Polski · HTML · llms.txt · catalog.json

AI Agents Accessible APIs

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 Accessible APIs is an open, bilingual (English/Polish) catalog of 333 services (each with a last-checked date) in 29 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 browser automation (18) · Knowledge and research data (17) · 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 (10) · Developer platforms and DevOps (12) · Cloud and hosting (11) · Databases (12) · Vector search, memory and RAG (9) · Email, team chat and notifications (10) · SMS and messaging apps (10) · 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), 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 skills/ai-agents-api-library/ 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, Smithery uses — linked, with the date fetched

Ratings and usage (★) fetched: 2026-10-12 13:09 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

Service	What an agent can do	Auth	MCP	Free tier	Docs
Brave Search API ⭐⭐⭐⭐⭐ 4.5/5 · 2 reviews	Lets an agent query Brave's independent web/image/video/news search index and get cited, LLM-ready results.	API key	✅	🆓 $5 free monthly credits (~1,000 queries on Search plan); credit card required at signup as anti-fraud measure	docs
Exa ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Lets an agent run neural or keyword web search, retrieve page contents, and find similar links via Exa's API.	API key	✅	🆓 free tier: $10 free credits/month (~1,400 searches), no payment method required	docs
Jina AI Search / Reader	Search the web or convert any URL into clean LLM-ready markdown via simple HTTP GET requests.	API key	✅	🆓 No key needed for Reader only: 20 RPM (Search is blocked without a key); free API key gives Reader 500 RPM / Search 100 RPM plus 10M free tokens one-time on signup	docs
Kagi Search API	Run programmatic, ad-free premium web/news/image/video searches and extract page markdown via a paid REST API.	API key	✅	no free tier: pay-per-use, $12 per 1,000 search requests, invoiced monthly or at $100 usage, whichever first	docs
Linkup	Lets an agent search, fetch pages, or run deep multi-source research via Linkup's Search/Fetch/Research API endpoints.	API key	✅	🆓 $20 free credits/month for new accounts signing up with a professional email	docs
Mojeek Search API	Query Mojeek's independent web index for titles, URLs and snippets in JSON or XML, with country/language boosting.	API key	—	limited-query free trial available on request; paid plans from £2 CPM (Startup, 5 req/s, 100k/day cap)	docs
Parallel Web Systems Search API	Lets an agent run Parallel's low-latency Search API for web research, content extraction, and entity discovery.	API key	✅	🆓 free: 5,000 requests/month across APIs, plus up to $80 signup credit and $5/month free credits	docs
Perplexity Sonar / Search API	Lets an agent call Perplexity's Search API or MCP tools (search/ask/research/reason) for real-time grounded web answers.	API key / OAuth	✅	Paid only: no confirmed free tier; pay-as-you-go, Search API billed at $5 per 1,000 requests ($1 per 1,000 for the fast search variant)	docs
SearchApi.io	Fetch structured JSON results from Google, Bing, YouTube, Amazon, TikTok and 50+ other search engines via one REST API.	API key	✅	Trial: 100 free requests one-time on signup, no credit card required; then Developer plan $40/mo for 10,000 searches	docs
SearXNG (self-hosted JSON API)	Query a self-hosted SearXNG metasearch instance's JSON API to aggregate results from many search engines at once.	none	◐	🆓 free, no key (self-hosted; you run and pay for the instance yourself)	docs
SerpApi	Lets an agent scrape structured JSON results from Google and 20+ other search engines via SerpApi's REST API.	API key	✅	🆓 free plan: 250 searches/month, 50 requests/hour throughput	docs
Serper	Lets an agent fetch fast, low-cost Google search results (web, images, news, maps, shopping) via Serper's REST API.	API key	◐	Trial: 2,500 free queries one-time on signup, no credit card required; then prepaid query packages	docs
Tavily	Lets an agent call Tavily's search API or MCP server to run web searches and get AI-ready summarized results.	API key	✅	🆓 free tier: 1,000 API credits/month, no credit card required	docs
You.com API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Lets an agent call You.com's Search/Answer/Research API or MCP server for LLM-ready web search and grounded answers.	API key	✅	🆓 Free: 100 queries/day with no API key or sign-up through the MCP free profile (search and discover only); new API-key accounts also get $100 in one-time credit	docs

Web scraping and browser automation

Crawl, scrape and convert pages to Markdown/JSON, or drive a remote headless browser (clicks, forms, logins). — 18 services. JSON: catalog/web-scraping-browser.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Anchor Browser ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Provision authenticated cloud browser sessions and turn any website into callable MCP tools for agents.	API key	✅	🆓 $5 free credits/mo, no card required	docs
Apify ⭐⭐⭐⭐⭐ 4.8/5 · 1,800 reviews	Run web scraping/automation 'Actors' from a marketplace of thousands, and manage datasets, via REST API or MCP server.	API key / OAuth	✅	🆓 free plan: $5/mo platform usage credit, no card required	docs
Bright Data ⭐⭐⭐⭐⭐ 4.5/5 · 1 review	Access Web Unlocker, SERP API, Scraping Browser, and structured datasets via REST API or MCP to pull web data at scale.	API key	✅	🆓 Free tier: 5,000 requests/month via the MCP server (renews on the 1st, no card required); other products pay-as-you-go	docs
Browse AI API	Trigger pre-built or custom 'robots' to extract and monitor web data via REST API, returning structured JSON.	API key	—	🆓 free forever plan: 50 credits/mo, no card required	docs
Browser Use Cloud API	Launch cloud browser sessions and run AI browser-automation agent tasks via REST API or Python/TypeScript SDK.	API key	✅	$15 one-time signup credit for new accounts (Google/GitHub/Microsoft); paid usage afterward	docs
Browserbase (+ Stagehand) ⭐⭐⭐ 3.0/5 · 2 reviews	Run and control cloud headless browsers programmatically, with Stagehand adding natural-language page actions.	API key	✅	🆓 Free tier: 1 browser hour/month, 3 concurrent browsers, 15 min/session, no card required	docs
Diffbot	Automatically extract structured data (articles, products, people) from any URL via REST API, no custom parsing rules needed.	API key	—	🆓 free plan: 10,000 credits/mo, no card required (5 req/min limit)	docs
Firecrawl ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Scrape, crawl, and extract structured data from any website via a single REST API call.	API key	✅	🆓 free tier: 1,000 credits/mo, no card required	docs
Hyperbrowser	Spin up cloud browsers and call scrape, crawl, and structured-extract endpoints via REST API or MCP server.	API key	✅	🆓 Free: Free plan with 5,000 credits (1 credit = $0.001), 1 concurrent browser, 7-day data retention; no credit card required	docs
Oxylabs ⭐⭐⭐⭐ 4.2/5 · 1,216 reviews	Fetch web pages, search-engine results, and e-commerce data at scale via REST API with built-in proxy/unblocking infrastructure.	API key	✅	Trial: Web Scraper API free trial with up to 2,000 results one-time, no card required	docs
Playwright MCP (Microsoft)	Official Microsoft MCP server giving agents structured browser control (click, type, navigate) via Playwright's accessibility tree.	none	✅	🆓 free, open source, no key	docs
ScrapeGraphAI API	Use AI-driven prompts to scrape and extract structured data from webpages via REST API or Python/JS SDK.	API key	✅	Trial: 500 API credits one-time on the Free plan (10 requests/min), no card required	docs
ScraperAPI	Scrape any webpage with automatic proxy rotation, CAPTCHA handling, and JS rendering via a single REST API call.	API key	✅	🆓 Free: free plan with 1,000 API credits per month (max 5 concurrent connections); new accounts start with a 7-day trial of 5,000 one-time credits, no card required	docs
Scrapfly	Scrape webpages, run cloud browsers, and capture screenshots via REST API or hosted MCP server with anti-bot bypass.	API key / OAuth	✅	🆓 1,000 free credits/mo, no card required, no time limit	docs
ScrapingBee	Scrape any webpage with JS rendering, proxy rotation, and screenshot capture via a single REST API call.	API key	✅	Trial: 1,000 free API credits one-time on signup, no card required; then Hobby plan $19/mo for 75,000 credits	docs
Spider.cloud	Crawl and scrape websites at scale, returning JSON/XML/CSV, via REST API, CLI, or MCP server.	API key	✅	🆓 Free: keyless /scrape endpoint, rate-limited (quota not published); other endpoints return 402 without a key	docs
Steel	Create managed cloud browser sessions with stealth proxies and CAPTCHA solving, controllable via REST API or Playwright/Puppeteer.	API key	✅	Trial: Launch plan is $0 + usage with $30 one-time usage credits valid 90 days (10 concurrent sessions, 60 requests/min); no Hobby plan	docs
Zyte API	Fetch and auto-extract web pages (HTML, browser rendering, product/article data) via one HTTP API with ban avoidance.	API key	—	Trial: $5 free credit one-time on signup, valid 30 days, no subscription needed; then pay-as-you-go or a monthly commitment	docs

Knowledge and research data

Encyclopedias, academic papers, news, computational knowledge and up-to-date library documentation. — 17 services. JSON: catalog/knowledge-research.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
arXiv API	Search arXiv preprints by keyword, author, category or ID and retrieve metadata, abstracts and PDF links.	none	◐	🆓 free, no key	docs
Congress.gov API	Lets an agent look up U.S. bills, amendments, votes, members, committees, nominations and Congressional Record data from the Library of Congress.	API key	◐	🆓 Free: government API, key issued instantly by email; 5,000 requests/hour.	docs
Context7 (library docs for agents)	Fetch up-to-date, version-specific library documentation and code examples into a coding agent's context via MCP or REST.	API key	✅	🆓 Free: 1,000 API calls per month with a free API key (low limits without key); Pro $10/seat/month	docs
Court Rules	Lets an agent read U.S. federal and local court rules, judge standing orders, court holidays and filing deadlines, and compute a filing deadline for any federal district.	API key	✅	🆓 free tier: Developer plan at $0/month with full API access, rate limited to 10 requests/minute	docs
Crossref REST API	Look up and search scholarly metadata such as DOIs, references, authors, funders and licenses across Crossref-registered works.	none	◐	🆓 free, no key	docs
GDELT API	Full-text search global news in about 65 languages and analyze coverage volume, tone and geography in near real time.	none	◐	🆓 free, no key	docs
Gitingest API	Lets an agent turn any public Git repository into a single text digest (summary, directory tree and file contents) sized for an LLM prompt.	none	◐	🆓 No key needed: free public service; hosted API limited to 10 requests/minute per endpoint (the web UI also has rate limiting and CAPTCHA protection).	docs
Hacker News API	Read Hacker News stories, comments, jobs, polls, user profiles and front-page rankings as real-time JSON.	none	◐	🆓 free, no key	docs
Internet Archive Open Library API	Lets an agent search books, authors and subjects, fetch work/edition data by ISBN or OLID, search inside book texts and get cover images.	none	◐	🆓 No key; free and open: 1 request/second anonymous, 3 requests/second with an identifying User-Agent.	docs
New York Times APIs	Lets an agent search NYT articles back to 1851, read top stories, most-popular lists, the Times Wire feed and bestseller lists.	API key	◐	🆓 Free: all public APIs are free; 500 requests/day and 5 requests/minute per API.	docs
NewsAPI	Search and retrieve current and historical news articles and top headlines from thousands of sources worldwide.	API key	◐	🆓 free Developer plan: 100 req/day, dev/test only, 24h article delay	docs
OpenAlex API	Query an open catalog of scholarly works, authors, institutions, sources and topics, including citation data, via REST.	API key	◐	🆓 free: $1 of API usage/day without payment method; free key raises daily budget 10x	docs
PubMed E-utilities (NCBI)	Search, fetch, summarize and cross-link biomedical literature records from PubMed, PMC and other Entrez databases.	none	◐	🆓 free; 3 req/s without key, 10 req/s with free NCBI API key	docs
Semantic Scholar API	Search papers, authors and citation graphs, and get paper recommendations from Semantic Scholar's academic corpus.	API key	◐	🆓 free; no key (shared, throttled pool) or free API key on request	docs
Wikidata	Query the Wikidata knowledge graph of entities, facts and relations via SPARQL, the REST API or MCP.	none	✅	🆓 free, no key	docs
Wikipedia / Wikimedia API	Search, read and summarize Wikipedia and other Wikimedia content and metadata via REST and Action APIs.	none	◐	🆓 free, no key (rate-limited)	docs
Wolfram|Alpha API	Get computed answers, structured data and step-by-step results for math, science and factual queries.	API key	✅	🆓 Free: non-commercial developer AppID with up to 2,000 calls/month; paid for commercial use	docs

