# Plan

The `plan` tool maintains a durable epic/task ledger in `ultimate.plan`.
Task-owned descendants read their top owner's ledger. Only that owner edits it.
Ownerless conversations maintain separate ledgers.

Edits and receipts commit together. Memo namespaces distinguish nested calls that share a task.
The tool returns both JSON text and structured content.
The compact prompt section excludes completed epics.

The root document `ultimate.plan.tasks` indexes linked child conversations.
A new link or task title change updates the child's metadata title.
Other edits preserve a title that the user supplied.

The first input of a new lineage branch clears its inherited plan atomically.
The hook preserves a branch's plan if the branch already answered.
The reader uses the existing `lineage.branch` document contract without requiring the lineage extension.

`host/tests/plan_todos.rs` verifies the port through the world extension loader.