Guide
If you want to use an AI provider that is not supported by Onyx, you can configure a custom inference provider.Your custom provider must provide OpenAI-compatible API endpoints.
1
Setup your Custom Inference Provider
Determine your provider’s API base URL.
It should look something like
https://yourprovider.com/v1 or http://localhost:12345/v1.2
Navigate to AI Model Configuration Page
Access the Admin Panel from your user profile icon → Admin Panel → LLM
3
Configure Custom Inference Provider
Select Add Custom LLM Provider from the available providers.Give your provider a Display Name.Enter your model’s Provider Name.In this example, the provider name is 
The Provider Name must match Litellm’s list of supported providers.
vertex_ai.
4
Configure Optional Fields and Models
Enter the provider’s Base URL.Fill out the other optional fields if applicable.In the Model Configurations section, enter each of the models you want to use with your provider.
5
Configure Default and Fast Models
The Default Model is selected automatically for new custom Agents and Chat sessions.Designating a Fast Model is optional.
This Fast Model is used behind the scenes for quick operations such as evaluating the type of message,
generating different queries (query expansion), and naming the chat session.
If you select a Fast Model,
make sure it is a relatively quick and cost-effective model like GPT-4.1-mini or Claude 3.7 Sonnet.
6
Designate Provider Access
Lastly, you may select whether or not the provider is public to all users in Onyx.If set to private,
the provider’s models will be available to Admins and User Groups you explicitly assign the provider to.