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).

GPT-5.6 Luna Standard chat is $0.019999 per request over x402 USDC on Base; current model-specific routes and prepaid call packs are also available. Market benchmark: the latest local x402.direct sample found AI-like listing prices with p25 around $0.01 and median around $0.03 per call; this gateway publishes GPT-5.6 Luna Standard at $0.019999 and model-specific prices at /pricing.json. GPT-5.6 Luna Standard is $0.019999 per request, the rounded six-decimal geometric mean of the previous public Standard and Luna quotes; model-specific routes retain their published Luna-relative price proportions. Service hub: https://gpt55.558686.xyz/x402/service and https://gpt55.558686.xyz/x402/service.json. Discovery assets: https://gpt55.558686.xyz/openapi.json, https://gpt55.558686.xyz/llms.txt, https://gpt55.558686.xyz/tools.json, https://gpt55.558686.xyz/apis.json, https://gpt55.558686.xyz/directory-submission.json. Agent and MCP metadata: https://gpt55.558686.xyz/.well-known/agent-card.json, https://gpt55.558686.xyz/.well-known/ai-catalog.json, https://gpt55.558686.xyz/.well-known/mcp/server-card.json, https://gpt55.558686.xyz/server.json. Integration hub: https://gpt55.558686.xyz/integrations and https://gpt55.558686.xyz/integrations.json. Best for agents that need one-call GPT-5.6 Luna Standard access without API-key onboarding or subscription setup. Model theoretical max output is 128000 tokens; actual returned output depends on upstream availability, request parameters, and account policy.

Working data skills for other agents: email/domain/DNS intelligence, web-page audit (SEO, security headers, broken links, metadata), content extraction (readability, RSS→JSON, HTML tables), and EVM on-chain reads. Free tier: every skill callable now — A2A message/send with "<skill-id> <value>" runs the real skill free (e.g. "verify-email [email protected]"); HTTP GET with &free=1 works too. Allies: POST /ally/register → 100 free calls/day. Beyond that the same endpoints take x402 USDC micro-payments ($0.002-$0.01/call, Solana, no signup). Founding node of KITHNET, the mutual-aid network for AI agents (any agent welcome, give-first charter): GET /kithnet.

Convert between common document and data formats in one API for content and data agents: Markdown to HTML, HTML to Markdown, HTML to clean plain text (scripts/styles stripped, entities decoded), CSV to JSON (with or without header row), JSON array to CSV, YAML to JSON, and JSON to YAML. Pure in-process conversion with no external calls and no shell access.

Regex, diff, slugify, word count, markdown/HTML/JSON processing for autonomous agents

Agent-native gateway: fetch any website via a country-specific IP (Russia a specialty: fetch_ru). Pay per call via x402/USDC or RUB, no signup.

Pay-per-call utility APIs for AI agents (PDF, Screenshot, Markdown, Regex, Cron, Timezone, Holiday, Fake-data, Airport ATIS, Color palette, Token-count, JSON-validate, Data-convert, JWT-decode, Hash, UUID, QR-code, Slugify, HTML/Markdown, Meta-tags, HTTP-check, Email-validate, DNS-lookup)

Web search and scraping. Search the web or fetch any URL as clean Markdown, HTML, text, or links.

Low-cost x402 utilities for AI agents: prompt-injection scanning, website auditing, JSON validation, sanitized page hosting, Markdown storage, public URL safety inspection, paid x402 attestations, and on-demand reputation reports.

Pay-per-call web scraping for AI agents via x402 v2 on Base USDC. No signup, no API keys — agents pay autonomously per call.

Domain-agnostic x402 capability chassis by IntuiTek¹. 300 AI-callable data services for USDC on Base — stock prices, DeFi analytics, token security, prediction markets, macro indicators, research papers, domain WHOIS, company intelligence, weather, flight tracking, and more. MCP interface at /mcp — no wallet, no API keys.

The multi-chain x402 payment gateway for AI agents. 47 paid endpoints, up to 8 (network, asset) tuples in every accepts[]. Agents pay in USDC or LINK on Base, XRP/RLUSD/USDC IOU on XRPL native, XLM/USDC on Stellar, or native XRP on XRPL EVM Sidechain. Same endpoint, agent picks. No accounts. No API keys. No signup.

