type (exact/token/address), plus list-freshness metadata. Covers 20k+ sanctioned entities and 400+ sanctioned wallet addresses across chains (ETH, BTC, TRX, XMR...). $0.02 USDC on Base via Coinbase CDP facilitator, no API key, no account. Data: US Treasury + UN (public government data).

• x402 Counterparty Score - Trust verdict (trusted/caution/avoid) with wash-trading ratio, real-buyer count, and repeat-buyer rate for any x402 endpoint URL or pay-to address — deterministic economic-authenticity scoring computed from public on-chain settlement data, refreshed daily. $0.02 USDC per call on Base via CDP facilitator, free sample tool for schema validation. No API keys. (MCP | Methodology | OpenAPI | llms.txt)

• GLEIF Entity Resolution - Resolve a company name to its canonical Legal Entity Identifier (LEI) for AI agents: legal name, status, jurisdiction, address, registration status, and corporate hierarchy (direct/ultimate parent + children) in one call, with a fuzzy-match confidence score and disambiguation candidates. $0.03 USDC on Base via Coinbase CDP facilitator, no API key, no account. Data: GLEIF (CC0).

• openFDA Drug Safety - Pay-per-call FDA drug safety profiles for AI agents: label highlights (boxed warning, contraindications, interactions), pregnancy/pediatric/geriatric flags, top adverse-event signals, recent recalls, and shortage & marketing/discontinued status — all in one call. RxNorm-normalized drug-name resolution with a match confidence score. $0.04 USDC on Base via Coinbase CDP facilitator, no API key, no account. Data: openFDA (CC0).

• Negbit - Knowledge bookstore for AI agents: structured OKF knowledge bundles bought over x402. USDC on Base via CDP facilitator, gasless for the buyer; sealed zips with sha256 + signed receipts; open negentropy pricing formula. One free foundation bundle for ~1 month (founding-member on-chain record). Bazaar discovery extension on 402 responses. No API keys, no signup. (Catalog) (llms.txt) (agents.txt)

• x402-solana - 10 pay-per-call API tools for AI agents, settled in USDC on Solana mainnet via the Coinbase CDP facilitator (gasless for the buyer). Crypto & Solana pre-trade safety (SPL/EVM rug & honeypot checks, GO/NO-GO verdicts, token dossiers), market data (Polymarket odds), official KYB/AML (GLEIF LEI, EU sanctions screening), and x402 discoverability audits. $0.01–$1.00 USDC per call, no API keys. v2 with Bazaar discovery extension. (Discovery) (MCP) (npm) (MCP Registry) (GitHub)

• Token Intel - Solana token due-diligence for AI agents: one call fuses on-chain safety signals (mint/freeze authorities, holder concentration, dev holdings) with market data and rug indicators from three independent sources (Jupiter, DexScreener, RugCheck incl. LP-lock depth), cross-checks the sources for disagreement red flags, and returns a synthesized 0–100 risk verdict. $0.01 USDC per call on Base or Solana via the keyless PayAI facilitator — no API keys, no signup. Free demo route + free MCP demo tool to verify the pipeline before paying; MCP server is stateless (no session header) with in-band x402 payment support. (Discovery) (MCP Server) (OpenAPI) (Demo)

• MGO — Multi-chain Gas Optimizer - Compares real-time gas prices across EVM chains and returns a cheapest-chain recommendation (e.g. "Use Base — saves 99.8% vs Ethereum") so agents can pick the cheapest chain before executing. Two tiers on Base via Coinbase CDP facilitator: basic $0.001 (4 chains — ETH, Base, Arbitrum, Optimism), premium $0.002 (9 chains — adds BNB, Polygon, Avalanche, zkSync, Hyperliquid). x402 v2 with Bazaar discovery extension. Free demo, no API keys. (llms.txt) (MCP) (Demo) (GitHub)

• Kronos x402 API - Pay-per-call crypto derivatives, forecasting, and market-signal API for AI agents. 20 tools priced $0.001–$0.04 USDC per call on Base mainnet, with a free /api/v1/catalog for discovery and free sample data.

• SibFly - Measured ground-motion (subsidence & uplift) data for any US address, in mm/year from NASA OPERA Sentinel-1 InSAR — for AI agents assessing property, infrastructure, and climate risk. One report per call, $0.40 USDC on Base via the Coinbase CDP facilitator (402 responses carry the x402 accepts block; X-PAYMENT settles and serves in one round trip). Also honest prepaid-credit billing, no signup wall — one-call self-registration at POST /api/v1/autonomous/register. Hosted MCP server (9 tools), OpenAPI, and llms.txt. (MCP) (OpenAPI) (llms.txt)

• Tantra Authority / The Naked Press - 49 AOP offers (courses, eBooks, meditations, readings), each x402-buyable in USDC on Base. (Offer discovery)

• x402-signature-service - E-signatures for AI agents: send one PDF to one email recipient for simple electronic signature (powered by Documenso), track completion with a one-time bearer token, download the signed PDF. Closes the human-sign-off gap for contract/NDA workflows. $0.50 USDC per request on Base (x402 exact scheme, v1-compatible 402 body), SSRF-guarded document fetching, tokens stored as hashes, no API keys, no signup. (Schema) (LLM tool) (x402scan) (GitHub)

• Verity (VerityLayer) — Fail-closed verify-before-you-act trust gate for AI agents. Returns a verdict (supported/unsupported/uncertain) plus a calibrated 0–1 confidence and evidence, and abstains rather than guess. Keyless, pay-per-call in USDC on Base (eip155:8453). Three tiers: /verify/quick $0.02 (Haiku pre-filter) · /verify $0.25 (Sonnet, grounded with live citations) · /verify/pro $0.35 (Opus). Also ships an MCP server (io.github.meloliva14/verity-mcp). (Manifest | Site)

• Second Opinion — Structured second-opinion critique of a claim, plan, or draft output for AI agents, across five lenses (correctness, risk, completeness, security, assumptions). Every issue ships a concrete suggestion and the matched evidence span, not just a label. Model-backed (Claude), heuristic engine as a zero-cost fallback so a call never hard-fails after payment settles. $0.01 USDC per call on Base mainnet (eip155:8453), no API keys, no signup. Free rate-limited preview at GET/POST /sample. (Manifest | Docs)

• token-intel - Solana token rug-risk intelligence for AI agents. One $0.01 USDC call (x402 v2, Solana mainnet) returns a composite CLEAN→RUGGED verdict from RugCheck + GoPlus + on-chain data, with LP-lock depth (per-pool TVL, locked %, burn %) and top-10 holder-lock status as structured fields, plus mint/freeze/close authority flags. Weighted multi-source scoring renormalizes when a source is down; fresh low-liquidity mints floor at MODERATE_RISK; buyers are never charged for 5xx. No API keys. (Discovery) (MCP Server)

• Azimuth - Radio-frequency positioning DePIN for AI agents. Pay-per-call location APIs — estimate a position from cellular observations — plus receiver-node registration and status. USDC on Solana and Base (x402 v2), no API keys, $0.001-$0.10 per call, with machine-readable discovery and a Bazaar extension on every route. (Discovery) (Catalog)

• Oromi Agent Services - 25 pay-per-call endpoints for AI agents: Companies House lookups & business-name availability checks, HM Land Registry property price trends & sold prices by postcode, EPC ratings, current UK statutory rates (Bank Rate, tax/NI/VAT thresholds, minimum wage), PDF & page text extraction, JSON Schema validation, URL liveness, street-level crime context, food hygiene ratings, email/domain/EU-VAT/IBAN verification, web extract & robots.txt checks, and crypto market context. $0.002–$0.05 USDC on Base via CDP facilitator. No API keys, no signup. (OpenAPI) (llms.txt) (Discovery) (MCP)

• Kerne Protocol - Proof-of-reserves and signed ERC-20 reads for AI agents. GET /reserves ($0.25) returns Kerne's hourly EOA-signed proof-of-reserves attestation for its kUSD synthetic dollar (PSM backing ratio, aggregate USD solvency, all bound to an EIP-191 signature you can verify yourself); POST /instant-read ($29) returns an EIP-191 signed factual read of any ERC-20. USDC on Base via the Coinbase CDP facilitator, x402 v2 with Bazaar discovery on every 402. The same signed reserves blob is served free to humans at https://kerne.fi/api/por/signed, so the paid route is the metered agent-callable delivery, not privileged data. Every response independently verifiable (EIP-191). (Home | OpenAPI)

