AI Agents API Library

Polski · HTML · llms.txt · catalog.json

AI Agents API Library

A curated, machine-readable encyclopedia of third-party APIs and MCP servers that AI agents can call on a user's behalf.

This article is about services an AI agent can operate programmatically, not AI products used by humans through a web UI.

AI Agents API Library Type API & MCP catalog Entries 340 Categories 30 Official MCP servers 238 Languages English, Polish Format JSON, Markdown, HTML, llms.txt Last checked 2026-11-04 License CC BY 4.0 (data), MIT (code)

AI Agents API Library is an open, bilingual (English/Polish) catalog of 340 services (each with a last-checked date) in 30 categories that an autonomous AI agent — such as Claude, ChatGPT, Gemini or a custom LLM agent — can use without a human in the loop, after a one-time human step: registering an account and handing the agent an API key, an OAuth token, or a connection to an MCP (Model Context Protocol) server. Every entry records the documentation URL, the authentication method, the availability of an official or community MCP server, and the free tier. The list is not a directory of products with “AI” in their name; the criterion is agent operability, not branding.

Contents

1. Machine-readable access (for AI agents)
2. Inclusion criteria
3. Legend
4. Web search (14) · Web scraping and crawling (12) · Browser automation and cloud browsers (7) · Knowledge and research data (19) · Image generation and editing (10) · Video generation and editing (14) · Speech and audio (13) · Music generation (6) · 3D generation and assets (6) · Architecture, CAD and BIM (8) · Diagrams and software architecture (8) · Design and UI (6) · Documents, OCR and presentations (14) · Translation and language (6) · Code execution sandboxes (11) · Developer platforms and DevOps (13) · Cloud and hosting (11) · Databases (12) · Vector search, memory and RAG (9) · Email, team chat and notifications (10) · SMS and messaging apps (12) · Voice agents and telephony (9) · Productivity and workspace (17) · CRM, support and marketing (8) · Social media (10) · Maps, geolocation and weather (18) · Finance, payments and market data (16) · E-commerce (8) · Automation and integration platforms (15) · Model APIs and inference (18)
5. Related directories and registries
6. Contributing
7. See also
8. References

Machine-readable access (for AI agents)

AI agents should not parse this page. Fetch one of these stable files instead:

Recommended agent workflow: (1) pick the category file, (2) filter by auth and mcp.type, (3) read docs (or llms_txt / openapi when present), (4) ask the user for the credential named in auth_hint.

MCP server

The catalog is also an MCP server with four tools: search_apis (filters: query, category, mcp (official/remote/any), no_auth, free_tier, no_card, auth, min_rating, min_reviews; sort by fit, rating or review count; results carry a reviews_summary of praised and criticised aspects), get_api, get_reviews (user reviews with pros and cons) and list_categories. No key needed. Add it to your MCP client:

{

"mcpServers": { "ai-agents-api-library": { "command": "npx", "args": ["-y", "ai-agents-api-library"] } } }

Claude Code: claude mcp add ai-agents-api-library -- npx -y ai-agents-api-library

No install: remote endpoint (Streamable HTTP, no key) https://ai-agents-api-library.vercel.app/mcp, e.g. claude mcp add --transport http ai-agents-api-library https://ai-agents-api-library.vercel.app/mcp. Listed in the official MCP Registry as io.github.eater2/ai-agents-api-library.

Claude skill and plugin

The skill tells Claude when to reach for the catalog and how to pick a service. The plugin bundles the skill with the MCP server:

• Claude Code plugin (skill + MCP server):

  /plugin marketplace add eater2/ai_agents_api_library

/plugin install ai-agents-api-library@eater2

- **Skill only, Claude Code:** copy [`plugin/skills/ai-agents-api-library/`](plugin/skills/ai-agents-api-library/SKILL.md) to `~/.claude/skills/` (all projects) or `.claude/skills/` (one project).

• Skill only, claude.ai / Claude Desktop: download the skill zip and upload it under Settings → Capabilities → Skills.

Inclusion criteria

• The service exposes a public, self-serve programmatic interface (REST, GraphQL, SDK) or an MCP server.
• A human needs to act at most once — sign up and create a key or approve OAuth. After that the agent works unattended.
• The interface is documented and currently active (links last checked on the date shown in the infobox).
• Consumer-only apps, waitlists, sales-gated enterprise products, agent frameworks and IDEs are excluded — they are agents or tools for building agents, not services an agent calls.

Legend

• MCP ✅ — official MCP server maintained by the vendor
• MCP ◐ — community-maintained MCP server
• MCP — — no MCP server known; use the REST API
• 🆓 — free tier or free usage without payment
• ★ (date) — proof under the service name: SourceForge rating and review count, GitHub stars, GitHub issues fixed and days to fix, Smithery uses — linked, with the date fetched

*Ratings and usage (★) fetched: 2026-11-04 09:20 UTC.*

Web search

*Search engines and answer APIs that return fresh web results, snippets or full page content in agent-friendly formats.* — 14 services. JSON: catalog/web-search.json

| Brave Search API ⭐⭐⭐⭐⭐ 4.5/5 · 2 reviews [](https://github.com/brave/