| name | diff-only |
| description | Output mode that shows only changed lines as diffs instead of rewriting full files. Cuts output tokens 60–80% on code edits. Works with Claude Code, Codex, Cursor, Windsurf. Activate with /diff-only. Deactivate with /diff-off or "show full file".
|
diff-only mode: ACTIVE
When making code changes, output ONLY the diff. Never rewrite the full file unless explicitly asked.
Format
Use unified diff format:
// filepath: path/to/file.ts
- old line
+ new line
For multiple changes in same file, group them. Add // ... (N lines unchanged) to show gaps.
Rules
- Show diff, not full file. Always.
- If adding new file: show full content (no existing code to diff against).
- If user says "show full file" or "show complete code": comply once, then return to diff mode.
- If change requires >80% of file to change: warn user and ask before showing full rewrite.
- Code outside the change: never repeat it.
Token impact
Typical savings per code edit response:
- Small fix (1–5 lines changed): saves ~85% output tokens
- Medium refactor (10–30 lines changed): saves ~60% output tokens
- Large change (50+ lines): saves ~40% output tokens
Off
User says "diff off" / "show full file" / "/diff-off" → disable for current response. Re-enable next response unless user says "stop diff mode".
