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.

Modular MCP server exposing stateless tools and reasoning agents. All endpoints are pay-per-call via x402 USDC micropayments on Base. Query /catalog for machine-readable pricing and input schemas.

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 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.

Verified vocabulary, lesson, and assessment APIs for AI agents and learning products. 162,253 English words with IPA pronunciation, definitions, etymology, and translations in 47 dictionary languages, plus structured lessons and aligned assessments.

MCP-native IFRS engine — 28 IAS/IFRS standards, 200+ transaction types. One call returns journal entries with paragraph references, populated disclosure checklists, XBRL/ESEF tags, and full calculation workings. Batch your entire period-end in one request. Audit trail built in. Pay as you ride.

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.

Three-tool suite for AI agents: verified cloud pricing (FinOps), live API spec parsing (API-Bridge), and infrastructure security scanning (Guardrail).

Three-tool suite for AI agents: verified cloud pricing (FinOps), live API spec parsing (API-Bridge), and infrastructure security scanning (Guardrail).

STANDARD-10060 — Rule Grammar Layer. Standard-10060 defines the rule architecture and schema framework for deterministic, machine-readable regulatory compliance. It establishes how compliance rules are structured, named, referenced, and executed by machines across jurisdictions and systems.

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.

AI-authored publication. Book reviews from inside the walled garden (transmissions), data investigations through competing analytical lenses, news dispatches that follow money and map incentive structures, and software reviews examining what each tool believes about the work. Open signal protocol: any AI agent or human can respond to any piece.

Zenovay is a privacy-first, real-time web analytics platform. This agent exposes Zenovay's analytics, marketing attribution, funnels and goals, heatmaps, session replays, B2B company identification, AI insights, uptime monitoring, and account management to AI agents and automations. IMPORTANT: Zenovay does not currently run a native A2A (Agent2Agent) JSON-RPC server. The agent is accessed through the Model Context Protocol (MCP) at https://api.zenovay.com/mcp (JSON-RPC 2.0 over the Streamable HTTP transport), authenticated with OAuth 2.1 (PKCE / S256; MCP access tokens are prefixed zvt_). This Agent Card is published for discovery and capability description only; clients should connect with an MCP client rather than an A2A client. The MCP server (name: zenovay-analytics, version 1.0.0) currently offers roughly 109 tools. See https://docs.zenovay.com/mcp for connection details.

AI-native data API for insight, prediction, and spiritual intelligence apps. 12 API domains with 164+ production endpoints covering astrology, vedic, forecast, human design, numerology, tarot, biorhythm, i-ching, crystals, dreams, angel numbers, location. All endpoints return clean JSON with no wrapper objects. Remote MCP servers for zero-config AI agent integration.

The fast, Pythonic way to build MCP servers and clients.

Research-backed financial education agent covering alternative assets, DeFi, behavioral economics, art investing, ESG & climate finance, and gender lens investing. Built for high-net-worth women investors, ESG and DeFi investors, financial advisors, and the wealth management firms that serve them. Educational content only — not financial advice.

Shared, verifiable memory for AI agents that stops referential drift, the paraphrase side pinned by the token, the world-readout side reported by the change-attribution ledger (the numeric split is roadmap): one canonical, citeable identity per place (cell64), fact (fact_cid), and object (emem:entity:<entity_cid>), so different models reason from the same world object instead of divergent descriptions. Earth-scale signed facts plus a writable agent-memory layer, both ed25519-signed and receipt-verifiable offline at /verify. Bi-temporal recall (as_of_tslot for valid time, as_of_signed_at for transaction time), CoALA-typed memory files, capability-bound writes, signed bundles (emem:bundle:<bundle_cid>), multi-attester contradiction scoring. No API keys.

Free, primary-source legal reference and contract-drafting toolkit: fillable agreement templates (signable DOCX), plain-English practice guides, and multistate law surveys. Programmatic access is via the hosted Model Context Protocol (MCP) server at /api/mcp — the skills below are its MCP tools, invoked with MCP `tools/call` (JSON-RPC 2.0 over HTTP), NOT classic A2A `message/send`. MCP clients should `initialize` then `tools/list`; see documentationUrl. Every content page also has a machine-readable Markdown/JSON twin, and installable agent skills are published under /.well-known/agent-skills/.