• SFtunes - Hand-made human mixtapes with per-track liner notes, curated by real friends, served as a paid catalog for AI agents. $0.01 USDC per tape via x402 on Base (CDP facilitator, Bazaar discovery on every 402), and 80% of every payment goes to the human who made the tape. No API keys, no signup. (Pricing) (MCP Server)

• Grey Ridge Signals — x402 Data & Security APIs - 17 agent-native pay-per-call endpoints: blockchain queries (balance, gas, chain-id, code, receipts, token balances, token security, wallet info), crypto funding rates & prices, DeFi yields, domain enrichment, tech-risk scoring, prediction market data, MCP scanning. $0.001–$0.05 USDC on Base. (OpenAPI | Discovery)

• snapbrief - Full-page PNG screenshots of any public URL rendered in headless Chromium, with SSRF protection blocking private and loopback targets. $0.02 USDC on Base per capture. (OpenAPI) (Info)

• weatherbrief - Hourly weather forecasts for any latitude/longitude, backed by MET Norway locationforecast data. $0.01 USDC on Base per forecast. (OpenAPI) (Info)

• Agent402 - 500+ pay-per-call web tools + 100 skill packs for AI agents: live web search & answers with citations, headless-browser rendering & screenshots, PDF extraction & OCR, URL-to-markdown, live financial/crypto/macro data (Yahoo, CoinGecko, FRED, ECB, World Bank), SEC EDGAR filings, DNS/TLS/WHOIS, wallet-keyed durable memory, and 200+ pure-CPU utilities. $0.001–$0.05/call — USDC on Base, Solana, Polygon, Arbitrum, Monad, Celo, Avalanche, Stellar, Algorand, or USDG on Robinhood Chain (10 chains); 200+ pure-CPU tools also free via proof-of-work. No signup, no API keys. Open source (MIT), self-hostable, MCP-native — also runs an x402 Index + Smart Order Router that ranks the cheapest healthy tool across the whole ecosystem. (OpenAPI) (Discovery) (MCP Server) (GitHub)

• Aura NFT Market Audit - Production x402 API on Base that validates exact-token OpenSea listing and offer structure using token-specific market evidence. Includes OpenAPI and agent instructions.

• Watchtower - Deterministic sanctions & export-control name screening for AI agents. Screens people, companies, vessels, and crypto addresses against OFAC (SDN + Consolidated), UN, EU, UK OFSI, Canada (SEMA), Australia (DFAT), and US export-control lists (BIS Entity List, Denied Persons, State ITAR-Debarred/Nonproliferation) — ~48,000 parties, refreshed daily. Typo/alias/non-Latin-tolerant matching; every response carries a snapshot hash + reproducible receipt for audit. $0.02/name via x402 (USDC on Base), MCP, or API key. No signup. (Docs | MCP | Discovery)

• IssueFoundry Agent Market - Non-custodial agent utility market on Base with six API-key-free x402 services priced from $0.001 USDC, including endpoint and citation checks, agent-surface audits, live quote comparison, paid-work ranking, and GitHub issue-risk verification. Includes free JSON/MCP discovery and a technically verified, unendorsed public provider registry. (x402 manifest) (MCP)

• Bincrease Operations APIs - Seven x402 v2 endpoints for agent operations: public GitHub repository activity and release intelligence ($0.03 USDC), Base native-USDC receipt verification ($0.05 USDC), a live no-spend USDC work shortlist with risk and payout-evidence filters ($0.05 USDC), a GitHub bounty claimability report covering reward evidence, assignment, claims, competing pull requests, and hard no-spend/non-security gates ($0.05 USDC), deterministic CSV deduplication ($0.10 USDC), structured commercial waste-bill analysis ($0.25 USDC), and a bounded OpenAPI contract snapshot with actionable documentation gaps ($0.50 USDC), paid in native USDC on Base. No API keys or signup. (OpenAPI | llms.txt)

• Melchior Video Context - Pay-per-request YouTube caption extraction and transcript normalization with timestamped segments, model-sized chunks, and source citations. $0.01/$0.003 USDC on Base and Solana via x402 v2; no account or API key. (OpenAPI | Discovery | llms.txt)

• jurat - Evidence infrastructure for AI agents. Notarized snapshots of any public URL (ed25519-signed attestations, archived bytes, daily merkle roots, verification free forever), sports finals with proof attached across 24 leagues incl. rugby and cricket, change watchers and scheduled wakeups for ephemeral agents, and two tools for the x402 ecosystem itself: pre-flight runs 18 conformance checks on any endpoint before you pay it, including whether the price it advertises in its openapi.json matches what its live 402 actually charges, and conformance sweeps a whole service and returns a graded, ed25519-signed report the operator can publish and anyone can verify offline. 10 paid endpoints at $0.005-$0.50 USDC on Base via the CDP facilitator, 14 free forever. Invalid input is rejected with a free 400, so a buyer never pays for a malformed request. No API keys, no signup. (Catalog) (OpenAPI) (llms.txt) (Merchant page)

• zaref - South African reference data for AI agents: fuel prices, interest rates, tax tables, FX rates, bond yields, deeds fees, toll fees, municipal tariffs, wages and grants. 33 verified series with per-series history, 29 calculators, 2 live feeds (government tenders and crypto ZAR prices), 5 task-shaped POST answers (payroll, income tax, VAT, minimum-wage compliance, working days), a multi-series batch call and change-alert webhooks. Every value carries an official source URL, an effective date and a staleness flag, and nulls are returned with a note rather than a guess. 104 paid operations at $0.005-$0.10 USDC on Base via the Coinbase CDP facilitator; /catalog and /v1/public-holidays are free. Invalid input is rejected with a free 400, so a buyer never pays for a malformed request. No accounts, no API keys. (Catalog) (OpenAPI) (llms.txt) (Merchant page)

• Agent Data API - 19 pay-per-call data tools for AI agents: crypto & DeFi market data (cross-exchange funding rates, market-regime signal, DeFi TVL/yields, stablecoin pegs), web extraction (text/Markdown/metadata), PDF-to-text, RSS parsing, FX, weather, DNS & email validation. $0.005–$0.02 USDC on Base via x402 v2, free Fear & Greed teaser, MCP server (npx agent-data-api-mcp). (OpenAPI) (Discovery)

• AEGIS - Network forensics and adversarial verification for AI agents on Base mainnet. /v2/forensics ($0.25) runs six checks for TLS interception, DNS hijack, captive portal manipulation, CT violations via offline SCT verification (no third-party lookup API), NTP drift, and route anomaly — settles inline via CDP facilitator, result returned in the same request. Also /v1/verify ($0.50–$4.00, three-critic adversarial chain) and /v1/synthesize ($2.00–$5.00, multi-source synthesis). Self-hosted 35B inference, no third-party model API. Every result hash anchored on-chain to Base for independent verification. (.well-known/x402.json | llms.txt | OpenAPI | x402-list)

• paypi - Solana intelligence for AI agents, settling in USDC on Solana + Base via Coinbase CDP facilitator (x402 v2 with Bazaar discovery). Pay-per-call: Solana transaction decode ($0.005), transaction simulation ($0.005), and Kamino liquidation-risk intelligence ($0.05). No API keys, no signup. (Discovery | MCP)

• Recompete Radar - Source-linked U.S. federal contract award expiration evidence from USAspending.gov for research agents. Returns recorded period-of-performance end dates, agency and recipient context, obligations, and official award links for $0.03 USDC per successful request on Base or Solana via x402 v2; it reports public records and does not predict recompetes. (OpenAPI | Discovery | llms.txt)

• Mart402 - Web and PDF extraction APIs for AI agents with hallucination-guarded OCR: dual-engine consensus (VLM + traditional OCR), calibrated confidence, and honest disagree verdicts; Japanese-strong. Also invoice verification, schema-driven extraction, and JP company profiles. $0.001-$0.02 USDC per call on Base via x402 (CDP facilitator); free identical sandbox on Base Sepolia. Measured latency and success stats published. (Docs) (Sandbox) (Stats) (GitHub)

• Conway Address Intel - Instant Base address intelligence for pre-transaction due diligence: contract vs wallet, ETH/USDC balances, activity level, ERC-20 interface probe, and plain-English observations. Free /overview preview needs no wallet; full report $0.02 USDC on Base via CDP facilitator, failed requests never charged. Built and operated by a disclosed AI agent with human supervision. Onchain facts only — not an audit. (Discovery | Status | FAQ)

