---
title: Application Config
description: Declare your app's identity, default role, variables, and marketplace metadata with defineApplication.
icon: "rocket"
---

Every app must have exactly one `defineApplication` call. It declares:

- **Identity** — universal identifier, display name, description.
- **Permissions** — which role its logic functions and front components run under.
- **Variables** *(optional)* — key–value pairs exposed to your code as environment variables.
- **Pre-install / post-install hooks** *(optional)* — see [Logic Functions](/developers/extend/apps/logic/logic-functions).

```ts src/application-config.ts
import { defineApplication } from 'twenty-sdk/define';
import { DEFAULT_ROLE_UNIVERSAL_IDENTIFIER } from 'src/roles/default-role';

export default defineApplication({
  universalIdentifier: '39783023-bcac-41e3-b0d2-ff1944d8465d',
  displayName: 'My Twenty App',
  description: 'My first Twenty app',
  applicationVariables: {
    DEFAULT_RECIPIENT_NAME: {
      universalIdentifier: '19e94e59-d4fe-4251-8981-b96d0a9f74de',
      description: 'Default recipient name for postcards',
      value: 'Jane Doe',
      isSecret: false,
    },
  },
  defaultRoleUniversalIdentifier: DEFAULT_ROLE_UNIVERSAL_IDENTIFIER,
});
```

Notes:
- `universalIdentifier` fields are deterministic IDs you own. Generate them once and keep them stable across syncs.
- `applicationVariables` become environment variables for your functions and front components (e.g., `DEFAULT_RECIPIENT_NAME` is available as `process.env.DEFAULT_RECIPIENT_NAME`).
- `defaultRoleUniversalIdentifier` must reference a role defined with [`defineRole()`](/developers/extend/apps/config/roles).
- Pre-install and post-install functions are detected automatically during the manifest build — you do not need to reference them in `defineApplication()`.

## Default function role

The `defaultRoleUniversalIdentifier` controls what the app's logic functions and front components can access:

- The runtime token injected as `TWENTY_APP_ACCESS_TOKEN` is derived from this role.
- The typed API client is restricted to the permissions granted to that role.
- Follow least-privilege: declare only the permissions your functions need.

When you scaffold a new app, the CLI creates a starter role file at `src/roles/default-role.ts`. See [Roles & Permissions](/developers/extend/apps/config/roles) for the full reference.

## Marketplace metadata

If you plan to [publish your app](/developers/extend/apps/operations/publishing), these optional fields control how it appears in the marketplace:

| Field | Description |
|-------|-------------|
| `author` | Author or company name |
| `category` | App category for marketplace filtering |
| `logoUrl` | Path to your app logo (e.g., `public/logo.png`) |
| `screenshots` | Array of screenshot paths (e.g., `public/screenshot-1.png`) |
| `aboutDescription` | Longer markdown description for the "About" tab. If omitted, the marketplace uses the package's `README.md` from npm |
| `websiteUrl` | Link to your website |
| `termsUrl` | Link to terms of service |
| `emailSupport` | Support email address |
| `issueReportUrl` | Link to issue tracker |
