packages/twenty-docs/developers/extend/apps/getting-started/concepts.mdx
Twenty apps are TypeScript packages that extend your workspace with custom objects, logic, UI components, and AI capabilities. They run on the Twenty platform with full sandboxing and permission controls.
An app is a collection of entities declared using defineEntity() functions from the twenty-sdk package. The SDK detects these declarations via AST analysis at build time and produces a manifest — a complete description of what your app adds to a workspace. These functions validate your configuration at build time and provide IDE autocompletion and type safety.
your-app/
├── src/
│ ├── application-config.ts ← defineApplication (required, one per app)
│ ├── roles/ ← defineRole
│ ├── objects/ ← defineObject
│ ├── fields/ ← defineField
│ ├── logic-functions/ ← defineLogicFunction
│ ├── front-components/ ← defineFrontComponent
│ ├── skills/ ← defineSkill
│ ├── agents/ ← defineAgent
│ ├── views/ ← defineView
│ ├── navigation-menu-items/ ← defineNavigationMenuItem
│ └── page-layouts/ ← definePageLayout
├── public/ ← Static assets (images, icons)
└── package.json
| Entity | Purpose | Docs |
|---|---|---|
| Application | App identity, default role, variables | Application Config |
| Role | Permission sets on objects and fields | Roles & Permissions |
| Object | Custom record types with fields | Objects |
| Field | Add fields to objects from other apps | Extending Objects |
| Relation | Bidirectional links between objects | Relations |
| Logic Function | Server-side TypeScript with triggers | Logic Functions |
| Skill | Reusable AI agent instructions | Skills & Agents |
| Agent | AI assistants with custom prompts | Skills & Agents |
| Connection Provider | OAuth credentials for third-party APIs | Connections |
| View | Pre-configured record list views | Views |
| Navigation Menu Item | Custom sidebar entries | Navigation Menu Items |
| Page Layout | Tabs and widgets on a record's detail page | Page Layouts |
| Front Component | Sandboxed React UI inside Twenty | Front Components |
| Command Menu Item | Quick actions and Cmd+K entries | Command Menu Items |
TWENTY_APP_ACCESS_TOKEN) is derived from the role defined in defineApplication().┌─────────────────────────────────────────────────────────┐
│ Development │
│ npx create-twenty-app → yarn twenty dev (live sync) │
├─────────────────────────────────────────────────────────┤
│ Build & Deploy │
│ yarn twenty build → yarn twenty deploy │
├─────────────────────────────────────────────────────────┤
│ Install flow │
│ upload → [pre-install] → metadata migration → │
│ generate SDK → [post-install] │
├─────────────────────────────────────────────────────────┤
│ Publish │
│ npm publish → appears in Twenty marketplace │
└─────────────────────────────────────────────────────────┘
yarn twenty dev — watches your source files and live-syncs changes to a connected Twenty server. The typed API client is regenerated automatically when the schema changes.yarn twenty build — compiles TypeScript, bundles logic functions and front components with esbuild, and produces a manifest.