An Azure service that provides access to OpenAI’s GPT-3 models with enterprise capabilities.
Hello Truong, David,
Welcome to Microsoft Q&A .Thank you for reaching out to us.
The observed behavior aligns with an API operation mismatch rather than a service outage or regional failure.After carefully reviewing the behavior, the response returned (400 – The requested operation is unsupported) confirms that the service endpoint is reachable, while the specific operation being invoked is not supported for the current request shape or API surface. This typically indicates a request‑level incompatibility rather than a regional or platform availability issue.
The deployment in Sweden Central is responding correctly at the network and service layer. A clean HTTP 400 response means the request is being actively validated and rejected, which differs from symptoms normally associated with regional outages such as timeouts or 5xx errors. This helps narrow the scope to API usage rather than availability.
Based on the current configuration, the most likely cause is a mismatch between the model deployment and the operation being called. As foundry supports multiple inference surfaces and given that not every model deployment behaves identically across all API operations, newer Foundry‑hosted models may expose inference primarily through the Responses API, which unifies chat‑style interactions with newer features.
To resolve the issue, please check if the following steps help
- Please confirm the API surface being used
- Ensure the base URL follows the OpenAI‑compatible v1 pattern:
https://<resource-name>.openai.azure.com/openai/v1 - When using the v1 API, dated api-version query parameters are not required.
- Validate that the OpenAI SDK is being used against the v1 endpoint rather than a project or agent endpoint.
- Please refer the following Azure OpenAI in Microsoft Foundry Models v1 API - Microsoft Foundry | Microsoft Learn Get started with Microsoft Foundry SDKs and Endpoints - Microsoft Foundry | Microsoft Learn
- Ensure the base URL follows the OpenAI‑compatible v1 pattern:
- Validating operation compatibility
- If the current call uses chat.completions, test the same deployment using the Responses API instead.
- The Responses API is the recommended interface for newer Foundry deployments and supports chat‑style prompts using a unified request model.
- Please refer the following - Use the Azure OpenAI Responses API - Microsoft Foundry | Microsoft Learn
- Confirming deployment configuration
- Please verify that the deployment name passed to the SDK exactly matches the configured deployment in the Foundry resource.
- Ensure the deployment is in a ready state and not paused or quota‑restricted.
- Ruling out regional constraints pragmatically
- Model availability can vary by region and tenant, but an active deployment returning HTTP 400 indicates the region is functioning.
- If verification is needed, deploying the same model to a second supported region and testing the identical request can help compare behavior.
- Please refer the following Azure OpenAI in Microsoft Foundry Models REST API reference - Microsoft Foundry | Microsoft Learn Work with chat completion models - Microsoft Foundry | Microsoft Learn
Testing the deployment with the Responses API and validating the endpoint and deployment configuration should help moving forward.
Thank you