Concepts

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.

How apps work

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

File organization is up to you. Entity detection is AST-based — the SDK finds export default defineEntity(...) calls regardless of where the file lives. The folder structure above is a convention, not a requirement.

Entity types

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

Sandboxing

Logic functions run in isolated Node.js processes on the server. They only access data through the typed API client, scoped to the app’s role permissions.
Front components run in Web Workers using Remote DOM — sandboxed from the main page but rendering native DOM elements (not iframes). They communicate with Twenty via a message-passing host API.
Permissions are enforced at the API level. The runtime token (TWENTY_APP_ACCESS_TOKEN) is derived from the role defined in defineApplication().

App lifecycle

┌─────────────────────────────────────────────────────────┐
│ Development                                             │
│   npx create-twenty-app → yarn twenty dev (live sync)   │
├─────────────────────────────────────────────────────────┤
│ Build & Deploy                                          │
│   yarn twenty dev:build → yarn twenty app:publish        │
├─────────────────────────────────────────────────────────┤
│ Install flow                                            │
│   upload → [pre-install] → metadata migration →         │
│   generate SDK → [post-install] → … → [uninstall]       │
├─────────────────────────────────────────────────────────┤
│ 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 dev:build — compiles TypeScript, bundles logic functions and front components with esbuild, and produces a manifest.
Pre/post-install and uninstall hooks — optional functions that run during installation or right before removal. See Install Hooks for details.

Next steps

Config

Application identity, default role, and install and uninstall hooks.

Data

Objects, fields, and bidirectional relations.

Logic

Logic functions, skills, agents, and OAuth connections.

Layout

Views, navigation, page layouts, front components.

Operations

CLI, testing, remotes, CI, and publishing your app.

Overview

Apps

API

Self-Host

Contribute

How apps work

Entity types

Sandboxing

App lifecycle

Next steps

Config

Data

Logic

Layout

Operations

​How apps work

​Entity types

​Sandboxing

​App lifecycle

​Next steps

Config

Data

Logic

Layout

Operations

How apps work

Entity types

Sandboxing

App lifecycle

Next steps