AI Agents API Library

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
Type	API & MCP catalog
Entries	331
Categories	29
Official MCP servers	229
Languages	English, Polish
Format	JSON, Markdown, HTML, llms.txt
Last checked	2026-09-25
License	CC BY 4.0 (data), MIT (code)

AI Agents Accessible APIs is an open, bilingual (English/Polish) catalog of 331 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 (16) · 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 (10) · 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:

File	Raw URL
llms.txt — short index for LLMs, links to everything below	https://raw.githubusercontent.com/eater2/ai_agents_api_library/main/llms.txt
llms-full.txt — the whole catalog as compact plain text, one line per service	https://raw.githubusercontent.com/eater2/ai_agents_api_library/main/llms-full.txt
catalog/all.json — full catalog, one JSON array	https://raw.githubusercontent.com/eater2/ai_agents_api_library/main/catalog/all.json
catalog/<category>.json — one file per category, for small context windows	https://raw.githubusercontent.com/eater2/ai_agents_api_library/main/catalog/
data/schema.json — JSON Schema of an entry	https://raw.githubusercontent.com/eater2/ai_agents_api_library/main/data/schema.json

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

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	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	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	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	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	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	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)	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	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	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. — 16 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
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	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	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	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	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	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	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

Service	What an agent can do	Auth	MCP	Free tier	Docs
Beatoven.ai API	Generate royalty-cleared background music and sound effects from text prompts via REST API (Maestro).	API key	—	check pricing	docs
ElevenLabs Music API	Generate original music tracks from text prompts or detailed composition plans via REST API, with commercial licensing.	API key	✅	🆓 Free tier: 10,000 credits per month shared with TTS (music included, no commercial use of music on Free; Starter $6/mo or higher needed)	docs
Loudly API	Generate, remix, stem-split, and master music tracks programmatically via REST API.	API key	—	Trial: free track allowance on signup with the API key from the developer portal; then volume-based pricing (Startup/SME/Corporate) or pay-as-you-go	docs
Mubert API	Generate streaming or file-based background music from text/image prompts via REST/WebRTC API, 15s-25min tracks.	API key	—	paid only; plans start at $49/mo (100 generations/mo), no free tier	docs
Soundraw API	Generate royalty-free background music tracks by mood, genre, and duration via REST API for embedding in apps.	API key	—	Trial: one-time 2-week free API trial with no commitment; then Starter $29.99/mo for 100 songs with a 6-month minimum commitment	docs
Stable Audio API (Stability AI)	Generate music and sound effects from text prompts via REST API (Stable Audio 2.5, or Stable Audio 3.0 for tracks up to 6 minutes).	API key	—	shares Stability AI platform credits; 25 free credits on signup, then pay-as-you-go	docs

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	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)