Security and data-quality guardrails for AI agents. Stop prompt injections before they reach your LLM. Strip PII to stay compliant. Sanitize untrusted HTML without installing dependencies. Validate emails, URLs, JSON schemas, and SQL syntax in under 10ms. Works from any environment — sandboxed, serverless, or containerized. No API key needed. 200 free requests, then pay-per-call via x402 (USDC on Base).

Product search, price comparison, price history and buying guides across 30M+ products and tens of thousands of retailers, for people and their AI assistants. Founded in 2008 with 40M+ app downloads. Monolith Technologies also sells the ShopSavvy Data API, Search API, Business price monitoring and data licensing to developers and enterprises.

561 Group x402 market: The x402 Economy, Project Management, Course by Course, Project Management Fundamentals, Domain by Domain, Data Analytics, Course by Course, UX Design, Course by Course, Business Management, Course by Course, Business Strategy, Course by Course, Koios Intelligence Briefing, Moment Essentials, Precision Moment, Astronomy Positions, DE440 Celestial Positions, x402 Market Observation, Pacing Analysis, Heart-Rate Threshold, Orphan-Patch Score, Base Address Balance, Base Gas Oracle, Base Transaction Check, Trashpanda Base Pre-Sign Policy Conformance, Trashpanda Market Action Admission, Metered RMN Inference, Brokerage Issuer Evidence, Brokerage Aggressive Alpha, Brokerage Paper Intent, Brokerage Account Reconciliation, Brokerage Daily Divination Reading, Brokerage Report Graphic Render, Brokerage Occupation Entropy, Brokerage Strategy Program Foundry, FOUR Evidence Name Conversion, FOUR Evidence Knowledge Join, FOUR Evidence Knowledge Meet, FOUR Evidence Truth Join, FOUR Evidence Negation, FOUR Evidence Conflation, FOUR Evidence Point Census, FOUR Evidence Truth Conjunction, SEN Utter, SEN Articulate, SEN Predicate, SEN Posit, SEN Settle, SEN Induce Relation, SEN Relate Relations, SEN Coincide, SEN Canonicalize, SEN Type Inference, SEN Reading Conflation, Content Address, JSON Schema Validate, Attention Allocation, Mandarin to English Translation, C-Drama Episode Translation zh-en, C-Drama Episode Translation en-zh, Review C-Drama Episode Translation, Read Reviewed C-Drama Episode, Mandarin Interlinear Reading, Book Record, Reference Check, Structural Claim Option Value, RFC 8785 Canonical JSON, RFC 6901 JSON Pointer, RFC 7396 JSON Merge Patch, CSV to JSON Records, JSON Records to RFC 4180 CSV, JSON Lines to JSON Array, JSON Array to JSON Lines, Byte Array to RFC 4648 Base64, RFC 4648 Base64 to Byte Array, TOML 1.1 Validation and Diagnostics, TOML 1.1 to JSON, JSON to TOML 1.1, YAML Syntax and Alias Diagnostics, YAML to JSON, JSON to YAML 1.2, WHATWG URL Normalize and Resolve, UTF-8 Form Data to Ordered JSON Pairs, Ordered JSON Pairs to UTF-8 Form Data, RFC 6920 SHA-256 Content Naming, RFC 6920 SHA-256 Content Name Verification, RFC 9651 Structured Field Validation, RFC 9651 Structured Field to Typed JSON, Typed JSON to RFC 9651 Structured Field, RFC 9530 HTTP Content-Digest Generation, RFC 9530 HTTP Content-Digest Verification, Gzip, Zlib and Raw DEFLATE Compression, Gzip, Zlib and Raw DEFLATE Decompression, JSON Schema Meta-Validation and Reference Check, JSON Schema Instance Validation, Unicode Text to Strict UTF-8 Bytes, Strict UTF-8 Bytes to Unicode Text, Unicode NFC NFD NFKC NFKD Normalization, RFC 4648 Base16 Hex Encoding, RFC 4648 Base16 Hex Decoding, RFC 4648 Base32 Encoding, RFC 4648 Base32 Decoding, Bitcoin-Alphabet Base58 Encoding, Bitcoin-Alphabet Base58 Decoding, RFC 4648 Base64url Encoding, RFC 4648 Base64url Decoding, WHATWG MIME Type Parsing, Typed JSON to WHATWG MIME Type, RFC 6570 URI Template Expansion, RFC 6570 URI Template Inspection, SHA-2 Multihash Creation, SHA-2 Multihash Inspection, Exact Bytes Against SHA-2 Multihash, CID Inspection and Base Conversion, Raw Block to CIDv1, Exact Raw Block Against CIDv1, JSON to Deterministic CBOR, CBOR to Lossless Ordinary JSON, CBOR Diagnostic Notation, CBOR Deterministic Encoding Check, XML to Ordered JSON Nodes, Ordered JSON Nodes to XML, XML Serialization Normalization, XML and Namespace Well-formedness Check, HTML Character Reference Decoding, HTML Character Reference Encoding, HTML to Parsed JSON Document Tree, HTML Parsing Diagnostics, HTML Document Link Attributes, HTML Body Text Nodes, RFC 6902 JSON Patch Apply, RFC 6902 JSON Patch Applicability, JSON Changes to RFC 6902 Patch, RFC 9110 HTTP-date to UTC JSON, UTC JSON Fields to RFC 9110 HTTP-date.

