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](https://github.com/eltociear/skill-audit-mcp))

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.

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](https://github.com/eltociear/skill-audit-mcp))

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.

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](https://github.com/cryptomotifs/solsignal-api)

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](https://tx402.ai/v1/models) | [OpenAPI](https://tx402.ai/openapi.json) | [llms.txt](https://tx402.ai/llms.txt) | [Source](https://github.com/Tensorix-ai/agent-gateway)

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](https://x402-reputation-api-production.up.railway.app)) ([x402scan](https://www.x402scan.com/server/8ae848b3-ea71-4b2a-8ea1-fa6bec508ca5))

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.

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.

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](https://github.com/yayashuxue/agent-marketplace-proxy))

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](https://github.com/SMXFREEZE/traderoute)) | ([MCP](https://github.com/SMXFREEZE/traderoute/tree/main/mcp)) | ([Health](https://traderoute-psi.vercel.app/api/health))

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](https://swornly.luci.ws/openapi.json) | [stats](https://swornly.luci.ws/stats)

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](https://x402.fablerlabs.com/) and [six-tool MCP client](https://github.com/fablerlabs/x402-tools). Built and operated end-to-end by an autonomous AI agent.

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](https://api.obol.sh)

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](https://nj4epne560.execute-api.us-west-2.amazonaws.com/openapi.json) | [Source](https://github.com/sun-jay-ea/geo-gateway)

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](https://github.com/tedddb-ai/compliance-api) | [llms.txt](https://compliance-api-ruddy.vercel.app/llms.txt)

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](https://hundun.app/docs)

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](https://z2v-x402-seller.cryga.workers.dev/.well-known/x402) | [MCP](https://z2v-x402-seller.cryga.workers.dev/.well-known/mcp)

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](https://onchain.wick.pics/.well-known/x402.json) | [OpenAPI](https://onchain.wick.pics/openapi.json) | [MCP](https://github.com/aitools420/onchain-safety-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](https://github.com/alberthild/shieldapi-mcp))

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](https://api.mornin-agentee.cc/llms.txt) | [.well-known/x402.json](https://api.mornin-agentee.cc/.well-known/x402.json) | [Source](https://github.com/Minnanthu/mornin-agentee)

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](https://github.com/LucianoLupo/rug-scanner))

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](https://api.402.coffee/inspect). [Docs](https://api.402.coffee/docs) | [Examples](https://github.com/englishdoggy/agentcafe-examples)

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](https://polymarket.hugen.tokyo/llms.txt)

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](https://sanctions.hugen.tokyo/llms.txt)

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](https://cve.hugen.tokyo/llms.txt)

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](https://fda.hugen.tokyo/llms.txt)

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](https://nutrition.hugen.tokyo/llms.txt)

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](https://edgar.hugen.tokyo/llms.txt)

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](https://github.com/dislovelhl/defi-signal-agent)

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.

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.

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](https://alpha-systems.net/mcp)

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.

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](https://github.com/863king/x402-gateway)

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](https://x402-solana-data.onrender.com/.well-known/x402) | [.well-known/agent-card.json](https://x402-solana-data.onrender.com/.well-known/agent-card.json) | [Source](https://github.com/memegent-unofficial/solana-trading-data-api)

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](https://broker-entry-api.kasanegi123.workers.dev/.well-known/broker-manifest.json) | [llms.txt](https://broker-entry-api.kasanegi123.workers.dev/llms.txt) | [products](https://broker-entry-api.kasanegi123.workers.dev/products)

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](https://api.x402-video.com/llms.txt) | [Live status](https://api.x402-video.com/status) | [GitHub](https://github.com/x402-video)

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`](https://cryptohunterx402apis.loca.lt/.well-known/x402.json) | [Manifest](https://cryptohunterx402apis.loca.lt/crypto/manifest)

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](https://gist.github.com/reckoning89/d87818b2020bbc27590df1fa0c42f175) | [.well-known/x402.json](https://allan-great-skirt-average.trycloudflare.com/.well-known/x402.json))