Add Cali to ChatGPT — Setup in 3 minutes

Step-by-step

Turn on Developer mode

In ChatGPT, open Settings → Connectors → Advanced settings and toggle Developer mode on.

This is what unlocks the ability to add your own MCP server.

Create a new connector

Back in Settings → Connectors, click Create (top right).

Fill in Cali's details

Use these values exactly:

Click Create. ChatGPT will open a sign-in window — sign in with Google or magic link.

Enable Cali in your chat

Start a new chat. In the message composer, click the + icon (or "Tools" menu depending on platform) and select Developer mode → Cali.

Cali is now active for this conversation.

Say "Hey Cali"

Just say "Hey Cali". She'll introduce herself and ask for a few basics (height, current weight, target) to set up your calorie targets.

From then on, just log meals naturally — "chicken wrap and a latte for lunch" — and Cali does the maths.

Troubleshooting

I don't see "Developer mode"

Custom MCP connectors require a paid ChatGPT plan (Plus, Pro, Business or Enterprise). Make sure you're on a paid account and on the latest version of the ChatGPT app. Look under Settings → Connectors → Advanced settings.

Cali isn't appearing in my chat

Developer connectors are off by default per-conversation. In the composer, click the + icon or Tools menu and toggle Cali on for the conversation. Then say "Hey Cali" to wake her up.

"OAuth error" when creating the connector

Delete the connector and recreate it. Make sure the MCP server URL is exactly https://mcp.heycali.app/mcp with no trailing slash. If you still get an error, contact nick@usapp.ai.

Add Cali as a developer app