Important: You need an API key from your provider (OpenAI, Mistral, etc.) before they will appear in Alter.
What’s happening?
You’ve added your API key, but when you press/ to see models:
- The Custom section is empty
- You don’t see your provider’s models
- You only see Alter Cloud models
Common setup mistakes
Custom Provider is turned off
Custom Provider is turned off
Even with an API key entered, you need to enable custom providers:
- Open Alter Settings (
Cmd + ,) - Go to API Keys tab
- Find Custom Provider section
- Toggle Enable Custom Provider to ON
- You should see a ✓ next to “Custom Endpoint”
Wrong endpoint format (especially for Azure)
Wrong endpoint format (especially for Azure)
For most providers: Just paste your API key – the endpoint is automaticFor Azure specifically, you need the full URL:Make sure your URL includes:
- Your instance name
- The deployment name
- The api-version parameter
Invalid or expired API key
Invalid or expired API key
Quick checks:
- Did you copy the full key? (They usually start with
sk-) - Has the key expired?
- Do you have billing set up with the provider?
- Did you accidentally include extra spaces?
Quick setup guide
1
Get your API key
2
Enter it in Alter
- Settings (
Cmd + ,) → API Keys - Select your provider from the dropdown
- Paste your key
- Toggle Enable Custom Provider ON
3
Check the model selector
- Press
/in the Alter prompt box - Look for the Custom section
- You should see your provider’s models listed
Verify it’s working
After setup:- Press
/to open the model picker - Look for the Custom category
- Select one of your custom models
- Send a test message
- Success: The model responds using your own API key!