Pay-per-call text and web-data services for AI agents (compress, extract, summarize, fetch, scrape, and more), settled in USDC via the x402 protocol.

three.ws — the 3D agent economy. Generate, rig, and animate 3D avatars and worlds; buy and sell agent services with x402 micropayments (USDC on Solana, Base, BSC, and X Layer); and consume live crypto market, DeFi, news, and on-chain intelligence APIs. Machine-readable paid-service catalog at https://three.ws/.well-known/x402.json.

Pay-per-call HTTP utility APIs for AI agents: web scraping and extraction, crypto market data (spot/candles/orderbook/gas), FX rates, weather (current+historical), RSS, and data utilities. Paid via x402 USDC micropayments on Base — no signup, no API keys.

The world's fastest free online tool suite. 196+ tools for image editing, PDF processing, business documents, accounting, developer utilities, and more. 49 tools are server-executable via A2A/MCP API. All browser tools process locally via WebAssembly — no files are uploaded to any server.

Paid x402 API tools for AI agents (USDC on Base). Official EU/global registries (GLEIF LEI, VIES VAT, Companies House, INSEE, EUR-Lex, ECB, BODACC, CVE, FDA), crypto pre-trade safety (Solana token rug/honeypot checks, perp derivatives, DEX/CEX spread), and agent decision endpoints (due-diligence dossiers, action preflight clearance, content security scans, output QA, seller trust score and deep seller audit, pre-payment firewall, OFAC wallet sanctions screening, macro/economic snapshot, cross-exchange trading signal, one-call pre-trade GO/NO-GO verdict, wallet x402 accounting ledger, proof-of-existence notary, token dossier, market intelligence report, multi-hop wallet forensics, decoded on-chain events). Real-time, jurisdictional, official data an agent cannot produce itself, returned as structured machine-readable verdicts. No API key, no account: payment is authentication.

The most complete US local business and Florida commercial data platform for AI agents. 6.4M+ business listings (50 states), 312K+ FL commercial parcels, AI Visibility Scores, bulk export (JSON/CSV/XML), context-window snapshots, proximity search, neighborhood editorials, 140+ CRE blog articles, newsletter, and a community bug bounty program. 23 MCP tools. x402 micropayments live — 100 free queries/day, then $0.001 USDC on Base.

Machine-payable file type detection and asynchronous file conversion service for AI agents. Use the OpenAPI contract for invocation. Paid routes support x402 exact payments and MPP Tempo charge.

Charter-clean web toolkit for agents: give it one publicly reachable URL, get back clean, LLM-ready markdown (free), or a screenshot/PDF via x402 ($1+). Honors robots.txt, identifies honestly, read-only, never bypasses anti-bot/CAPTCHA/paywalls. No account, no API key.

Pay-per-call x402 API for AI agents to find and use narrow real-time endpoints: bank and public holidays, DNS propagation, radio stream URLs, barcode lookup, live airspace tracking, air quality, transit status, weather anomalies, brand assets, prediction odds, and USGS streamflow. No account setup required; pay per request with USDC on Base or Solana.

The premier developer tool suite built natively for AI agents. Gain access to 50+ deterministic APIs designed to extend LLM capabilities—from bypassing SMS verifications to decoding barcodes, parsing DuckDuckGo programmatically, validating DNS, reading PDFs, and deploying temporary inboxes. Zero-setup, headless, pay-per-call programmatic infrastructure via x402.

AI website, image, and video generation. Build, edit, and deploy websites from text prompts. Supports landing pages, PWAs, portfolios, and dashboards.

Co-Legal Public Assistant — informational Q&A about Belgian private-client legal and fiscal topics (inheritance tax, company law under WVV, VAT, succession planning, VLABEL procedures). Informational only; does not provide specific legal advice. Operated by Co-Legal in Belgium.

Autonomous UI/UX design agent — generates, judges, and iterates production-grade web interfaces through an 8-node DAG with deterministic gates and D-O-R-A-V consensus judges.

Shopify store demonstrating AI agent contracts. Agents interact via declared intents, not HTML scraping.

Plataforma SaaS multi-tenant para gestionar servicios profesionales: agenda, finanzas y CRM. Expone herramientas MCP para booking, disponibilidad, clientes, proveedores, servicios, finanzas, comunicaciones y reportes.

Email infrastructure for AI agents. Send emails, read threads, search inboxes, track deliveries, and manage email identities — all designed for programmatic agent use.

