How do I combine 4 apps into one merged version without it changing the existing apps?
What I am building is a 4 part test, and I want to unify them into one so you don’t have to log into 4 different apps and then there is a dashboard, progress bar, etc
As a less technical builder myself, I feel like there are a lot of questions you should map out in terms of why you would want / should merge 4 apps into one new app and maybe you’ve already done that. I’m assuming there are features or functionality that you’ve built async, but maybe you now see them working together and converging as you’ve been building.
Could you possibly download the projects as 4 different .zip files and ask in a new project in “Plan” mode how Replit would merge all four projects? Or do you already have them in a github repo you could reference?
yes, that’s what I did and Replit wanted to ‘simplify’ things and started changing them and removing parts of each
What’s an example of something it was “simplifying”? What was the prompt you used when you asked it to combine the apps? I feel like there are A LOT of guardrails needed in the initial prompt. Are all of the apps built using the same stack?
It makes some sense that Agent’s instinct was to remove redundancies from the combined app. You’d have to tell it otherwise to avoid this happening in the future.
I connected two of my apps via a Replit built API so they can talk to each other. The user logs into one app and it is granted access to the functionality of the second app. Depending upon how you want the apps to work together, you could do something similar.
You’ll need to set up external APIs on each of the 4 apps, add API key management to each one, then build a 5th unified dashboard app that hits those endpoints. It’s a PITA and expect a lot of trial and error getting it all wired up. Going forward, if it makes sense commercially, build everything in one project space from the start. Way less headache.
So I asked Claude if an easier way would be to upload the apps to Claude and have him/her/they/it (!) create separate PRD’s for each app and then you upload those PRD’s into Replit and ask it to create a single app and this was the reply…
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For each app: Upload the code to Claude and ask: “Generate a detailed PRD for this app covering: purpose, data models, API routes, UI flows, user roles, dependencies, and any third-party integrations.”
Then in a new Claude conversation: Upload all 4 PRDs and ask: “Create a unified architecture PRD for a single app that integrates all four of these, identifying shared components, a unified data model, and a recommended build sequence.”
Then take that to Replit Agent and build module by module rather than all at once.
The key caveat to include: the quality of the output depends heavily on the quality of the existing code. If the 4 apps are clean and well-structured, Claude will generate accurate PRDs. If they’re spaghetti, the PRDs will reflect that and he’ll need to do some manual cleanup before handing off to Replit Agent.
A refinement I’d suggest for your workflow:
Rather than going straight to Replit Agent with the combined PRD, consider one extra step: after Claude generates the consolidated PRD, ask Claude to also generate a build sequence — i.e. the order in which to build modules so each stage is testable. That gives Replit Agent smaller, verifiable chunks rather than one massive instruction.
One question worth answering before they start: are any of the 4 apps sharing a database or user authentication already? If yes, the consolidation is simpler. If they’re completely siloed with separate data stores, the PRD process needs to include a data migration/unification plan, which adds meaningful complexity.
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Good luck!
TFS