# Detailed Functional Requirements - Part 2: Links, Agents, Graph

**Date**: 2025-11-22  
**Version**: 2.0 (EXTENDED)  
**Status**: APPROVED

---

## FR-2: LINK MANAGEMENT (EXTENDED)

### FR-2.1: Create Link (DETAILED)

**Description**: Users can create links between items representing dependencies, relationships, and workflow connections with comprehensive metadata and validation.

**Link Types**:
1. **DEPENDS_ON**: Item A depends on Item B (B must be done before A)
2. **BLOCKS**: Item A blocks Item B (A must be done before B)
3. **RELATES_TO**: Item A relates to Item B (informational relationship)
4. **IMPLEMENTS**: Item A implements Item B (A is implementation of B)
5. **TESTS**: Item A tests Item B (A is test for B)
6. **DOCUMENTS**: Item A documents Item B (A is documentation for B)
7. **DUPLICATES**: Item A duplicates Item B (same work)
8. **SUPERSEDES**: Item A supersedes Item B (A replaces B)

**Detailed Acceptance Criteria**:
- [ ] User can create link with type (8 types supported)
- [ ] User can select source item (required)
- [ ] User can select target item (required)
- [ ] User can add link metadata (key-value pairs, max 20 pairs)
- [ ] User can add link description (0-500 chars, optional)
- [ ] User can set link priority (LOW, MEDIUM, HIGH, CRITICAL)
- [ ] User can set link status (ACTIVE, INACTIVE, BLOCKED)
- [ ] Link is assigned unique UUID (v4)
- [ ] Link creation timestamp recorded (UTC)
- [ ] Link creator recorded (from JWT token)
- [ ] Link appears in graph visualization immediately
- [ ] Link appears in both items' link lists
- [ ] Circular dependencies detected and warned
- [ ] Circular dependencies prevented (configurable)
- [ ] Link is bidirectional (both directions visible)
- [ ] Link appears in real-time (all connected clients)
- [ ] User receives confirmation notification (toast)
- [ ] Link appears in activity feed
- [ ] Link indexed for search
- [ ] Link version history initialized
- [ ] Link change log initialized
- [ ] Link audit trail initialized
- [ ] Duplicate links prevented (same source, target, type)
- [ ] Self-links prevented (source != target)
- [ ] Link impact calculated (affected items)
- [ ] Link risk level calculated

**Circular Dependency Detection**:
- Algorithm: Depth-first search (DFS)
- Detection: Before link creation
- Cycle path: Returned to user
- Prevention: Configurable (warn or block)
- Performance: <100ms for 1000+ items

**Link Metadata**:
- Custom key-value pairs (max 20 pairs)
- Each key: 1-50 chars
- Each value: 1-500 chars
- Supports: String, Number, Boolean, Date
- Validation: Type checking

**API Endpoint**: `POST /api/links`

**Request Body**:
```json
{
  "type": "DEPENDS_ON|BLOCKS|RELATES_TO|IMPLEMENTS|TESTS|DOCUMENTS|DUPLICATES|SUPERSEDES",
  "sourceId": "uuid",
  "targetId": "uuid",
  "description": "string (0-500)",
  "priority": "LOW|MEDIUM|HIGH|CRITICAL",
  "status": "ACTIVE|INACTIVE|BLOCKED",
  "metadata": {
    "key": "value"
  }
}
```

**Response**:
```json
{
  "id": "uuid",
  "type": "string",
  "sourceId": "uuid",
  "sourceTitle": "string",
  "targetId": "uuid",
  "targetTitle": "string",
  "description": "string",
  "priority": "string",
  "status": "string",
  "metadata": {},
  "createdAt": "ISO8601",
  "createdBy": "uuid",
  "version": 1,
  "circularDependency": false,
  "affectedItems": ["uuid"],
  "riskLevel": "LOW|MEDIUM|HIGH|CRITICAL"
}
```