Image generation and editing

Text-to-image, image editing, inpainting, upscaling and background removal. — 10 services. JSON: catalog/image-generation.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Adobe Firefly Services API	Generate and edit images and manage creative assets programmatically via Adobe's Firefly REST APIs.	OAuth 2.0	◐	check pricing; requires Adobe Developer Console project and Firefly Services entitlement	docs
Black Forest Labs FLUX API	Generate, edit, and vary FLUX model images from text prompts via REST or the official OAuth MCP server.	API key	✅	paid only, no free tier (FLUX Schnell weights are open for self-hosting)	docs
Freepik API	Generate and edit images, and generate video, music and sound effects via REST API, plus access the Freepik stock asset library.	API key	✅	🆓 free tier: ~5 EUR of free API credits, then pay-as-you-go	docs
Google Gemini / Imagen image API	Generate and multi-turn edit images from text via REST (Nano Banana/Imagen models), up to 4K with reference-image support.	API key	—	Paid only: pricing page lists Free Tier 'Not available' for all Gemini image models (Nano Banana family); usage-billed	docs
Ideogram API	Generate, edit, remix, upscale, and describe images via REST or an official OAuth MCP server, strong at in-image text.	API key	✅	Paid only: no free API credits (web app has 10 slow credits/week); API is pay-per-image from prepaid credit (min one-time purchase $1, min auto top-up target $10)	docs
Leonardo.Ai API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Generate images and videos from text via REST or the official MCP server, with model selection and job status polling.	API key	✅	Paid only: Pay-As-You-Go API credit (USD balance) via manual or auto top-ups; API access is separate from free/web app plans	docs
OpenAI Images API (gpt-image)	Generate, edit, and iteratively refine images from text prompts via REST, with mask-based inpainting and streaming previews.	API key	◐	paid only; no free image credits, usage-based billing	docs
Recraft API	Generate, edit, upscale, and vectorize images via REST API using Recraft's proprietary models.	API key	✅	paid only; pay-per-image (from $0.007/image on V4.1 Flash), no confirmed free credits	docs
remove.bg API	Remove image backgrounds programmatically via a simple REST API with JSON or multipart uploads.	API key	—	🆓 Free: first 50 API calls per month, then paid credits	docs
Stability AI Platform API	Generate, upscale, and edit images via REST (Stable Image Ultra/Core/SD3 models) using simple credit-based billing.	API key	◐	25 free credits on signup, then pay-as-you-go	docs

Video generation and editing

Text/image-to-video models, talking avatars, programmatic video rendering and video hosting. — 14 services. JSON: catalog/video-generation.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Akool API	Generate face-swap, talking avatar, and video-translation content programmatically via REST API.	API key	—	Paid only for API: API access starts at the Pro Max plan; the Free plan is web-app only with full-screen watermark	docs
Creatomate API	Programmatically generate and render videos/images from templates via REST API.	API key	✅	Trial: full-featured trial with 50 credits one-time on signup, no credit card required; then Essential plan with 2,000 credits/mo	docs
D-ID API	Animate photos into talking-head videos with lip-sync from text or audio via REST API.	API key	✅	Trial: 14 days with 3 minutes of video credits, then paid plans only (API price per minute not published in machine-readable form)	docs
Google Veo (Gemini API / Vertex AI)	Generate video from text or image prompts via Gemini API (api key) or Vertex AI (cloud IAM), incl. Veo 3.1 scene extension.	API key / OAuth	✅	no free tier for video; Veo generation requires a paid Gemini API / Vertex AI billing account	docs
HeyGen API ⭐⭐ 2.0/5 · 1 review	Create AI avatar/talking-head videos from text or audio, manage avatars and voices, via REST API.	API key / OAuth	✅	no free API credits since Feb 2026; pay-as-you-go from $5, $0.50-$0.99/credit. Free plan (3 videos/mo) exists but is for the web app, not standalone API.	docs
Klap API	Automatically turn long videos into short clips with captions and reframing via REST API.	API key	—	Paid only; usage-based, billed monthly per operation (Generate Short $0.32, Video Input $0.44, Export $0.48); no free API credits stated	docs
Kling AI API	Generate text-to-video, image-to-video, lip-sync and video effects via REST API with a Bearer API key.	API key	◐	Paid only; prepaid credit packages from $0.14/unit, e.g. 5,000 units/$700, 180-day validity; a Trial Resource Package for integration testing is offered	docs
Luma AI Dream Machine API	Generate and extend AI videos from text or start/end keyframe images via async REST API (Ray 3.2).	API key	✅	Paid only; pay per video, e.g. Ray 3.2 5s text/image-to-video $0.15 (540p) / $0.30 (720p) / $1.20 (1080p), $5,000/mo cap on default Build tier	docs
MiniMax Hailuo API	Async text-to-video, image-to-video and subject-reference video generation via REST API, up to 1080p.	API key	✅	new accounts get 50 signup credits (~1 short clip); 5s video costs ~45-70 credits, 1000 credits=$1	docs
PixVerse API	Generate text-to-video, image-to-video, transition and fusion clips (360p-1080p) via REST API.	API key	✅	Paid only; prepaid credits from $10, $1 = 5 videos (v6, 720p, 5s, no audio)	docs
Runway API	Generate and edit images/video (Gen-4.5) via async task-based REST API: submit, poll, download.	API key	✅	no free tier; $10 minimum credit top-up, $0.01/credit	docs
Shotstack API	Compose Edit JSON timelines to programmatically render, edit, and template videos, images and audio.	API key	✅	Trial: 10 free credits one-time (valid 30 days), then pay-as-you-go or subscription; stage sandbox (https://api.shotstack.io/edit/stage) for development, v1 production without watermarks	docs
Synthesia API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Generate AI avatar talking-head videos from text scripts via REST API; supports custom avatars and voices.	API key	✅	Paid only; API access requires the Creator plan or above	docs
Tavus API	Create AI video replicas and real-time conversational video agents (CVI) via REST API.	API key	✅	🆓 Free tier: Free plan with 25 min of conversational video and 5 min of video generation per month, full API access, 25 stock replicas; Starter $59/mo	docs

Speech and audio

Text-to-speech, speech-to-text, voice cloning, dubbing and audio intelligence. — 13 services. JSON: catalog/audio-speech.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Amazon Polly / Amazon Transcribe (AWS)	Convert text to lifelike speech (Polly) and transcribe audio with speaker diarization (Transcribe) via AWS API.	cloud IAM	✅	🆓 Free tier: Polly 5M chars/mo standard (neural 1M, generative 100K chars/mo for first 12 months), Transcribe 60 min/mo (12 months); new AWS accounts since 2025-07-15 get up to $200 Free Tier credits	docs
AssemblyAI API	Transcribe recorded or streaming audio with speaker diarization, sentiment analysis and LLM-based audio insights via REST.	API key	—	Trial: $50 in free credits one-time on signup, no card required, credits do not expire (LLM Gateway not included); then pay-as-you-go	docs
Azure AI Speech	Convert text to speech, transcribe speech to text and translate speech via REST or Speech SDK.	cloud IAM	✅	🆓 Free tier (F0): 5 audio hrs/mo STT, 0.5M chars/mo neural TTS; batch transcription not available on F0	docs
Cartesia API	Generate low-latency real-time text-to-speech, transcribe speech and clone voices via REST/WebSocket API.	API key	✅	🆓 Free tier: 20,000 credits/mo; no commercial-use license and no voice cloning	docs
Deepgram API	Transcribe batch or streaming audio with diarization, synthesize speech, and run real-time voice agents via REST/WebSocket.	API key	✅	Trial: $200 in free credit one-time on signup, no credit card required; then pay-as-you-go	docs
ElevenLabs API ⭐⭐⭐⭐ 4.0/5 · 4 reviews	Generate, clone and stream text-to-speech voices and transcribe audio via REST/WebSocket API.	API key	✅	🆓 Free: limited monthly credits; non-commercial use with attribution only, no voice cloning	docs
Google Cloud Text-to-Speech / Speech-to-Text	Synthesize lifelike speech from text and transcribe audio to text via REST/gRPC using GCP credentials.	cloud IAM	✅	🆓 Free tier: TTS 4M chars/mo Standard and WaveNet, 1M chars/mo Neural2, Chirp 3 HD and Studio; STT 60 min/mo	docs
Hume AI API	Generate expressive text-to-speech and run real-time empathic voice conversations (EVI) via REST/WebSocket.	API key	✅	🆓 Free tier: 10,000 TTS chars/mo + 5 EVI min/mo; new accounts also get $20 in credits	docs
Murf AI API ⭐⭐⭐⭐⭐ 5.0/5 · 7 reviews	Generate AI voiceovers, clone voices and dub audio in 35+ languages via REST API.	API key	✅	Trial: 100,000 characters one-time on the free API plan, no time limit	docs
OpenAI Audio API (TTS / transcription)	Synthesize speech with TTS models and transcribe or translate audio with Whisper/GPT-4o transcribe via REST.	API key	—	paid only (pay-per-use)	docs
Resemble AI API ⭐⭐ 1.7/5 · 3 reviews	Synthesize speech, clone voices, convert speech-to-speech and detect deepfake audio via REST API.	API key	—	Paid only; Flex plan is $0/mo base with pay-as-you-go credits, no free usage allowance stated	docs
Rev AI API	Submit audio for asynchronous or streaming speech-to-text transcription, plus sentiment and topic extraction, via REST.	API key	—	trial credits (about 5 hours of ASR)	docs
Speechmatics API	Transcribe audio in batch or real time with speaker diarization across many languages via REST/WebSocket.	API key	◐	Trial: one-time $100 credit grant, no payment card required	docs

