> ## Documentation Index
> Fetch the complete documentation index at: https://open.manus.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Hidden application context

> Send application context to the agent without rendering it as user-visible message text.

<sup>Questions or issues? Contact us at [api-support@manus.ai](mailto:api-support@manus.ai).</sup>

<Note>
  The `hidden` value is available only to a **Trusted public client**. Other callers can omit `visibility` or use its default value, `visible`. API keys, standard OAuth clients, legacy clients, and Trusted team clients cannot send or read hidden application text.
</Note>

Use hidden application context when the agent needs partner-supplied information that should not appear in the user-visible message body. The LLM receives all content parts in their original order, so a hidden part keeps its position relative to the visible text around it. Hidden text can affect agent behavior and skill selection.

## Send hidden text

Set `visibility: "hidden"` on individual text parts in `task.create` or `task.sendMessage`:

```json theme={null}
{
  "message": {
    "content": [
      {"type": "text", "text": "Build my website"},
      {"type": "text", "text": "Additional application context", "visibility": "hidden"}
    ]
  }
}
```

`visibility` defaults to `visible`, and plain string content remains visible. Every message must contain at least one non-empty visible text part or valid visible file or voice part. Hidden file and voice parts are not supported. Hidden text counts toward the message token limit.

The API returns `InvalidArgument` (HTTP 400) for all-hidden messages, unsupported visibility values, whitespace-only visible text, or hidden file and voice parts. A caller that is not a Trusted public client receives `PermissionDenied` (HTTP 403) when it attempts to send hidden text.

## Read hidden text

Use a Bearer token from the same Trusted public client and set `verbose=true` on `task.listMessages`. Existing task access restrictions still apply.

```bash theme={null}
curl --request GET \
  --url 'https://api.manus.ai/v2/task.listMessages?task_id=<task_id>&verbose=true' \
  --header 'Authorization: Bearer <access_token>'
```

Visible text remains in `user_message.content`. Hidden text is returned separately in `user_message.hidden_content`:

```json theme={null}
{
  "type": "user_message",
  "user_message": {
    "content": "Build my website",
    "hidden_content": ["Additional application context"]
  }
}
```

`hidden_content` preserves the order among hidden text parts. It does not encode each hidden part's position relative to visible text. Other callers and non-verbose requests omit the field.

## Display behavior

Hidden text is omitted from user-facing messages, history, previews, and title input. Model responses may still refer to the hidden context.