Bug: Copilot title generation sends invalid reasoning_effort=minimal to gpt-5-mini #22919

Description

I hit a GitHub Copilot provider error during a normal interactive OpenCode session on macOS.

OpenCode made a title-generation request using gpt-5-mini, but the request included reasoning_effort="minimal". Copilot rejected it with:

reasoning_effort "minimal" is not supported by model gpt-5-mini; supported values: [low medium high]

This did not kill the whole session in my case, so it looks like a non-fatal bug in the title-generation / small-model path. But it does generate a real provider error in the logs.

Relevant log details from the same session:

• providerID=github-copilot
• modelID=gpt-5-mini
• agent=title
• request failed with invalid_reasoning_effort

I also confirmed that the main session continued after this, so this seems separate from normal session loop exit / idle behavior.

Plugins

None

OpenCode version

1.4.6

Steps to reproduce

1. Use OpenCode with the GitHub Copilot provider on macOS.
2. Start a normal interactive session.
3. Let OpenCode perform its automatic title-generation request.
4. Check the log file for the request made by the title/small-model path.
5. Observe that the request can include reasoning_effort="minimal" for gpt-5-mini.
6. Copilot returns a 400 with invalid_reasoning_effort.

Screenshot and/or share link

No share link. I investigated from local logs.

Error payload from the log:

reasoning_effort "minimal" is not supported by model gpt-5-mini; supported values: [low medium high]

Operating System

macOS 25.4.0

Terminal

Unknown