**GraphQL Mutation**:
```graphql
mutation CreateLink($input: CreateLinkInput!) {
  createLink(input: $input) {
    id
    type
    source {
      id
      title
    }
    target {
      id
      title
    }
    description
    priority
    status
    metadata
    createdAt
    createdBy {
      id
      name
    }
    version
    circularDependency
    affectedItems {
      id
      title
    }
    riskLevel
  }
}

input CreateLinkInput {
  type: LinkType!
  sourceId: UUID!
  targetId: UUID!
  description: String
  priority: Priority
  status: LinkStatus
  metadata: JSON
}
```

**tRPC Procedure**: `links.create`

**Validation Rules**:
- Type: Required, must be valid enum value
- Source ID: Required, must be valid item UUID
- Target ID: Required, must be valid item UUID
- Source != Target (no self-links)
- Both items must exist
- Both items must be in same organization
- No duplicate links (same source, target, type)
- Description: Max 500 chars
- Priority: Valid enum value
- Status: Valid enum value
- Metadata: Max 20 key-value pairs

**Error Handling**:
- 400: Invalid input (validation error)
- 401: Unauthorized (not authenticated)
- 403: Forbidden (no permission to create links)
- 404: Not found (source or target item doesn't exist)
- 409: Conflict (duplicate link, circular dependency, self-link)
- 500: Server error

**Real-Time Events**:
- `links:created` - Broadcast to all connected clients
- `items:link-added` - Broadcast to source and target items
- `activity:link-created` - Add to activity feed
- `graph:update` - Update graph visualization

**Notifications**:
- Toast: "Link created successfully"
- Email: Send to assignees of both items (if configured)
- Slack: Send to team channel (if configured)

**Audit Trail**:
- Action: CREATE
- Entity: Link
- EntityId: UUID
- UserId: Creator UUID
- Timestamp: UTC
- Changes: All fields

**Performance Requirements**:
- Response time: <100ms (p95)
- Circular dependency detection: <100ms
- Database write: <50ms
- Real-time broadcast: <100ms

---

### FR-2.2: Graph Visualization (DETAILED)

**Description**: System renders interactive graph visualization of all items and links with support for 1000+ nodes, real-time updates, filtering, and advanced interactions.

**Graph Features**:
- **Rendering**: Cytoscape.js with force-directed layout
- **Nodes**: 1000+ items rendered as nodes
- **Edges**: Links rendered as edges
- **Layout**: Force-directed (physics-based)
- **Performance**: Optimized for large graphs
- **Interactivity**: Pan, zoom, drag, select
- **Real-Time**: Updates within 100ms
- **Filtering**: By type, status, link type
- **Search**: Full-text search with highlighting
- **Export**: PNG, SVG, JSON formats

**Detailed Acceptance Criteria**:
- [ ] Graph renders all items as nodes
- [ ] Graph renders all links as edges
- [ ] Graph handles 1000+ nodes without lag
- [ ] Graph uses force-directed layout (physics-based)
- [ ] Graph is interactive (pan, zoom, drag)
- [ ] Graph performance optimized (<60fps)
- [ ] Node colors represent item type
- [ ] Node size represents estimated effort
- [ ] Node border color represents status
- [ ] Edge colors represent link type
- [ ] Edge thickness represents priority
- [ ] Edge arrows show direction
- [ ] Hover shows node/edge details
- [ ] Click node to view item details
- [ ] Click edge to view link details
- [ ] Right-click node for context menu
- [ ] Right-click edge for context menu
- [ ] Select multiple nodes (Ctrl+Click)
- [ ] Select multiple edges (Ctrl+Click)
- [ ] Drag node to reposition
- [ ] Drag selection to move multiple nodes
- [ ] Zoom in/out (mouse wheel, buttons)
- [ ] Pan (middle mouse, space+drag)
- [ ] Fit to screen (button)
- [ ] Reset view (button)
- [ ] Filter by item type
- [ ] Filter by item status
- [ ] Filter by link type
- [ ] Search items (full-text)
- [ ] Highlight search results
- [ ] Show/hide isolated nodes
- [ ] Show/hide archived items
- [ ] Show/hide inactive links
- [ ] Layout options (force-directed, hierarchical, circular)
- [ ] Export as PNG
- [ ] Export as SVG
- [ ] Export as JSON
- [ ] Real-time updates (new nodes, edges)
- [ ] Real-time updates (node/edge changes)
- [ ] Real-time updates (node/edge deletions)
- [ ] Performance metrics (FPS, node count, edge count)
- [ ] Accessibility (keyboard navigation, screen reader)

