v3/implementation/plugins/README.md
Domain-Driven Design Plugin-Based Architecture (ADR-004)
The V3 Plugin System implements a microkernel architecture enabling modular extension points for:
import { ClaudeFlowPlugin, PluginContext } from '@claude-flow/shared';
class MyPlugin implements ClaudeFlowPlugin {
readonly name = 'my-plugin';
readonly version = '1.0.0';
async initialize(context: PluginContext): Promise<void> {
context.logger.info('MyPlugin initialized');
}
async shutdown(): Promise<void> {
// Cleanup
}
}
┌─────────────────────────────────────────────────────┐
│ Plugin Loader │
│ - Dependency resolution │
│ - Lifecycle management │
│ - Health checks │
└──────────────────────┬──────────────────────────────┘
│
┌──────────────────────┴──────────────────────────────┐
│ Plugin Registry │
│ - Plugin tracking │
│ - Extension point registration │
│ - Status/metrics collection │
└──────────────────────┬──────────────────────────────┘
│
┌──────────────────┼──────────────────┐
│ │ │
┌───┴───┐ ┌────┴────┐ ┌────┴────┐
│Plugin │ │ Plugin │ │ Plugin │
│ A │ │ B │ │ C │
└───────┘ └─────────┘ └─────────┘
All plugins must implement this interface:
interface ClaudeFlowPlugin {
// Required
readonly name: string;
readonly version: string;
initialize(context: PluginContext): Promise<void>;
shutdown(): Promise<void>;
// Optional extensions
dependencies?: string[];
description?: string;
author?: string;
// Extension points
registerAgentTypes?(): AgentTypeDefinition[];
registerTaskTypes?(): TaskTypeDefinition[];
registerMCPTools?(): MCPToolDefinition[];
registerCLICommands?(): CLICommandDefinition[];
registerMemoryBackends?(): MemoryBackendFactory[];
// Health monitoring
healthCheck?(): Promise<boolean>;
}
Provided during initialization with access to core services:
interface PluginContext {
config: PluginConfig; // Plugin configuration
eventBus: IEventBus; // Pub/sub events
logger: ILogger; // Logging
services: ServiceContainer; // DI container
}
Central registry for plugin and extension tracking:
const registry = new PluginRegistry();
// Plugin management
registry.registerPlugin(plugin, 'uninitialized', context);
registry.getPlugin('my-plugin');
registry.getAllPlugins();
registry.getPluginsByState('initialized');
// Extension queries
registry.getAllAgentTypes();
registry.getAllMCPTools();
registry.getAllCLICommands();
registry.getAllMemoryBackends();
// Status
registry.getStatusSummary();
Handles lifecycle and dependency resolution:
const loader = new PluginLoader(registry, {
initializationTimeout: 30000,
shutdownTimeout: 10000,
parallelInitialization: false,
strictDependencies: true,
enableHealthChecks: true,
healthCheckInterval: 60000,
});
// Load plugins
const result = await loader.loadPlugins([pluginA, pluginB], context);
console.log(`Loaded: ${result.successful.join(', ')}`);
// Unload
await loader.unloadPlugin('my-plugin');
await loader.unloadAll();
registerAgentTypes(): AgentTypeDefinition[] {
return [{
type: 'custom-agent',
name: 'Custom Agent',
description: 'Specialized agent for custom tasks',
defaultConfig: {
model: 'claude-3-opus',
maxTokens: 4096,
},
requiredCapabilities: ['custom-capability'],
}];
}
registerTaskTypes(): TaskTypeDefinition[] {
return [{
type: 'custom-task',
name: 'Custom Task',
description: 'Specialized task processing',
defaultPriority: 50,
defaultTimeout: 60000,
inputSchema: {
type: 'object',
properties: {
input: { type: 'string' }
},
required: ['input']
}
}];
}
registerMCPTools(): MCPToolDefinition[] {
return [{
name: 'custom_tool',
description: 'Custom MCP tool',
inputSchema: {
type: 'object',
properties: {
param: { type: 'string', description: 'Input parameter' }
},
required: ['param']
},
handler: async (input, context) => {
return { result: `Processed: ${input.param}` };
}
}];
}
registerCLICommands(): CLICommandDefinition[] {
return [{
name: 'custom-cmd',
description: 'Custom CLI command',
aliases: ['cc'],
options: [
{
name: 'verbose',
short: 'v',
description: 'Enable verbose output',
type: 'boolean',
default: false
}
],
handler: async (args) => {
console.log('Custom command executed', args);
}
}];
}
registerMemoryBackends(): MemoryBackendFactory[] {
return [{
name: 'custom-backend',
description: 'Custom memory backend',
capabilities: {
supportsVectorSearch: true,
supportsFullText: true,
supportsTransactions: false,
supportsPersistence: true
},
create: async (config) => new CustomMemoryBackend(config)
}];
}
uninitialized → initializing → initialized → shutting-down → shutdown
│ │
└──────── error ◄─────────────┘
| State | Description |
|---|---|
uninitialized | Registered but not yet initialized |
initializing | Currently running initialize() |
initialized | Successfully initialized and active |
shutting-down | Currently running shutdown() |
shutdown | Successfully shut down |
error | Error during lifecycle transition |
Plugins can declare dependencies on other plugins:
class DependentPlugin implements ClaudeFlowPlugin {
readonly name = 'dependent-plugin';
readonly version = '1.0.0';
readonly dependencies = ['base-plugin', 'auth-plugin'];
async initialize(context: PluginContext): Promise<void> {
// Dependencies guaranteed to be initialized first
}
}
The PluginLoader:
Located in @claude-flow/shared/src/plugins/official/:
Workflow orchestration with phase management:
Collective intelligence coordination:
import { PluginError, PluginErrorCode } from '@claude-flow/shared';
// Error codes
type PluginErrorCode =
| 'INITIALIZATION_FAILED'
| 'SHUTDOWN_FAILED'
| 'DEPENDENCY_NOT_FOUND'
| 'CIRCULAR_DEPENDENCY'
| 'INVALID_PLUGIN'
| 'DUPLICATE_PLUGIN'
| 'HEALTH_CHECK_FAILED';
// Throwing errors
throw new PluginError(
'Failed to connect to database',
'my-plugin',
'INITIALIZATION_FAILED',
originalError
);
Plugins receive configuration through PluginContext:
interface PluginConfig {
[key: string]: unknown;
features?: Record<string, boolean>;
resources?: {
maxMemoryMb?: number;
maxCpuPercent?: number;
};
}
| File | Purpose |
|---|---|
plugin-interface.ts | Core interfaces and types |
plugin-registry.ts | Extension registration |
plugin-loader.ts | Lifecycle management |
plugins/official/ | Built-in plugins |