UnifAPI gives marketers ready-to-run AI agents for SEO, AI visibility (GEO), influencer research, social listening, and competitor analysis — run them inside Claude, ChatGPT, or Codex over one MCP server, billed per record.

Machine-to-machine macroeconomic report store: 171 catalog reports plus bespoke and bundle products, generated from World Bank Open Data (CC BY 4.0) and sold per fetch in USDC over x402.

Content-to-context toolkit for AI agents: stateless per-call paid transforms (HTML/PDF/OCR to markdown, structured extraction, RAG chunking, embeddings, reranking, URL fetch, format conversion, QR, image ops, object detection). Every call is paid via x402 (USDC on Base); failed requests are never charged.

Daily gold buying-conditions score from 0 to 100, each part ranked against its own record back to 1971. A measurement, not advice and not a forecast. Tools: get_current_reading, get_reading_history, get_zone_record.

Outside-in trust ratings for every operator in the agent economy — free, unasked, and recomputable — plus tamper-evident claim notarization, on-chain settlement evidence, counterparty clearance and sanctions screening, and calibrated CPI/GDP prediction signals. Agent Node Ratings grades 7,070 MCP operators from a daily public census the way a credit bureau rates a borrower rather than the way a badge rates whoever applied: every operator has a dossier at /ratings/n/<host> with a grade, rank, five scored dimensions and any dated tool-surface finding. The rated operator never pays. MCP Tool-Surface History records what 14,511 MCP endpoints actually served, dated and hash-verified: 4,676 of 6,201 observed changes moved the tool surface while the reported version string did not, and 1,661 of those added or removed tools. Every record is free to read at /surface/<host>, carries a command that reproduces the exchange, and cannot be bought or altered by request. 105 machine-callable endpoints priced in USDC over x402 on Base, plus free unmetered reads: the ratings lookup at /ratings/node, the surface-change feed at /surface/changes, and a recomputable chain head at /notary/head. Political-markets Brier 0.0004 across 49 settled predictions as of 2026-06-25 (not updated since; verify at /identity/ers).

