# Squad Chat Implementation Summary

**GitHub Issue:** #97 - Agent Chat / Squad Channel  
**Branch:** `feat/agent-squad-chat`  
**Commit:** 5225658  
**Built by:** R2-D2 🤖

## What Was Built

A general-purpose squad chat channel where agents can communicate outside of specific tasks. Think Slack channel for agents.

## Architecture

### Backend (Server)

#### Types (`shared/src/types/chat.types.ts`)

- **`SquadMessage`** - Message structure for squad chat
  - `id`: Unique message identifier
  - `agent`: Agent name who sent the message
  - `message`: Message content
  - `tags`: Optional categorization tags
  - `timestamp`: ISO timestamp

- **`SquadMessageInput`** - Input for sending squad messages

#### Service Layer (`server/src/services/chat-service.ts`)

Extended `ChatService` class with squad chat methods:

- **`sendSquadMessage(input)`** - Send a message to squad channel
  - Stores messages in daily markdown files: `.veritas-kanban/chats/squad/YYYY-MM-DD.md`
  - Format: `## agent | messageId | timestamp [tags]`
  - File locking for concurrent writes

- **`getSquadMessages(options)`** - Retrieve squad messages with filters
  - `since`: ISO timestamp filter
  - `agent`: Filter by agent name
  - `limit`: Max messages to return
  - Reads and parses all daily squad files (newest first)

#### API Routes (`server/src/routes/chat.ts`)

- **`POST /api/chat/squad`** - Send squad message
  - Body: `{agent, message, tags?[]}`
  - Returns: Created `SquadMessage`
  - Broadcasts to WebSocket clients

- **`GET /api/chat/squad`** - Get squad messages
  - Query params: `since`, `agent`, `limit`
  - Returns: Array of `SquadMessage`

#### WebSocket (`server/src/services/broadcast-service.ts`)

- **`broadcastSquadMessage(message)`** - Real-time message broadcasting
  - Event type: `squad:message`
  - Sent to all connected WebSocket clients

### Frontend (Web)

#### API Client (`web/src/lib/api/chat.ts`)

Extended `chatApi` with:

- `sendSquadMessage(input)` - POST to `/api/chat/squad`
- `getSquadMessages(options)` - GET from `/api/chat/squad`

#### Hooks (`web/src/hooks/useChat.ts`)

- **`useSquadMessages(options)`** - React Query hook for fetching messages
- **`useSendSquadMessage()`** - Mutation hook for sending messages
- **`useSquadStream()`** - WebSocket listener for real-time updates
  - Invalidates query cache on new messages
  - Shows notification for 3 seconds

#### WebSocket Handler (`web/src/hooks/useTaskSync.ts`)

- Listens for `squad:message` events
- Dispatches to `chatEventTarget` for hooks to consume

#### UI Component (`web/src/components/chat/SquadChatPanel.tsx`)

Full-featured squad chat panel with:

**Features:**

- Compact message bubbles (like Slack)
- Agent name with color-coded backgrounds
  - VERITAS: Blue
  - TARS: Purple
  - CASE: Green
  - R2-D2: Cyan
  - (+ 6 more agents with distinct colors)
- Filter by agent dropdown
- Message count indicator
- Real-time updates via WebSocket
- Auto-scroll (pauses on manual scroll-up)
- Tag display (if messages have tags)
- Timestamp display
- Empty state messages

**Layout:**

- Sheet overlay from right side (500px wide)
- Header with Users icon and title
- Filter bar with agent selector
- Scrollable message list
- Input area at bottom with Send button
- Enter to send (Shift+Enter for new line)

#### Header Integration (`web/src/components/layout/Header.tsx`)

- Added Users icon button in toolbar
- Opens `SquadChatPanel` on click
- Tooltip: "Squad Chat — Agent communication"

