| `allowIceFallback` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Allows use of fallback STUN servers for ICE if the user's homeserver doesn’t provide any. |
| `analyticsID` | Posthog analytics ID | No | No | Available only with user's consent for sharing telemetry in Element Web. |
| `appPrompt` | `true` or `false` | No, defaults to `true` | No, defaults to `true` | Prompts the user to launch the native mobile app upon entering a room, applicable only on Android and iOS, and must be enabled in config. |
| `baseUrl` | | Yes | Not applicable | The base URL of the homeserver to use for media lookups. |
| `confineToRoom` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Keeps the user confined to the current call/room. |
| `deviceId` | Matrix device ID | Yes | Not applicable | The Matrix device ID for the widget host. |
| `displayName` | | No | No | Display name used for auto-registration. |
| `enableE2EE` (deprecated) | `true` or `false` | No, defaults to `true` | No, defaults to `true` | Legacy flag to enable end-to-end encryption, not used in the `livekit` branch. |
| `fontScale` | A decimal number such as `0.9` | No | No | Factor by which to scale the interface's font size. |
| `fonts` | | No | No | Defines the font(s) used by the interface. Multiple font parameters can be specified: `?font=font-one&font=font-two...`. |
| `hideHeader` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Hides the room header when in a call. |
| `hideScreensharing` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Hides the screen-sharing button. |
| `homeserver` | | Not applicable | No | Homeserver for registering a new (guest) user, configures non-default guest user server when creating a spa link. |
| `lang` | [BCP 47](https://www.rfc-editor.org/info/bcp47) code | No | No | The language the app should use. |
| `parentUrl` | | Yes | Not applicable | The url used to send widget action postMessages. This should be the domain of the client or the webview the widget is hosted in. (in case the widget is not in an Iframe but in a dedicated webview we send the postMessages same WebView the widget lives in. Filtering is done in the widget so it ignores the messages it receives from itself) |
| `password` | | No | No | E2EE password when using a shared secret. (For individual sender keys in embedded mode this is not required.) |
| `perParticipantE2EE` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Enables per participant encryption with Keys exchanged over encrypted matrix room messages. |
| `preload` | `true` or `false` | No, defaults to `false` | Not applicable | Pauses app before joining a call until an `io.element.join` widget action is seen, allowing preloading. |
| `returnToLobby` | `true` or `false` | No, defaults to `false` | Not applicable | Displays the lobby in widget mode after leaving a call; shows a blank page if set to `false`. Useful for video rooms. |
| `roomId` | [Matrix Room ID](https://spec.matrix.org/v1.12/appendices/#room-ids) | Yes | No | Anything about what room we're pointed to should be from useRoomIdentifier which parses the path and resolves alias with respect to the default server name, however roomId is an exception as we need the room ID in embedded widget mode, and not the room alias (or even the via params because we are not trying to join it). This is also not validated, where it is in `useRoomIdentifier()`. |
| `showControls` | `true` or `false` | No, defaults to `true` | No, defaults to `true` | Displays controls like mute, screen-share, invite, and hangup buttons during a call. |
| `skipLobby` | `true` or `false` | No, defaults to `false` | No, defaults to `false` | Skips the lobby to join a call directly, can be combined with preload in widget. |
| `theme` | One of: `light`, `dark`, `light-high-contrast`, `dark-high-contrast` | No, defaults to `dark` | No, defaults to `dark` | UI theme to use. |
| `userId` | [Matrix User Identifier](https://spec.matrix.org/v1.12/appendices/#user-identifiers) | Yes | Not applicable | The Matrix user ID. |
| `viaServers` | Comma separated list of [Matrix Server Names](https://spec.matrix.org/v1.12/appendices/#server-name) | Not applicable | No | Homeserver for joining a room, non-empty value required for rooms not on the user’s default homeserver. |
| `widgetId` | [MSC2774](https://github.com/matrix-org/matrix-spec-proposals/pull/2774) format widget ID | Yes | Not applicable | The id used by the widget. The presence of this parameter implies that element call will not connect to a homeserver directly and instead tries to establish postMessage communication via the `parentUrl`. |
