feat: surface subagent optimization diffs in IDE's native diff view

[aseembits93]

Summary

• Updated subagent mode's <action> instructions to tell Claude Code to use the Write tool instead of AskUserQuestion
• When Claude Code writes optimized code to files, the connected IDE (VS Code, Cursor, Windsurf) surfaces the changes in its native diff viewer
• Users can accept or reject optimizations through the IDE's diff UI rather than reading a text diff in the chat

Test plan

• Run codeflash --subagent and verify the XML output contains the updated <action> block
• Invoke via Claude Code in an IDE-connected session and confirm the diff appears in the IDE's diff viewer

🤖 Generated with Claude Code

[aseembits93]

@KRRT7 the existing style of diff would collapse if the diff is large enough, if we rely on claude's native style of diff, it handles it slightly better imo

[KRRT7]

personally, I've been using Claude Code + Warp which has a built in diff view, which allows me to view them without ever using my IDE, so I keep that open less and less, and the creator of Claude Code has said he and a lot of engineers have stopped using IDEs entirely, this will break that flow, so you should look into how to support both

[aseembits93]

@KRRT7 in the current setup are you able to amend the diff, make changes which are not part of the diff?

[claude]

PR Review Summary

Prek Checks

✅ All checks passed — ruff check and ruff format clean, no fixes needed.

Mypy

✅ All mypy errors in console.py are pre-existing (lines 125-229: paneled_text, code_print, progress_bar, test_files_progress_bar). The PR only modifies string literals at lines 470-482, which are not type-checked. No new type issues introduced.

Code Review

✅ No critical issues found.

The change is minimal and well-scoped — it updates the XML <action> instructions in subagent_log_optimization_result to:

• IDE mode: Use the Write tool to surface diffs in the IDE's native diff viewer
• Terminal mode: Fall back to AskUserQuestion with markdown diff preview (previous behavior)

No logic changes, no API changes, no security concerns.

Test Coverage

File	Stmts (PR)	Miss (PR)	Cover (PR)	Cover (main)	Delta
codeflash/cli_cmds/console.py	267	217	19%	19%	0%

• No coverage regression — coverage unchanged at 19% on both branches
• The changed lines are string literals inside subagent_log_optimization_result which is a UI/output function — the low coverage is pre-existing and not introduced by this PR
• No new files added

Codeflash Optimization PRs

No open optimization PRs targeting main.

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Last updated: 2026-02-25

[aseembits93]

anthropics/claude-code#6735 it's a feature request unfortunately with CC . once CC presents a diff, the user cannot manually modify it, the user can only instruct claude in english to make the necessary change

[aseembits93]

anthropics/claude-code#27708 this one too

[KRRT7]

i prompt it to make the changes, or i make the changes thru nano / warp and tell claude i've made the changes and it auto shows me the changes

the workflow with Claude Code has largely changed to just prompting Claude to make the changes itself

@misrasaurabh1 thoughts?

[misrasaurabh1]

I would need to see how this looks like compared the the alternative - at a very high level I like the native claude diff handling since it makes people feel more comfortable with the new code.

[KRRT7]

@aseembits93 I guess we can.merge?

[aseembits93]

@KRRT7 let's merge, will iterate more with new PRs

[misrasaurabh1]

i am merging so that i can try with the latest version