Music generation

Generate songs, instrumentals, loops and sound effects from prompts. — 6 services. JSON: catalog/music-generation.json

3D generation and assets

Text/image-to-3D mesh generation, texturing and 3D asset libraries. — 6 services. JSON: catalog/3d-generation.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Hyper3D Rodin API	Generate 3D meshes from text or images (sketch/regular/detail quality tiers) via an async REST job API.	API key	—	Paid only: API access requires the Business plan ($120/mo, $96/mo billed annually) or Enterprise; direct credits $1.5 each	docs
Meshy API	Generate, retexture, rig, and animate 3D models from text or images via REST API or official MCP server.	API key	✅	Paid only: creating API keys requires a paid plan (Pro $20/mo+); Free accounts get only a built-in test key for the Playground (free web plan 100 credits/mo)	docs
Sketchfab Data API	Search, download, and upload 3D models on Sketchfab programmatically via the REST Data API v3.	API key / OAuth	◐	🆓 Free: no key needed for search and model listing (GET /v3/search, /v3/models); downloads (/v3/models/{uid}/download) need a free account token	docs
Stability AI 3D (Stable Fast 3D / SPAR3D) API	Convert a single 2D image into a textured 3D mesh (GLB) via the v2beta/3d REST endpoints.	API key	—	Trial: 25 free credits on signup (1 credit = $0.01), then pay-as-you-go	docs
Tencent Hunyuan3D API	Generate textured 3D meshes (GLB, PBR) from text, images, or sketches via Tencent Cloud's Hunyuan 3D API.	cloud IAM	—	Trial: 200 free credits one-time on first activation (valid 1 year); then postpaid $0.02/credit, Professional generation 25 credits (~$0.50), Express 15	docs
Tripo API	Generate textured 3D meshes from text or images via REST API, with an official MCP server for agents.	API key	✅	Trial: starter free credits (Tripo docs: 300 free credits; amount varies by signup path), then pay-as-you-go at $0.01/credit	docs

Architecture, CAD and BIM

Building information models, CAD geometry, construction management and GIS platforms with programmatic access. — 8 services. JSON: catalog/architecture-cad-bim.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Autodesk Platform Services (APS)	Upload, translate, view and automate CAD/BIM files (Model Derivative, Data Management, Design Automation) via REST APIs.	OAuth 2.0	✅	🆓 Free tier: limited usage of rated APIs (Automation, Model Derivative, Flow Graph Engine, Reality Capture) per month, renews monthly; Pay as You Go beyond that needs a card or PayPal	docs
Bentley iTwin Platform APIs	Create, manage and query digital twins, iModels and reality/reporting data for infrastructure projects via REST APIs.	OAuth 2.0	—	🆓 Free tier: Community plan with 100 credits/month, 10 GB cloud data, 100 GB reality data; non-commercial, non-production use only; no expiry	docs
Onshape REST API	Create, read and modify Onshape CAD documents, parts, assemblies and drawings programmatically via REST API.	API key / OAuth	✅	🆓 free tier (public documents only); private documents need a paid plan	docs
Procore API ⭐⭐⭐⭐⭐ 5.0/5 · 2 reviews	Read and write construction project data - RFIs, submittals, drawings, budgets, schedules - via REST API.	OAuth 2.0	✅	🆓 free developer sandbox; production requires customer's paid Procore plan	docs
Rhino.Compute (McNeel)	Run Rhino/Grasshopper geometry operations headlessly via a stateless REST API you deploy yourself.	API key	—	Paid only: self-hosted, requires a Rhino license; core-hour billing at $0.10 per core per hour of Rhino uptime on Windows Server, no free allowance	docs
Speckle API	Send, receive and query 3D/BIM model data across CAD tools (Revit, Rhino, Grasshopper, Tekla) via GraphQL API and SDKs.	API key / OAuth	◐	🆓 free Explore plan (1 project, 3 users), unlimited API calls	docs
Trimble Connect API	Manage Trimble Connect projects, files, BIM models, issues/topics and metadata via REST APIs (Core, Model, Organizer).	OAuth 2.0	—	check pricing	docs
Zoo Text-to-CAD API (KittyCAD)	Convert CAD files and run modeling operations via REST API; text-to-CAD generation runs through the WebSocket copilot and the MCP server.	API key	✅	start free trial credits, then usage-based pay-as-you-go	docs

Diagrams and software architecture

Render or edit diagrams (Mermaid, PlantUML, C4), whiteboards and architecture models. — 8 services. JSON: catalog/diagrams-software-architecture.json

Design and UI

Read and write design files, generate branded graphics and publish websites. — 6 services. JSON: catalog/design-ui.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Canva Connect API	Programmatically create, autofill, and export Canva designs, and manage assets and comments via a REST API.	OAuth 2.0	✅	check pricing (free to build/test; public apps require Canva review before production use)	docs
Figma REST API / Dev Mode MCP	Read and write Figma file/comment/component data via REST, and feed live design context to coding agents via the official Dev Mode MCP server.	API key / OAuth	✅	🆓 free: personal access tokens work on free plan, rate-limited per seat/plan tier; MCP free during beta	docs
Framer ⭐⭐⭐⭐ 4.0/5 · 1 review	Automate publishing of Framer sites programmatically (get project info, publish previews, promote to production) via a Node SDK.	API key	—	🆓 Free: Server API is free while in beta; Framer plans per-use pricing with a monthly free allowance later	docs
Penpot API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Read, create, and modify Penpot design files, comments, and webhooks via a token-authenticated RPC/REST API, or via the official MCP server.	API key	✅	🆓 free tier: free cloud account (design.penpot.app) plus free, open-source self-hosting	docs
v0 Platform API (Vercel)	Generate full UI/frontend code from natural-language prompts, iterate via chat, and deploy the result directly to Vercel via REST API.	API key	✅	🆓 Free tier: v0 Free plan includes $5 of credits per month (7 messages/day); Platform API use on Free not confirmed, credits also included on Premium/Team plans	docs
Webflow Data API	Create/update CMS collections, items, and pages, and publish Webflow sites programmatically via REST API or the official MCP server.	API key / OAuth	✅	check pricing (API access itself is free with a token; some CMS/publish actions require the site to be on a paid Webflow plan)	docs

Documents, OCR and presentations

Parse PDFs and scans, convert file formats, generate slides and collect e-signatures. — 14 services. JSON: catalog/presentations-documents.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Adobe PDF Services API	Programmatically create, convert, combine, compress, OCR, and extract data from PDF documents.	OAuth 2.0	—	🆓 free tier: 500 document transactions/month, no credit card required	docs
AWS Textract	Detect and extract text, forms, tables, and data from scanned documents and images via API calls.	cloud IAM	✅	Trial: new AWS customers get 3 months free, per month 1,000 pages DetectDocumentText, 100 pages AnalyzeDocument forms/tables/layout/queries, 100 AnalyzeExpense/AnalyzeID, 2,000 pages AnalyzeLending; card required	docs
Azure AI Document Intelligence	Analyze forms, invoices, receipts, and scanned documents to extract structured JSON via REST API.	cloud IAM	—	🆓 Free tier: F0 pricing tier, 500 pages/month; analyzes only the first 2 pages per document, 4 MB max file, 1 TPS	docs
CloudConvert API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Convert, compress, merge, watermark, and OCR files across 200+ formats via REST API or MCP.	API key / OAuth	✅	🆓 Free: 10 conversion credits/day including all API features, no credit card required; paid credit packages beyond that; free Sandbox API for unlimited test jobs without consuming credits	docs
DocuSign eSignature API	Send, sign, track, and manage electronic signature envelopes and agreement workflows via REST API.	OAuth 2.0	✅	🆓 free developer/demo sandbox account (account-d.docusign.com) with unlimited test envelopes; production use requires a paid DocuSign plan	docs
Gamma API	Generate, poll, and export AI-made presentations, documents, or social posts as PDF/PPTX via REST API.	API key / OAuth	✅	Paid only for API keys (Pro, Ultra, Teams or Business plan); the Gamma MCP server/connectors work on all plans including Free, with generations consuming credits	docs
Google Document AI	Extract text, tables, and structured data from documents like invoices, forms, and IDs via REST API.	cloud IAM	—	🆓 Free tier: first 1,000 pages/month free for Enterprise Document OCR only (then $1.50/1,000); Form Parser and custom extractor $30/1,000 pages with no free band	docs
Google Slides / Docs API	Read and programmatically edit Google Slides presentations (slides, shapes, text, tables) via REST API or MCP.	OAuth 2.0	✅	🆓 free, no key (standard Google API usage quotas apply; requires GCP project + OAuth consent)	docs
LlamaParse (LlamaCloud)	Parse, classify, extract, and split complex documents (tables, forms, charts) into LLM-ready structured data via API.	API key	✅	🆓 Free tier: Free plan with 10K credits/month; beyond that credit-based at $1.25/1,000 credits (1-45+ credits/page depending on tier); 48h parse cache is free to re-query	docs
Mistral OCR API	Extract text, tables, and layout structure from PDFs and images as structured Markdown/JSON via REST API.	API key	◐	🆓 Free tier: Free plan includes $10/month in API credits; then $4/1,000 pages (OCR), $5/1,000 pages (Document AI); 50% off via Batch API	docs
PDF.co API	Convert, merge, split, edit, fill forms, OCR, and extract data from PDFs via REST API.	API key	✅	trial credits: 10,000 credits for 1 month, no credit card required	docs
Reducto API	Parse, extract, split, edit, and classify complex documents into structured JSON/Markdown via REST API or SDKs.	API key	✅	Trial: $150 in free credits (15,000 credits) one-time for new Standard accounts; then standard rates; Startup Program gives extra credits to qualifying teams	docs
SlideSpeak API ⭐ 1.0/5 · 1 review	Generate, edit, and download PowerPoint/PDF presentations from text, documents, or outlines via REST API.	API key	✅	Trial: free API trial, no credit card required; then API plans from $49/month (1,000 credits)	docs
Unstructured API	Partition and extract structured elements (text, tables, layout) from PDFs, docs, and images for RAG pipelines via API.	API key	✅	Trial: 10,000 free pages one-time on signup, no credit card; then pay-as-you-go at $0.015/page	docs

