pi-tasklists

Multi-list task management for the Pi coding agent. Where a single global todo list is limiting, pi-tasklists lets you segregate tasks into named contexts — work, personal, project-x — and switch between them. It registers a todo tool the model can call and /tasklist, /tasklists, /todos commands for you.

State lives in the session (not external files), so it stays correct across branching, reload, and compaction — the same pattern as the SDK's examples/extensions/todo.ts.

Features

• Multiple named lists — keep separate task lists and switch the active context.
• todo tool — the model manages tasks via create, update, list, get, delete, clear. Pass listId to target a specific list, or omit it to use the active one.
• Rich task fields — subject, description, status (pending / in_progress / completed / deleted), activeForm, owner, blockedBy, metadata.
• Survives reload & compaction — tasks are rebuilt from each tool result's details snapshot, and the active list is persisted as a session entry. Compaction never loses your lists or which one is active.
• Session isolation — state is per-session; /new, /resume, and /fork don't leak tasks between sessions.
• PI_TASKLIST_ID — seeds the initial active list (fallback only; a saved /tasklist choice always wins on resume).

Installation

Install from this repo as a Pi package:

pi install git:github.com/strugglingcomic/pi-tasklists

Or load a local checkout directly:

pi -e ./src/index.ts

Or place the package under ~/.pi/agent/extensions/ (global) or .pi/extensions/ (project-local) for auto-discovery and /reload support.

Usage

Commands

Command	Description
/tasklist <name>	Switch the active tasklist (creates it if new).
/tasklists	List all tasklists, marking the active one with * and showing open-task counts.
/todos	Show the active list's tasks, grouped by status.

The todo tool

The model calls todo with an action:

{ "action": "create", "subject": "Write the migration" }
{ "action": "create", "listId": "work", "subject": "Review PR #42" }
{ "action": "update", "id": 1, "status": "in_progress", "activeForm": "Writing the migration" }
{ "action": "list", "status": "pending" }
{ "action": "delete", "id": 1 }
{ "action": "clear" }

A bare listId on a todo call targets that list without changing your active context; use /tasklist to switch the active list.

Environment

PI_TASKLIST_ID=work pi

Starts with work as the active list. This is only a fallback — once you switch lists with /tasklist, that choice is what's restored on resume.

How state survives compaction

Compaction doesn't delete session entries; it only changes what the LLM sees. On every session_start / session_tree, the extension rebuilds state from ctx.sessionManager.getBranch():

• Each todo tool result carries a details snapshot of the single list it touched (listId, tasks, nextId). Replaying these per-listId (last-write-wins) reconstructs every list and keeps sibling lists independent under branching.
• /tasklist writes a pi-tasklists:active-list custom entry via pi.appendEntry, so the active list is restored too.

All state transitions go through a pure reducer — no in-place mutation.

Development

Runtime needs no build step: Pi loads the TypeScript directly via jiti. To typecheck:

npm install   # pulls peer deps for type resolution
npm run typecheck

Layout

src/
├── index.ts            # Default-export factory; wires events, tool, commands
├── state/
│   ├── types.ts        # Task, TaskList, GlobalState, details/entry types
│   ├── reducer.ts      # Pure immutable state transitions
│   ├── store.ts        # Per-load state holder
│   └── replay.ts       # Rebuild GlobalState from the session branch
├── tool/todo.ts        # `todo` tool (pi.registerTool, TypeBox params)
└── view/commands.ts    # /tasklist, /tasklists, /todos (pi.registerCommand)

See spec.md for the full technical specification.

License

MIT