I asked claude to research something with sonnet agents it started with 5 but then they spawn their agents in total 273 background agents

Bug Description
I asked Claude to research VLM/human/gender recognition using Sonnet agents. The process started with 5 agents, but they unexpectedly spawned a total of 273 background agents. I did not initiate any ultracode or workflows. These agents consumed my entire usage limit in approximately 5 minutes. This issue occurred during a previous run as well, but I was unable to capture it at the time. Model is Opus 4.8 and it consumed 20 percent of my weekly limit in 2 prompts with these.

<img width="962" height="1488" alt="Image" src="https://github.com/user-attachments/assets/cca57331-5e41-49a1-b5d2-ce4c762e2fc8" />

Environment Info

• Platform: darwin
• Terminal: ghostty
• Version: 2.1.179
• Feedback ID: c430db4f-974b-426c-acb9-b8c12a23152a

Errors

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