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

# Task Lifecycle

> How tasks are created, routed, and updated

A task is one running unit of work for an agent. Most product integrations map one user session, conversation, or job to one task.

## Lifecycle Hooks

The public Python runtime exposes three handlers:

* `@server.on_create`
* `@server.on_event`
* `@server.on_cancel`

There is no public `on_complete` hook.

## Typical Flow

1. Your app creates a task with `agent_name` or `agent_id`.
2. You optionally attach an existing filesystem with `filesystem_id`, or ask Terminal Use to create one from a `project_id`.
3. Terminal Use resolves the target version for the requested branch.
4. The runtime calls `on_create`.
5. Your app sends follow-up events and the runtime calls `on_event`.
6. The agent emits messages and updates state.
7. If the task is cancelled, the runtime calls `on_cancel`.

## What Lives On A Task

| Resource         | Scope                                         |
| ---------------- | --------------------------------------------- |
| Messages         | Per task                                      |
| Events           | Per task                                      |
| State            | Per task and agent                            |
| System folders   | Per task                                      |
| Filesystem mount | Shared only if you attach the same filesystem |

## Filesystem Behavior

If a task has a filesystem, Terminal Use syncs that filesystem into `/workspace` before `on_create` and `on_event`, and syncs changes back after those handlers complete.

`on_cancel` is different: the current runtime registers cancel handlers with sync disabled, so you should not rely on writing files in `on_cancel` and expecting those workspace changes to persist.

If the caller can run the task but does not have filesystem update permission, `/workspace` is mounted read-only. See [Access Control](/concepts/access-control).

## TaskContext

`TaskContext` gives your handler pre-bound helpers for the current task:

* `ctx.task`
* `ctx.agent`
* `ctx.messages`
* `ctx.state`
* `ctx.events`

See [Building Agents](/introduction/building-agents) for examples.

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