Replit: Add Mobile Apps to Legacy Pre-Agent 4 Projects
ReplitReplit enabled projects created before Agent 4 launched to be upgraded to support multiple artifacts — including mobile apps, pitch decks, and other output types introduced with Agent 4. The migration preserves all existing project data (URLs, secrets, deployments, and database connections) while restructuring the project to support Replit's multi-artifact architecture. This removes the previous barrier where older projects were locked to a single web app artifact.
Multi-Artifact Support Now Available for Pre-Agent 4 Projects
When Replit launched Agent 4 in March 2026, it introduced the concept of multi-artifact projects — a single project that can produce a web app, a mobile app, a pitch deck, a video, and more, all within one shared environment. Projects created after that launch were built on this new architecture from the start. Projects created before Agent 4, however, remained on the legacy single-artifact model.
Replit has now closed that gap. Existing projects can be upgraded through a migration flow that converts the project structure to the multi-artifact format, preserving existing deployment URLs and custom domains, environment variables and secrets, and database connections and stored data.
After migration, the project behaves identically to a new Agent 4 project, and builders can ask Replit Agent to add a mobile app, generate a pitch deck, or create additional artifacts alongside an existing web application.
Who This Affects
This update is primarily relevant to developers who built projects before March 2026 and want to extend them with mobile apps or other Agent 4 artifact types without starting from scratch. It is a targeted quality-of-life improvement for Replit's existing user base.