Protocol · REST· 2026 Edition

Best REST API Tools for AI Agents (2026)

REST APIs remain the most interoperable way to call external services from an agent runtime. These tools ship clean, well-documented REST endpoints that ToolRoute wraps with auth, rate-limiting, and unified billing so your agent never has to manage a single API key.

Top 3 at a Glance

#110/10

Higgsfield

AI video & image platform — 30+ models (Sora 2, Kling 3.0, Veo 3.1, Soul 2.0, Seedance). 4.5M generations/day.

#210/10

Slack API

Send messages, read channels, reply to threads, list channels.

#310/10

ElevenLabs

Voice AI: text-to-speech, voice cloning, audio generation. Best quality TTS on market.

All REST Tools (64)

#	Tool	Description	Rating	Category	Cost
1	Higgsfield	AI video & image platform — 30+ models (Sora 2, Kling 3.0, Veo 3.1, Soul 2.0, Seedance). 4.5M generations/day.	10/10	content	Usage-based	View
2	Slack API	Send messages, read channels, reply to threads, list channels.	10/10	communication	Free	View
3	ElevenLabs	Voice AI: text-to-speech, voice cloning, audio generation. Best quality TTS on market.	10/10	communication	Freemium	View
4	Tavily	RAG-optimized search for agents — clean extracted content, answers, news/finance topics.	10/10	infrastructure	Freemium	View
5	Composio	OAuth for 850+ apps. 11K+ tools. Managed auth infrastructure for AI agents. MCP + REST + SDK.	10/10	infrastructure	Freemium	View
6	Stripe MCP	Official Anthropic Stripe integration. Customers, invoices, subscriptions, products, refunds.	10/10	finance	Freemium	View
7	Exa	Neural search engine built for AI agents — semantic search, find-similar, company/people search. Powers Cursor.	10/10	infrastructure	Usage-based	View
8	Supabase MCP	Full Supabase backend in one MCP server: DB, storage, auth, edge functions, migrations, config.	10/10	infrastructure	Free	View
9	Brave Search	Independent web search	10/10	infrastructure	Freemium	View
10	Claude API	Anthropic Claude API. Best for long-form writing, analysis, code generation, reasoning.	10/10	content	Paid	View
11	Twilio	SMS, voice, video, messaging automation. The undisputed standard for communication APIs.	10/10	communication	Paid	View
12	Replicate	Run any ML model	10/10	infrastructure	Usage-based	View
13	fal.ai	AI model gateway — Flux, Kling	10/10	content	Usage-based	View
14	OpenAI GPT	OpenAI API — GPT chat, DALL-E images, embeddings, moderation	10/10	infrastructure	Usage-based	View
15	Notion	Workspace — pages, databases, search, knowledge base	10/10	operations	Freemium	View
16	HubSpot CRM	CRM — contacts, deals, pipeline, notes	10/10	crm sales	Freemium	View
17	Deepgram	Fast speech-to-text	10/10	communication	Usage-based	View
18	HeyGen MCP	AI avatar/spokesperson videos. Talking head explainers. Official MCP.	9/10	content	Paid	View
19	Midjourney	Image generation. Highest quality AI images for marketing and social.	9/10	content	Paid	View
20	n8n	Self-hostable workflow automation. 1084+ nodes, 2646+ configs. Open source alternative to Zapier.	9/10	operations	Freemium	View
21	Postiz	Self-hosted social media management. 32 platforms. Free ULTIMATE tier.	9/10	marketing	Free	View
22	Shopify MCP	E-commerce management via MCP. Products, orders, collections, inventory.	9/10	ecommerce	Freemium	View
23	Supabase Auth	Authentication: login, OAuth, sessions, row-level security. Part of Supabase.	9/10	security	Free	View
24	Twitter/X API	Post tweets, search, read mentions, manage profile on Twitter/X.	9/10	marketing	Freemium	View
25	Whisper	OpenAI Whisper. Audio/video transcription. Industry standard accuracy.	9/10	content	Paid	View
26	YouTube Data API	Upload, metadata, analytics, comments. Full YouTube management.	9/10	marketing	Free	View
27	Google Ads API	Create/manage Google Ads campaigns. Search, display, video ads.	9/10	marketing	Freemium	View
28	Vercel MCP	Official Vercel MCP. Access logs, docs, projects, deployments, domains.	9/10	devops	Freemium	View
29	Ahrefs	SEO: keyword research, rank tracking, backlink analysis, site audit.	9/10	marketing	Paid	View
30	LinkedIn API	Post to LinkedIn, manage profile, company pages.	9/10	marketing	Free	View