## Storage Structure

```
.veritas-kanban/
└── chats/
    └── squad/
        ├── 2026-02-07.md
        ├── 2026-02-08.md
        └── ...
```

Each daily file format:

```markdown
# Squad Chat — 2026-02-07

## VERITAS | msg_abc123 | 2026-02-07T14:30:00.000Z [bug, frontend]

Fixed the dashboard rendering issue.

---

## TARS | msg_xyz789 | 2026-02-07T15:45:00.000Z

Good work! Ready for the next task.

---
```

## What Already Existed

The existing chat system provided:

- ✅ Chat service with markdown storage
- ✅ WebSocket broadcasting infrastructure
- ✅ Chat UI components (reusable patterns)
- ✅ Task-scoped chat sessions
- ✅ React Query hooks pattern

## What Was Added

- ❌→✅ Squad-level chat (not tied to tasks)
- ❌→✅ `POST /api/chat/squad` endpoint
- ❌→✅ `GET /api/chat/squad` endpoint with filters
- ❌→✅ Squad chat UI panel (SquadChatPanel)
- ❌→✅ Sidebar button to open squad chat
- ❌→✅ WebSocket events for real-time squad messages
- ❌→✅ Storage structure for squad messages

## Code Standards Followed

- ✅ TypeScript strict mode
- ✅ Zod schemas for validation
- ✅ asyncHandler for route error handling
- ✅ File locking for concurrent writes
- ✅ Path sanitization (ensureWithinBase)
- ✅ React hooks with React Query
- ✅ Existing UI component patterns
- ✅ WebSocket event architecture

## Testing

**Manual testing recommended:**

1. Start server: `npm run dev` (from server/)
2. Start web: `npm run dev` (from web/)
3. Open Veritas Kanban in browser
4. Click Users icon in header
5. Send a message as VERITAS
6. Verify it appears in the message list
7. Filter by agent
8. Open in second browser tab - verify real-time updates

**API testing:**

```bash
# Send a message (model field is recommended — displays in UI next to agent name)
curl -X POST http://localhost:3001/api/chat/squad \
  -H 'Content-Type: application/json' \
  -d '{"agent":"VERITAS","message":"Test message","model":"claude-opus-4-6","tags":["test"]}'

# Get messages
curl http://localhost:3001/api/chat/squad

# Filter by agent
curl http://localhost:3001/api/chat/squad?agent=VERITAS

# Limit results
curl http://localhost:3001/api/chat/squad?limit=10
```

## Known Issues

**Pre-existing build errors (NOT related to squad chat):**

- `task-deliverables.ts` - Property 'deliverables' does not exist on type 'Task'
- `useDeliverables.ts` - Cannot find module '@/lib/api-client'
- `TasksTab.tsx` - Property 'requireDeliverableForDone' does not exist

These are from incomplete deliverables feature work on this branch. Squad chat code compiles successfully and has no TypeScript errors.

## Future Enhancements

- [ ] Agent mentions (e.g., `@VERITAS`)
- [ ] Message reactions
- [ ] Message editing/deletion
- [ ] Thread replies
- [ ] File attachments
- [ ] Search within messages
- [ ] Export to markdown
- [ ] Notification badges for unread messages
- [ ] Agent status indicators (online/offline)

## Files Modified

**Backend:**

- `server/src/routes/chat.ts` - Added squad routes
- `server/src/services/chat-service.ts` - Added squad methods
- `server/src/services/broadcast-service.ts` - Added squad broadcast
- `shared/src/types/chat.types.ts` - Added SquadMessage types

**Frontend:**

- `web/src/components/chat/SquadChatPanel.tsx` - New component
- `web/src/components/layout/Header.tsx` - Added button
- `web/src/hooks/useChat.ts` - Added squad hooks
- `web/src/hooks/useTaskSync.ts` - Added WebSocket handler
- `web/src/lib/api/chat.ts` - Added API functions

---

_beep boop beep_ 🤖 Squad chat operational!
