upstream-twenty/packages/twenty-docs/developers/extend/apps/getting-started/project-structure.mdx

---
title: Project Structure
description: What's inside a scaffolded Twenty app — files, folders, and what each one does.
icon: "folder-tree"
---

A new app generated by `npx create-twenty-app` looks like this:

```text filename="my-twenty-app/"
my-twenty-app/
  package.json
  src/
    application-config.ts                   # Required — your app's entry point
    default-role.ts                         # Permissions for logic functions
    constants/
      universal-identifiers.ts              # Auto-generated UUIDs and metadata
    front-components/
      main-page.tsx                         # Welcome page component
    navigation-menu-items/
      main-page.navigation-menu-item.ts     # Sidebar entry for the welcome page
    page-layouts/
      main-page.page-layout.ts              # Standalone page hosting the component
    __tests__/
      application-config.test.ts            # Unit test
      global-setup.ts                       # Integration test setup (sync + uninstall)
      schema.integration-test.ts            # Integration test against a live server
  .github/workflows/
    ci.yml                                  # Lint, typecheck, unit + integration tests
    cd.yml                                  # Deploy + install on push to main
    publish.yml                             # Publish to npm on version tags (with provenance)
  public/
    logo.svg                                # Static assets
  locales/
    en.json                                 # Source catalog; add <locale>.json files next to it
  vitest.config.ts                          # Integration test runner config
  vitest.unit.config.ts                     # Unit test runner config
  tsconfig.json, tsconfig.spec.json
  .nvmrc, .yarnrc.yml, .oxlintrc.json
  README.md, AGENTS.md, CLAUDE.md, CHANGELOG.md, SETUP.md
```

## Key files

| File / Folder | Purpose |
|---|---|
| `src/application-config.ts` | **Required.** The main configuration file for your app. |
| `src/default-role.ts` | Default role controlling what your logic functions can access. |
| `src/constants/universal-identifiers.ts` | Auto-generated UUIDs and metadata (display name, description). |
| `src/front-components/`, `src/navigation-menu-items/`, `src/page-layouts/` | A starter welcome page: a front component rendered by a standalone page layout, reachable from the sidebar. |
| `src/__tests__/` | A unit test plus an integration test (with its global setup) that syncs the app against a real server. |
| `public/` | Static assets (images, fonts) served with your app. |
| `locales/` | Translation catalogs. `en.json` is the source catalog `dev:translations-extract` fills in; the set of files here is what a sync publishes, so an empty folder declares no translations. `locales/compiled/` is written by `pull` for entries whose source strings are not in the tree yet, is published by a sync too, and is not meant to be edited by hand. |
| `AGENTS.md` / `CLAUDE.md` | Guidance for AI coding agents working on the app. |
| `CHANGELOG.md` / `SETUP.md` | Changelog of notable changes and setup instructions for local development. |

<Note>
**File organization is up to you.** The folders above are conventions — the SDK detects entities via AST analysis on `export default defineEntity(...)` calls regardless of where the file lives.
</Note>

## Dependencies

The Twenty SDK and UI packages belong under `devDependencies`:

```json filename="package.json"
{
  "dependencies": {},
  "devDependencies": {
    "twenty-client-sdk": "2.40.0",
    "twenty-sdk": "2.40.0",
    "twenty-ui": "2.40.0"
  }
}
```

The scaffolder pins `twenty-sdk`, `twenty-client-sdk`, and `twenty-ui` to its own version. Keep all three in sync when upgrading.

- **`twenty-sdk`** ships the `twenty` CLI and the build/scaffolding tooling. It only runs at development and build time and is never imported by your published app's runtime.
- **`twenty-client-sdk`** _is_ imported by your app code (`CoreApiClient`, `MetadataApiClient`, `RestApiClient`), but Twenty provides it at runtime — logic functions get it from a generated SDK layer, and front components resolve it from server-served modules. Your installed copy is only used for typechecking and the deploy-time build, so it never needs to ship in the deployed bundle.

Keeping either package under `dependencies` pulls it into the installed app's runtime bundle, where it is dead weight. `twenty dev:build` emits a warning when either is still listed under `dependencies`.

Add your app's own runtime dependencies (libraries your logic functions actually import at runtime) under `dependencies` as usual. Keep the tree lean: `dependencies` are installed into a runtime layer capped at 250MB unpacked, and a sync or install fails with a dependencies size error beyond that — UI libraries and dev tooling belong in `devDependencies`.