How Callio Works
One key. One gateway. A predictable way to call external APIs from products, agents, and automation workflows.
1. Pick the tools your agent needs
Browse the catalog by category: search, communications, data, payments, identity, AI tooling, and more. Find the right APIs for whatever your agent needs to accomplish, in one place.
Browse APIs2. Create a Callio API key
Generate a Callio API key in your dashboard. Use this single key for authenticating with the gateway across all tools you enable.
Create API key3. Call through the gateway
Make standard HTTP requests or use the Callio MCP server. Requests follow a simple URL pattern:
curl -X POST https://callio.dev/api/proxy/openai/v1/chat/completions \
-H "Authorization: Bearer callio_live_your_key_here" \
-H "Content-Type: application/json" \
-d '{"model":"gpt-4o-mini","messages":[{"role":"user","content":"Hello!"}]}'Why builders choose Callio
One key, every tool
No more juggling N provider signups and N auth flows. One Callio key handles the whole catalog.
Consistent proxy shape
Use one URL pattern across providers instead of rebuilding auth, headers, and endpoint handling for every integration.
BYOK + encrypted
Save your provider keys once. They are encrypted at rest and injected at the proxy, without exposing raw secrets in dashboard logs.
Observable by default
Track status codes, latency, usage, and failures from one dashboard before integration issues reach users.