Callio
The API gateway for AI agents

One API gateway for AI agents.

Give agents one unified way to discover, authenticate, and call 90+ APIs so developers can ship faster with less integration overhead.

Get Started Browse APIs
90+
APIs available
1
API key needed
<2 min
Setup time
Works with
Claude
Cursor
Antigravity
|View all integrations →

How it works

Three steps. That's it.

1

Connect once

Get one Callio key and connect to the entire gateway instead of setting up every API separately.

2

Discover APIs

Browse available APIs or let your agent find the right one. Callio handles discovery, auth, and routing.

3

Execute & ship

Call any API through one unified interface. Your team spends less time on plumbing and more time shipping.

Callio - Connect any API with AI Agent under 1 minute | Product Hunt

Simple to integrate

One key and one interface for the APIs your agents need, without the usual auth work and custom integrations.

Works with any language or framework
One unified proxy — just change the slug
Bring your own provider keys (BYOK)
# 1. Install the SDK
npm install callio-sdk
# 2. Initialize with your single Callio key
import { CallioClient } from 'callio-sdk';
const callio = new CallioClient('callio_your_api_key');
# 3. Call ANY API through the unified proxy
/* OpenAI */
await callio.post('openai', 'v1/chat/completions', {
model: 'gpt-4',
messages: [{ role: 'user', content: 'Hi!' }]
});
/* Same key, different API - just change the slug! */
await callio.post('sendgrid', 'v3/mail/send', {
to: 'user@co.com', subject: 'Hello'
});
Built with Security

Your credentials, your control

Provider keys are AES-256 encrypted at rest. Callio keys are hashed. We never store request or response data.

Encrypted at rest

All provider credentials are AES-256-GCM encrypted before storage.

Zero data logging

Request and response bodies pass through — we only log metadata.

Built-in rate limits

Per-plan quotas and real-time usage monitoring from your dashboard.

MCP Server

Connect Antigravity, Cursor & more

Install the MCP server and your AI agent gets instant access to 90+ APIs through the same unified gateway.

Antigravity→MCP Settings panel
Cursor→.cursor/mcp.json
Claude Code→~/.claude/claude_desktop_config.json
Setup guide View source
mcp config
{
"mcpServers": {
"callio": {
"command": "npx",
"args": ["-y", "github:hmadhsan/callio-mcp"],
"env": {
"CALLIO_API_KEY": "callio_your_key"
}
}
}
}

APIs for everything

Search, payments, AI, scraping, messaging, and more through one gateway for agents.

Search
Web, news, products
Email
Send, verify, find
Data
Enrich, scrape, extract
Messaging
SMS, chat, notifications
Analytics
Tracking, insights
Cloud
AWS, GCP, Azure
Identity
Auth, KYC, verify
Social
LinkedIn, X, Instagram
AI / ML
Models, embeddings
Dev Tools
GitHub, CI/CD, logs
Storage
Files, S3, CDN

And many more. New APIs added every week.

Built for

Whether you build agents or provide APIs — Callio is for you.

AI developers

Give your agents real-world capabilities without stitching together dozens of integrations yourself.

API providers

List your API on Callio and get distribution into the growing ecosystem of AI agents and agentic products.

Startups

Ship faster by skipping auth, routing, and API plumbing. Focus your team on product, not infrastructure glue.

Frequently asked questions

What is Callio?
Callio is the API gateway for AI agents. It gives developers one interface to discover, authenticate, and call 90+ APIs.
How is this different from just calling APIs directly?
Instead of wiring up separate APIs one by one, you use one gateway. Callio handles auth, routing, and integration overhead for you.
Who is Callio for?
AI developers building agent workflows, API providers wanting distribution to AI agents, and startups that need to ship fast without infrastructure overhead.
How much does it cost to get started?
Our Starter plan is just $5/month and includes enough API requests and keys to build and test your integration.
Can I add my own API to Callio?
Absolutely. API providers can list their APIs on Callio and get instant distribution to thousands of AI agents. Book a demo to learn more.

Get in touch

Have questions, feedback, or want to list your API? We'd love to hear from you.

Book a demoContact UsGet Started