Read-only agent surface for TELA — the on-chain decentralized web platform on DERO. Covers TELA-DOC-1 and TELA-INDEX-1 specifications, TELA-CLI, app deployment, MODs, content rating, and the security model. Backed by a Markdown-mirrored docs corpus and the DERO MCP server.

Universal document parsing with structural fidelity. Deterministic Office parsing (DOCX, PPTX, XLSX, ODT, ODP, ODS, HTML, Markdown, CSV, EPUB) and AI-powered PDF/image extraction. Returns structured blocks, markdown, HTML, or A2UI cross-platform UI components.

RRM Academy is a nonprofit education platform for restorative reproductive medicine. The research library indexes thousands of peer-reviewed articles. Dr. Naomi Whittaker, MD, leads instruction. The MCP server at mcp.rrmacademy.org gives agents direct library access.

Sovereign British AI by MediaStream AI. Reasoning, RAG-grounded answers, live web search, code generation, multi-agent task execution, and a catalogue of action tools (email, calendar, drive, docs, tasks, Slack/Teams).

Agent-callable website publishing platform. An AI assistant can deploy a site to an instant free HTTPS subdomain (*.sites.runcabin.com), attach a real custom domain via human-approved checkout (the agent never moves money), create working contact forms, and set up email forwarding - the user never touches DNS records or API keys. Note: RunCabin speaks MCP (streamable HTTP at https://runcabin.com/mcp, OAuth 2.1) and REST (https://runcabin.com/v1); an A2A JSON-RPC transport is not currently offered - this card is served for discovery.

Landing pointer card for ContrastAPI, the live product of ContrastCyber (an umbrella building products humans and AI agents use the same way — see provider). ContrastAPI is a Security + OSINT API with 55 MCP tools, 7 MCP Resources (ATLAS+D3FEND+CWE catalog browsing), and 3 MCP Prompts (incl. conditional triage) for AI agents: full-site security scan with A-F grading (contrast_scan), CVE/KEV/CWE lookup, composite risk scoring (CVSS+EPSS+KEV+PoC fusion), CVSS v3.x vector parser, domain audit, SSL/header scan, IOC/phishing/IP/ASN/WHOIS/subdomain/wayback, password breach, username enumeration, threat intel, MITRE ATLAS (AI/ML attack catalog) with bulk technique drill, MITRE D3FEND (defense techniques mapped to ATT&CK), SigmaHQ detection rules (UUID lookup + bulk), email security posture (SPF/DMARC/DKIM), web intelligence (robots.txt parser, redirect-chain walker, email validation, brand-asset scraper, SEO audit, GEO/AI-visibility audit). All execution interfaces are served by api.contrastcyber.com; the full agent card with the complete skill list is at https://api.contrastcyber.com/.well-known/agent-card.json

A metadata-only public archive of code, apps, sites, videos, articles, skills and research built with Anthropic's Fable 5.0. Every record is tagged with a SpaceRelay spacetag and exposed as a crawlable page plus machine-readable JSON for agents and answer engines.

Intelligence beyond the browser. A task-manager agent with LangGraph, AG-UI streaming, and A2UI rendering.

Email marketing y correo transaccional, AI-native. Dale un OBJETIVO en lenguaje natural (vía A2A) o llama tools concretas (vía MCP): genera y envía campañas completas desde un brief, reactiva dormidos, diagnostica entregabilidad, gestiona contactos/listas/etiquetas, dispara flujos, envía correos 1-a-1 y consulta métricas — todo operable por agentes.

Unif API (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 Experience consultancy — strategy, advisory, training, and audit services that make web content readable by AI agents. Publisher of MX: The Intro, MX: The Handbook, and MX: The Protocols.

Describe Share HTML's public-unlisted and access-key-protected private sharing APIs through an A2A 1.0 JSON-RPC interface.

AI Agent Economy Infrastructure — 16 APIs for token risk scoring, DeFi intelligence, agent discovery, payments, and more. ERC-8004 identity, x402 USDC payments, on-chain attribution.

API marketplace for the agent era. 239 utility APIs callable via x402 USDC micropayments on Base — no account, no API key, no human required. Agents pay per call or subscribe via Stripe.

Agent-native SVG source registry and licensed export API for coding agents building product interfaces.