Claude code sdk randomly adding thinking budget to some requests

Preflight Checklist

• [x] I have searched existing issues for similar behavior reports
• [x] This report does NOT contain sensitive information (API keys, passwords, etc.)

Type of Behavior Issue

Claude's behavior changed between sessions

What You Asked Claude to Do

I was using claude code and I noticed that my requests are automatically adding a thinking parameter. This is not for all requests but this is one-off requests and I have no real realistic way to reproduce this or figure out why.

The issue is that thinking tokens get exceeded and my request fails

What Claude Actually Did

Claude added a thinking token budget on its own. I don't know why it got added. It should not have been added.

Expected Behavior

No thinking budget if not set

Files Affected

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Sometimes (intermittent)

Steps to Reproduce

Not reproducible

Claude Model

Sonnet

Relevant Conversation

Impact

High - Significant unwanted changes

Claude Code Version

1.0.107

Platform

Anthropic API

Additional Context

_No response_