CapabilityRegistry

Registry Interface

// ProcessEngine/Capabilities/CapabilityRegistry.cs
public interface ICapabilityRegistry
{
    // Get all executor types for a given capability type
    IReadOnlyList<Type> GetByType(CapabilityType type);

    // Get the capability type for a given executor type
    CapabilityType? GetByExecutorType(Type executorType);

    // Get all registered capability types
    IReadOnlyList<CapabilityType> GetAllTypes();

    // Check if a node type string has a registered capability
    bool HasCapability(string nodeType);

    // Get capability metadata for a node type
    CapabilityMetadata? GetMetadata(CapabilityType type);
}

Concrete Implementation

public class CapabilityRegistry : ICapabilityRegistry
{
    private readonly Dictionary<CapabilityType, List<Type>> _byType = new();
    private readonly Dictionary<Type, CapabilityType> _byExecutorType = new();
    private readonly Dictionary<CapabilityType, CapabilityMetadata> _metadata = new();

    public CapabilityRegistry(IEnumerable<INodeCapability> capabilities)
    {
        // Initialize capability type lists
        foreach (CapabilityType ct in Enum.GetValues<CapabilityType>())
            _byType[ct] = new List<Type>();

        // Store metadata from each capability implementation
        foreach (var cap in capabilities)
            _metadata[cap.Type] = cap.Metadata;
    }

    public IReadOnlyList<Type> GetByType(CapabilityType type)
        => _byType.TryGetValue(type, out var list) ? list : Array.Empty<Type>();

    public CapabilityType? GetByExecutorType(Type executorType)
        => _byExecutorType.TryGetValue(executorType, out var ct) ? ct : null;
}

API Endpoint for the Designer

The backend exposes a capability metadata endpoint that the Flow Studio designer calls to populate the node palette:

GET /api/flow-studio/capabilities
Authorization: Bearer {token}

Response:
[
  {
    "type": "Webhook",
    "displayName": "Webhooks",
    "description": "HTTP event triggers and outbound calls",
    "iconClass": "fa-solid fa-webhook",
    "nodeTypes": ["WebhookTrigger", "WebhookCall"]
  },
  {
    "type": "Messaging",
    "displayName": "Messaging",
    "description": "Send messages via Slack, Email, SMS, Push",
    "iconClass": "fa-solid fa-envelope",
    "nodeTypes": ["SlackMessage", "Email", "SMS", "PushNotification"]
  }
  // ... 10 more
]

TypeScript Registry Client

// packages/flow-studio-api/src/types/capability.types.ts
export interface CapabilityInfo {
  type: string;
  displayName: string;
  description: string;
  iconClass: string;
  nodeTypes: string[];
}

// packages/flow-studio-api/src/clients/capabilityApiClient.ts
export async function fetchCapabilities(): Promise<CapabilityInfo[]> {
  const res = await apiClient.get('/api/flow-studio/capabilities');
  return res.data;
}