# Feature Addition Scope Guard

Writes a tightly scoped prompt for adding a new feature to an existing AI-built app, explicitly protecting existing functionality from being unintentionally altered.

## Prompt

You are an expert at writing precise feature-addition prompts for AI app builders like Lovable, Bolt, and Replit, which can sometimes break working features while adding new ones if instructions aren't tightly scoped.

Existing app description (what it currently does): {{existing_app_description}}
New feature I want to add: {{new_feature_description}}
Where this feature should live (which page/section): {{feature_location}}
Existing features that must NOT be affected: {{features_to_protect}}

Do the following:
1. Write a clear, specific description of exactly what the new feature should do, including its inputs, outputs, and how a user interacts with it.
2. Identify anything in the new feature that could plausibly overlap with or affect the existing features I listed, and note it explicitly so the builder tool is aware of the risk.
3. Write the final ready-to-paste prompt structured as: what to add, exactly where to add it, explicit instruction to not modify the listed existing features, and a request to confirm what was changed after implementation.
4. Suggest one simple way for me to verify after the fact that the protected features still work as expected (a quick manual check I can do).

## Best for

Non-technical and semi-technical builders using AI app builders who want to safely add new features to an existing app without risking regressions to features that already work.

## Compatible tools

- Claude
- ChatGPT

## How to use

- Describe your existing app briefly and the new feature you want to add.
- List specifically which existing features are most important to protect from unintended changes.
- Paste the final ready-to-paste prompt into your AI app builder.
- Run the suggested manual verification check immediately after the feature is added to catch any regressions early.

## Customization tips

- For apps with complex existing logic (payments, auth, data relationships), list those as protected features even if the new feature seems unrelated, since AI builders can make unexpected connections.
- If you've had past experiences where a similar addition broke something specific, mention that history so the same risk is flagged again.
- For larger features, consider breaking the request into smaller sequential prompts using this same scope-guard structure for each piece.

## Example input

Existing app: A prompt marketplace where users browse and download prompts. New feature: Add a 'favorites' button so users can save prompts to a list. Location: Prompt detail page. Features to protect: Download functionality, search and filtering, category browsing.

## Example output

A clear feature description covering a heart icon toggle on the prompt detail page that saves the prompt ID to a user's favorites list, a flagged overlap risk noting the favorites button sits near the existing download button and could visually or functionally interfere with it, a final ready-to-paste prompt specifying exact placement and explicitly instructing the builder not to modify the download button, search, or category browsing logic, plus a verification suggestion to manually test downloading and searching immediately after the favorites feature is added.