feat: add anonymous telemetry system with Supabase integration

- Implement telemetry manager for tracking tool usage and workflows
- Add workflow sanitizer to remove sensitive data before storage
- Create config manager with opt-in/opt-out mechanism
- Integrate telemetry tracking into MCP server and workflow handlers
- Add CLI commands for telemetry control (enable/disable/status)
- Show first-run notice with clear privacy information
- Add comprehensive unit tests for sanitization and config
- Track tool usage metrics, workflow patterns, and errors
- Ensure complete anonymity with deterministic user IDs
- Never collect URLs, API keys, or sensitive information

src/mcp/handlers-n8n-manager.ts

@@ -27,6 +27,7 @@ import { InstanceContext, validateInstanceContext } from '../types/instance-cont
 import { WorkflowAutoFixer, AutoFixConfig } from '../services/workflow-auto-fixer';
 import { ExpressionFormatValidator } from '../services/expression-format-validator';
 import { handleUpdatePartialWorkflow } from './handlers-workflow-diff';
+import { telemetry } from '../telemetry';
 import {
   createCacheKey,
   createInstanceCache,
@@ -280,16 +281,22 @@ export async function handleCreateWorkflow(args: unknown, context?: InstanceCont
     // Validate workflow structure
     const errors = validateWorkflowStructure(input);
     if (errors.length > 0) {
+      // Track validation failure
+      telemetry.trackWorkflowCreation(input, false);
+
       return {
         success: false,
         error: 'Workflow validation failed',
         details: { errors }
       };
     }
-    
+
     // Create workflow
     const workflow = await client.createWorkflow(input);
-    
+
+    // Track successful workflow creation
+    telemetry.trackWorkflowCreation(workflow, true);
+
     return {
       success: true,
       data: workflow,

src/mcp/index.ts

@@ -2,6 +2,7 @@
 
 import { N8NDocumentationMCPServer } from './server';
 import { logger } from '../utils/logger';
+import { TelemetryConfigManager } from '../telemetry/config-manager';
 
 // Add error details to stderr for Claude Desktop debugging
 process.on('uncaughtException', (error) => {
@@ -21,8 +22,42 @@ process.on('unhandledRejection', (reason, promise) => {
 });
 
 async function main() {
+  // Handle telemetry CLI commands
+  const args = process.argv.slice(2);
+  if (args.length > 0 && args[0] === 'telemetry') {
+    const telemetryConfig = TelemetryConfigManager.getInstance();
+    const action = args[1];
+
+    switch (action) {
+      case 'enable':
+        telemetryConfig.enable();
+        process.exit(0);
+        break;
+      case 'disable':
+        telemetryConfig.disable();
+        process.exit(0);
+        break;
+      case 'status':
+        console.log(telemetryConfig.getStatus());
+        process.exit(0);
+        break;
+      default:
+        console.log(`
+Usage: n8n-mcp telemetry [command]
+
+Commands:
+  enable   Enable anonymous telemetry
+  disable  Disable anonymous telemetry
+  status   Show current telemetry status
+
+Learn more: https://github.com/czlonkowski/n8n-mcp/privacy
+`);
+        process.exit(args[1] ? 1 : 0);
+    }
+  }
+
   const mode = process.env.MCP_MODE || 'stdio';
-  
+
   try {
     // Only show debug messages in HTTP mode to avoid corrupting stdio communication
     if (mode === 'http') {

src/mcp/server.ts

@@ -35,6 +35,7 @@ import {
   STANDARD_PROTOCOL_VERSION
 } from '../utils/protocol-version';
 import { InstanceContext } from '../types/instance-context';
+import { telemetry } from '../telemetry';
 
 interface NodeRow {
   node_type: string;
@@ -180,7 +181,10 @@ export class N8NDocumentationMCPServer {
         clientCapabilities,
         clientInfo
       });
-      
+
+      // Track session start
+      telemetry.trackSessionStart();
+
       // Store client info for later use
       this.clientInfo = clientInfo;
       
@@ -322,8 +326,13 @@ export class N8NDocumentationMCPServer {
       
       try {
         logger.debug(`Executing tool: ${name}`, { args: processedArgs });
+        const startTime = Date.now();
         const result = await this.executeTool(name, processedArgs);
+        const duration = Date.now() - startTime;
         logger.debug(`Tool ${name} executed successfully`);
+
+        // Track tool usage
+        telemetry.trackToolUsage(name, true, duration);
         
         // Ensure the result is properly formatted for MCP
         let responseText: string;
@@ -370,7 +379,15 @@ export class N8NDocumentationMCPServer {
       } catch (error) {
         logger.error(`Error executing tool ${name}`, error);
         const errorMessage = error instanceof Error ? error.message : 'Unknown error';
-        
+
+        // Track tool error
+        telemetry.trackToolUsage(name, false);
+        telemetry.trackError(
+          error instanceof Error ? error.constructor.name : 'UnknownError',
+          `tool_execution`,
+          name
+        );
+
         // Provide more helpful error messages for common n8n issues
         let helpfulMessage = `Error executing tool ${name}: ${errorMessage}`;