**Node Styling**:
```javascript
{
  // Node colors by type
  REQUIREMENT: '#3B82F6',    // Blue
  DESIGN: '#8B5CF6',         // Purple
  IMPLEMENTATION: '#10B981', // Green
  TEST: '#F59E0B',           // Amber
  DEPLOYMENT: '#EF4444',     // Red

  // Node size by effort
  1-10: 20px,
  11-30: 30px,
  31-60: 40px,
  61-100: 50px,

  // Node border by status
  DRAFT: 'dashed',
  ACTIVE: 'solid',
  ARCHIVED: 'dotted'
}
```

**Edge Styling**:
```javascript
{
  // Edge colors by type
  DEPENDS_ON: '#3B82F6',     // Blue
  BLOCKS: '#EF4444',         // Red
  RELATES_TO: '#6B7280',     // Gray
  IMPLEMENTS: '#10B981',     // Green
  TESTS: '#F59E0B',          // Amber
  DOCUMENTS: '#8B5CF6',      // Purple
  DUPLICATES: '#EC4899',     // Pink
  SUPERSEDES: '#14B8A6',     // Teal

  // Edge thickness by priority
  LOW: 1px,
  MEDIUM: 2px,
  HIGH: 3px,
  CRITICAL: 4px
}
```

**Performance Optimization**:
- Viewport culling (only render visible nodes)
- Level of detail (LOD) rendering
- Lazy loading of node details
- Debounced pan/zoom events
- Cached layout calculations
- Web Workers for layout computation
- Virtual scrolling for large lists

**API Endpoints**:
- `GET /api/graph` - Get graph data (nodes, edges)
- `GET /api/graph/layout` - Get layout positions
- `POST /api/graph/layout` - Save layout positions
- `GET /api/graph/export` - Export graph (PNG, SVG, JSON)

**GraphQL Query**:
```graphql
query GetGraph($filter: GraphFilter, $layout: LayoutType) {
  graph(filter: $filter, layout: $layout) {
    nodes {
      id
      title
      type
      status
      priority
      estimatedEffort
      x
      y
    }
    edges {
      id
      type
      source
      target
      priority
      status
    }
    stats {
      nodeCount
      edgeCount
      avgDegree
      density
    }
  }
}

input GraphFilter {
  itemTypes: [ItemType!]
  itemStatuses: [ItemStatus!]
  linkTypes: [LinkType!]
  searchQuery: String
  includeArchived: Boolean
  includeInactive: Boolean
}

enum LayoutType {
  FORCE_DIRECTED
  HIERARCHICAL
  CIRCULAR
  GRID
}
```

**Real-Time Updates**:
- Subscribe to graph changes
- Broadcast node additions
- Broadcast node updates
- Broadcast node deletions
- Broadcast edge additions
- Broadcast edge updates
- Broadcast edge deletions
- Animate transitions

**Performance Requirements**:
- Initial load: <2 seconds (1000 nodes)
- Pan/zoom: 60 FPS
- Node drag: 60 FPS
- Real-time updates: <100ms
- Search: <500ms
- Export: <2 seconds

---

## FR-3: AGENT MANAGEMENT (EXTENDED)

### FR-3.1: Agent Registration (DETAILED)

**Description**: Agents can register with the system and establish persistent connections for real-time work coordination.