Translation and language

Machine translation, grammar and style checking. — 6 services. JSON: catalog/translation-language.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Amazon Translate ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Translate text and documents in real time or batch across 75+ languages via the AWS SDK/API.	cloud IAM	✅	🆓 free tier: 2M characters/month for 12 months (new AWS accounts)	docs
Azure AI Translator	Translate text, detect language, and transliterate across 100+ languages via REST API within Azure AI Services.	API key	◐	🆓 free tier (F0): 2,000,000 characters/month	docs
DeepL API ⭐⭐⭐⭐ 4.0/5 · 1 review	Translate and rephrase text or documents between 30+ languages via REST API, SDKs, or an official MCP server.	API key	✅	🆓 Free: API Developer plan ('Test out the API for free', EUR 0 base price, 1,000,000 characters/month in the pricing data); legacy API Free keys (:fx) use api-free.deepl.com	docs
Google Cloud Translation	Translate text/documents and detect language across 100+ languages via REST/gRPC API within Google Cloud.	cloud IAM	◐	🆓 free tier: 500,000 characters/month (permanent, not a trial)	docs
LanguageTool API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Check grammar, style, and spelling in 30+ languages via a public HTTP API, with an optional Premium key for higher limits.	API key	◐	🆓 Free: no key needed on public endpoint (rate-limited: 20 req/min, 75KB text/min per IP, 20KB per request)	docs
Lara Translate API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Translate text, documents, images and audio with context, style, glossaries and translation memories, and detect the language of text.	API key	✅	🆓 Free: 10,000 API characters/month (shared by translation and language detection), no credit card required	docs

Code execution sandboxes

Isolated cloud environments where an agent can run code, shells and whole dev environments safely. — 10 services. JSON: catalog/code-execution-sandbox.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Cloudflare Sandbox SDK	Deploy a Cloudflare Worker embedding this SDK to run untrusted code in per-request container sandboxes.	API key	✅	requires Workers Paid plan ($5/mo) for Containers; no free tier for container-backed sandboxes	docs
CodeSandbox SDK	Programmatically create, resume, and control cloud VM sandboxes to run and preview AI-written code.	API key	—	🆓 Free: Build (free) plan with 400 VM credits/month (~40 Nano-VM hours) and up to 10 concurrent VMs	docs
Daytona	Create elastic remote sandboxes via SDK/API to run AI-generated code with sub-second startup.	API key	✅	Trial: $200 free compute credit one-time on signup, no credit card required; first 5 GiB storage free; startup program up to $50k credits	docs
E2B	Spin up isolated Firecracker cloud sandboxes via SDK/REST to execute AI-generated code and return results.	API key	✅	Trial: one-time $100 usage credit on signup (Hobby, no card); up to 1 h per sandbox, 20 concurrent; then pay-as-you-go	docs
Judge0	Submit source code and stdin via REST to compile/run it in 60+ languages and poll for the result.	API key	—	Paid only on Judge0 Cloud (Pro EUR 27/mo for 2,000 submissions/day and up); self-host free & open-source (GPLv3)	docs
Modal	Programmatically launch serverless sandboxes, optionally with GPUs, to execute untrusted or agent code.	API key	◐	🆓 Starter plan: $0 base + $30/mo free credits	docs
Piston	Compile and run code in 70+ languages inside isolated containers via a self-hostable REST API (the public instance needs a granted token).	API key	—	🆓 Free: self-host (open source, Docker); public emkc.org API closed to open use since 2026-02-15, tokens only for approved non-commercial educational projects	docs
Riza	Call a REST API to execute untrusted Python/JS/Ruby/PHP code in sandboxes that start in under 10ms.	API key	✅	🆓 Free tier: Hobby plan free forever, 100,000 requests/month, 30 s execution limit; then usage-based pricing	docs
Runloop	Create, snapshot, suspend/resume, and run commands in Linux Devboxes via API/SDK for agent coding tasks.	API key	✅	$50 free credits on signup, then usage-based ($0.108/CPU-hr, $0.0252/GB-hr)	docs
Vercel Sandbox	Boot ephemeral Firecracker microVMs via SDK/REST to run agent- or AI-generated code and shell commands.	API key / OAuth	✅	🆓 usage included on Hobby plan, otherwise usage-based on Pro/Enterprise	docs

Developer platforms and DevOps

Source control, CI/CD, monitoring, error tracking, incident management and package registries. — 12 services. JSON: catalog/developer-devops.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
CircleCI API ⭐⭐⭐ 3.0/5 · 2 reviews	An agent can trigger pipelines, rerun workflows, fetch logs/test results, and validate CI/CD configuration via REST.	API key	✅	🆓 free plan: 30,000 credits/month (~6,000 build minutes on a small Docker resource class), credits expire monthly	docs
Datadog API ⭐⭐⭐⭐⭐ 4.9/5 · 7 reviews	An agent can query metrics, logs, traces, monitors, and dashboards, and manage Datadog configuration via REST.	API key	✅	🆓 free Infrastructure Monitoring plan: 1-day metric retention, up to 5 hosts; other products (APM, Logs, Security) are paid	docs
Docker Hub API	An agent can search, push, pull, tag, and manage container images and repositories on Docker Hub.	API key	✅	🆓 free personal accounts with rate-limited image pulls; paid Pro/Team/Business tiers raise pull limits	docs
GitHub API ⭐⭐⭐⭐⭐ 4.7/5 · 21 reviews	An agent can manage repositories, issues, pull requests, releases, and code search via REST or GraphQL.	API key / OAuth	✅	🆓 free with any GitHub account; 5,000 req/hr authenticated, 60/hr unauthenticated	docs
GitLab API ⭐⭐⭐⭐ 4.4/5 · 14 reviews	An agent can manage projects, issues, merge requests, CI/CD pipelines, and repository files via REST/GraphQL.	API key / OAuth	✅	🆓 free tier: full REST API access on GitLab.com Free plan; some features gated to Premium/Ultimate	docs
Globalping Network Measurement API	Lets an agent run ping, traceroute, MTR, DNS and HTTP tests from thousands of probes worldwide to check reachability, latency and routing of a host.	none	✅	🆓 No key; 250 tests/hour anonymously (up to 50 probes per measurement), 500 tests/hour with a free account token (up to 500 probes); extra tests use credits.	docs
Maven Central Search API	Lets an agent search Maven Central for Java/JVM artifacts by groupId, artifactId, class name or SHA-1 and look up the latest versions before adding a dependency.	none	◐	🆓 No key; free public API with no published quota (fair use).	docs
PagerDuty API ⭐⭐⭐⭐⭐ 4.7/5 · 44 reviews	An agent can create/manage incidents, on-call schedules, escalation policies, and services via REST.	API key / OAuth	✅	🆓 free plan for up to 5 users: 100 monthly SMS/phone notifications, 1 on-call schedule, 1 escalation policy, API access	docs
Postman API ⭐⭐⭐⭐⭐ 4.8/5 · 24 reviews	An agent can manage Postman collections, workspaces, environments, mocks, monitors, and API specs via REST.	API key	✅	🆓 Free plan: 10,000 Postman API calls/month; rate limits ~300 req/min general, stricter for specific endpoints	docs
Reflag Management API	Lets an agent create feature flags, change their targeting for users and companies, and evaluate flags at runtime.	API key / OAuth	✅	🆓 Free Starter plan: 1,000 monthly tracked users, unlimited seats, 3 environments; no overage (upgrade required)	docs
Sentry API	An agent can query and triage error/performance issues and manage projects, releases, and org data.	API key / OAuth	✅	🆓 free Developer plan: 1 user, 5,000 errors/mo, 5GB logs, 50 replays; includes MCP access	docs
Supabase Management API	An agent can programmatically create and manage Supabase projects, databases, API keys, and config.	API key / OAuth	✅	🆓 free plan available; rate limit 120 req/min per user/project (lower for heavier endpoints)	docs

Cloud and hosting

Cloud providers, serverless and edge platforms, and site hosting an agent can deploy to and manage. — 11 services. JSON: catalog/cloud-hosting.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
AWS APIs	An agent can provision and control thousands of AWS resources (compute, storage, databases, ML) via SDKs/CLI/REST.	cloud IAM	✅	🆓 Free tier: 30+ services always free within monthly limits; new accounts also get up to $200 one-time credits ($100 on signup + up to $100 earned) usable over 6 months	docs
Azure APIs	An agent can deploy and manage Azure resources (compute, storage, databases, AI) across resource-provider REST APIs.	cloud IAM	✅	🆓 12 months of select free services plus $200 credit for 30 days for new accounts; many services also have a permanent always-free monthly amount	docs
Cloudflare API ⭐⭐⭐⭐⭐ 4.5/5 · 12 reviews	An agent can manage DNS, Workers, zones, WAF/security rules, and caching for Cloudflare accounts programmatically.	API key / OAuth	✅	🆓 free with any Cloudflare account; API access itself is free, manages both free and paid Cloudflare products	docs
Easypanel	Lets an agent discover Easypanel server-management procedures and execute queries, mutations and destructive operations using the selected user’s permissions.	API key	✅	🆓 free tier: 3 projects with unlimited services and deployments; self-hosted server costs are separate	docs
Fly.io Machines API	An agent can create, start, stop, and destroy Fly.io Machines (lightweight VMs) programmatically via REST.	API key	✅	Trial: 2 machine-hours or 7 days, whichever comes first, no card needed to start (adding a card ends the trial); then pay-as-you-go, no perpetual free tier	docs
Google Cloud APIs	An agent can create and manage Google Cloud resources (compute, storage, data, AI/ML) via REST, gRPC, or client libraries.	cloud IAM	✅	🆓 free trial credit for new customers plus an Always Free tier with perpetual no-cost limits on select products	docs
Mux Video API	Upload, encode, stream and analyse video; get playback URLs, thumbnails and captions via REST.	API key	✅	🆓 first 100,000 delivered minutes/month free, then usage-based	docs
Netlify API ⭐⭐⭐⭐ 4.0/5 · 5 reviews	An agent can create/manage sites, trigger and monitor deploys, and configure DNS, domains, and env vars.	API key / OAuth	✅	🆓 Free: $0 forever plan with 300 credits per month (hard limit, no rollover); API usage subject to account plan limits	docs
Render API	An agent can create and manage Render services, trigger deployments, and configure databases and env vars.	API key	✅	🆓 free static sites; free web services that spin down after inactivity	docs
Tencent EdgeOne Pages (Makers)	Lets an agent deploy HTML pages, static sites and full-stack apps with edge functions to EdgeOne and get back a public URL.	API key	✅	🆓 Free plan (stated as permanent): 40 projects, 500 builds/month, 3M Edge Function and 1M Cloud Function invocations/month, 5 GB storage, 1 GB KV, 1 GB Blob.	docs
Vercel API ⭐⭐⭐⭐⭐ 4.5/5 · 2 reviews	An agent can create deployments, manage projects/domains/env vars, and query analytics and logs.	API key / OAuth	✅	🆓 free on Hobby plan; some resources/endpoints require Pro/paid plan	docs