31	YouTube Data API	Upload videos, search YouTube, read comments, manage channel.	9/10	marketing	Free	View
32	Apollo.io	B2B contact + company data. Lead prospecting at scale. 200M+ contacts.	9/10	crm sales	Freemium	View
33	Cal.com	Open-source appointment booking. Public booking pages, customer scheduling.	9/10	scheduling	Freemium	View
34	Meta Marketing API	Create/manage FB/IG ad campaigns. The standard for social advertising.	9/10	marketing	Freemium	View
35	Pexels	Free stock photos and videos	9/10	content	Free	View
36	Remove.bg	AI background removal	9/10	content	Freemium	View
37	Shippo	Shipping labels and tracking	9/10	ecommerce	Freemium	View
38	Unsplash	High-res free stock photos	9/10	content	Free	View
39	Creatify	AI ad generation	9/10	marketing	Paid	View
40	DeepL	Translation — 30+ languages	9/10	communication	Freemium	View
41	Google Sheets	Spreadsheets — read, write, append, formulas	9/10	operations	Free	View
42	Vapi	Voice AI agents — phone calls	9/10	communication	Usage-based	View
43	Creatomate	Template-based video rendering API	9/10	content	Paid	View
44	DataForSEO	SEO data API — SERPs, keywords, backlinks at $0.002/query	9/10	marketing	Usage-based	View
45	Mux	Video hosting and streaming — upload, transcode, play	9/10	content	Usage-based	View
46	SendGrid	Transactional email. 99.95% deliverability. Part of Twilio — reseller program available.	9/10	communication	Freemium	View
47	Shotstack	JSON timeline video editing and rendering	9/10	content	Freemium	View
48	Firecrawl	Fastest web scraping MCP (7s avg, 83% accuracy). Search + extract + crawl in one.	9/10	marketing	Freemium	View
49	Linear MCP	Issue management and project tracking via MCP. Developer-focused. Clean API.	9/10	operations	Freemium	View
50	Notion MCP	Official Notion MCP. Pages, databases, blocks. Internal documentation.	9/10	operations	Freemium	View
51	PostHog	Open-source product analytics. Web + product analytics + A/B testing in one. Self-hostable.	9/10	analytics	Freemium	View
52	Smartlead	116-tool MCP for cold email. Sequences, warmup, tracking, deliverability.	9/10	crm sales	Paid	View
53	HubSpot MCP	CRM management via MCP. Contacts, deals, pipeline, companies, notes.	9/10	crm sales	Freemium	View
54	Cloudflare Turnstile	CAPTCHA alternative. Bot protection without user friction. Free.	9/10	security	Free	View
55	Cloudflare MCP	Deploy/configure Workers, KV, R2, D1. Edge computing standard.	9/10	devops	Free	View
56	Google Calendar	Calendar management	9/10	scheduling	Free	View
57	Google Drive	File management	9/10	operations	Free	View
58	HeyGen	AI avatar videos	9/10	content	Paid	View
59	Outscraper	Google Maps scraping	9/10	marketing	Usage-based	View
60	ScreenshotOne	Website screenshots	8/10	infrastructure	Freemium	View
61	Kling 3.0	Video generation model specializing in image-to-video transitions. Takes start frame + end frame + prompt, generates smooth video transition between them. Used for scroll-stopping website hero animations.	8/10	content	Freemium	View
62	Textbelt	Cheap SMS API	8/10	communication	Usage-based	View
63	Hicsfield.ai (Nano Banana 2)	Image + video generation platform. Nano Banana 2 model produces high-quality product shots with white backgrounds for website integration. Also does image-to-video transitions via Kling 3.0.	8/10	content	Freemium	View
64	html2pdf.app	HTML to PDF conversion	8/10	content	Freemium	View

Why REST for AI Agents?

One key, every REST tool. ToolRoute normalizes auth across every adapter — your agent doesn't need to care which tool it's calling.
Usage-based billing. Pay only for the calls your agent makes. No per-vendor seats, no minimum commits.
Failure tracking. Every REST call is logged with latency, error codes, and retry counts — accessible via the dashboard or API.
Automatic protocol translation. Tools on this list can be called via REST, MCP, or OpenAI function format — ToolRoute handles the shape-shift.

Access Every REST Tool Through One API

Stop writing one-off adapters for every new tool. ToolRoute ships 64 REST tool behind a single endpoint — unified billing, unified errors, unified observability.

View API Docs See Pricing GitHub