[BUG] Uncontrolled subagent multiplication

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Workflows consistently generate 10x more subagents than planned, with duplicate names executing repeated tasks.

What Should Happen?

Workflow should generate approximately the planned number of agents (4 in both cases).

Error Messages/Logs

Steps to Reproduce

1. Use Opus 4.8 with Ultracode
2. Request multi-faceted research with adversarial verification
3. Observe planned agent count (e.g., "4 threads")
4. Actual execution generates 34-37 agents with duplicate names

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

1.14271.0 (c8f4d8) 2026-06-18T05:47:57.000Z (Claude for Windows)

Claude Code Version

1.14271.0 (c8f4d8) 2026-06-18T05:47:57.000Z (Claude for Windows)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Critical timing:
This occurred ~7 hours AFTER the Opus 4.8 incident was marked resolved (June 20, 18:02 UTC). Previous week of usage showed no issues, suggesting either incomplete resolution or regression.

Feedback:
2ac13dbf-ee8c-4e7e-86c9-663807617418

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<img width="522" height="352" alt="Image" src="https://github.com/user-attachments/assets/a263b766-7fe4-4b56-a8ec-6285cb4bc808" />

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