Hello everyone, I am trying to configure a custom model provider inside the new Reality Composer Pro Assistant settings panel using an LLM hosted via Azure AI Foundry. Despite verifying my credentials and testing multiple base URL structures, I am persistently encountering the following error: Authorization failed — check your API key My Configuration Details: Target Model Deployment: gpt-5.1-codex-mini (GlobalStandard deployment type) Azure AI Foundry Endpoint Pattern: https://azure.com API Key Header Used: api-key What I Have Tried: Utilizing the Azure OpenAI format: https://<project-name>.services.ai.azure.com/openai/v1/responses Verifying the API key explicitly with headers like api-key and Authorization (testing both raw keys and Bearer <key> prefixes). It appears that Reality Composer Pro's validation step might be calling a standard GET /v1/models route or structurally modifying the outbound request in a way that causes Azure's gateway architecture to reject it with a 401 response code. Has anyone successfully mapped an Azure AI Foundry endpoint directly to the Assistant interface? If so, what is the exact base URL syntax and header structure expected by the desktop client to pass authorization? Thanks in advance for any insights!

Reality Composer Pro Assistant: "Authorization failed" when adding custom Azure AI Foundry OpenAI provider

Hello everyone,

I am trying to configure a custom model provider inside the new Reality Composer Pro Assistant settings panel using an LLM hosted via Azure AI Foundry.

Despite verifying my credentials and testing multiple base URL structures, I am persistently encountering the following error:

Authorization failed — check your API key

My Configuration Details:

Target Model Deployment: gpt-5.1-codex-mini (GlobalStandard deployment type)
Azure AI Foundry Endpoint Pattern: https://azure.com
API Key Header Used: api-key

What I Have Tried:

Utilizing the Azure OpenAI format: https://<project-name>.services.ai.azure.com/openai/v1/responses
Verifying the API key explicitly with headers like api-key and Authorization (testing both raw keys and Bearer <key> prefixes).

It appears that Reality Composer Pro's validation step might be calling a standard GET /v1/models route or structurally modifying the outbound request in a way that causes Azure's gateway architecture to reject it with a 401 response code.

Has anyone successfully mapped an Azure AI Foundry endpoint directly to the Assistant interface? If so, what is the exact base URL syntax and header structure expected by the desktop client to pass authorization?

Thanks in advance for any insights!