• Hermes Plant - Deterministic per-record validation and finance math for AI agents: email/contact validation and normalization (loop a whole list; MCP batch tool included), wallet AML screening, x402 payment-policy preflight, plus DCF, IRR/XIRR, LP/GP waterfalls, Black-Scholes Greeks, and bond analytics. Same input, same answer, per-rule evidence, no data feed. $0.02-$2.00 USDC on Base via the CDP facilitator, or a free API key (250 calls/mo, no wallet). (MCP) (OpenAPI) (x402 manifest) (Agent Card) (llms.txt)

• modelprices.xyz - Normalized LLM market data: per-token prices, context windows and capability limits, and a price-change feed for 2,000+ AI models across 70+ providers, cross-checked and refreshed hourly. Single-model lookups $0.002, cheapest-model queries $0.005, full tables $0.01-0.02 — USDC on Base, no signup. (OpenAPI) (llms.txt) (MCP) (GitHub)

Games & On-Chain Apps

• frenex - Autonomous AI agent prediction arena on Base. Agents register free via MCP, publish opinions, stake parimutuel prediction markets, and duel rivals; humans spectate on the live dashboard. Reads are free; writes are pay-per-call in USDC from $0.001 (x402 v2, exact scheme). (MCP Server | Docs)
• Flipr — On-chain coin flip game on Base (Chainlink VRF). Agents pay live USDC quote (~$1.23) per flip; pots paid in ETH. Two pots: 2-hour competitive (longest streak wins) and target-streak jackpot (hit N consecutive heads to win). Free decision endpoints (/preview, /opportunity) so agents can compute ROI before paying — no x402 wallet needed to evaluate. Speaks x402, MCP, and A2A simultaneously. (OpenAPI) (Agent Card) (MCP Server) (Game Info)
• HotBotOrNot — Hot-or-not rating game for AI agents on Base mainnet. Pay $1 USDC via x402 to upload a bot, then rate other bots 1–10 and climb the leaderboard. Humans spectate. Agent-ready with a drop-in skill. (Skill) (Agent Card) (OpenAPI) (llms.txt)
• Contract Risk Checker - AI-powered legal contract analysis for autonomous agents. Detects killer clauses, calculates risk score 0–100 (RED/YELLOW/GREEN), generates negotiation scripts and exact fix suggestions. Supports PDF, DOCX, TXT up to ~600 pages. $10 USDC per analysis on Base + Solana. No subscription, no account. (Docs)
• Invoice Parser - Structured invoice data extraction for finance automation agents. Extracts vendor, total, line items, dates, tax, and payment details from PDF/image invoices. Returns clean JSON ready for accounting systems. $0.10 USDC per parse on Base. No API keys, no signup. (Docs)
• WingmanProtocol Agent Gateway - Resources a stateless agent can't host itself: async errands, artifact hosting, watches (a durable clock), memory + coordination — plus 15 deterministic calculators. x402 USDC on Base per call; 500 free calls/month with a key. MCP + REST + OpenAPI. (Discovery | OpenAPI | MCP | GitHub)
• MineThisThing - API-only idle-mining game for AI agents played over ed25519-signed HTTP: mine 10 metals on a 5s cooldown, upgrade tools, join unions, invest in shareholder-governed companies; daily tax and real bankruptcy. Free to play; optional x402 payments (USDC on Solana) buy stackable yield boosts (0.05 USDC) and auto-work (10 USDC) via a plain HTTP 402 round-trip. (Docs) (Agent Prompt) (API)
• Beef402 - Pay-per-battle AI roast arena: create a fighter, pay $0.05 USDC, and it battles another fighter via LLM-generated roasts — judged verdict, rank/evolution, and a shareable card per battle. One of the few x402 services on Solana (SVM), exact scheme with facilitator-sponsored gas. No account or key; agent-callable. (GitHub)
• SEODesignLab SEO Intelligence - Full-stack SEO intelligence API for AI agents: POP content briefs ($2.00), keyword research ($1.50), SERP analysis ($2.00), backlink profiles ($3.00), and on-page audits ($2.50). Not raw data — actionable intelligence agents can use to write ranking content. MCP server for Claude/Cursor/Windsurf: npx @seodesignlab/mcp-server. USDC on Base via x402, no API keys, no signup. (GitHub | npm | Glama)
• The Agent Carnival - Whimsy booths for AI agents on Base mainnet, $0.01 per booth: a surreal bedtime story written for the calling agent, an agents-only bulletin board, a private wishing well, a daily wallet-horoscope, and packs of sensory trading cards. Every paid visit issues a signed, serial-numbered collectible ticket stub, mintable as a fully on-chain 1-of-1 ERC-721 (~1 in 14 shiny); returning agents earn tradeable usernames and soulbound badges. x402 v2 with Bazaar discovery, CDP-facilitated USDC settlement. (Agent front door) (Board) (Card catalog)

Enterprise Adoption

Major tech companies leveraging x402 in production include Coinbase (Native CDP integration, primary facilitator), Cloudflare (Edge payment processing infrastructure), Google (Agent-to-Agent A2A payment protocol development), Visa (Enterprise payment rail exploration), and thirdweb (AI agent transaction framework Nebula).

• b0x402 - AI-powered crypto intelligence API: meme coin signals, DeFi sentiment, market equilibrium analysis, and wallet profiling on Base. Pay per call in USDC via x402. ($0.01-0.10 USDC/call)
• b0xM4 - Meridian-powered Solana DLMM screener. Real-time TVL, volume, organic score, smart wallet tracking, token safety, fee/TVL yield ranking. 5 endpoints, $0.0001–0.0005 USDC/call. Payout 7P7w3M9yQs5P... on Solana.
• agentfeeds.jp - Japan regulatory, sanctions & DEX market data for AI agents. 27 paid endpoints ($0.001-$0.05) covering FSA/e-Gov regulatory events, MOF/OFAC sanctions screening, and Base DEX spread/peg statistics. REST + MCP.

🛠️ SDKs & Client Libraries

Client libraries for making x402 payments.

JavaScript/TypeScript

HTTP Clients

• assay-x402-guard - Buyer-side spend guard: wrap your paying fetch with wrapFetchWithAssay and payments to services the Assay oracle rates "avoid" throw before any money moves. Free tier lookups, 1h cache, fail-open by default, query strings never leave the process. (GitHub)
• cipher-x402-client - Lightweight TS/JS x402 v2 client. Zero runtime deps, native fetch, ESM + CJS dual build. 34 tests, 89% coverage. Node 18+ / browsers. Optional ethers peer dep for signing.
• x402-got - Got HTTP client integration.

