# One MCP server. Every API your agent needs.

Drop the Callio MCP server into Cursor, Claude, Antigravity, or any MCP-compatible client and your agent can call 143 APIs through one Callio key.

## How MCP works with Callio

[Model Context Protocol (MCP)](https://modelcontextprotocol.io/) is how tools like Cursor and Antigravity connect to external capabilities. The editor starts a small MCP server; the AI can call **tools** that server exposes (instead of you wiring one integration per API).

### End-to-end flow

1. You add the Callio MCP server to your config and set `CALLIO_API_KEY`.
2. Cursor / Antigravity launches that server as a subprocess (stdio). It appears under **Settings → MCP** with three tools.
3. When you chat, the model can invoke **search\_apis** and **get\_api\_info** — they read Callio's public catalog (same data as [Browse](/content/browse/index.html)).
4. To actually **execute** an API through Callio's gateway, the model uses **call\_api**. That sends a request to `https://callio.dev/api/proxy/…` with your key — same as the HTTP proxy in our [docs](/content/docs#api-proxy/index.html).
5. For upstream APIs that need your own provider key (OpenAI, SendGrid, etc.), save it once on the API's page on Callio; the proxy attaches it when **call\_api** runs.

### Why only three tools?

One tool per vendor would mean hundreds of MCP tools. Callio exposes **discover → describe → call** so the agent can use any listed API without new MCP releases per provider.

### After you edit config

Restart the MCP server (Cursor: Command Palette → MCP restart, or restart the app) so new env vars and keys load. Confirm the server shows a green status and lists all three tools.

## Works with your favorite AI tools

### Claude Code

Anthropic's coding agent

`~/.claude/claude_desktop_config.json`

### Cursor

AI-powered code editor

`.cursor/mcp.json`

### Antigravity

AI development platform

`MCP Settings`

## Setup in 2 minutes

### Get your Callio API key

Sign up at callio.dev and generate an API key from your dashboard.

### Add to your AI tool config

Copy this JSON into your MCP configuration file. Replace the API key with your own.

```
{
  "mcpServers": {
    "callio": {
      "command": "npx",
      "args": ["-y", "github:hmadhsan/callio-mcp"],
      "env": {
        "CALLIO_API_KEY": "callio_your_key_here"
      }
    }
  }
}
```

**Claude Code:** `~/.claude/claude_desktop_config.json`

**Cursor:** `.cursor/mcp.json`

**Antigravity:** MCP Settings panel

### Start using APIs

Your agent now has 3 powerful tools. Just ask in natural language:

"Search for email APIs on Callio"

"What endpoints does the SendGrid API have?"

"Get post #1 from JSONPlaceholder through Callio"

"Search for AI companies using Apollo API"

## 3 tools, unlimited power

### search\_apis

Discover and browse 143 APIs by name, category, or description.

### get\_api\_info

Get full details — endpoints, parameters, examples, auth info.

### call\_api

Execute any API call. Auth, rate limits, and routing all handled.

## Ready to supercharge your agent?

Get started in under 2 minutes. Free accounts include 5 proxy requests/month; paid plans add more.