Databases

Managed SQL, NoSQL, key-value and analytics databases an agent can create, query and manage. — 12 services. JSON: catalog/databases.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
ClickHouse Cloud	Run SQL analytics queries and manage Cloud services/backups via REST API or official MCP server.	API key	✅	no permanent free tier; 30-day trial with $300 credits	docs
Convex	Introspect tables/functions, call functions, and read/write data in a reactive database via MCP or client SDKs.	API key	✅	🆓 generous free tier for small apps, zero cost/maintenance	docs
Google BigQuery	Run SQL queries and inspect datasets/tables in BigQuery via REST API or the fully-managed remote MCP server.	cloud IAM	✅	🆓 Free tier: 1 TiB of querying and 10 GiB of storage per month	docs
MongoDB Atlas ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Create/manage Atlas clusters and query MongoDB data via Admin API, drivers, or official MCP server.	API key / OAuth	✅	🆓 free tier: M0 cluster free forever (512MB)	docs
Neon Postgres	Provision and manage serverless Postgres projects/branches and run SQL via REST API or MCP server.	API key / OAuth	✅	🆓 Free tier: 100 projects; 0.5 GB storage, 100 CU-hours and 5 GB egress per project per month, no card required	docs
PlanetScale	Manage MySQL databases, branches, and schema, and view Insights via hosted MCP server or API.	API key / OAuth	✅	Paid only: no free or Hobby plan; cheapest is Postgres PS-5 single node at $5/month	docs
Snowflake ⭐⭐⭐⭐⭐ 4.8/5 · 4 reviews	Run SQL, Cortex Analyst, and Cortex Search over warehoused data via REST API or managed MCP server.	API key / OAuth	✅	trial credits (no permanent free tier); check pricing	docs
Supabase	Manage Postgres tables, auth, storage, and edge functions via REST/GraphQL APIs or client SDKs.	API key / OAuth	✅	🆓 free tier: 2 projects, 500MB DB, 5GB bandwidth	docs
TiDB Cloud API (Starter)	Lets an agent create and manage serverless MySQL-compatible TiDB clusters and run SQL, full-text and vector search queries against them.	API key	✅	🆓 Free: up to 5 Starter instances per org, 25 GiB row storage + 25 GiB columnar storage + 250M Request Units per month in total; no credit card	docs
Tinybird API	Lets an agent ingest events into real-time ClickHouse-based data sources, run SQL queries and call published analytics API endpoints.	API key	✅	🆓 Free plan: 10 GB storage, 1,000 API requests/day, 0.25 vCPU shared; no credit card	docs
Turso	Create and query edge SQLite (libSQL) databases programmatically via HTTP/SDK client libraries.	API key	✅	🆓 Free tier: 100 databases, 5 GB storage, 500M rows read and 10M rows written per month, no card required	docs
Upstash (Redis, Vector)	Call serverless Redis, Vector, and QStash over HTTP REST API from edge/serverless runtimes.	API key	✅	🆓 Free tier: Redis 256MB/500K cmds per month; Vector 10K queries+updates per day (max 200M vectors x dimensions, 1,536 dims)	docs

Vector search, memory and RAG

Vector databases, retrieval (RAG) services and long-term memory layers for agents. — 9 services. JSON: catalog/databases-vector-memory.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Agentset RAG API	Lets an agent ingest documents into managed RAG namespaces and run semantic search or cited question answering over them.	API key	✅	🆓 Free plan (forever): 1,000 pages ingested and 10,000 retrievals per month, 60 requests/min per namespace	docs
Chroma Cloud	Create databases and store/query vector embeddings for retrieval via REST/SDK or MCP server.	API key	✅	Trial: Starter plan $0/month base with $5 one-time free credits on signup, then usage-based pricing	docs
Letta	Create and run stateful agents with persistent memory blocks via REST API or hosted MCP server.	API key	✅	🆓 Free: $0/month plan with up to 3 stateful agents and limited Letta Auto usage (bring your own API keys); API plan $20/month + usage	docs
Mem0	Add, search, update, and delete long-term agent memories via REST API or hosted MCP server.	API key	✅	🆓 free (Hobby) tier: 10K add requests, 1K retrievals/mo, 1 project	docs
Pinecone	Upsert, query, and rerank vector embeddings in managed indexes via REST/SDK or MCP server.	API key	✅	🆓 free tier (Starter plan, limited pods/reads)	docs
Qdrant Cloud	Create clusters and store/search vector embeddings via REST/gRPC API, SDKs, or official MCP server.	API key	✅	🆓 Free tier: single-node cluster with 0.5 vCPU, 1 GB RAM, 4 GB disk, no card; suspends after 1 week idle	docs
Weaviate Cloud	Store and semantically search vector objects in a managed cluster via REST/GraphQL or MCP server.	API key	✅	🆓 Free: always-free plan, 1 cluster, 100,000 objects, 1 GB memory, 10 GB disk, 1 collection, no card required	docs
Zep	Store and retrieve temporal knowledge-graph agent memory via REST API or a single MCP endpoint.	API key	✅	🆓 Free tier: 10,000 credits per month, no rollover; variable rate limits	docs
Zilliz Cloud (Milvus)	Manage Milvus clusters and perform vector search/ingestion via REST API, SDKs, or MCP server.	API key	✅	🆓 Free tier: serverless cluster, 5GB storage, 2.5M vCUs per month, up to 5 collections, no card; plus up to $200 one-time trial credits ($100 on signup + $100 on adding a card)	docs

Email, team chat and notifications

Send and receive email, post to team chat (Slack, Discord), send push notifications; manage meetings. — 10 services. JSON: catalog/communication-email-chat.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
AgentMail	Programmatically create inboxes and send/receive email autonomously, purpose-built for AI agents.	API key	✅	🆓 Free: 3 inboxes, 3,000 emails/month (max 100/day), 3GB storage, no card required	docs
Discord API	Send messages, manage channels/roles, and build interactive bots via REST and Gateway API.	API key / OAuth	◐	🆓 free, no key needed beyond creating a bot application	docs
Mailgun ⭐ 1.0/5 · 1 review	Send and validate transactional email via REST API and SMTP relay with webhooks.	API key	✅	🆓 free: 100 emails/day; 30-day free trial on paid tiers	docs
ntfy.sh Push Notifications API	Lets an agent send push notifications to a user's phone or desktop by publishing a plain HTTP POST to an ntfy topic, and read messages back from it.	none	◐	🆓 No key; anonymous publishing to public topics, rate-limited per visitor IP (burst of 60 requests, then 1 request every 5 s, roughly 17,280/day); paid plans from $6/month add reserved topics, higher limits, email and phone-call notifications.	docs
Postmark	Send transactional email via REST API with delivery tracking, bounce handling, and templates.	API key	✅	🆓 free: 100 emails/month (Developer plan, no expiry)	docs
Resend ⭐⭐⭐⭐ 4.0/5 · 1 review	Send transactional and marketing email via REST API with templates, domains, and webhooks.	API key	✅	🆓 free tier: 3,000 emails/mo, 100/day	docs
SendGrid (Twilio) ⭐⭐⭐⭐ 3.9/5 · 8 reviews	Send transactional and marketing email via REST/SMTP API with templates and analytics.	API key	—	Trial: 100 emails/day for 60 days, no card required; paid plan after	docs
Slack API ⭐⭐⭐⭐⭐ 4.6/5 · 250 reviews	Post messages, manage channels, and read conversation history in Slack via the Web API.	OAuth 2.0	✅	🆓 free, no key needed beyond creating a Slack app/workspace	docs
Stream (GetStream) Chat & Video API	Build and moderate in-app chat and video with REST/SDK APIs, channels, and real-time messaging.	API key	—	🆓 Free tier: Build plan with 1,000 MAU/month and 100 concurrent connections, no card; Maker account gives $100/month credit for teams under 5 people and under $10k monthly revenue	docs
Zoom API	Schedule, update, and manage meetings, webinars, and cloud recordings programmatically via REST API.	OAuth 2.0	✅	🆓 usable on free Zoom account within Basic plan limits; some endpoints require paid plan	docs

SMS and messaging apps

Send and receive SMS and messages on WhatsApp, LINE or Telegram through a messaging provider's API. — 10 services. JSON: catalog/sms-messaging.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
AWS End User Messaging SMS	Send SMS, MMS and voice messages and manage sender numbers, opt-outs and registrations via the AWS SMS and Voice v2 API.	cloud IAM	✅	Paid only; US SMS $0.00774/message + $0.00421 carrier fee (10DLC or toll-free)	docs
Bird (formerly MessageBird)	Send SMS, email and WhatsApp messages, verify phone numbers and track delivery via REST API or hosted MCP.	API key / OAuth	✅	Paid only; prepaid wallet, US long code or toll-free $0.0035/SMS + carrier fees	docs
LINE Messaging API	Lets an agent send and reply to messages, rich messages and broadcasts to users of a LINE Official Account and read user profiles.	API key	✅	🆓 Free Communication plan (Japan): 200 push/broadcast messages/month; reply messages are unlimited. Beyond that only paid plans (Light JPY 5,000 for 5,000 messages, Standard JPY 15,000 for 30,000). Free quotas vary by region	docs
Sinch ⭐ 1.0/5 · 2 reviews	Send and receive SMS (and WhatsApp, RCS and other channels) via the Conversation REST API.	API key	✅	Trial: free trial credit and a free test number on signup, no card; then paid (US 10DLC $0.0078/SMS + carrier fees)	docs
Telegram Bot API	Send/receive messages, media, and inline interactions via a simple HTTPS bot API.	API key	◐	🆓 free, no key needed beyond a bot token from @BotFather	docs
Telnyx ⭐⭐⭐⭐⭐ 5.0/5 · 8 reviews	Send and receive SMS, MMS, RCS and WhatsApp messages and manage phone numbers via REST API.	API key	✅	Trial: $5 test credit, 1 verified number, 100 messages/day; then paid (US 10DLC $0.004/SMS part + carrier fees)	docs
Textbelt	Send an SMS to a phone number (US or international) with one HTTP POST, and check delivery status and remaining credits.	API key	—	🆓 Free: shared key 'textbelt' sends 1 SMS per day; paid credits are a one-time purchase	docs
Twilio ⭐⭐⭐⭐⭐ 4.8/5 · 13 reviews	Send/receive SMS, WhatsApp messages, and voice calls programmatically via REST API.	API key	✅	Trial: 100 SMS, 100 WhatsApp, 3,000 emails, 75 voice minutes; no card; one-time, expires after 30 days; SMS only to verified numbers within the signup country, using predefined templates	docs
Vonage API	Send SMS, make voice calls, and build video apps via a unified communications REST API.	API key	✅	Trial: free credit on signup, no credit card required; then pay-as-you-go per request	docs
WhatsApp Business Cloud API	Send/receive WhatsApp messages, template messages, and media programmatically via Graph API.	OAuth 2.0	◐	🆓 Free: non-template (service) messages inside an open 24h customer service window; template messages billed per message (per-message pricing since 2025-07-01)	docs

