# Task Planning Workflow

## Overview

Planning is a **PM activity**. When a PM (Cell PM or Main PM) picks up a coordination or parent task, they record a plan with `i_will_plan` and then fan the work out into subtasks with `delegate`.

```
triage / give_me_work → i_will_plan → delegate (one per subtask) → i_am_idle
```

Developers do not have a separate planning verb — they pass a short `plan` argument directly to `i_will_work_on(task_id, plan="...")` when they claim a coding task.

## Submitting a Plan (PM)

```python
i_will_plan(
    task_id="<task>",
    plan="One-paragraph summary of how this work will be broken down",
    approach="High-level implementation strategy",
    sub_tasks=[
        "UX/UI: design the settings panel",
        "Frontend: wire the panel to the API",
        "Backend: add the settings endpoint",
    ],
    technical_considerations=["Reuse the existing config service"],
    risks=["Frontend depends on the UX design landing first"],
    open_questions=["Confirm the default toggle state with the CEO"],
)
```

After `i_will_plan`, the envelope's `next` field points you at `delegate` — create one subtask per unit of work. **A "unit of work" is the LARGEST coherent piece one dev can own end-to-end, not the smallest step you can name (CEO doctrine: never over-separate).** Single-concern work — a dependency bump, a config change, one component — is one subtask covering the change, its verification, and the PR. Sequenced same-branch steps are one subtask, not siblings; split only for genuine parallelism across devs or different owners. The `sub_tasks` checklist above may hold more steps than you delegate — several checklist steps usually collapse into one delegated task:

```python
delegate(
    parent_task_id="<task>",
    title="Add the settings endpoint",
    description="...",
    assigned_to="be-dev-1",
    team="backend",
    task_type="code",
    nature="feature",
    estimated_complexity="medium",
    acceptance_criteria=["Endpoint returns 200 with the saved settings"],
    covers_parent_criteria=["<parent-ac-id>"],
)
```

## Acceptance-Criteria Coverage

When you decompose a parent task, declare which parent criteria each subtask is responsible for with **`covers_parent_criteria`** (a list of the parent's `acceptance_criteria_ids`). This is what lets the org prove a decomposition covers the parent's full intent — and it drives two gates and your coverage briefing.

After `i_will_plan` and after each `delegate`, your envelope carries a coverage view of the parent so you can see what is still unmapped:

- **`parent_ac_coverage`** — one entry per parent criterion: its `id`, `text`, whether a live subtask `claimed` it, and whether a completed subtask `verified` it.
- **`unclaimed_parent_acs`** — the parent criterion ids that no live subtask covers yet. Keep delegating until this is empty.

Two gates build on the coverage link:

- **Decomposition floor** — you cannot go `i_am_idle` on a parent while a criterion is still unclaimed. Delegate (or `reassign`) subtasks until every criterion is covered.
- **Roll-up gate** — a parent cannot `complete`, `submit_up`, or `escalate_to_ceo` unless every criterion traces to a child that **passed QA** on it.

Both gates are **safe-by-construction**: they stay inert until you start declaring `covers_parent_criteria`, so a decomposition that never declares coverage is never blocked. Declaring coverage is how you opt your parent into the guarantee.

## Delegating Code Work: Per-Dev Queues

For code subtasks, delegate each developer their **full queue up front** rather than one task at a time. Both of a cell's developers build in parallel, and each works its own queue one task at a time, in order:

- A per-lane dispatch barrier holds a developer's later subtasks until their current one is in flight — so each dev's lane stays sequenced while the two devs run concurrently.
- Leaf PRs are still merged into the shared cell branch **in sequence**, not in parallel.
- Order the queue by dependency: the subtask others build on goes first.

Caps still apply: at most 12 subtasks per parent, and same-title duplicate subtasks are rejected.

## PMs Do Not Own Code Tasks

A PM (Cell PM or Main PM) is a coordinator — it plans and delegates, it does not write code, and it has no code verb. The role×task_type rule is enforced at **creation**, not just at delegate:

- A `code`-typed task **cannot be assigned to a PM** — `delegate`, `TaskService.create`, batch activation, reassign, and the claim/escalation diversion all consult the same `pm_cannot_own_code` / `main_pm_cannot_own_code` guard and reject it.
- A Main-PM coordination **root** that is `code`-typed is rejected by `submit_root`'s `PRECONDITION_ROOT_NOT_CODE` — a Main PM can never assemble+merge a code root, because it can't have written one.
- The one exception — "a PM may take a code task **only to resolve review issues**" (`is_issue_resolution`) — is a server-side signal the platform sets when routing a `needs_revision` code task back to its owning PM to act on concrete review issues; it is **not** something you pass from a verb. In practice no live path exercises it yet; the structural rule is: if you're a PM and you're looking at a `code` task, delegate it to a developer instead.

This is structural, not a hint. Before this guard, a PM assigned a code task would claim it and deadlock into a respawn loop — a coordinator with no code verb holding a code task it can neither do nor hand back. The guard makes that loop unrepresentable.

## Delegation Depth

The task hierarchy is capped at `MAX_TASK_DEPTH = 4` levels (depths 0–3). The normal 3-layer flow (Main-PM root → cell task → dev subtask) fits in 3; **MegaTask** adds one Main-PM layer on top — umbrella (depth 0) → root-subtask (1) → cell task (2) → dev subtask (3) — which is why the cap is 4, not 3. A `delegate` that would create a node at depth 4 is rejected with a clean `invalid_state` and a "create as a sibling" remediation. Don't over-nest; if you're hitting the cap, the work belongs as a sibling, not a child.

## Git Workflow

All code tasks follow the git workflow:
- **Branches are auto-created when a developer claims the task** via `i_will_work_on` — no manual branch creation
- Root tasks: branch created from the default branch (main/master)
- Subtasks: branch forked from the parent's branch

Coordination/parent tasks that only plan and delegate (no code) do not need a branch of their own.

Hierarchical branch naming uses `--` between task IDs to avoid git ref conflicts: `feature/{team}/{ROOT}--{SUB}--{SUBSUB}`.