# Ea Studio Shark Lean Code Diff Only > diff-only mode: ACTIVE - Skill: `tomevault-io/ea-studio-shark-lean-code-diff-only` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/ea-studio-shark-lean-code-diff-only` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/ea-studio-shark-lean-code-diff-only/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/ea-studio-shark-lean-code-diff-only --- ## 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". --- > Source: [EA-Studio-SHARK/lean-code](https://github.com/EA-Studio-SHARK/lean-code) — distributed by [TomeVault](https://tomevault.io).