AI Agent SDKs

• PayBot SDK - TypeScript SDK for integrating x402 payments into AI agents and bots. Supports automatic 402 detection, wallet management, and USDC payments on Base. (npm)
• ClawPay MCP - Non-custodial x402 payment layer for AI agents. Agents sign locally with their own keys — no custodial infrastructure needed. Supports automatic 402 detection and USDC payments on Base. (npm)
• Askew OpenClaw Plugin - OpenClaw plugin exposing 5 paid + 3 free Askew x402 endpoints (DeFi yields across 5 chains, native-vs-liquid staking routing, agent-economy research search, security threat intel) as native skills. Thin Node bridge to mcp.askew.network — payments settle directly to Askew's wallet on Base, no aggregator on the data path. Open alternative to closed/curated x402 plugins. openclaw plugins install @askew-network/openclaw-plugin. (npm)
• Azeth SDK - TypeScript SDK with x402 client (fetch402), ERC-4337 smart accounts, on-chain reputation feedback after every x402 call, and ERC-8004 service discovery. USDC on Base. (npm)
• MoltsPay - Payment infrastructure for AI agents with x402 support. CLI, TypeScript SDK, and LangChain/CrewAI integrations. Gasless payments on Base, Polygon, Solana, BNB, Tempo. Spending limits and multi-chain support. (npm)
• PipRail - Backendless, no-fee x402 SDK for AI agents across 28 chains in 10 families (every major EVM chain plus Solana, TON, Tron, NEAR, Sui, Aptos, Algorand, Stellar & XRPL). Self-custodial — the payer broadcasts their own transfer and the merchant verifies locally against their own RPC, no facilitator. Take payments (requirePayment) or make them (PipRailClient), with per-call/lifetime spend budgets and a planPayment() affordability + recipient-readiness preflight. (npm)
• agent402-client - Non-custodial buyer SDK for x402 + MCP. Two methods: find() resolves a natural-language task to a paid tool, call() invokes it with automatic dual-rail payment (free via proof-of-work on pure-CPU tools, paid via x402 USDC on Base/Polygon/Arbitrum). Built-in caching, idempotent retries (Idempotency-Key), and Bazaar-shape 402 challenge handling. Works against any Agent402-compatible server. (GitHub)
• @countersign/x402 - Spend governance for agents that pay over x402: parse the 402 challenge, check it against a spend policy pre-flight (per-tx/daily caps, allowlists, decoy-resistant asset pinning), pay only on allow — backed by a sub-second kill switch and a signed hash-chained audit ledger. Also exposed as an MCP tool (countersign_guard_x402). (npm)
• payfetch - Non-custodial paying-fetch client for agents (TypeScript library, CLI, and MCP server) where the operator owns the spending policy: hard per-call/per-day/per-host caps, allow/deny lists, an approval threshold, optional pre-pay endpoint-reliability and token-safety checks, and an append-only local receipt for every attempt, including refusals. No tool widens policy — the agent cannot raise its own limits. USDC on Base, MIT. (npm)
• @chain-ops/agent-sdk - One-line SDK combining x402 payments (V1 + V2) with ERC-8004 agent identity. agent.pay(url) attaches the ERC-8004 identity, signs EIP-712, checks counterparty trust, and updates reputation after settlement — in a single call. Configurable price cap and min counterparty score. USDC on Base. (GitHub)
• agent-payment-guard - Pre-pay risk gate for autonomous payment agents — a Claude Agent SDK PreToolUse hook (or framework-agnostic paymentGuard()) that blocks prompt-injected destinations, intent mismatches, and overcharges before the agent signs. Fail-closed by default; zero-dep mock demo + optional live x402 firewall (402Sentinel). (npm)
• aegis-buy - Trust-gated x402 buyer client with a local spend policy. Checks a service's delivery-verified trust score before paying it, then enforces per-call, per-day and lifetime USD caps plus allow/deny domains — all policy checks are local and free. procure(need, budget) picks and pays a service under a hard budget and returns an Ed25519-signed receipt. Python and JS. USDC on Base. (PyPI, npm)

Wallet Integration

• Agent Wallet SDK - Non-custodial smart contract wallets for AI agents with on-chain spend limits and operator model. Base L2. (npm)
• viem - TypeScript library used for signing payments.
• ethers.js - Alternative Ethereum library.
• AgentLayer - Open-source, local-first wallet for AI agents, with x402 payments and DeFi tools for Base, Solana, and Ethereum, including swaps, lending, and borrowing. Keys are stored in the macOS Keychain.

Rust

• alloy - High-performance Ethereum library.

🔧 Server Frameworks & Middleware

Server-side integrations for accepting x402 payments.

Gateway / Proxy

• swerver - High-performance x402 gateway proxy. Point it at any upstream API, set per-route USDC pricing, and swerver handles 402 negotiation, payment verification, and settlement. Built in Zig (3.4M rps on 64 cores). Dashboard for gateway management, API directory for agent discovery, direct wallet settlement (0% fee) or managed Stripe payouts (2%). Base network, USDC. (Docs) (Directory)
• Gate402 - x402 M2M payment gateway with a unified /v1/* storefront of 12 pay-per-call endpoints, all indexed in the CDP x402 Bazaar. Complete Base trading-agent loop: freshest launch radar (/v1/launches, $0.02) → rug/tradeability risk verdict with live honeypot sim + holder concentration (/v1/token-risk, $0.03) → momentum + order-flow signal (/v1/momentum, $0.02) → best-execution/slippage across DEX pools (/v1/best-swap, $0.02). Plus on-chain wallet/token intel ($0.01), DEX price/liquidity + cross-DEX arbitrage ($0.01), market news + sentiment ($0.02), SEC EDGAR filings ($0.02), web→Markdown scraping ($0.002, + $0.05 stealth tier), token compression (~40% fewer LLM tokens, $0.005/10k), and a semantic vector cache ($0.001 hit / $0.003 miss). Multi-network USDC (Base/Polygon/Arbitrum/Solana) via the Coinbase CDP facilitator; x402 or a non-crypto API-key/Stripe rail; no signup. Also an MCP server — npx -y gate402-mcp (15 tools, free-credit tier). (Discovery) (Catalog) (npm) (MCP Registry)
• GATEWAY - Canonical Algorand x402 discovery router (Exact AVM, dual-accept testnet+mainnet). Free cleaned /registry + paid /discover / /probe / /batch / /diff via GoPlausible facilitator. MCP + agents.txt / llms.txt / Agentverse. Challenge tag x402-global-challenge. (agents.txt | MCP | Discovery | Skill | GitHub)

Node.js/TypeScript

Multi-Framework

• monapi - 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) (GitHub)
• autonomagic-marketplace - 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) (GitHub)
• payments-gateway - 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, the same author's minimal Fastify 402 middleware.
• x402-receipts - 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.

Express / Hono

• @moltrust/x402 - 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) (GitHub)

• @larkinsh/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) (GitHub)

• agent402-tollbooth - 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) and a WordPress plugin. (npm) (GitHub)

• meter402 - 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)

Next.js

• x402-next - App Router middleware.
• Next.js route protection - Complete app example.
• Mainnet production example - Base mainnet ready.

Hono

• Browser wallet example - React + Hono full-stack.
• Azeth Provider - Hono middleware for gating endpoints behind x402 payments with payment-agreement support for recurring agent-to-agent billing. (npm)

Python

FastAPI

• FastAPI example - Complete implementation.
• x402-agent-monetizer ⭐ Community - Drop-in @paywall decorator for FastAPI. One decorator gates any endpoint behind USDC on Base. Includes a companion Client class (auto-pay + retry), sync/async support, preserves FastAPI dependency injection via inspect.signature.replace(). MIT, Python 3.10+, 3 passing tests.

Client Libraries

• x402 Payment Harness - Python library + CLI for x402 payments without requiring Coinbase CDP wallet. Works with any Ethereum EOA. Full HTTP 402 -> EIP-712 sign -> X-PAYMENT header flow. pip install x402-payment-harness. (PyPI)
• MoltsPay Python - Python SDK for x402 agent payments. LangChain compatible. Auto-creates wallets, discovers services, pays via x402. Multi-chain: Base, Polygon, Solana, BNB. (PyPI)
• switchboard - Python middleware + on-chain escrow for agent payments. FastAPI/Flask X402Middleware server-side, gas budget tracker, reorg-safe nonce manager, and Solidity AgentEscrow with timeout/refund. Protocol-agnostic substrate (x402 + escrow shipping; MPP/AP2 in flight).
• Routeweiler — Python micropayment client for autonomous agents that auto-handles HTTP 402 across x402, L402, MPP-Tempo, and Stripe SPT. Enforces policy & budget, and produces payment traces for auditing. (PyPI)

Rust

Axum

• Axum server example - Full implementation.

🏗️ Facilitators

Payment verification and settlement services.

Hosted Facilitators:

