Same assistant response rendered 16 times in terminal for a single user message

Environment

• Claude Code version: 2.1.119
• Platform: macOS Darwin 24.6.0
• Shell: zsh in macOS Terminal (not iTerm2, not tmux — confirmed neither was running)
• Model: claude-sonnet-4-6 (1M context)

What happened

During a normal session, a single user message produced one assistant turn that was rendered 16 times in the terminal. The repeated block included tool output (a large grep result across a docs directory) followed by the assistant's analysis.

The turn that repeated was triggered by this Bash tool call:

\\\
grep -rn "christacarmen-ai" /Users/trust/Dev/tessera/CLAUDE.md /Users/trust/Dev/tessera/_docs/
\\\

That command produced approximately 40 lines of output across many files. Immediately after, the assistant composed a multi-paragraph categorized response. That entire block — tool output + response — appeared 16 times.

Relevant configuration

Two superpowers plugins were loaded simultaneously, both registering a SessionStart hook with "matcher": "startup|resume|clear|compact":

• superpowers@superpowers-marketplace v4.3.1 (since removed)
• superpowers@claude-plugins-official v5.0.7

Global settings at the time:

• "verbose": true
• "alwaysThinkingEnabled": true

Hypothesis

The large grep output may have triggered a context compaction event. Both plugins registered on the compact matcher and fired simultaneously. It is unknown whether the 16x repetition is a display/rendering bug (one API call, output shown 16 times) or 16 actual API calls — the raw stream log was not captured.

Impact

• Unpredictable token usage (16x for that turn)
• No way for the user to distinguish rendering artifact from actual repeated inference

Steps to reproduce

Not yet reproducible on demand. Likely requires:

1. Two plugins with SessionStart hooks registered on compact
2. A large Bash tool result (40+ lines) triggering compaction
3. verbose: true

The duplicate plugin has been removed. A session log capture strategy (claude 2>&1 | tee /tmp/claude-session.log) has been suggested to isolate whether this is rendering or inference repetition if it recurs.