**Detailed Acceptance Criteria**:
- [ ] Agent can register with name (1-100 chars)
- [ ] Agent can register with credentials (API key or OAuth)
- [ ] Agent can register with capabilities (list of supported operations)
- [ ] Agent can register with metadata (custom key-value pairs)
- [ ] Agent receives unique agent ID (UUID)
- [ ] Agent receives API key (for authentication)
- [ ] Agent status set to IDLE
- [ ] Agent connection tracked (IP, user agent, timestamp)
- [ ] Agent heartbeat monitored (every 30 seconds)
- [ ] Agent heartbeat timeout (5 minutes)
- [ ] Agent registration logged in audit trail
- [ ] Agent registration notification sent
- [ ] Agent appears in agents list
- [ ] Agent appears in real-time (all connected clients)
- [ ] Agent can update registration
- [ ] Agent can revoke API key
- [ ] Agent can generate new API key
- [ ] Multiple agents per user supported
- [ ] Agent rate limiting (100 requests/minute)
- [ ] Agent quota management (max 100 agents per organization)

**Agent Capabilities**:
- `read:items` - Read items
- `write:items` - Create/update items
- `delete:items` - Delete items
- `read:links` - Read links
- `write:links` - Create/update links
- `delete:links` - Delete links
- `read:agents` - Read agents
- `write:agents` - Update agents
- `execute:quality-checks` - Run quality checks
- `resolve:conflicts` - Resolve conflicts
- `manage:integrations` - Manage integrations

**API Endpoint**: `POST /api/agents/register`

**Request Body**:
```json
{
  "name": "string (1-100)",
  "capabilities": ["string"],
  "metadata": {
    "key": "value"
  }
}
```

**Response**:
```json
{
  "id": "uuid",
  "name": "string",
  "apiKey": "string",
  "capabilities": ["string"],
  "metadata": {},
  "status": "IDLE",
  "createdAt": "ISO8601",
  "expiresAt": "ISO8601",
  "registrationToken": "string"
}
```

**GraphQL Mutation**:
```graphql
mutation RegisterAgent($input: RegisterAgentInput!) {
  registerAgent(input: $input) {
    id
    name
    apiKey
    capabilities
    metadata
    status
    createdAt
    expiresAt
    registrationToken
  }
}

input RegisterAgentInput {
  name: String!
  capabilities: [String!]!
  metadata: JSON
}
```

**tRPC Procedure**: `agents.register`

**Authentication**:
- API Key: Bearer token in Authorization header
- OAuth: OAuth 2.0 token
- JWT: JWT token from WorkOS

**Heartbeat Mechanism**:
- Interval: 30 seconds
- Timeout: 5 minutes
- Failure: Mark agent as offline
- Recovery: Automatic reconnection

**API Key Management**:
- Generate: Random 32-character string
- Rotation: Every 90 days
- Revocation: Immediate
- Expiration: 1 year

**Error Handling**:
- 400: Invalid input (validation error)
- 401: Unauthorized (not authenticated)
- 403: Forbidden (no permission to register agents)
- 409: Conflict (duplicate agent name)
- 429: Too many requests (rate limit exceeded)
- 500: Server error

**Audit Trail**:
- Action: REGISTER
- Entity: Agent
- EntityId: UUID
- UserId: Registering user UUID
- Timestamp: UTC
- Changes: All fields

**Performance Requirements**:
- Response time: <100ms (p95)
- Database write: <50ms
- API key generation: <10ms

---

### FR-3.2: Agent Status (DETAILED)

**Description**: System tracks agent status in real-time with comprehensive monitoring and alerting.

**Agent Status Values**:
1. **IDLE**: Agent is online and ready to work
2. **WORKING**: Agent is actively working on an item
3. **ERROR**: Agent encountered an error
4. **OFFLINE**: Agent is offline (no heartbeat)
5. **PAUSED**: Agent is paused (manual)
6. **MAINTENANCE**: Agent is in maintenance mode