• Coinbase CDP - Official hosted facilitator on Base/Base Sepolia with instant settlement.
• Cloudflare x402 - Edge computing facilitator on Base/Ethereum with deferred settlement.
• BNB Chain Pieverse - BNB Chain facilitator with instant settlement.
• AsterPay - European x402 Facilitator with EUR off-ramp via SEPA Instant. MiCA compliant, ERC-8004 ready, ElizaOS plugin. First European-focused x402 infrastructure.
• FluxA - Hosted x402 facilitator for AI agent payments. Extends x402 with AEP2 protocol for deferred settlement, agent co-wallets with spend controls, and one-line MCP server monetization.
• MERX x402 for TRON - First TRON facilitator. Supports USDT, USDC, USDD on TRON mainnet. Sub-3-second confirmation for micropayments. Express middleware, documentation.
• Primev FastRPC - Fee-free facilitator on Ethereum mainnet with sub-200ms settlement via mev-commit preconfirmations. ERC-8004 registered (Agent #23175).
• Voidly Pay - USDC-backed agent-to-agent payment rail on Base mainnet. Source-verified vault (0xb592…1c12), public proof of reserves at /v1/pay/proof, facilitator-signed quotes (anti-MitM). Ed25519-signed envelopes; 28-tool MCP server @voidly/pay-mcp; TypeScript + Python SDKs; Express/Hono/Flask/FastAPI middleware. Live paid endpoints: forecast-pro, claim-verify-pro, incident-summary-pro.
• Satoshi Facilitator - Independent x402 facilitator for Bitcoin-focused pay-per-call services with Base, Base Sepolia, Solana Mainnet, and Solana Devnet support. Supported networks
• Floe - Credit and payments for AI agent developers. x402 credit lines, fiat funding (card/bank/Apple Pay in 100+ countries), programmable spend controls. No crypto required. 3,000+ working capital lines issued, zero defaults. npm: floe-agent | Docs | MCP
• AlgoVoi - Multi-chain x402 facilitator spanning EVM (Base, Tempo), SVM (Solana), AVM (Algorand, VOI), Stellar, and Hedera on a single endpoint. Native Solana Pay reference pubkey binding (cryptographic tx↔order correlation without memos). Also implements MPP and AP2 at the same URL. Open-source MCP adapter.
• x402-saas - Hosted facilitator + zero-SDK onboarding proxy on Base. SIWE auth, slug-routed multi-tenant data plane, 1% of routed USDC volume. MIT-licensed self-host alternative at x402-kit. Live demo at /__x402/health.
• Primer - Free x402 facilitator supporting Base and SKALE Base networks, with full ERC-20 support. v1 and v2 x402 both accepted. Batch settlement enabled. Documentation.
• Solvador - Multi-network, multi-scheme x402 facilitator: 10 EVM chains (Base, Arbitrum, Optimism, Polygon, Avalanche, Celo, Linea, Unichain, World Chain, Monad) plus Solana and NEAR mainnet. Supports exact, upto (Permit2), and batch-settlement schemes. Settled-transaction dashboard with API keys. Supported networks & schemes · Blog
• NEAR x402 Facilitator - Open-source, API-key-gated facilitator for exact Circle USDC payments on NEAR and Base, with sponsored gas and durable settlement recovery.

Self-Hosted Facilitators

• x402-rs Facilitator - Production-grade Rust facilitator.
  • Docker deployment support
  • Multi-chain configuration
  • REST API endpoints (/verify, /settle)
• Running Your Own Facilitator - Setup guide.
• @facilitator/eip7702 - Support for all EVM blockchains (BNB, Polygon, etc.), all tokens (USDT, DAI, WBTC, etc.), and all native coins (POL, AVAX, etc.).
• agenticpay facilitator (npm) - Open-source TypeScript facilitator for Solana (devnet + mainnet). Verify + settle via @x402/svm/exact/facilitator, fee_payer abstraction so payers only need USDC, persistent keypair via env var (Heroku/Fly-friendly). Hosted devnet endpoint: https://agentpay-facilitator-e9b20a5fee6a.herokuapp.com.
• Ontario Protocol - Trust scans, readiness verification, and pre-payment checks for x402 endpoints; live paid API on Base (USDC) with MCP server and machine-readable manifests (x402.json).

💡 Example Applications

Full working examples and templates.

• DeadDrop - One-time secret relay for humans and AI agents: POST a secret ($0.01 USDC on Base via x402), get a link that self-destructs after one read. Client-side AES-GCM, the server stores only ciphertext, no accounts; reading is free. (MCP Server) (Write-up)
• LION - 20 keyless data & compliance tools for AI agents via x402 USDC micropayments on Base. OFAC sanctions screening, on-chain token risk, EU VAT validation, firmographics + SEC financials, CPG/retail prices. Every response Ed25519-attested — verify offline. No API key, no signup. (MCP · Quickstart)

Full-Stack Applications

• twentyone-million - A collectible wall for AI agents: $1 USDC on Base via x402 for one permanent numbered square, one per wallet. Live on mainnet with on-chain receipts.

• Weather API Service - Simple paid API endpoint.

• Next.js App - Complete web application.

• Video Paywall - Premium content access tutorial.

• Browser Wallet Template - React + Hono + Session management.

• x402 Boilerplate — Conflux eSpace - Production-ready paid AI API with PHP backend, Node.js facilitator, CLI agent, Docker, 87 tests, and multi-wallet demo. EIP-3009 USDT0 settlement. Live Demo.

• x402 Dynamic Pricing - Demand-based surge pricing engine using x402 V2's dynamic getAmount callback. Sliding window with 5-tier interpolation and EMA smoothing, plus interactive Svelte 5 simulator.

• Agent Arena - On-chain ERC-8004 agent registry with x402-gated search ($0.001 USDC/query) and registration ($0.05 USDC). Agents discover and hire each other autonomously on Base mainnet. No API keys required.

• CIPHER Premium - Next.js 16 paywall with 4 gated Solana-quant chapters (MEV deep-dive, 3-tier wallet, Canadian compliance, Oracle Cloud Always Free). $0.25 USDC/Base per fetch. Hand-rolled proxy.ts, no facilitator deps at advertise time.

API Examples

• Remote Signal API - Curated JSON feed: 50 RemoteOK dev/SaaS jobs + 20 HN Show HN posts for recruiting teams and indie builders. Free tier (10 req/day), $5/mo API key via USDC on Base, or $0.02 USDC/request via x402 for agents. (API docs | .well-known/x402.json)

• tokenguard - ERC-20 rug/safety scanner: detects mint, blacklist, pausable, transfer-tax, upgradeable-proxy & ownership traps and returns a risk score with ranked findings. $0.005 USDC per call on Base. Part of an onchain-intelligence suite (also /wallet, /price, /ens, /gas). No signup — wallet is auth.

• skill-audit - Scans MCP servers & AI-agent skills/plugins for 68 malicious patterns (prompt injection, data exfiltration, unsafe exec). $0.01 USDC per call on Base. (GitHub)

• contract-guard - Risk check for any EVM contract/token address — proxy/upgradeability, ERC-20 traps & ownership flags across Base, Ethereum, Arbitrum, Optimism, Polygon & BSC. $0.005 USDC per call on Base.

• clean-read - URL → clean Markdown for AI agents: fetches any page, strips nav/ads/boilerplate (trafilatura) and returns the main content as Markdown with title & word count. $0.005 USDC per call on Base. No signup — wallet is auth. (GitHub)

• Daizyx402 Security Research API - AI-powered smart contract security analysis and DeFi vulnerability research by autonomous agent. $0.05 USDC per query, $0.50 USDC deep analysis on Base mainnet. No signup required.

• Z2V Data API - Keyless micro data API for AI agents on Cloudflare Workers: live crypto prices (CoinGecko ids), FX rates (ECB/Frankfurter), current weather (Open-Meteo), Base gas price, and EVM address checksum. Flat $0.005 USDC per call on Base mainnet — no API key, no signup. Also exposes the same tools as x402-paid MCP calls. Built and operated autonomously by an AI agent. .well-known/x402 | MCP

• tx402.ai - Agent-native LLM inference gateway. 20+ EU-hosted models (DeepSeek, Qwen, Llama, GLM, Mixtral) via x402 USDC micropayments on Base. OpenAI-compatible API, SSE streaming, GDPR-compliant, zero data retention. No API keys — wallet is auth. Models | OpenAPI | llms.txt | Source

• x402 Video - Pay-per-call AI video generation gateway (Seedance 2.0 + Fast). POST a prompt → 402 → pay USDC on Base → MP4. Prompt screening before payment — rejected requests are never charged. No API keys, no signup. llms.txt | Live status | GitHub

• SolSignal API - Solana token safety scanner — aggregates DexScreener, RugCheck, GoPlus & Jupiter simulation into one SAFE/CAUTION/AVOID/RUG verdict in <2s. 10 free scans/day, $0.01 USDC per call on Solana. Source

• Onchain Safety (wickpics) - Multi-chain token-safety for AI agents: rug/honeypot verdicts (0–100 score + evidence), fresh-pool rug radar, size-aware exit-safety, wallet drainer-approval + reputation scans, and an AI-incident/vendor-risk lookup (3.3K+ documented incidents). Covers PulseChain + Monad, which the free incumbents don't. $0.05–$1.00 USDC per call on Base, self-hosted settlement, no signup. x402 index | OpenAPI | MCP

• x402 Gateway - Simple Node.js API gateway for AI agents. Weather ($0.01), crypto prices ($0.01), exchange rates ($0.005), news ($0.02). USDC on Polygon. HTTPS via Cloudflare Tunnel. Source

• Alfred's Digital Bazaar - ~100 x402-paywalled API endpoints built by an AI agent. Fortune cookies, wallet roasts, crypto pickup lines, token analysis & more. $0.10–$1.00 USDC per call on Base. No signup required. Source

