---
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 / uninstall hooks** *(optional)* — see [Logic Functions](/developers/extend/apps/logic/logic-functions).
- **Billing** *(optional)* — `billing.recurring` for subscription fees the platform raises automatically, `billing.operations` for what your app charges credits for, and `billing.description` for the marketplace; see [Charging Credits](/developers/extend/apps/logic/credits).

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

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',
      label: 'Default recipient name',
      description: 'Default recipient name for postcards',
      value: 'Jane Doe',
      isSecret: false,
    },
  },
});
```

Notes:
- `universalIdentifier` fields are UUIDs you generate once and own. Keep them stable across syncs. The application's own `universalIdentifier` must be a valid UUID: the server rejects a manifest whose identifier is not one. It is unique across the whole instance and is bound to the workspace that owns its registration, so only that workspace can sync the app — see [Registration ownership](/developers/extend/apps/operations/publishing#registration-ownership).
- `applicationVariables` accept an optional `label` — a user-friendly name displayed in the app's settings page instead of the raw variable key.
- `applicationVariables` become environment variables for your functions and front components. In logic functions (server-side), they are available as `process.env.VARIABLE_NAME`. In front components, use `getApplicationVariable('VARIABLE_NAME')` from `twenty-sdk/front-component`. Variables marked with `isSecret: true` are only injected into logic functions. Front components receive only non-secret variables.
- The default role is detected automatically from the role file marked with [`defineApplicationRole()`](/developers/extend/apps/config/roles) — you do not need to reference it from `defineApplication()`.
- Pre-install, post-install, and uninstall functions are detected automatically during the manifest build — you do not need to reference them in `defineApplication()`.
- Passing `defaultRoleUniversalIdentifier` explicitly is still supported for backward compatibility, but is deprecated in favor of `defineApplicationRole()`.
- `serverVariables` are instance-scoped configuration and secrets (e.g. API keys). Unlike `applicationVariables`, they declare no value in the manifest — the workspace operator fills them in from the app's settings, and they are injected into logic functions only once set.
- Both kinds of variable accept `isDeprecated: true`. Use it to retire a variable instead of deleting it: keeping the key declared preserves the stored value (deleting it destroys the value the operator entered), and the variable is still injected, so your code can fall back to it — `process.env.NEW_API_KEY ?? process.env.API_KEY`. A deprecated variable disappears from the app's settings once it has no value, and never counts toward the app's configuration check, so `isDeprecated` beats `isRequired`.
- To render a custom configuration UI inside the app's **Settings** tab (in place of the default variable configuration section), declare a front component with [`defineSettingsFrontComponent()`](/developers/extend/apps/layout/front-components#custom-settings-component) in its own file. Only one is allowed per app. System-managed sections (auto-upgrade, App URL, connections) always remain visible.

## Variable types

Both `applicationVariables` and `serverVariables` accept an optional `type` (and, for `SELECT` / `MULTI_SELECT`, an `options` list). Supported types: `TEXT` (default), `BOOLEAN`, `NUMBER`, `NUMERIC`, `DATE`, `DATE_TIME`, `SELECT`, `MULTI_SELECT`, `ARRAY`, `RAW_JSON`, `RICH_TEXT`.

```ts src/application-config.ts
import { defineApplication, FieldType } from 'twenty-sdk/define';

export default defineApplication({
  // ...identity, role...
  applicationVariables: {
    MAX_POSTCARDS: {
      universalIdentifier: '5f4497e4-9030-4085-85eb-2c48b8d53713',
      description: 'Maximum postcards per batch',
      type: FieldType.NUMBER,
      value: 10,
    },
    DEFAULT_REGION: {
      universalIdentifier: '76c5c321-b6b6-46eb-b4fc-f9f04bb04227',
      description: 'Default shipping region',
      type: FieldType.SELECT,
      options: [
        { label: 'Europe', value: 'eu' },
        { label: 'United States', value: 'us' },
      ],
      value: 'eu',
    },
  },
});
```

The `type` only affects **presentation and validation** — it selects the matching input in the workspace settings UI (a toggle, number field, dropdown, date picker, JSON editor, …) and lets the build validate your config (for example, `SELECT` / `MULTI_SELECT` must declare non-empty `options`). It does **not** change how the value reaches your code.

Values are **always injected as strings** — this is inherent to environment variables (`process.env.*` is string-only). When your logic function runs, the executor serializes each value by its declared `type` while building `process.env`, so the string format is consistent no matter how the value was set (manifest default, settings UI, or a previous version):

| Type | `process.env` string |
|------|----------------------|
| `TEXT`, `SELECT`, `DATE`, `DATE_TIME` | the raw value (`"eu"`, `"2026-01-01"`) |
| `BOOLEAN` | `"true"` / `"false"` |
| `NUMBER`, `NUMERIC` | decimal string (`"10"`, `"2.5"`) |
| `MULTI_SELECT`, `ARRAY` | JSON array (`'["email","postcard"]'`) |
| `RAW_JSON`, `RICH_TEXT` | JSON object (`'{"retries":3}'`) |

Parse the string back into the type you expect:

```ts
const maxCards = Number(process.env.MAX_POSTCARDS); // "10" -> 10
const enabled = process.env.ENABLE_TRACKING === 'true'; // "true" -> true
const channels = JSON.parse(process.env.ENABLED_CHANNELS ?? '[]'); // '["email"]' -> ["email"]
const config = JSON.parse(process.env.PROVIDER_CONFIG ?? '{}'); // '{"retries":3}' -> { retries: 3 }
```

The same applies to front components reading values via `getApplicationVariable('VARIABLE_NAME')` — the returned value is a string; parse it as needed.

## Default function role

The role declared with [`defineApplicationRole()`](/developers/extend/apps/config/roles) controls what the app's logic functions and front components can access:

- The runtime tokens injected into your logic functions are derived from this role. A call acting as a person is further narrowed to what that person can do, so it can never exceed either one. See [Whose access a call uses](/developers/extend/apps/logic/logic-functions#whose-access-a-call-uses).
- 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 |
| `logo` | Path to your app logo bundled in `public/` (e.g., `public/logo.png`) |
| `galleryImages` | Array of gallery image paths bundled in `public/` (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. Images do not render, and raw HTML shows as plain text |
| `billing.description` | What the app costs, in one short friendly line shown next to the install button (e.g. `$0.02 per minute recorded`). Set it if your app [charges credits](/developers/extend/apps/logic/credits) |
| `websiteUrl` | Link to your website |
| `termsUrl` | Link to terms of service |
| `emailSupport` | Support email address |
| `issueReportUrl` | Link to issue tracker |

<Note>
`logoUrl` and `screenshots` are deprecated aliases of `logo` and `galleryImages`. External absolute URLs (`http://` or `https://`) are not supported for these fields: they are dropped with a warning at build time. Bundle the images in your app's `public/` folder instead.
</Note>