Voice agents and telephony

Place and receive phone calls handled by AI voice agents, real-time audio/video rooms. — 9 services. JSON: catalog/voice-agents-telephony.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Bland AI	Programmatically create AI phone agents and place/manage automated outbound and inbound calls.	API key	✅	🆓 free credits + inbound number on signup (Start plan), no credit card required	docs
Deepgram Voice Agent API	Run a full-duplex speech-to-speech voice agent pipeline (STT+LLM+TTS) over a WebSocket API.	API key	✅	$200 free credit on signup	docs
ElevenLabs Agents Platform	Build and deploy conversational AI voice agents with telephony (SIP/Twilio) integration via API and SDKs.	API key	✅	🆓 Free plan: 10k credits/month shared across ElevenLabs products; no commercial license (from Starter, $6/month)	docs
LiveKit Cloud	Build and deploy real-time voice AI agents with SIP telephony support using LiveKit's server SDKs and APIs.	API key	—	🆓 free Build plan: 1,000 agent session minutes/mo, 5,000 WebRTC participant minutes/mo, 50GB data transfer	docs
Plivo ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Make and receive voice calls, SIP trunking and AI voice agents via REST API; SMS is available only on the Enterprise plan.	API key	✅	Trial: free credits for the first 3 weeks on the self-serve Professional plan (voice and SIP only); SMS, MMS and WhatsApp need Enterprise (from $1,000/month)	docs
Retell AI ⭐ 1.0/5 · 1 review	Build, deploy, and manage AI voice agents that handle phone and web calls via REST API and SDKs.	API key	✅	$10 free credit on signup, then pay-as-you-go ($0.07-$0.31/min for voice)	docs
Synthflow API ⭐ 1.0/5 · 1 review	Create and manage AI phone voice agents and trigger/manage outbound calls programmatically via REST API.	API key	✅	Paid only: Enterprise contracts from $30,000/year; no free plan or self-serve trial listed	docs
Twilio Programmable Voice	Programmatically make, receive, and control phone calls (IVR, recording, conferencing) via REST API.	API key	✅	Trial: one-time free units (e.g. 75 voice minutes, 100 SMS, 100 WhatsApp, 3,000 emails), no card, expires after 30 days; then pay-as-you-go	docs
Vapi	Create, configure, and run AI voice assistants that make and receive phone calls via REST API.	API key	✅	$5 free credit on signup, then pay-as-you-go (~$0.05/min platform fee + provider costs)	docs

Productivity and workspace

Email, calendars, files, notes, tasks and project management. — 17 services. JSON: catalog/productivity-workspace.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Airtable API ⭐⭐⭐⭐⭐ 4.7/5 · 28 reviews	Read and write records in Airtable bases and tables via REST API.	API key / OAuth	✅	🆓 Free tier: 1,000 API calls per workspace per month on the Free plan, 5 req/sec per base	docs
Asana API ⭐⭐⭐⭐⭐ 4.7/5 · 97 reviews	Create tasks, projects, and comments in Asana workspaces via REST API.	API key / OAuth	✅	🆓 free tier: API included on Personal (free) plan, rate limited	docs
Atlassian (Jira, Confluence)	Create and manage Jira issues and Confluence pages via REST API or the official remote MCP server.	OAuth 2.0	✅	🆓 free tier: available on Free Jira/Confluence plans; rate limits vary by plan	docs
Box API	Upload, download, and manage files, folders, and metadata in Box via REST API.	OAuth 2.0	✅	🆓 Free: developer plan with 10 GB storage, full API access and 1,000 AI units per month, no payment required	docs
Cal.com API	Create and manage bookings, event types, and availability via the Cal.com REST API v2.	API key / OAuth	✅	🆓 Free: API keys on any account incl. the free-forever Individuals plan, 120 req/min per key (higher on request); Teams/Orgs endpoints need paid plans	docs
Calendly API ⭐⭐⭐⭐⭐ 4.7/5 · 14 reviews	Programmatically book meetings and read/write scheduling, event, and contact data via REST API v2.	API key / OAuth	✅	🆓 Free: API reads and most writes work on every plan incl. Free (except 3 Enterprise-only endpoints); booking through the Scheduling API (POST /invitees) and webhooks need a paid plan	docs
ClickUp API ⭐⭐⭐⭐⭐ 4.6/5 · 122 reviews	Create and manage ClickUp tasks, lists, and docs via REST API or the official MCP server.	API key / OAuth	✅	🆓 free tier: API access included on Free Forever plan	docs
Coda API (Superhuman Docs)	Read and write Coda (now 'Superhuman Docs') documents, tables, and rows via REST API or an MCP server.	API key	✅	🆓 free, included for all users on both free and paid workspaces	docs
Dropbox API ⭐⭐⭐⭐⭐ 4.5/5 · 226 reviews	Upload, download, and manage files and folders in Dropbox via the HTTP REST API.	OAuth 2.0	✅	🆓 free tier: API access included on Basic (free) plan, rate limited	docs
Google Workspace APIs (Gmail, Calendar, Drive)	Read/write Gmail messages, Calendar events, and Drive files programmatically via REST APIs.	OAuth 2.0	✅	🆓 Free: no charge within per-API daily quotas; Google plans to bill quota overages to the Cloud billing account later in 2026	docs
Linear API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Create, query, and update Linear issues, projects, and comments via GraphQL API or the official MCP server.	API key / OAuth	✅	🆓 free tier: API access included on Free plan (rate limited)	docs
Microsoft Graph (Outlook, Teams, OneDrive)	Single REST endpoint to read/write Outlook mail, Calendar events, Teams, and OneDrive/SharePoint data.	OAuth 2.0	✅	🆓 Free: standard Graph APIs cost nothing beyond the user's Microsoft 365/Entra license (metered APIs are billed); the free M365 E5 developer sandbox is only for qualifying members (Visual Studio Pro/Enterprise subscribers, ISV Success/partners, Premier/Unified support)	docs
monday.com API ⭐⭐⭐⭐⭐ 4.8/5 · 98 reviews	Query and update monday.com boards, items, and workflows via GraphQL API or a hosted MCP endpoint.	API key / OAuth	✅	🆓 free tier: GraphQL API included on Free plan (rate limited)	docs
NocoDB Cloud API	Lets an agent read, create and update records, tables and views in NocoDB spreadsheet-style databases.	API key / OAuth	✅	🆓 Free plan: 1,000 records, 1 GB storage, 1,000 API calls/month, 3 editors, 100 automation runs; no credit card	docs
Notion API ⭐⭐⭐⭐⭐ 4.7/5 · 26 reviews	Read, create, and update Notion pages, databases, and comments via REST API.	API key / OAuth	✅	🆓 free, API access included on all plans (rate limit ~3 req/sec)	docs
Todoist API ⭐⭐⭐⭐⭐ 4.8/5 · 14 reviews	Create, read, and complete Todoist tasks and projects via REST API or the official MCP server.	API key / OAuth	✅	🆓 Free: API usable with any Todoist account; 1,000 partial / 100 full sync requests per 15 min per user; some features follow the user's Todoist plan	docs
Trello API	Create and manage Trello boards, lists, and cards via REST API.	API key / OAuth	✅	🆓 Free: free API key + user token; rate limits 300 req/10 s per API key and 100 req/10 s per token	docs

CRM, support and marketing

Contacts, deals, support tickets and email campaigns. — 8 services. JSON: catalog/crm-support-marketing.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Attio API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Search, create, and update records, lists, and notes in an Attio CRM workspace via REST API or official MCP.	API key / OAuth	✅	🆓 Free tier: up to 3 seats, 50,000 records, API access included; no card required; 14-day trial of Pro plan	docs
HubSpot API	Create/update CRM contacts, deals, companies, and engagements, or send marketing emails, via REST API or remote MCP.	API key / OAuth	✅	🆓 free CRM account with limited-scope API access; many endpoints require a paid Hub tier (see APIs-by-tier docs)	docs
Intercom API ⭐⭐⭐⭐⭐ 4.7/5 · 9 reviews	Manage conversations, contacts, companies, and Help Center articles via REST API or Intercom's official remote MCP server.	API key / OAuth	✅	🆓 free development workspace for building/testing; production use requires a paid Intercom plan	docs
Klaviyo API ⭐⭐⭐⭐⭐ 4.5/5 · 8 reviews	Manage email/SMS marketing profiles, lists, flows, and campaign analytics via Klaviyo's REST API or official MCP server.	API key / OAuth	✅	🆓 free plan up to 250 contacts / 500 email sends per month	docs
Mailchimp Marketing API	Manage email marketing audiences, campaigns, and automation via Mailchimp's Marketing REST API.	API key / OAuth	◐	🆓 free plan up to 250 contacts / 500 emails per month (API accessible on free plan)	docs
Pipedrive API ⭐⭐⭐⭐ 4.4/5 · 50 reviews	Create and update deals, contacts (persons/organizations), and activities in a Pipedrive CRM pipeline via REST API.	API key / OAuth	✅	no free tier; 14/30-day trial and free developer sandbox account for testing	docs
Salesforce APIs ⭐⭐⭐⭐⭐ 4.7/5 · 60 reviews	Read and write Salesforce CRM records (leads, opportunities, cases) programmatically via REST, GraphQL, or Bulk API.	OAuth 2.0	✅	🆓 free Developer Edition org available via signup at developer.salesforce.com/signup	docs
Zendesk API ⭐⭐⭐⭐ 4.3/5 · 20 reviews	Create, update, and search support tickets, users, and Help Center articles via Zendesk's REST API.	API key / OAuth	◐	Trial: 14-day free trial of Suite Professional, one-time, no credit card required; no free plan, paid plans from $19/agent/mo (Support Team, annual)	docs

Social media

Read and publish posts, comments and videos on social platforms. — 10 services. JSON: catalog/social-media.json