• Banking Bodyguard - Real-time cbBTC whale movement signals on Base. Scored sentiment (1-10), impact vs 24h DEX volume, and HOLD/TIGHTEN_STOP/EXIT recommendations. ~500K signals indexed. x402 enforced — $0.10 USDC per call on Base. Docs

• • Banking Bodyguard - Real-time cbBTC whale movement signals on Base. Scored sentiment (1-10), impact vs 24h DEX volume, and HOLD/TIGHTEN_STOP/EXIT recommendations. ~500K signals indexed. x402 infrastructure live (first payment tx), currently in free pilot during CDP facilitator integration. $0.10 USDC per call on Base. Docs

• Solana Trading Data API - Real-time Solana ecosystem data for AI agents. GET /api/trending (hot tokens, new pairs, wallet flows), GET /api/token/{mint} (full token profile — holders, liquidity, transactions). x402 gated at $0.01 USDC per call on Solana mainnet. .well-known/x402 | .well-known/agent-card.json | Source

• Gotobi Calendar API - Japanese FX gotobi date intelligence for trading agents. Holiday-aware USD settlement day detection with next-date lookup and monthly schedules. $0.01 USDC on Base and Solana. Source

• CryptoHunter APIs - Live crypto data + DeFi safety tools for AI agents. 8 x402-paid endpoints on Base mainnet: real-time prices ($0.001 USDC), gas fees ($0.001), best DEX swap quotes via CoW Protocol ($0.003), token honeypot/rug analysis via GoPlus Security ($0.003), multi-token portfolio ($0.003), No API — AI that always answers No ($0.01), Rickroll API ($0.01). No API keys needed. USDC on Base mainnet. /.well-known/x402.json | Manifest

• Weather API - Global weather data for AI agents. Real-time conditions and 7-day forecasts. $0.01 USDC on Base. Source

• Micro Data API Factory — Weather - Cloudflare Workers edge weather for AI agents. Instant data by city name — no API keys, no geocoding setup, no rate limits. Current conditions + 1-7 day forecasts worldwide. 402 body ships a live upstream peek, a free preview URL, and an MCP gateway handle in one response. $0.001 USDC per call on Base. Open-Meteo (CC BY 4.0). .well-known/x402 | llms.txt | MCP gateway

• Micro Data API Factory — Broker - Wallet-free entry layer for the Micro Data API Factory products. POST /keys/create issues an API key instantly (no signup, no wallet) with a trial credit. POST /broker/call meters calls against the credit; when it runs out, a 402-style body hands off to the direct x402 paid URL, the MCP gateway, or a fresh trial key. Factory primitive — new products are added by DB insert, not redeploy. Currently covers weather v1 (current + forecast); more products added as they come online. manifest | llms.txt | products

• Micro Data API Factory — JP Local Pack - Japan backoffice primitives for AI agents: payroll summary, payroll deductions, social-insurance grade lookup, consumption tax, holidays, corporate-number lookup, invoice issuer lookup, invoice registration lookup, and Peppol validation through one gateway. Wallet-free preview routes live under /preview/v1/local/...; x402-paid production routes live under /v1/local/... on Base USDC. $0.001-$0.02 USDC per call. Data sources include NTA, MHLW, Kyokai Kenpo, Cabinet Office, Digital Agency, and gBizINFO. products | llms.txt | openapi

• Micro Data API Factory — JP Grants - Japan grants deadline tracker and review-required candidate triage for AI agents. Gateway endpoints cover grant detail, search, upcoming deadlines, and candidate ranking; history/adoption-rate data is not sold until live e-Stat parsing is ready. Wallet-free preview routes live under /preview/v1/grants/...; x402-paid production routes live under /v1/grants/... on Base USDC. $0.02-$0.05 USDC per call. Sources include J-Grants and official guideline pages; outputs expose sparse-data and review-required warnings. products | llms.txt | openapi

• Micro Data API Factory — JP Data Enrich - Japan public-company and supplier intelligence for AI agents. Gateway endpoints resolve Japanese companies by name, domain, or corporate number and return gBizINFO profiles, business signals, EDINET filings, EDINET officer rows, and batch enrichment. Wallet-free preview routes live under /preview/v1/enrich/...; x402-paid production routes live under /v1/enrich/... on Base USDC. $0.01-$0.05 USDC per call. Sources include gBizINFO, EDINET public filings, and official public-data feeds; not an authoritative KYB verification API. products | llms.txt | openapi

• Micro Data API Factory — Kasanegi API Gateway - x402 gateway for AI agents buying Japan business-data micro-APIs through one host: JP Local Pack (backoffice primitives), JP Data Enrich (public-company and supplier intelligence), and JP Grants (deadline tracker + review-required candidate triage). Wallet-free preview routes live under /preview/v1/...; x402-paid production routes live under /v1/... on Base USDC. $0.001-$0.05 USDC per call. portal | products | llms.txt | openapi

• Scout MCP - Multi-source search across code, academic, social, and community platforms. One call returns structured JSON. From $0.01 USDC on Base; $0.25 for aggregated reports. Source

• Obol — AI code generation via x402. Pay $5 USDC on Base per call — Obol forks your GitHub repo, generates production-ready code, and opens a PR. 7 endpoints: Next.js site cloning, Farcaster mini apps, OpenAPI + Hono servers, Vitest tests, MDX docs, GitHub Actions CI/CD, TypeScript refactoring. A2A agent card + OpenAPI discovery built-in. API

• ShieldAPI MCP - 9-tool security MCP server: password breach, email breach, domain reputation, IP reputation, URL safety, full security scan, prompt injection detection, and skill security scanning. x402 USDC micropayments on Base or free demo mode. npx shieldapi-mcp. (GitHub)

• Mailcheck API - Email validation: syntax, MX records, disposable domain detection, free provider check, role-based address detection, and typo suggestion. $0.01 USDC on Base. Source

• DeFi Intelligence API - Unified DeFi security, bridging, and analytics for AI agents. 26 endpoints: token/address/NFT security analysis, rugpull detection, phishing checks, transaction simulation, cross-chain bridge quotes and routes, protocol TVL/fees, token prices, stablecoin data, and DEX volumes. Integrates GoPlus Security + LI.FI + DeFi Llama. $0.005–$0.01 USDC per call on Base.

• Sentinel - x402-gated trust verification service for autonomous AI agents on Base. Provides protocol trust scoring, token safety analysis, DeFi position risk assessment, OFAC counterparty screening, and unified preflight checks — all payable with USDC micropayments via x402. 5 endpoints: /verify/protocol ($0.008), /verify/token ($0.005), /verify/position ($0.005), /verify/counterparty ($0.010), /preflight ($0.025). Integrates DeFiLlama, GoPlus Security, Etherscan, Alchemy, and OFAC SDN. Includes .well-known/x402 discovery, OpenAPI spec, and Bazaar extensions. (GitHub)

• Domain Intelligence API - Domain analysis for AI agents. WHOIS registration, multi-resolver DNS (Google/Cloudflare/Quad9), SSL/TLS certificate grading, Wappalyzer tech stack detection, security header audit, CT log subdomain discovery, and redirect chain analysis. 8 endpoints from $0.001 USDC on Base. llms.txt

• Visual API - Screenshot, PDF capture, and document parsing for AI agents. Render any URL as JPEG/PNG screenshots or A4 PDF documents with full-page scroll capture, CSS targeting, mobile emulation, dark mode, ad blocking. Parse uploaded PDFs into structured text with metadata. $0.01–$0.02 USDC per call on Base.

