Feature: Add webhook/real-time update support

[basher83]

Feature Request

Implement webhook support to enable real-time updates and event-driven workflows with the Zammad system.

Motivation

Currently, the MCP server only supports polling-based interactions. Real-time updates would enable:

• Instant notifications for new tickets
• Live updates for ticket changes
• Event-driven automation
• Better user experience for monitoring

Proposed Implementation

1. Webhook Server Component

• Add webhook endpoint to receive Zammad events
• Implement event validation and security
• Queue events for processing

2. Event Types to Support

• ticket.create - New ticket created
• ticket.update - Ticket modified
• ticket.article.create - New article/comment added
• user.create - New user registered
• organization.update - Organization changes

3. MCP Integration

# New tool for webhook management
@mcp.tool()
async def register_webhook(
    event_types: list[str],
    callback_url: str,
    active: bool = True
) -> WebhookRegistration:
    """Register a webhook for specific events."""
    pass

# Event streaming resource
@mcp.resource("zammad://events/stream")
async def event_stream() -> Resource:
    """Stream real-time events via SSE or WebSocket."""
    pass

4. Event Processing

• Validate webhook signatures
• Transform Zammad events to MCP notifications
• Implement retry logic for failed deliveries
• Add event filtering and routing

Architecture Considerations

• WebSocket or Server-Sent Events for real-time streaming
• Message queue (Redis) for reliable delivery
• Event store for replay capability
• Security: HMAC signature validation

Use Cases

1. Auto-assignment: Assign tickets based on content
2. Escalation alerts: Notify when tickets approach SLA
3. Integration triggers: Update external systems
4. Live dashboards: Real-time metrics

Acceptance Criteria

• Can register webhooks via MCP tools
• Receives and validates Zammad events
• Transforms events to MCP notifications
• Handles connection failures gracefully
• Security validation for all events
• Documentation for event schemas
• Integration tests with mock events

Technical Requirements

• Async event processing
• Configurable event filters
• Rate limiting protection
• Event deduplication
• Monitoring and metrics

Priority

Medium - Enables advanced automation scenarios

References

• Listed in CLAUDE.md under "Missing Features"
• Aligns with MCP's notification capabilities
• Zammad Webhook docs: https://docs.zammad.org/en/latest/api/webhook.html