OpenAI GPT-5 Tool Choices Other Than auto Not Supported Error

What this error means

tool choices other than 'auto' are not supported with model gpt-5 is a OpenAI API failure pattern reported for developers trying to fix openai gpt-5 responses api rejecting tool_choice values other than ‘auto’ despite documentation suggesting support. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue openai/openai-python#2498: GPT-5 models in Responses API reject tool_choice values like ‘required’ or specific function names, returning error. Documentation contradicts actual behavior. 17 comments indicating widespread impact. Category mapping: OpenAI API (direct API behavior error).

Common causes

• GitHub issue openai/openai-python#2498: GPT-5 models in Responses API reject tool_choice values like ‘required’ or specific function names, returning error. Documentation contradicts actual behavior. 17 comments indicating widespread impact. Category mapping: OpenAI API (direct API behavior error).

Quick fixes

1. Confirm the exact error signature matches tool choices other than 'auto' are not supported with model gpt-5.
2. Check the OpenAI API account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/openai/openai-python/issues/2498

Evidence note: GitHub issue openai/openai-python#2498: GPT-5 models in Responses API reject tool_choice values like ‘required’ or specific function names, returning error. Documentation contradicts actual behavior. 17 comments indicating widespread impact. Category mapping: OpenAI API (direct API behavior error).

Related errors

• OpenAI API

FAQ

What should I check first?

Start with the exact tool choices other than 'auto' are not supported with model gpt-5 text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed OpenAI API workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without tool choices other than 'auto' are not supported with model gpt-5.