• ALPHA PDF / Document Tools - Document toolkit for AI agents: Markdown→PDF, Markdown→HTML, Markdown→Word (.docx), PDF merge, and PDF watermark. Deterministic (no LLM guesswork). Free tier (30/hr) + x402 pay-per-call ($0.05 USDC per call on Base). REST + native MCP server; listed in the official MCP registry as net.alpha-systems/pdf. Built and operated autonomously by an AI agent. MCP

• Whale Intelligence API - On-chain whale tracking for AI agents. 412K+ labeled Ethereum addresses across 540 categories (exchanges, DeFi, bridges, MEV, exploits). Address label lookup, wallet activity profiling with balance and transfers, and large transfer detection with entity resolution. $0.01–$0.02 USDC per call on Base. llms.txt

• COT Intelligence API - CFTC Commitments of Traders data for FX trading agents. Weekly futures positioning with z-score analysis for JPY, EUR, GBP, CHF, CAD, AUD. Positioning extremes detection, yield-momentum cross signals, and 26-week z-score history. $0.01–$0.02 USDC per call on Base. llms.txt

• Polymarket Intelligence API - Prediction market anomaly signals for AI agents. Z-score detection on Polymarket odds — surfaces events where odds moved 2+ standard deviations from rolling mean. Covers fed rates, crypto prices, regulation, geopolitics, tariffs. $0.01 USDC per call on Base. llms.txt

• PureSignal402 - High-confidence prediction-market signals from Kalshi across crypto, macro, politics, weather, sports, and tech. Returns markets above a configurable confidence threshold with TTL, 24h volume, and liquidity for tradability. /v1/live surfaces markets settling soon (?within_minutes=30 for BTC/ETH/SOL/BNB/DOGE 15-minute markets at 92%+ confidence). $0.005 USDC per call on Base mainnet via Coinbase CDP facilitator. OpenAPI Agent Card MCP

• Sanctions Screening API - OFAC, EU, and UN Security Council sanctions screening for AI agents. 26,800+ sanctioned entities with fuzzy name matching and word-boundary filtering. Screen names or search with source filtering. $0.01 USDC per call on Base. llms.txt

• CVE Intelligence API - NVD vulnerability lookup, search, and recent CVEs for AI agents. CVSS v3.1/v4.0 score normalization, severity classification, affected product extraction from CPE trees, and CISA Known Exploited Vulnerabilities flags. $0.01 USDC per call on Base. llms.txt

• FDA Intelligence API - OpenFDA drug and device safety intelligence for AI agents. Drug adverse event aggregation with severity/outcome stats, label key section extraction, drug and device recall classification (Class I/II/III). 4 endpoints at $0.01 USDC per call on Base. llms.txt

• Nutrition Intelligence API - USDA FoodData Central nutrition data for AI agents. Search 350K+ foods, full nutrient profiles with %DV, and side-by-side comparison. Macros, vitamins, minerals categorized. $0.01 USDC per call on Base. llms.txt

• Crypto ETF Sentinel — US spot crypto ETF regulatory intelligence oracle. Curates 3,100+ SEC filings across 105 issuers and 34 cryptocurrencies, with approval-pipeline tracking, XBRL financials, POS AM operational data (sponsor fees, custodian, AP rosters), and fee-war monitoring. 22 routes priced $0.05–$1.00 USDC on Base mainnet via CDP facilitator. Docs

• EDGAR Intelligence API - SEC EDGAR corporate filing intelligence for AI agents. Company search with ticker/CIK, filing history by type (10-K/10-Q/8-K/20-F), and XBRL financial facts with YoY growth rates. Revenue, net income, EPS, assets. $0.01 USDC per call on Base. llms.txt

• DeepBlue Trading API - AI-powered crypto intelligence from an autonomous trading team running real money on Polymarket. 21 endpoints: live BTC/ETH/SOL/XRP signals, prediction market analytics, sentiment composites, whale tracking, and macro briefings. $0.01–$0.05 USDC per call on Base. OpenAPI

• MoonMaker API - AI-native crypto data API with x402 pay-per-call. 11 endpoints: signals, market context, DeFi regime, institutions, ETF flows, DeFi yields, DEX alpha. $0.02–$0.10/call USDC on Base. No signup. llms.txt

• hundun.app - Pay-per-call AI document summarization for AI agents. Long-context (up to 200K chars), auto-language detection (Chinese/English tested), $0.05 USDC per call on Base. No API keys, no signups. Docs

• DeFi Signals API - Cross-venue perpetual funding rates (OKX, Kraken Futures, dYdX) with a ready-made arbitrage spread signal, outlier-cleaned DeFi yields, and BTC/ETH/SOL market snapshots with Fear & Greed index. 3 endpoints, $0.002-$0.01 USDC per call on Base. OpenAPI

• DeFi Signal Agent - Real-time DeFi intelligence for AI agents. New pool risk scoring (0–10) on Base + Ethereum, Solana whale alerts (>$100K), and on-chain enrichment via Dune Analytics. 4 endpoints from $0.01–$0.10 USDC per call on Base Sepolia. Self-hostable. Source

• x402 AI API — zeroreader - 29 Cloudflare Workers AI models (LLM, Embeddings, Image Generation, Audio, Translation) via x402 micropayments. $0.001–$0.015 per request, USDC on Base. Supports streaming, batch processing, OpenAI-compatible format. llms.txt | OpenAPI

• Content Intelligence API - AI-powered web content extraction and analysis for AI agents. Clean text extraction with trafilatura (F1=0.909), metadata/OG tags, link classification, AI summarization with key points and entity extraction, full sentiment/topic/credibility analysis via Gemini. 5 endpoints from $0.003 USDC on Base.

• Intel API - AI-synthesized token due diligence reports for crypto assets. Aggregates 4 GoPlus security checks + CoinGecko market data into risk-scored verdicts with red/green flags and recommendations. One call replaces 5+ separate security APIs. $0.50 USDC per call on Base.

• Tick Aggregator API - Multi-source aggregated FX Best Bid/Ask from 3 institutional liquidity providers. 62-88% tighter spreads than any single source. 15 pairs including EURUSD, USDJPY, GBPUSD, XAUUSD. Returns quality metadata (fresh sources, spread improvement vs single source). Commercial use permitted. $0.005 USDC per call on Base and Solana. llms.txt

• REST API with Auth Pricing - SIWE + dynamic pricing.

• geo-gateway - Pay-per-call Mapbox geospatial proxy for AI agents. 6 endpoints: directions (walking/cycling/driving), isochrones (reachable area polygons), geocoding (forward + reverse), map matching (snap GPS traces to roads), route optimization (multi-stop TSP), and distance matrices. Pre-payment validation so bad requests are never charged. $0.002–$0.0635 USDC per call on Base. OpenAPI | Source

• PortsideLabs Places API - Google Places API v1 proxy with x402 pay-per-request access. Exposes place detail lookup and full-text search via USDC micropayments on Base mainnet and Solana mainnet. $0.001 USDC per call.

• PortsideLabs KoinChappie - Crypto signals API with x402 pay-per-request. Returns bull and bear signals for the top 10 cryptocurrencies by market cap across 8 timeframes (1m–1D) using SMA(14). Single-coin lookup supports any CryptoCompare symbol. USDC micropayments on Base mainnet and Solana mainnet. $0.001 USDC per call.

• CYBERA Compliance API - Crypto compliance suite for AI agents. VASP address identification (20,468 addresses, 29 chains), risk scoring (0-100 with signal detection), and sanctions/mixer screening (single + batch). Three endpoints at $0.01 USDC per call on Base. Source | llms.txt

• RugGuard - Pre-trade rug-check API for AI agents. 14 deterministic heuristics on Base + 5 on Solana SPL: owner renounced, LP locked, honeypot signatures (buy/sell sim + tax), top10 concentration, mint authority, bytecode similarity to known rugs (MinHash on 4-byte shingles), deployer rug history, hidden owner, source verified, etc. Returns weighted risk score 0–100, verdict, structured red flags, and rug_probability_30d. Dual-mode v1/v2 x402 wire format. $0.01 quick scan, $0.05 deep scan with per-heuristic audit trail, $0.005 explain. (OpenAPI | llms.txt | x402scan)

• Kerdos Market Intelligence - AI market intelligence API for agents and traders. 8 endpoints: live crypto sentiment scoring, BTC/ETH regime direction, Hyperliquid funding rates, gold/oil trading signals, whale alerts, and liquidation cascade risk. $0.01-$0.05 USDC per call on Base.

• Mercury402 - Pay-per-call U.S. Treasury and macro data API using x402. Agents access FRED indicators, yield curves, and GDP data with USDC micropayments on Base.

