[BUG] Detailed transcript for "Edit|Write" hook says "2 PostToolUse hooks ran", but only 1 hook actually ran (once)

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?

My PostToolUse hook runs 1 time for each file edit, exactly as intended. However, the Claude detailed transcript (opened with Ctrl-O) says, "2 PostToolUse hooks ran". The bug is the incorrect transcript message.

I confirmed (by adding logging to the formatter) that the hook only runs once. There is no other hook installed; /hooks shows "1 hook configured" at the top (i.e. 1 hook across all types).

The matcher line is "matcher": "Edit|Write",.

I ran the verbose logger as follows:

pwsh -Command { $env:CLAUDE_CODE_DEBUG_LOG_LEVEL = 'verbose'; claude --debug-file 'some_filename.log' --resume 'some_session_name' }

That shows inconsistent information, such as:

• "[VERBOSE] Matched 2 unique hooks for query "Write" (2 before deduplication)"
• "[DEBUG] Hook output does not start with {, treating as plain text" (only once, suggesting it's actually only called once)
• "PostToolUse hook modified C:\[Redacted] after Write — re-synced readFileState" (again, only once)

Background:

I wrote a simple hook very similar to "Auto-format code after edits", but setting "powershell" as the shell and using a custom PowerShell formatter script (not Prettier).

As with the Prettier example, the matcher is "matcher": "Edit|Write",.

The hook does not output anything.

Claude Code is using a Microsoft Foundry-hosted Sonnet model.

What Should Happen?

Should say "1 PostToolUse hook ran"

Error Messages/Logs

Steps to Reproduce

1. Create "Auto-format code after edits" hook.
2. Tell Claude:

Create a Test.txt file with "Hello, world!" and 10 newlines.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.284 (Claude Code)

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

<img width="329" height="145" alt="Image" src="https://github.com/user-attachments/assets/840261cd-4226-4a74-acbd-7de0c2ec141b" />