How to Add Features to an Existing Lovable Project

Add a feature to an existing Lovable project by describing the user action, expected saved result and access rules, then implement it in a small, testable change. For larger changes, use Plan mode to investigate the current app before approving work.

What you will learn and need

You will learn how to scope a feature, uncover dependencies and verify it without breaking existing behaviour. You need access to the project and a clear feature goal. If starting from someone else’s app, make your own remix first. Join Lovable if you need an account.

1. Describe the outcome, not just a button

Write a short user story: who uses the feature, what they do and what should happen. Include cancellation, validation and failure states. For example, “a signed-in user can save a project and find it again in their account” is more useful than “add a heart icon.”

2. Inspect the current app in Plan mode

Ask Lovable to review existing patterns and identify the affected pages, stored data and permissions. Plan mode is for investigation and review before changes; it does not mean implementation or research is free. Check the current usage guidance rather than relying on promised fixed credit savings.

Plan a saved-project feature for this existing app. First inspect its account system and current project pages. Signed-in users should save and unsave a project, and only see their own saved list. Preserve all current permissions and routes. Include empty, loading and error states and concrete verification checks. Do not implement until the plan is approved.

3. Agree what is outside this change

State what must stay untouched. A saved-list feature should not silently redesign the homepage or replace the account system. Split optional notifications, social sharing and analytics into later work if they are not required for the first usable version.

4. Implement a complete small workflow

Ask for the control, stored result and readback together. A button that appears to work but loses its state on reload is not a complete feature. If the feature needs private data, enforce access rules outside the visible interface too.

Implement the approved saved-project plan only. Persist each user’s saves, support undo, prevent duplicate saves and show clear failures. Reuse the app’s existing account and permission patterns. Test save, reload, unsave and the separation between two users. Do not change unrelated layouts.

5. Re-test the original workflow

Use real, safe test input. Confirm the feature works after reload and on a fresh session. Test signed-out behaviour and the relevant permissions. Then recheck the main workflow that existed before the feature was added.

How to verify it works

Write acceptance checks before implementation: one save creates one entry; repeating it does not duplicate the entry; unsaving removes it; another user cannot read or alter it. Adapt these checks to your feature rather than checking only its visual appearance.

Common errors

• Feature request too vague: provide a user story and expected result.
• State disappears on reload: request persistence and readback verification.
• Everyone can access private data: review server-side or database permissions, not only hidden controls.
• Too many changes at once: return to an ordered plan and one testable milestone.

Frequently asked questions

Can I add a feature to a published app?

Yes, but test changes carefully before updating what visitors see.

Does adding features to a remix update the source?

No. Remixes do not stay synchronised.

Should every tiny change start in Plan mode?

Not necessarily. Use it when investigating dependencies or an expensive-to-undo change is valuable.

Official sources and next steps

Plan mode, Security and Remix a project. Continue with breaking large projects into smaller tasks.