Performance Regression: Extremely Slow "Thinking" Phase After Updating to v1.17.20 #36815

Description

Summary

After updating OpenCode Desktop to v1.17.20 on 14 July 2026, I noticed a significant performance regression.

The application itself opens normally, but the Thinking phase has become extremely slow. Even simple prompts that previously received responses almost instantly now spend a long time in the "Thinking" state before generating any output.

This issue started immediately after updating to v1.17.20.

Environment

• OpenCode Version: v1.17.20
• Operating System: Windows 11
• Installation: Official OpenCode Desktop application

Steps to Reproduce

1. Update OpenCode Desktop to v1.17.20.
2. Open any project.
3. Ask a simple question or request.
4. Observe the Thinking phase.

Expected Behavior

The Thinking phase should complete quickly, similar to previous versions.

Actual Behavior

The Thinking phase takes significantly longer than before, even for simple prompts. The delay happens before any response starts generating, making the application feel much slower overall.

The issue occurs across different projects and is not limited to a specific workspace.

Additional Notes

Before updating to v1.17.20, OpenCode responded much faster under the same conditions. The slowdown only appeared after installing this update.

If needed, I can provide logs or additional information to help diagnose the issue.

Thank you for your work on OpenCode!

Plugins

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OpenCode version

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Steps to reproduce

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Screenshot and/or share link

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Operating System

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Terminal

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