change-logger — Claude Code hook: log every file change to CSV
This hook writes each file mutation to a CSV: timestamp, tool, path, action and details. Handy when you are prepping a demo and need to show what the agent touched.
npx claude-code-templates@latest --hook automation/change-loggerWhat change-logger does
The hook listens on PostToolUse and fires after Edit, MultiEdit, Write and Bash. Every call runs python3 .claude/hooks/change-logger.py, and the script appends a row to .claude/critical_log_changes.csv. A row carries the timestamp, tool name, file path, action and operation details.
There is one executable script, change-logger.py, dropped into .claude/hooks/. No extra logic to configure: whatever the hook catches lands in the file. You need Python 3 in the environment, since the command goes through python3.
Keep in mind that Bash sits in the matcher list, so shell commands end up in the log alongside file edits. Run a lot of terminal work and the CSV grows fast — decide up front where the log lives and when you clear it.
What it helps with
- capture every file edit from a session in one CSV
- build an evidence trail for a demo
- see which tools the agent called and when
- track Bash commands next to file edits
- reconstruct a timeline of agent activity in a project
Example prompts for the agent
- turn on change-logger and show me what it logged after the last edit
- check
.claude/critical_log_changes.csvand tell me which files changed - why is there a Bash entry in the log?
How to install change-logger
1claude-code-templates
npx claude-code-templates@latest --hook automation/change-logger2Manually: put the files in place
.claude/settings.jsonThe hooks block: event (PreToolUse, PostToolUse, Stop…) → command. Personal ones go to ~/.claude/settings.json
Step by step, with commands for each platform: Claude Code hooks: what they are, where to configure them, how to block a risky command
Questions about change-logger
How do I install change-logger in Claude?
Run npx claude-code-templates@latest --hook automation/change-logger, then check .claude/settings.json — the hook should be registered there.
What does change-logger do?
It logs file mutations to CSV: timestamp, tool, path, action and details. It fires after Edit, MultiEdit, Write and Bash, writing to .claude/critical_log_changes.csv.
What does the hook need to run?
Python 3 in the environment: the hook command runs python3 .claude/hooks/change-logger.py, and the script itself sits in .claude/hooks/.
Source text
change-logger.json · MIT
{
"description": "Log every file mutation to CSV for demo prep. Records timestamp, tool, file path, action, and details for Edit, MultiEdit, Write, and Bash operations. Output: .claude/critical_log_changes.csv",
"supportingFiles": [
{
"source": "change-logger.py",
"destination": ".claude/hooks/change-logger.py",
"executable": true
}
],
"hooks": {
"PostToolUse": [
{
"matcher": "Edit",
"hooks": [
{
"type": "command",
"command": "python3 .claude/hooks/change-logger.py"
}
]
},
{
"matcher": "Write",
"hooks": [
{
"type": "command",
"command": "python3 .claude/hooks/change-logger.py"
}
]
},
{
"matcher": "MultiEdit",
"hooks": [
{
"type": "command",
"command": "python3 .claude/hooks/change-logger.py"
}
]
},
{
"matcher": "Bash",
"hooks": [
{
"type": "command",
"command": "python3 .claude/hooks/change-logger.py"
}
]
}
]
}
}
© davila7 · MIT · davila7/claude-code-templates