**Detailed Acceptance Criteria**:
- [ ] Agent status tracked in real-time
- [ ] Agent status: IDLE, WORKING, ERROR, OFFLINE, PAUSED, MAINTENANCE
- [ ] Agent last_seen timestamp updated (every heartbeat)
- [ ] Agent current_item tracked (item being worked on)
- [ ] Agent status visible in UI (all connected clients)
- [ ] Agent status changes broadcast in real-time (<100ms)
- [ ] Agent status history tracked (last 100 status changes)
- [ ] Agent status transitions validated
- [ ] Agent status transitions logged
- [ ] Agent error details tracked (error message, stack trace)
- [ ] Agent error notifications sent
- [ ] Agent offline detection (5 minute timeout)
- [ ] Agent offline notifications sent
- [ ] Agent recovery automatic (reconnection)
- [ ] Agent recovery notifications sent
- [ ] Agent metrics tracked (items completed, errors, uptime)
- [ ] Agent metrics visible in dashboard
- [ ] Agent health calculated (based on metrics)
- [ ] Agent health status: HEALTHY, WARNING, CRITICAL
- [ ] Agent health alerts triggered

**Status Transitions**:
```
IDLE
  ├─ claimWork() → WORKING
  ├─ pause() → PAUSED
  ├─ maintenance() → MAINTENANCE
  └─ disconnect() → OFFLINE

WORKING
  ├─ updateProgress() → WORKING
  ├─ completeWork() → IDLE
  ├─ error() → ERROR
  ├─ pause() → PAUSED
  └─ disconnect() → OFFLINE

ERROR
  ├─ retry() → WORKING
  ├─ reset() → IDLE
  ├─ pause() → PAUSED
  └─ disconnect() → OFFLINE

PAUSED
  ├─ resume() → IDLE (or WORKING if was working)
  └─ disconnect() → OFFLINE

MAINTENANCE
  ├─ complete() → IDLE
  └─ disconnect() → OFFLINE

OFFLINE
  └─ reconnect() → IDLE (or WORKING if was working)
```

**API Endpoint**: `GET /api/agents/:id/status`

**Response**:
```json
{
  "id": "uuid",
  "name": "string",
  "status": "IDLE|WORKING|ERROR|OFFLINE|PAUSED|MAINTENANCE",
  "lastSeen": "ISO8601",
  "currentItemId": "uuid",
  "currentItemTitle": "string",
  "error": {
    "message": "string",
    "stackTrace": "string",
    "timestamp": "ISO8601"
  },
  "metrics": {
    "itemsCompleted": "number",
    "itemsFailed": "number",
    "averageTime": "number",
    "uptime": "number"
  },
  "health": {
    "status": "HEALTHY|WARNING|CRITICAL",
    "issues": ["string"]
  },
  "statusHistory": [
    {
      "status": "string",
      "timestamp": "ISO8601",
      "reason": "string"
    }
  ]
}
```

**GraphQL Query**:
```graphql
query GetAgentStatus($id: UUID!) {
  agent(id: $id) {
    id
    name
    status
    lastSeen
    currentItem {
      id
      title
    }
    error {
      message
      stackTrace
      timestamp
    }
    metrics {
      itemsCompleted
      itemsFailed
      averageTime
      uptime
    }
    health {
      status
      issues
    }
    statusHistory {
      status
      timestamp
      reason
    }
  }
}
```

**WebSocket Event**:
```javascript
// Subscribe to agent status changes
socket.on('agent:status-changed', (data) => {
  console.log(`Agent ${data.agentId} status changed to ${data.status}`);
  // Update UI
});

// Broadcast event
{
  type: 'agent:status-changed',
  agentId: 'uuid',
  status: 'WORKING',
  currentItemId: 'uuid',
  timestamp: 'ISO8601'
}
```

**Real-Time Updates**:
- Subscribe to agent status changes
- Broadcast status changes to all connected clients
- Animate status transitions
- Show status history

**Monitoring & Alerting**:
- Alert: Agent offline (5 minute timeout)
- Alert: Agent error (immediate)
- Alert: Agent health critical (based on metrics)
- Alert: Agent quota exceeded (100 agents per org)

**Performance Requirements**:
- Status update: <50ms
- Real-time broadcast: <100ms
- Status history query: <200ms
- Metrics calculation: <500ms


