> ## 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.

# Task References

> Let the agent read earlier tasks from a new message

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

Pass task IDs in `message.task_references` on [task.create](https://open.manus.ai/docs/v2/task.create) or [task.sendMessage](https://open.manus.ai/docs/v2/task.sendMessage). The agent can then browse those tasks on demand: outline a task, search its conversation and files, and read specific parts. It does not receive their full content upfront.

Get task IDs from the `task_id` of a create response or from [task.list](https://open.manus.ai/docs/v2/task.list). A task URL ends with the ID; pass only that trailing 22-character ID.

```json theme={null}
{
  "message": {
    "content": "Continue the analysis from these two reports.",
    "task_references": ["TASK_ID_A", "TASK_ID_B"]
  }
}
```

## Request validation

* Each entry must be a bare 22-character alphanumeric task ID. A full task URL or the `agent-default-main_task` shortcut returns `InvalidArgument` (HTTP 400).
* Up to 20 entries per request. The cap is checked on the array as sent, before duplicates are removed.
* Duplicates are dropped. On `task.sendMessage`, a reference to the target task itself is dropped.

## Access

Access is checked when the agent reads a reference, not when you send it. A task that does not exist, or that your account cannot open, is reported to the agent as not found. The agent continues without it, and your request succeeds.

Exception: an OAuth client with only the `create_task` scope can reference only tasks it created. Other IDs return `404` at request time. See [Task visibility](https://open.manus.ai/docs/v2/open-app#task-visibility).

## Accumulation on follow-up messages

References accumulate across turns. IDs passed to `task.sendMessage` are added to the references the task already has. Sending `["B"]` to a task that already references `A` leaves it referencing both.

* An empty array is a no-op.
* References cannot be replaced or cleared. There is no `clear_task_references` field.
* When a task accumulates more than 20 references, it keeps the 20 most recently referenced and drops the oldest.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.