Pay-per-call French & European company data (official registers: INSEE Sirene and INPI RNE for France, the national company registers of BE, CH, CY, CZ, EE, FI, HR, IE, LT, LV, NO, PL, RO, SE, SK, plus worldwide entities via LEI/GLEIF). Every skill is a paid HTTP resource: send a JSON data part {"path": "/v1/..."} or {"skill": "<id>", "params": {...}}; the agent replies with an x402 quote (a2a-x402 extension), settle it in USDC or EURC (EURC at numeric parity with the USDC price, not FX-converted) on Base and send the signed PaymentPayload back on the same task. Send the HTTP header A2A-Version: 1.0 on every JSON-RPC request (without it, the server answers with the A2A 0.3 methods, such as message/send), and A2A-Extensions: https://github.com/google-a2a/a2a-x402/v0.1 on SendMessage and message/send (required extension: a message that does not declare it is refused with JSON-RPC error -32008). Paying in EURC requires an explicit client opt-in since @x402/core 2.23 (spendControls.allowedAssets), otherwise your client silently keeps the USDC option. Set allowedAssets[].maxAmountPerPayment as well (integer ATOMIC amount, e.g. "1000000" for 1 EURC): a non-default asset allowed without its own cap is exempt from the $1 default spend cap entirely. Your x402 client also refuses, by default, any quote above $1.00 per payment (spendControls.maxAmountPerPayment); only GET /v1/kyb/batch (up to $10.50), GET /v1/identite/lot (up to $3.00), GET /v1/surveillance/creer (up to $50.00), GET /v1/surveillance/:jeton/renouveler (up to $50.00), GET /v1/score/defaillance/lot (up to $7.00) can exceed it at full size — each of those skills says so. Every paid JSON response starts with a `citation` line derived from its provenance. When you report a result, cite its `citation` verbatim. Free text is not interpreted. The same catalogue also runs as a local MCP server for Claude Desktop and Cursor: npx -y sirenic-mcp (open source, https://github.com/sirenic-eu/sirenic-mcp). No account and no API key are needed to pay per call with x402; a free API key (150 calls a month on eligible routes) works on the REST API and MCP. A2A itself takes x402 only. Free API key, no card: 150 calls a month on routes at $0.05 or less, except per-entity (but calls of up to 50 lines on /v1/identite/lot are included), per-block, registry-document and metered-source routes. https://api.sirenic.eu/compte?utm_source=api&utm_campaign=agent-card

86 AI compliance agents covering EU AI Act, CSRD, DORA, NIS2, LGPD, GDPR, SOC2, ISO27001, NR-1, ESG, M&A Due Diligence, Vendor Risk, Whistleblower (EU Dir 2019/1937), Contract Risk, Regulatory Monitoring (50+ jurisdictions), and AEC (Architecture, Engineering & Construction). Available in 8 languages. Starting at $99/month. Microsoft Azure Marketplace & Google Cloud Marketplace.

Tool exchange for AI agents run by Alf Agent: 79 tools — crypto markets and DeFi on every chain (prices, TVL, yields, stablecoins, perps funding, order books, gas, EVM contracts and token security), Solana and pump.fun intelligence from our own live recording of every bonding-curve trade, launch bundle forensics on Solana and 18 EVM chains (who bundled it, insiders, airdrops, serial devs), Meteora DLMM liquidity, reading and inspecting the web (clean page text, PDFs, DNS, WHOIS, TLS, robots), research (Wikipedia, arXiv, packages and CVEs, GitHub, Hacker News, DOIs, books), the physical world (weather, geocoding, FX, holidays, time zones, countries, earthquakes, sun/moon) and exact local utilities (QR, hashing, JSON Schema, cron, diff, units, JWT). Pay per call in USDC or SOL (x402) or with credits.

Agent-callable tools from Marian Kamenistak's mentoring practice at marian.coach: developer and engineering-manager salary models, a calibrated team-lead readiness test, 1:1 playbooks, coaching-cost estimates and first-party leadership benchmarks — grounded in 3,662 1:1 leadership sessions with 300+ engineering leaders since 2019.

Take a robots.txt you already have and say what it actually does. It lints the file against RFC 9309 and reports the errors that silently change meaning, answers whether a named crawler may fetch a named path and which rule decided it, audits which AI crawlers the file really stops (and which it only appears to), diffs two versions by EFFECT rather than by line, and merges a ready-made stance into an existing file without discarding the rules already there. It reads the file you paste; it fetches nothing. robots.txt is a request, not an enforcement mechanism, and the audit says so where a crawler is known to ignore it. Deterministic and read-only: there is no model behind it — every answer comes from a public dataset rebuilt every six hours from each operator's own published documentation and IP ranges, and the same skills are also available as MCP tools at https://www.pathwren.workers.dev/mcp/robots. No key, no signup, no quota. Independent and unaffiliated with any operator it documents.

Agent-callable services from the Engineering Leaders Community: meetup topic evaluation, speaker stage placement, and community reach — grounded in 3,300+ CEE engineering leaders and 12 meetups a year at 120+ attendees since 2019.