Bug: Kiro models fail with REQUEST_BODY_INVALID after setting thinking intensity in dashboard

[OlyMarco]

Description

After updating 9router and configuring the thinking intensity option in the dashboard, Kiro models that previously worked correctly start returning HTTP 400 errors.

Affected models include:

• kiro/claude-sonnet-4.5-thinking-agentic
• kiro/glm-5-thinking-agentic
• ...

Error message:

HTTP 400:
[kiro/claude-sonnet-4.5-thinking-agentic]
[400]: {"message":"Improperly formed request.","reason":"REQUEST_BODY_INVALID"}

Expected behavior

For models that do not support explicit thinking intensity parameters, 9router should either:

1. Not send any thinking/reasoning parameter by default, or
2. Explicitly disable thinking when no value is configured.

Previously, these models worked normally before the thinking intensity setting was introduced.

Actual behavior

After updating the dashboard and setting thinking intensity support, it seems that all requests are being assigned:

thinking: AUTO

or an equivalent automatic reasoning parameter.

This causes Kiro upstream requests to contain invalid reasoning configuration, resulting in:

REQUEST_BODY_INVALID

Models such as claude-sonnet-4.5-thinking-agentic and glm-5-thinking-agentic can no longer be used.

Steps to reproduce

1. Update 9router to the latest version.

2. Open dashboard settings.

3. Configure thinking intensity.

4. Use Kiro provider models:

   • kiro/claude-sonnet-4.5-thinking-agentic
   • kiro/glm-5-thinking-agentic

5. Send a request.

The request fails with HTTP 400.

Possible cause

The new thinking intensity option may be globally injected into all provider requests.

However, different providers/models have different reasoning parameter formats. Kiro's agentic models may not accept:

thinking: AUTO

or similar automatic reasoning values.

Suggested fix

• Default thinking intensity should be empty/disabled instead of AUTO.
• Only inject reasoning parameters when the selected provider/model explicitly supports them.
• Add provider-specific handling for Kiro reasoning models.

Additional information

I have screenshots comparing behavior before and after enabling/configuring thinking intensity, which show that the failure starts only after this change.

Thanks for maintaining 9router. Hopefully this compatibility issue can be fixed soon.

[OlyMarco]

I tested the latest v0.5.40 release, but Kiro thinking-agentic models still return the same REQUEST_BODY_INVALID error.

It seems the reasoning/thinking parameter compatibility issue is still present. I attached screenshots for reference.

Thanks for your work, and hope this can be fixed in future updates.

[kypkk]

Also tested on the latest v0.5.40 release.Cloned 9router to my server and docker composed it. Kiro providers still return the same API Error: 400 {"error":{"message":"[model] [400]: {\"message\":\"Improperly formed request.\",\"reason\":\"REQUEST_BODY_INVALID\"} (reset after 2m)"}} error. Hope this can be fixed in future updates