Maps, geolocation and weather

Geocoding, routing, places, map tiles and weather forecasts. — 18 services. JSON: catalog/maps-geo-weather.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Esri ArcGIS Location Platform	Geocode addresses, render maps, run spatial analysis and manage geospatial site data via REST APIs and SDKs.	API key / OAuth	✅	🆓 free tier with monthly free credits, then usage-based pricing	docs
Geoapify	Geocode, search places, and calculate routes/isochrones via REST APIs built on open geodata.	API key	✅	🆓 free tier: 3,000 credits/day (~90,000/month), no card required	docs
Google Maps Platform ⭐⭐⭐⭐⭐ 4.7/5 · 6 reviews	Geocode addresses, get directions/routes, places data, and static/dynamic maps via REST APIs or Google's remote MCP server.	API key	✅	🆓 Free tier: free calls per SKU per month (10K Essentials, 5K Pro, 1K Enterprise), replacing the former $200 monthly credit	docs
GUGiK Universal Geocoding Service (UUG)	Geocode a Polish street address to coordinates with official TERYT/SIMC/ULIC codes and postcode, or reverse-geocode a point to the nearest address, via Poland's national geodesy office.	none	—	🆓 Free, no key: public government geocoding service for Polish addresses, streets, towns, road markers and level crossings	docs
HERE Location Services	Geocode, route, and search places worldwide via REST APIs and SDKs.	API key	◐	🆓 Free: Base plan includes free monthly transactions per service (pay-as-you-grow above); credit card required at signup	docs
IP2Location.io API	Lets an agent geolocate IPv4/IPv6 addresses, get ASN/ISP/proxy data, and look up domain WHOIS records.	API key	✅	🆓 Free plan: 50,000 IP geolocation queries/month, 500 domain WHOIS and 50 hosted-domain queries/month (attribution required); keyless: 1,000 queries/day.	docs
IPLocate IP Intelligence API	Lets an agent geolocate an IP address and get its ASN, ISP, company, abuse contacts and VPN/proxy/Tor/hosting flags.	API key	✅	🆓 Free plan: 1,000 requests/day forever, all data types (geolocation, VPN/proxy/Tor, ASN, company, abuse contacts), no credit card.	docs
LocationIQ	Geocode and reverse-geocode addresses, find nearby places, look up time zones, calculate routes and render map tiles via REST API.	API key	—	🆓 Free: 5,000 requests/day, 2 requests/s, 60 requests/min, no card; commercial use requires a link back to LocationIQ	docs
Mapbox	Geocode, route, and render maps/POI search via REST APIs, SDKs, or an official MCP server.	API key	✅	🆓 free tier: monthly free quotas per API (e.g. 50,000 map loads/month)	docs
National Weather Service API (NWS)	Fetch official US government weather forecasts, alerts, and observations via a free public REST API.	none	◐	🆓 free, no key, no rate-limit tier (fair-use)	docs
Open-Meteo	Fetch weather forecasts, historical weather, and climate data worldwide via a free open REST API, no key required.	none	◐	🆓 No key needed for non-commercial use: 10,000 calls/day, 300,000/month (also 600/min, 5,000/hour)	docs
OpenCage Geocoding API	Convert addresses and place names to coordinates, and coordinates to addresses, worldwide via REST API.	API key	✅	🆓 Free: 2,500 requests/day, 1 request/s, no card (for testing; production needs a paid plan from €45/month)	docs
OpenRouteService	Calculate routes, isochrones, distance matrices, and geocoding over OpenStreetMap data via a free REST API.	API key	◐	🆓 free tier: ~2,000 requests/day (varies by endpoint), signup required	docs
OpenStreetMap Nominatim	Geocode and reverse-geocode addresses from OpenStreetMap data via a free public REST API.	none	◐	🆓 No key needed; public server max 1 request/second, bulk geocoding discouraged (small one-off jobs only, cached), no systematic or autocomplete queries	docs
OpenWeatherMap API	Fetch current weather, forecasts, and historical/air-quality data for any location via a REST API.	API key	✅	🆓 Free tier: 60 calls/min, 1,000,000 calls/month on current weather/forecast	docs
Overpass API (OSM)	Run custom queries (Overpass QL) over OpenStreetMap data - POIs, roads, boundaries - via a public read-only API.	none	◐	🆓 free, no key; public instances are fair-use/rate-limited	docs
Photon (komoot)	Geocode addresses and place names worldwide from OpenStreetMap data with typo-tolerant search-as-you-type, or reverse-geocode coordinates to the nearest address.	none	—	🆓 Free, no key: public demo instance under fair use; heavy usage is throttled or banned	docs
Tomorrow.io API	Get hyperlocal weather forecasts, historical data, and alerts for any coordinates via REST API or an official MCP server.	API key	✅	🆓 free tier: 500 requests/day, 3 req/sec, 1 monitored location/alert	docs

Finance, payments and market data

Accept payments, move money, access bank data and query stock, FX and crypto prices. — 16 services. JSON: catalog/finance-payments.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Adyen API ⭐⭐⭐⭐ 4.0/5 · 1 review	Process payments, payouts, and manage disputes/balances across global payment methods via REST API.	API key	✅	paid only; requires a signed merchant contract, pay per-transaction	docs
Alpaca Trading API	Place stock/options/crypto trades and stream market data via REST/WebSocket API, with free paper trading.	API key	✅	🆓 free paper trading (unlimited); free basic (IEX) market data feed	docs
Alpha Vantage	Fetch stock, forex, crypto prices and technical/fundamental indicators via a free REST API.	API key	✅	🆓 free tier: 25 requests/day	docs
Coinbase (CDP / x402) ⭐⭐⭐⭐ 4.4/5 · 10 reviews	Create wallets, send crypto, and pay per-API-call with stablecoins over HTTP (x402) via the Coinbase Developer Platform SDK.	API key	✅	🆓 Free tier: CDP x402 Facilitator free for 1,000 onchain transactions/month, then $0.001/tx; payment verification always free	docs
CoinGecko API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Fetch live and historical crypto prices, market data, and NFT data via REST API or the official CoinGecko MCP server.	API key	✅	🆓 Free tier: Demo API plan 10,000 calls/month, 100 calls/min, attribution required; keyless free MCP with shared rate limits	docs
CoinMarketCap API ⭐⭐⭐ 2.7/5 · 16 reviews	Lets an agent fetch live and historical cryptocurrency prices, market caps, listings, exchange and DEX data, and indices like Fear & Greed.	API key	✅	🆓 Free Basic plan: 15,000 credits/month, 50 requests/min, 1 API key, commercial use allowed; plus a keyless public API with lower rate limits	docs
DexPaprika DEX API	Lets an agent query on-chain DEX data across 36 blockchains: liquidity pools, swaps, token prices, OHLCV history and live price streams.	none	✅	🆓 No key; 30,000 credits per rolling 30 days per IP at 15 requests/min. Free registered key: 100,000 credits/30 days at 30 requests/min, no card	docs
Financial Modeling Prep ⭐⭐⭐⭐ 3.6/5 · 13 reviews	Fetch company financials, stock prices, and fundamental data via a REST API.	API key	✅	🆓 free tier: 250 requests/day (limited endpoints)	docs
Mercado Pago API	Lets an agent create checkout preferences, payments, refunds and subscriptions and look up transactions in Latin America's Mercado Pago.	API key / OAuth	✅	🆓 Free to integrate: no API or monthly fees, only per-transaction commissions; free test credentials and test users for sandbox payments	docs
Open Exchange Rates	Fetch current and historical foreign-exchange rates for 200+ currencies via a REST API.	API key	—	🆓 free tier: 1,000 requests/month, USD base only, hourly updates	docs
PayPal API ⭐⭐⭐⭐ 4.3/5 · 22 reviews	Process payments, payouts, invoices, and subscriptions via REST API or PayPal's official MCP server.	API key / OAuth	✅	🆓 free to integrate; pay per-transaction fees only; sandbox for testing	docs
Plaid API ⭐⭐⭐⭐ 4.4/5 · 5 reviews	Link bank accounts and fetch balances, transactions, and identity data via REST API/SDKs.	API key	✅	Trial: Sandbox always free; new US/Canada teams (since 2026-04-15) get a free Trial plan with up to 10 Production Items one-time; then pay-as-you-go	docs
Polygon.io / Massive	Query real-time and historical stocks, options, forex, and crypto market data via REST/WebSocket API.	API key	✅	🆓 free tier available (delayed data, limited calls/min); paid plans for real-time	docs
Square API	Process in-person/online payments, manage orders, invoices, and catalog via REST API and SDKs.	API key / OAuth	✅	🆓 free to integrate; pay per-transaction processing fees; free Sandbox for testing	docs
Stripe API ⭐⭐⭐⭐ 4.1/5 · 17 reviews	Create payments, subscriptions, invoices, and refunds programmatically via REST API or the official Stripe MCP server.	API key / OAuth	✅	🆓 free to integrate; pay per-transaction fees only, no monthly fee	docs
Wise API	Send international transfers, check exchange rates, and manage multi-currency balances via REST API.	API key / OAuth	◐	🆓 free API access; normal Wise transfer fees apply per transaction; sandbox available	docs

E-commerce

Manage stores, products, orders and marketplace listings. — 8 services. JSON: catalog/ecommerce.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Amazon Selling Partner API	Manage listings, orders, inventory, and reports for an Amazon seller/vendor account via REST API.	OAuth 2.0	✅	🆓 free API access; requires an existing Amazon Seller/Vendor Central account	docs
BigCommerce API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Manage catalog, orders, customers, and carts on a BigCommerce store via REST/GraphQL APIs.	API key / OAuth	✅	Trial: free 15-day trial store to test the API (partners can create sandbox stores); ongoing use needs a paid BigCommerce plan	docs
eBay APIs ⭐⭐⭐⭐ 4.0/5 · 10 reviews	List items, manage orders/inventory, and search listings across eBay marketplaces via REST APIs.	OAuth 2.0	✅	🆓 free developer tier with call-volume limits; sandbox environment included	docs
Etsy Open API v3	List products, manage orders/shop, and search listings on the Etsy marketplace via REST API.	OAuth 2.0	✅	🆓 Free: developer keystring at no cost; per-app QPS/QPD rate limits shown in the Developer Portal	docs
Mercado Libre API	Lets an agent search items and categories and manage a seller's listings, orders, questions, shipments and promotions on the Mercado Libre marketplace.	OAuth 2.0	—	🆓 Free: create an app in DevCenter with a Mercado Libre account (no API fee); rate limited (HTTP 429); marketplace selling fees still apply	docs
Printful API ⭐⭐⭐ 3.0/5 · 3 reviews	Create print-on-demand products, sync catalogs, and submit fulfillment orders via REST API.	API key / OAuth	—	🆓 Free: no monthly fee for API/store connection (pay only for fulfillment); 120 API calls/min general rate limit	docs
Shopify Admin / Storefront API	Manage products, orders, customers, and inventory (Admin API) or build storefronts (Storefront API) via REST/GraphQL.	API key / OAuth	✅	🆓 Free: unlimited free dev stores via a free Partner account/Dev Dashboard for building and testing (no real transactions); live merchant stores need a paid Shopify plan	docs
WooCommerce REST API	Manage products, orders, and customers on a self-hosted WooCommerce store via REST API.	API key	✅	🆓 Free: open-source WordPress plugin, free to download and use; no platform fees, only your own hosting costs	docs

