---
url: https://docs.ridgedata.ai/reference/embed-api/TypeAlias.EmbedToHostMessage.md
---
# Type Alias: EmbedToHostMessage

```ts
type EmbedToHostMessage = 
  | {
  requestId: string;
  state: StateValues;
  type: typeof state;
}
  | {
  requestId: string;
  stateSchema: StateSchema;
  type: typeof stateSchema;
}
  | {
  state: StateValues;
  type: typeof stateChange;
}
  | {
  stateSchema: StateSchema;
  type: typeof ready;
}
  | {
  error: StateError;
  type: typeof error;
};
```

Messages an iframe sends to your app through the window's `message` event.
Check `event.origin` and `event.source` before reading the payload.

| Message `type` | Fields | When it is sent |
| --- | --- | --- |
| `ridge:ready` | `stateSchema` | Once, when the dashboard can receive state requests. Sent to the framing page before it has spoken; register your listener before loading the iframe. |
| `ridge:state` | `requestId`, `state` | In response to `ridge:getState`, with the matching request id and complete state. |
| `ridge:stateSchema` | `requestId`, `stateSchema` | In response to `ridge:getStateSchema`, with the matching request id. |
| `ridge:stateChange` | `state` | After a user interaction or a state update without `silent: true`. Contains the complete resulting state. |
| `ridge:error` | `error` | Once per rejected component update. Contains its component `id`, error `code`, and `message`. |

The state schema describes accepted values and write permissions. A state change message
contains the current values, with unset keys omitted. Error messages can occur even when
other updates in the same batch succeed.