Gemini CLI --yolo to read files, it uses the read_file tool

[generik0]

RTK only registers a BeforeTool hook on run_shell_command. But when Gemini CLI uses --yolo to read files, it uses the read_file tool

Can we extend rtk to hook into read_file also?

[pszymkowiak]

[w] wshm · Automated triage by AI

🔍 Automated Triage

✨ Category	feature
🟡 Priority	medium
🎯 Confidence	90%

Summary

Request to extend RTK's BeforeTool hook to also intercept the read_file tool, not just run_shell_command, to support Gemini CLI's --yolo file reading.

This looks like a simple fix. Only repo maintainers can trigger auto-fix.

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Triaged automatically by wshm · This is an automated analysis, not a human review.

[Ross-cripto]

Hey, picked this up and have a working fix ready.
run_gemini() had a hard guard that exited immediately for any tool that wasn't run_shell_command, so read_file was always passed through untouched — RTK never saw it.

What the fix does

Extends the Gemini BeforeTool hook to intercept read_file alongside run_shell_command:

1. Reads the file and applies RTK's existing FilterLevel::Minimal filter (same engine used by rtk read)
2. Writes the filtered content to a temp file at ~/.local/share/rtk/filtered/
3. Redirects Gemini to read the temp file via hookSpecificOutput.tool_input.file_path
4. Correctly handles start_line/end_line — the slice is pre-applied before filtering, and both fields are overridden in the response to prevent Gemini's merge from re-applying the original
   (now wrong) line numbers to the filtered file
5. Safe fallbacks — binary/unreadable files, small files (<500 chars), and files with negligible savings (<10%) are passed through unchanged
6. Temp file rotation — keeps last 20 filtered files, mirroring the existing tee.rs pattern

No new dependencies. All 1094 tests pass.

[Ziyad]

If we disable the tools (read_file, read_many_files) via policy/config then Gemini will fallback to using run_shell_command therefore using conventional shell commands and hitting the RTK hook path