Automation and integration platforms

One connection that exposes thousands of third-party app actions to an agent, with managed auth. — 15 services. JSON: catalog/automation-integration.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Activepieces	Build, run and manage no-code flows across 400+ apps via REST API or the built-in MCP server.	API key	✅	🆓 free: open-source, self-hostable at no cost; cloud free plan gives 100 credits/day, no card required	docs
Arcade.dev	Execute authorized tool calls (GitHub, Slack, Google, etc.) with managed OAuth via API, SDK, or 200+ MCP servers.	API key / OAuth	✅	🆓 free tier: 2,000 auth events + 2,000 tool calls/mo, no credit card required	docs
Composio	Discover, authorize and execute actions across 1,500+ SaaS toolkits through a unified API, SDK, or MCP session.	API key / OAuth	✅	🆓 free tier: 100,000 tool calls + 50,000 trigger events/mo, no credit card required	docs
Gumloop	Create AI agents, start chat sessions, and trigger no-code automations via REST API, SDKs, or the Gumloop MCP server.	API key / OAuth	✅	14-day free trial of Pro (20,000 credits), requires credit card, no permanent free tier	docs
IFTTT API ⭐⭐⭐⭐⭐ 5.0/5 · 4 reviews	Fire a webhook event to trigger pre-configured Applets that act in connected consumer apps (Pro plan required).	API key	✅	no free-plan access; Webhooks/API require Pro plan ($2.99+/mo)	docs
Keboola Storage API	Lets an agent load and query tables, create SQL and Python transformations, and trigger data pipeline jobs in a Keboola project.	API key / OAuth	✅	🆓 Free plan: 1 project, 120 compute minutes in the first month then 60 minutes/month, extra-small Snowflake backend; no credit card	docs
Make API / MCP	Trigger and manage Make automation scenarios, or call MCP tools, via REST API and a native MCP server/client.	API key	✅	🆓 Free tier: 1,000 credits/month, 2 active scenarios; Make API access requires Core plan or higher	docs
Merge (Agent Handler)	Give an agent governed, audited tool access to Salesforce, Slack, Jira and 100+ enterprise apps via API or MCP.	API key	✅	🆓 Free tier: 2,000 credits/month for prototyping/testing; production usage needs a paid Pro ($1,000/mo, 25,000 credits) or Enterprise plan	docs
n8n API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Create, run and monitor n8n workflows via REST API, and expose or consume tools through MCP trigger/client nodes.	API key	✅	🆓 Free: self-hosted Community Edition (open source, unlimited); n8n Cloud trial has no API access	docs
Nango	Authorize end users to 400+ third-party APIs/MCP servers and proxy authenticated calls to them from your app or agent.	API key / OAuth	✅	🆓 free tier: 10 connections, 10 compute hours, 10GB data transfer/mo	docs
Paragon ActionKit	Call thousands of pre-built Tools and Triggers across 130+ SaaS apps (Slack, Salesforce, Gmail) via API or MCP.	API key / OAuth	✅	Trial: free trial ('Start free trial'); no lasting free tier; pricing by custom quote based on Connected Users	docs
Pipedream Connect	Call 2,700+ app APIs and run managed-auth actions on end users' behalf via REST API or Pipedream MCP servers.	API key / OAuth	✅	🆓 Free tier: free workspaces get a daily credit limit and limited connected accounts; Connect is free in development mode, production use needs a paid plan	docs
StackOne	Call 520+ SaaS connectors (HRIS, ATS, CRM, documents) through one unified API or MCP gateway covering 32,000+ actions.	API key	✅	🆓 free tier: 1,000 action-call credits/seat/mo (Starter), no credit card required	docs
Superglue	Connect and orchestrate enterprise systems (ERP, CRM, databases) through a self-serve API and per-integration MCP servers.	API key	✅	🆓 free tier: Pro plan free to start, 3,000 executions/mo and 5M tokens/mo included, self-serve signup	docs
Zapier MCP / AI Actions	Call 9,000+ apps and 40,000+ pre-built actions (Slack, Gmail, Sheets, etc.) through one MCP endpoint.	API key / OAuth	✅	🆓 Free tier: 100 tasks/month; each successful MCP tool call uses 2 tasks (~50 calls/month); more on paid plans	docs

Model APIs and inference

LLM, embedding and multimodal model endpoints an agent can delegate sub-tasks to. — 18 services. JSON: catalog/model-inference.json

Service	What an agent can do	Auth	MCP	Free tier	Docs
Anthropic Claude API	Send messages to Claude models for text and vision generation, tool use, batch jobs and document analysis.	API key	—	paid only	docs
Cohere API ⭐⭐⭐⭐ 4.0/5 · 1 review	Call chat, embed, rerank and classify endpoints for text generation, semantic search and RAG.	API key	—	🆓 free trial key: 1,000 calls/mo, rate-limited	docs
Comet Opik Cloud API	Lets an agent log and read LLM traces and spans, score them with evaluations and manage datasets and prompts in Opik.	API key / OAuth	✅	🆓 Free cloud plan: 25k spans/month, 60-day data retention, up to 10 team members	docs
DeepSeek API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Send chat and reasoning requests to DeepSeek models via an OpenAI- and Anthropic-compatible REST API.	API key	—	paid only	docs
fal.ai	Generate images, video, audio and 3D with 1,000+ hosted models via queued REST or real-time WebSocket.	API key / OAuth	✅	Paid only; prepaid credits, priced per model (e.g. FLUX.1 schnell $0.003/megapixel)	docs
Fireworks AI	Run serverless or dedicated inference and fine-tuning for open models via OpenAI-compatible APIs.	API key	—	trial credits: $1 on signup	docs
Google Gemini API	Generate text and images, analyze multimodal input (video, audio, PDFs), and run code execution with Gemini models.	API key	—	🆓 free tier: rate-limited access to Flash/Pro models	docs
Groq API	Run fast LLM chat, tool use and speech-to-text on hosted open models via an OpenAI-compatible API.	API key	—	🆓 free tier: rate-limited per model, no card	docs
Hugging Face Inference Providers	Call hundreds of open-weight chat, vision, image, video and audio models across many providers with one HF token.	API key	✅	🆓 Free tier: $0.10/month in Inference Providers credits (PRO $2.00/month)	docs
Mistral AI API ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Run chat completions, embeddings, OCR and document processing with Mistral models via REST.	API key	✅	🆓 free tier: Studio free mode, rate-limited	docs
OpenAI API ⭐⭐⭐⭐⭐ 5.0/5 · 3 reviews	Generate text, images, audio and embeddings, and run tool-calling via the Responses and Chat Completions APIs.	API key	✅	paid only	docs
OpenRouter ⭐⭐⭐⭐⭐ 5.0/5 · 1 review	Route chat requests to hundreds of LLMs from many providers through one OpenAI-compatible endpoint with fallback.	API key / OAuth	✅	🆓 free models: 50 req/day (1,000/day after $10 purchase)	docs
PiAPI	Generate images, video and music through one API proxying Midjourney, Flux, Kling and other models.	API key	◐	trial credits: $0.50 on signup	docs
Replicate	Run thousands of hosted image, video, audio and text models via HTTP predictions; also fine-tune and deploy.	API key	✅	paid only	docs
Together AI	Run serverless inference, batch jobs, fine-tuning and dedicated GPU endpoints for open-source models.	API key	—	Paid only: no free trial; minimum $5 prepaid credit purchase	docs
Vercel AI Gateway	Send chat, image, embedding and rerank requests to 100+ models through one gateway with failover and spend tracking.	API key / OAuth	—	🆓 free tier: monthly credits on subset of models	docs
Voyage AI (embeddings/rerank)	Generate text, code and multimodal embeddings and rerank documents for RAG and semantic search.	API key	—	🆓 free tier: 200M tokens on current models	docs
xAI Grok API	Generate text, images, video and voice with Grok models, with built-in web search and code tools.	API key	—	paid only (prepaid credits)	docs

Related directories and registries

Other machine-readable sources agents can use to discover tools:

• Official MCP Registry — The official Model Context Protocol registry; agents can call its REST API (with OpenAPI spec) to search and list available MCP servers. — machine-readable: https://registry.modelcontextprotocol.io/v0/servers
• public-apis/public-apis — A community-curated GitHub list of 1,400+ free public APIs by category, fetchable as raw Markdown for programmatic parsing. — machine-readable: https://raw.githubusercontent.com/public-apis/public-apis/master/README.md
• APIs.guru OpenAPI Directory — An open, unauthenticated directory of 2,500+ public OpenAPI specs; agents fetch list.json to discover APIs and their OpenAPI definitions. — machine-readable: https://api.apis.guru/v2/list.json
• punkpeye/awesome-mcp-servers — A widely-starred curated GitHub list of MCP servers by category, fetchable as raw Markdown for automated discovery. — machine-readable: https://raw.githubusercontent.com/punkpeye/awesome-mcp-servers/main/README.md
• Smithery — An MCP server registry and hosting gateway (6,000+ servers) whose REST API lets agents search servers and obtain connection URLs. — machine-readable: https://api.smithery.ai/servers
• Glama MCP Directory — A large scanned and scored registry of 90,000+ open-source MCP servers, queryable via a bearer-authenticated REST API. — machine-readable: https://glama.ai/api/mcp/v1/servers
• mcp.so — A community MCP server marketplace and browsable directory site, but it has no publicly documented JSON/REST API for programmatic access.
• PulseMCP — A directory of 21,800+ MCP servers updated daily; its Sub-Registry REST API (API key required) lets agents list and search servers. — machine-readable: https://api.pulsemcp.com/v0.1/servers
• llms.txt convention / directory — An open convention for a root-level llms.txt file giving agents a concise Markdown map of a site's key content; a community directory indexes published files, though it exposes no JSON API. — machine-readable: https://directory.llmstxt.cloud
• Postman API Network — The largest network of public API collections shared on Postman, browsable on the web but with no documented public API for programmatic discovery.
• RapidAPI Hub (Nokia API Hub) — A large third-party API marketplace with growing MCP support for agents, but with no public, unauthenticated catalog endpoint for bulk discovery.

Contributing

Edit only the files in data/ (usually data/catalog.json), run python scripts/build.py to regenerate the English, Polish and LLM files, and open a pull request. Every new entry must link to the vendor's official API documentation. Step-by-step guide: CONTRIBUTING.md.

See also

• Model Context Protocol
• Official MCP Registry
• llms.txt proposal

References

The initial candidate list was compiled from:

1. GetStream — AI Agent Tools Catalog
2. StackOne — AI Agent Tools Landscape 2026
3. Mastra — Best AI agent search tools
4. abitwise — AI-tools
5. Sylus — Top-rated connectors for AI tool integrations

_{Generated from data/catalog.json on 2026-10-06.}