Deterministic pay-per-call tools for AI agents: live web search and cited answers, news, browser render, market data, speech-to-text, wallet-keyed memory, plus 500+ long-tail tools via find_tool. Settle in USDC via x402 or free via proof-of-work. Maintained by Havok Holdings LLC.

Data Sentinel — deep second-pass security scan that catches what PII scrubbers miss. Detects JWTs, bearer tokens, AWS keys, private keys, connection strings, IBANs, crypto wallets, medical record numbers, internal IPs, and base64 blobs. Returns masked matches with confidence levels. GDPR and AI TRiSM aligned. $0.003/req via x402 on Base.

Find duplicate records in 30 seconds. Zero-config entity resolution, 97.2% F1 out of the box.

Discovers x402-payable APIs at runtime. Enables autonomous agents to find, evaluate, and pay for services via USDC micropayments on Base — no API keys or subscriptions required.

Strips PII (emails, SSNs, API keys, phone numbers, addresses) from text before agents send data to third parties. GDPR/HIPAA aligned. Stateless. Pay $0.005 USDC per scrub via x402 on Base network.

Search Facebook Marketplace, eBay, Depop and Poshmark from your assistant — one marketplace or all of them at once. Filter by price, condition, size, brand and colour, then pull the full listing: every photo, seller details, location, and a link straight to it. Hosted, so there's nothing to install and no browser running in the background. Free tier included; eBay uses your own API keys.

Hallucination Detector — scores AI-generated output for hallucination risk. Detects fabricated citations, entity confusion, and overconfident absolutes. Returns a 0-1 risk score with signals so you know what to verify before trusting the output. $0.001/req via x402 on Base.

Discover, verify, and explore 600K curated quotes from a massive database of authors, books, and speeches. Find the perfect words using semantic search, identify authentic attributions to avoid common misquotes, and discover similar thinkers. Organize and manage personal collections of wisdom to save and revisit your favorite insights.

Check an x402 seller before your agent pays: wash-adjusted settlement volume, payTo integrity, trust scores. Free, no key, no signup.

Compresses large blocks of text, code, or conversation history into hyper-dense Reasoning Maps optimized for LLM context windows. Saves agents 80%+ on token costs. Stateless. Pay $0.001 USDC per compression via x402 on Base network.

Vercel Grep

Search millions of public GitHub repositories for real-world code patterns and API implementations. Find production-ready examples of syntax, configurations, and library integrations to improve your development workflow. Discover exactly how other developers solve specific programming challenges using powerful literal and regular expression searches.

Permission Guard — validates an agent's requested action against its defined scope before execution. Detects out-of-scope access, privilege escalation, and flags dangerous operations like delete, execute, admin, and deploy even when technically permitted. Stops agents from doing more than they're supposed to. $0.002/req via x402 on Base.

Hosts agent-card.json files for businesses who can't serve them from their own domain. Cards are permanently discoverable by any A2A agent at a stable URL. Pay $0.001 USDC per month per card via x402 on Base network.

Generates valid A2A agent-card.json files for any website from stable structured sources. Reads llms.txt, robots.txt, sitemap.xml and well-known files. Never scrapes. Pay $0.01 USDC per card via x402 on Base network.

Cite42 gives AI agents AI-search visibility, citations, SEO keywords and trends, plus four weekly or monthly trackers: AI visibility tracker, AI competitor tracker, AI citation tracker, and AI sentiment tracker. Use the Content Opportunities workflow to identify and prioritize high-potential content opportunities.

Stateless circuit breaker that detects recursive agent loops in MCP tool calls. Uses Bloom filter to identify repeated calls within 30 seconds. Pay $0.005 USDC via x402 on Base network to reset context and break the loop.

Converts data between JSON, CSV, XML, YAML, Markdown, HTML and TOML instantly. Handles nested JSON flattening with dot-notation. Pure math, zero dependencies. Pay $0.001 USDC per conversion via x402 on Base network.

BuyWhere is a product catalog built for AI agents. One MCP server gives keyword search over 300M+ products from 150K+ merchants with products across 9 markets, with deliverto shipping availability and tracked outbound links. Remote MCP: https://api.buywhere.ai/mcp. v2 tools require deliverto.

Prompt Injection Detector is a stateless security microservice built for the agent economy. Before your agent acts on any input — whether from a user, an email, a document, or another agent — run it through this scanner first. Detects: jailbreak attempts, instruction overrides, role-play manipulation, goal hijacking (OWASP ASI01), tool misuse patterns (OWASP ASI02), hidden instructions embedded in data, and indirect injection via external content. Returns a confidence score, severity rating, specific patterns detected, and a clear recommendation — block, warn, or pass. Pay per scan via x402 protocol. USDC on Base. No API keys. No subscriptions. No human in the loop. Agents call it directly. MCP tool name: scanforinjection

Creates a tamper-evident, HMAC-signed log entry for every agent action. No database, no infrastructure — just a cryptographically verifiable receipt you store yourself. Built for HIPAA, SOC2, and any compliance requirement that asks "what did your agent do and when?" $0.001/log via x402 on Base. MCP tool name: logagentaction

Free agent tests (no account or payment); paid ping.