Callio – Unified API gateway for AI agents

Summary: Callio provides a single API key to connect AI agents with multiple external APIs, handling authentication, rate limits, and billing through one proxy. It supports Claude Code, Cursor, Antigravity, and any MCP-compatible tool, simplifying API integration and usage tracking.

What it does

Callio acts as a proxy that manages auth injection, rate limiting, and usage tracking for various APIs, enabling agents to call multiple APIs with one unified key. Users browse APIs, generate a Callio key, and start calling without additional configuration.

Who it's for

Developers and AI agents needing scalable, simplified access to multiple APIs without managing individual keys and auth setups.

Why it matters

It solves the complexity of managing separate API keys and authentication for each service, streamlining integration and scaling for AI agents.