[BUG] ResponseServiceTier is missing the option to select Priority

[simon-k]

Describe the bug

Same as openai/openai-node#1556

ResponseServiceTier only supports "auto", "default", "flex"and "scale". It should also support "priority" as per https://platform.openai.com/docs/api-reference/chat/create#chat-create-service_tier

Steps to reproduce

Install the OpenAi nuget package, version 2.5.0 and try to

Code snippets

_options = new();
_options.ServiceTier = ResponseServiceTier.Priority;  // Compiler error
_options.ServiceTier = ResponseServiceTier.Scale;    // Works

OS

All

.NET version

9.0

Library version

2.5.0

[simon-k]

Oh, and by the way.... scale does not work

[2025-10-31T08:26:13.983Z] Exception: System.ClientModel.ClientResultException: HTTP 400 (invalid_request_error: invalid_value)
[2025-10-31T08:26:13.983Z] Parameter: service_tier
[2025-10-31T08:26:13.983Z]
[2025-10-31T08:26:13.983Z] Invalid value: 'scale'. Supported values are: 'auto', 'default', 'flex', and 'priority'.
[2025-10-31T08:26:13.983Z] at OpenAI.ClientPipelineExtensions.ProcessMessageAsync(ClientPipeline pipeline, PipelineMessage message, RequestOptions options)
[2025-10-31T08:26:13.983Z] at OpenAI.Responses.OpenAIResponseClient.CreateResponseAsync(BinaryContent content, RequestOptions options)
[2025-10-31T08:26:13.983Z] at OpenAI.Responses.OpenAIResponseClient.CreateResponseAsync(IEnumerable`1 inputItems, ResponseCreationOptions options, RequestOptions requestOptions)

[jsquire]

Hi @simon-k. Thanks for reaching out and we regret that you're experiencing difficulties. I'm a little confused by your context, as you're linking to Chat-related issues and docs but seem to be using the Responses API, based on the type name and stack trace. In either event, the priority value is a fairly recent addition and is not yet represented in the REST API spec used for client generation. Once the REST API spec is updated to include this area and a new version published, we'll include it in the client automatically.

In the meantime, the service tier types for both Chat and Responses are an open-set and can be created with arbitrary values via the constructor:

var chatOptions = new ChatCompletionOptions
{
    ServiceTier = new ChatServiceTier("priority")
};
    
var responseOptions = new ResponseCreationOptions
{
    ServiceTier = new ResponseServiceTier("priority")
};

[jsquire]

Oh, and by the way.... scale does not work

[2025-10-31T08:26:13.983Z] Exception: System.ClientModel.ClientResultException: HTTP 400 (invalid_request_error: invalid_value) [2025-10-31T08:26:13.983Z] Parameter: service_tier [2025-10-31T08:26:13.983Z] [2025-10-31T08:26:13.983Z] Invalid value: 'scale'. Supported values are: 'auto', 'default', 'flex', and 'priority'. [2025-10-31T08:26:13.983Z] at OpenAI.ClientPipelineExtensions.ProcessMessageAsync(ClientPipeline pipeline, PipelineMessage message, RequestOptions options) [2025-10-31T08:26:13.983Z] at OpenAI.Responses.OpenAIResponseClient.CreateResponseAsync(BinaryContent content, RequestOptions options) [2025-10-31T08:26:13.983Z] at OpenAI.Responses.OpenAIResponseClient.CreateResponseAsync(IEnumerable`1 inputItems, ResponseCreationOptions options, RequestOptions requestOptions)

The behavior that you're inquiring about with this error is controlled by the OpenAI service, which is rejecting the scale value. The client has no insight nor influence over it. As a result, the maintainers of the OpenAI client library are unable to assist with this inquiry.

Unfortunately, OpenAI does not offer service support from this repository. The most reliable and direct way to get support is by reaching out to the OpenAI Support Team. You can either email support@openai.com or start a new chat session via the Help Center. The OpenAI support team is available 24/7 and is equipped to assist with the full range of requests.

[simon-k]

Maybe it's not a bug but a feature request, and sorry about linking to the wrong documentation. Here is the documentation for the right documentation https://platform.openai.com/docs/api-reference/responses/object?api-mode=responses&lang=curl#responses-object-service_tier. It also mentions "priority" as a service tier and not "scale".