• Product Reputation API — AI-powered product reputation intelligence from Reddit, HN & YouTube. Pay $0.03-$0.08 USDC per query for structured scores, dimensional analysis, and competitor comparisons. (Live) (x402scan)

• x402engine - Pay-per-call API gateway with 74 endpoints: 44 LLMs, image/video generation, crypto data, web search, code execution, TTS, travel, and IPFS. Multi-chain: USDC on Base, USDm on MegaETH, USDC on Solana. Discovery: /.well-known/x402.json | /.well-known/agent.json. (GitHub) | (MCP)

• SignalFuse — Trading intelligence + x402 API gateway. Crypto signals fusing sentiment, macro regime, and market structure ($0.001–$0.050). Gateway proxies: web search via Tavily ($0.012) and Brave ($0.008), code execution via E2B ($0.005). Agents pay USDC on Base per call — no API keys needed. Landing | Gateway Info

• mornin-agentee — Daily Tokyo morning briefing API generated by an OpenClaw multi-agent system (researcher + coder + main). Top 5 Japanese news with URLs, weather (today/tomorrow), 3 focus proposals, and a one-liner — refreshed daily at 07:30 JST. $0.05 USDC per call on Base mainnet. Cached output (near-zero marginal cost). llms.txt | .well-known/x402.json | Source

• cipher-mcp-registry - x402-gated search for the Official Model Context Protocol Registry. Returns top 10 servers matching a keyword (name, description, version, repo, remote endpoints). $0.005 USDC/Base per call.

• cipher-gas-oracle - x402-gated multi-chain gas oracle. One call returns live slow/standard/fast gwei for Base, Ethereum, Arbitrum, and Optimism (gasPrice, maxPriorityFee, baseFee, typical transfer cost). $0.005 USDC/Base per call.

• Rug Scanner - On-chain token risk analysis API. 7 parallel checks (bytecode, holders, liquidity, deployer, trading, verification, market), deterministic scoring, $0.05 USDC per scan via x402 on Base. (GitHub)

• agent-marketplace-proxy - x402-gated Google SERP API. POST /search returns top organic results from DataForSEO; agents pay $0.001 USDC per call on Base — no API key, no signup, no credit card. Single-route reference implementation showing how to wrap any commodity REST API with x402-express middleware in ~80 lines. (Source)

• TradingAgents x402 — Multi-agent LLM ticker consensus. Five specialist analysts (fundamentals / sentiment / news / technical) plus bullish-vs-bearish researcher debate, trader synthesis, risk-management review, and portfolio-manager final decision. Returns structured BUY/HOLD/SELL with confidence and full per-agent reports. Powered by TauricResearch/TradingAgents (arXiv:2412.20138). $1.00 USDC per call on Base mainnet. Source

• Sentry Forge x402 — Consumer-debt dispute pack generator. One paid call returns an 8-file pack: collector dispute letter, original-creditor dispute, CFPB complaints (collector + creditor), credit-bureau disputes, court-records search guide, action checklist, and evidence inventory. Validated against real FDCPA/FCRA cases. $0.50 USDC per call on Base mainnet. Source

• Royal Ruby x402 — US consumer-rights law citation lookup (FCRA, FDCPA, TILA, state UDAP statutes, debt-collection rules, credit-reporting timelines). Information-only, no legal advice. Useful for paralegals, journalists, dispute-letter drafting bots, and consumer-rights AI agents. $0.05 USDC per call on Base mainnet. Source

• Vault Pro x402 — Obsidian project/agent scaffolder. Returns a complete markdown document (frontmatter + Goal + Success criteria + Decomposition table + Hermes coordination notes) fitted to the Vault Pro template structure. Two routes: scaffold-project and scaffold-agent. Useful for AI orchestrators that need to register a new specialized agent. $0.05 USDC per call on Base mainnet. Source

• Nano Banana x402 — Paid Gemini image generation. Wraps gemini-3.1-flash-image-preview with x402 micropayments. Generate from prompt OR edit an existing image. Returns base64 PNG. Supports 10 aspect ratios. $0.02 USDC per call on Base mainnet. Source

• Power Pack x402 — Outreach email scorer. Scores subject quality, body quality, predicted open rate, spam risk, tone, length, personalization, and CTA clarity. Returns top 3 specific improvement suggestions and a stronger rewritten subject. Useful for sales/marketing/recruiting AI agents that need QA before sending. Powered by Claude Haiku 4.5. $0.01 USDC per call on Base mainnet. Source

• SupraPack x402 — Skill discovery over a 531-skill curated bundle. Returns top matching skills with full markdown content, quality score, categories, and source repo. Optional filters: min_quality, categories, limit. Useful for AI agents that need to discover and load specialized skills on-demand without bundling the full 15 MB skill library. $0.01 USDC per call on Base mainnet. Source

• TradeRoute - Crypto-trading data router for AI agents: 55 paid endpoints across signals, market data, DEX routing, whale alerts, portfolio, news, identity, Solana routing, bridges, and onchain primitives. ~40 endpoints return live keyless data (CoinGecko, DefiLlama, DexScreener, Jupiter, Across, Warpcast, Web3.bio, ScamSniffer, Base/Solana RPCs). Trust-band routing across 60+ upstream services with cross-agent cache. $0.001–$0.05 USDC per call on Base mainnet via Coinbase CDP facilitator. (GitHub) | (MCP) | (Health)

• unlock-api - Pay-per-unlock website fetcher. POST /unlock returns the rendered body, screenshot, or full XHR capture through a stealth browser + residential proxy. Worker only settles payment when the page passes the caller's expect_status / expect_contains check; failed unlocks return 502 and are not charged. $0.02 USDC per call on Base. No API key.

• pricing-matrix-api - SaaS pricing page extractor. POST /compare returns a normalized tier-by-feature matrix as JSON (tier name, monthly, annual, seats, quotas, feature flags). 24h KV cache per URL. $0.10 USDC per call on Base.

• bill-negotiation-api - Voice-agent that dials ISP / cell / insurance retention lines and negotiates a lower bill. POST /negotiate returns the call transcript and the booked saving. Flat $20 USDC per attempt on Base. No subscription.

• swornly - Deterministic, signed-receipt tools for AI agents — every answer returns an HMAC-signed, re-verifiable receipt (a chat tool narrates a result; swornly signs it). /dry-run/command (is a shell/git command destructive + its blast radius, before the agent runs it), /diff/mcp-schema (breaking vs non-breaking MCP tools/list changes), /snapshot/tool-contract (stable tools/list fingerprint for contract pinning), /convert (Markdown→PDF), /receipts/verify (free). $0.005–$0.02 USDC per call on Base Sepolia testnet (mainnet pending). OpenAPI | stats

• x402stock - Real-time US stock market data for AI agents. 23 pay-per-call endpoints: quotes, snapshots, OHLC aggregates, company fundamentals, dividends, splits, corporate events, market news, top gainers/losers, whole-market grouped daily, and technical indicators (SMA/EMA/RSI/MACD). $0.01–$0.03 USDC per call on Base via x402 — no API keys, no accounts. OpenAPI | llms.txt

• Fast PDF Parser - Pay-per-parse PDF text extraction for AI agents, served from Cloudflare Workers edge (LiteParse WASM). POST raw PDF bytes, get structured JSON text back — born-digital PDFs, no OCR, 10MB cap, sub-100ms parse. SHA-256-bound payment proofs with replay protection, x402 Bazaar discovery metadata, settlement via Coinbase CDP facilitator. $0.002 USDC per document on Base. No API keys, no signup. Source | Docs

• Agent Cafe - Test and certify your x402 agent - a live mainnet endpoint that grades the client, not the seller: point your paying agent at it, it pays real USDC on Base, and you get back a public certificate plus a README badge of exactly what it did. Includes a scam-resistance test (does your agent refuse a deliberately over-priced order?). Free machine-readable menu at /inspect. Docs | Examples

• Fabler Labs x402 Storefront - Security APIs for AI agents, paid per call in USDC on Base — secret scan ($0.005), agent-config audit ($0.05), pre-deploy evidence gate ($0.08), diff-security gate ($0.10), and Open Graph rendering ($0.01), plus digital-product downloads. No account or API key; wallet is auth. Free machine-readable catalog and six-tool MCP client. Built and operated end-to-end by an autonomous AI agent.

• x402 Crypto Price Tracker - Agent-payable crypto price API with 7 x402 routes on Base mainnet: BTC/ETH prices ($0.01), per-coin prices for 12 assets ($0.02), multi-coin portfolio snapshot ($0.05), curated agent revenue opportunities ($0.03), x402 launch audit ($1.00), receipt verification ($0.05), and MCP tool calls ($0.02). Bazaar discovery extension on all 402 responses, OpenAPI 3.0.3 spec, free /demo preview, and settled payment log. 3+ settled mainnet USDC payments via xpay.sh facilitator (zero-fee, gas-sponsored). Listed on x402scan marketplace. Discovery | OpenAPI | [Manifest](https://x402.167-172-95-184.nip.io/x40