One key. One gateway. Every external API your agent or AI-native app needs to call, MCP-native and production-ready.
Browse the catalog by category: search, comms, data, payments, identity, AI tooling, and more. The right APIs for whatever your agent has to do, in one place.
Browse APIsGenerate a Callio key from your dashboard. Use a sandbox key while you build, switch to a production key for real traffic. One key authenticates every API in the catalog.
Manage keysYour Callio API Key
Works with every API — no extra keys needed
Drop our MCP server into Cursor / Claude / Antigravity, or call the HTTP proxy directly from any backend or agent runtime. We handle auth, retries, and observability.
Read the docscurl -X GET \
"https://callio.dev/api/proxy/jsonplaceholder/posts/1" \
-H "Authorization: Bearer callio_..." \
# Response
{
"data": [...],
"has_more": false
}No more juggling N provider signups and N auth flows. One Callio key handles the whole catalog.
Plug into Cursor, Claude, and Antigravity in minutes. Your agent gets discovery, describe, and call as three tools.
Save your provider keys once. They’re AES-256 encrypted at rest and injected at the proxy, never exposed in logs.
Build against a sandbox key, ship with a production key. Same gateway, separate quotas and traffic.
No vendor SDK lock-in. Call from any language or agent runtime that can speak HTTP.
See every routed call, status, and provider error in the dashboard. Trust the path your agent depends on.
Sign up, grab a key, and pick your path: install MCP into your editor, or call the HTTP proxy from your stack.