When using OpenCode with Azure OpenAI models, OpenCode appears to always include the reasoning_effort request argument, even when reasoning is explicitly disabled via --variant none.

Azure rejects this parameter for certain deployments with a hard error:

Error: Unrecognized request argument supplied: reasoning_effort

This makes it impossible to use some Azure models with OpenCode at the moment.

When I use gpt-4 based models this issue does not appear!

Environment

OpenCode version: 1.1.20
OS: Mac 26.2 (25C56)
Provider: azure-apim
Model: gpt-5
Azure OpenAI via APIM
Azure region: EU

Steps to reproduce

opencode run
-m "azure-apim/gpt-5"
--variant none
"Hello"

Returns:

Error: Unrecognized request argument supplied: reasoning_effort

Expected Behavior

When using --variant none, OpenCode should omit the reasoning_effort parameter entirely from the request.

Azure requires unsupported parameters to be omitted, not set to "none".

Also, how to indeed use the reasoning models gpt-5 on Azure with Opencode?