com.paca.checklist

First-party Paca plugin that adds checklist support to tasks.
Each task can have multiple checklists, and each checklist can have multiple items that can be checked off, assigned to a project member, and reordered by position.

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Architecture

The plugin follows the standard two-part plugin structure:

checklist/
├── backend/   — Go WASM plugin (runs inside the API host)
└── frontend/  — React micro-frontend (Module Federation remote)

Backend (backend/)

• Written in Go, compiled to wasip1/wasm for production.
• Registered as com.paca.checklist in the plugin registry.
• Owns its database schema (plugin_data_com_paca_checklist) and runs its own migration on startup.
• Listens on the task.deleted event to cascade-delete orphaned checklists.

Frontend (frontend/)

• Vite + React + TanStack Query.
• Exposed as a Module Federation remote (com_paca_checklist/ChecklistsSection).
• Rendered by the host app via the task.detail.section extension point.
• Communicates with the backend through the standard plugin API path:
  GET|POST|PATCH|DELETE /api/v1/plugins/com.paca.checklist/projects/:projectId/tasks/:taskId/checklists/…

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API Endpoints

All routes are prefixed with /projects/:projectId by the host.
The caller must be an authenticated member of the project.

Method	Path	Description
GET	/tasks/:taskId/checklists	List all checklists (with items) for a task
POST	/tasks/:taskId/checklists	Create a checklist
PATCH	/tasks/:taskId/checklists/:checklistId	Rename a checklist
DELETE	/tasks/:taskId/checklists/:checklistId	Delete a checklist and all its items
POST	/tasks/:taskId/checklists/:checklistId/items	Add an item to a checklist
PATCH	/tasks/:taskId/checklists/:checklistId/items/:itemId	Update an item (title / checked state / assignee)
DELETE	/tasks/:taskId/checklists/:checklistId/items/:itemId	Delete an item

Request / Response examples

Create checklist — POST /tasks/:taskId/checklists

{ "title": "Definition of Done" }

{
  "data": {
    "id": "a1b2c3d4-…",
    "task_id": "…",
    "title": "Definition of Done",
    "position": 0,
    "items": [],
    "created_at": "2026-05-05T10:00:00Z",
    "updated_at": "2026-05-05T10:00:00Z"
  }
}

Toggle item — PATCH /tasks/:taskId/checklists/:checklistId/items/:itemId

{ "is_checked": true }

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Database Schema

Tables live in the plugin_data_com_paca_checklist schema and are created by backend/migrations/0001_create_task_checklists.sql.

task_checklists
  id          UUID PK
  task_id     UUID → public.tasks(id) ON DELETE CASCADE
  title       TEXT
  position    INTEGER
  created_by  UUID → public.project_members(id)
  created_at  TIMESTAMPTZ
  updated_at  TIMESTAMPTZ

task_checklist_items
  id           UUID PK
  checklist_id UUID → task_checklists(id) ON DELETE CASCADE
  title        TEXT
  is_checked   BOOLEAN
  assignee_id  UUID → public.project_members(id)
  position     INTEGER
  created_by   UUID → public.project_members(id)
  created_at   TIMESTAMPTZ
  updated_at   TIMESTAMPTZ

The legacy public.task_checklists and public.task_checklist_items tables are dropped by core migration 000005_migrate_checklists_to_plugin.sql.

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Development

Backend

cd backend

# Run tests
go test -v ./...

# Build WASM binary (requires Go 1.24+)
GOOS=wasip1 GOARCH=wasm go build -buildmode=c-shared -o checklist.wasm .

Frontend

cd frontend

# Install dependencies
bun install

# Development build (watch)
bun run dev

# Production build (outputs remoteEntry.js)
bun run build

The frontend uses the @paca-ai/plugin-sdk-react package (resolved locally from plugins/sdk/frontend).
Shared singletons (react, react-dom, @tanstack/react-query) are provided by the host shell and must not be bundled.

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Extension Point

The frontend is mounted by the host at:

task.detail.section

Component props passed by the host:

Prop	Type	Description
projectId	string	Current project ID
taskId	string	Current task ID
canEdit	boolean	Whether the caller has write permission