Ask What Changed Only

Ask AI for Changes Only (The Delta/Diff Protocol) (AI Skill)

Overview

When asking an AI to tweak a sentence in a 1,500-word article or fix one function in a 400-line script, default model behavior is to regenerate the entire document from start to finish.

This creates two major problems:

1. Severe Token Waste: Generates thousands of unnecessary output tokens ($$$ and slow generation time).
2. Review Nightmare: You have to re-read the entire document just to find what tiny phrase or line actually changed.

The Delta / Diff Protocol instructs the model to output only the exact modified chunks, with clear before-and-after references or standard Git-style diffs.

Full Regeneration vs. Delta Output

┌─────────────────────────────────────────────────────────────┐
│                 Full Rewrite vs. Delta Output               │
│                                                             │
│  Full Document Regeneration:                                │
│  • 1,200 tokens generated                                   │
│  • 25 seconds wait time                                     │
│  • User must manually hunt for changes                      │
│                                                             │
│  Delta / Diff Output:                                       │
│  • 85 tokens generated (93% token reduction)                │
│  • 2 seconds generation time                                │
│  • Visual instant clarity on what changed                   │
└─────────────────────────────────────────────────────────────┘

Master Delta Prompt Templates

Pattern 1: The Unified Diff Directive (Code & Configs)

Use this for codebases, YAML, JSON, or configuration files:

Here is my code file: [PASTE CODE].

Task: [DESCRIBE THE REFACTOR / FIX].

Output Rules:
1. Do NOT reprint the entire file.
2. Provide ONLY a standard unified `diff` block showing `-` for removed lines and `+` for added lines.
3. Include 2 lines of unchanged context above and below each modification.

Pattern 2: The "Before vs. After" Snippet (Text & Copywriting)

Use this for essays, contracts, emails, and articles:

Here is my draft: [PASTE DRAFT].

Task: [MAKE THIS TONE MORE CONCISE / FIX GRAMMAR].

Output Rules:
- Do NOT rewrite the entire draft.
- List ONLY the specific sentences you changed.
- Format each change as:
  **Original**: "[Old sentence]"
  **Revised**: "[New sentence]"
  **Reason**: [1-sentence rationale for the change]

Real-World Examples

Example 1: Fixing a Single Backend Route

Wasteful Full Rewrite (300+ Lines Generated)

AI spits out the entire 350-line Flask server file just to change an HTTP status code from 200 to 201.

Unified Diff Output (15 Lines Generated)

@@ -42,7 +42,7 @@ def create_user_subscription():
     if not plan_id:
         return jsonify({"error": "Missing plan_id"}), 400
 
     subscription = billing_service.subscribe(user_id, plan_id)
-    return jsonify(subscription.to_dict()), 200
+    return jsonify(subscription.to_dict()), 201

Example 2: Copywriting Tone Edit

Delta Output for Article Edit

User Prompt: "Make paragraph 3 of my blog post punchier. Show ONLY the before and after."

AI Response:

Original: "It is widely believed by many industry practitioners that when you deploy software on Fridays, you are significantly increasing the probability of encountering weekend outages."

Revised: "Deploying on Friday is an open invitation to a ruined weekend."

Reason: Cut 21 filler words, switched from passive voice to an active, punchy hook.

When to Use Full Rewrite vs. Delta Output