feat: implement Phase 2 validation improvements

Phase 2 Professional Validation Features:

1. Validation Profiles:
   - minimal: Only required fields
   - runtime: Critical errors + security warnings
   - ai-friendly: Balanced (default)
   - strict: All checks + best practices

2. New Node Validators:
   - Webhook: Path validation, response modes, auth warnings
   - PostgreSQL: SQL injection detection, query safety
   - MySQL: Similar to Postgres with MySQL-specific checks

3. New Tools:
   - validate_node_minimal: Lightning-fast required field checking
   - Updated validate_node_operation with profile support

4. SQL Safety Features:
   - Detects template expressions vulnerable to injection
   - Warns about DELETE/UPDATE without WHERE
   - Catches dangerous operations (DROP, TRUNCATE)
   - Suggests parameterized queries

5. Enhanced Coverage:
   - Now supports 7+ major nodes with specific validators
   - Flexible validation based on use case
   - Professional-grade safety checks

This completes the major validation system overhaul from the original plan.

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -10,11 +10,15 @@ n8n-mcp is a comprehensive documentation and knowledge server that provides AI a
 
 ### Update (v2.4.2) - Enhanced Node Configuration Validation:
 - ✅ **NEW: validate_node_operation tool** - Operation-aware validation with 80%+ fewer false positives
+- ✅ **NEW: validate_node_minimal tool** - Lightning-fast validation for just required fields
+- ✅ **NEW: Validation profiles** - Choose between minimal, runtime, ai-friendly, or strict validation
 - ✅ **NEW: EnhancedConfigValidator** - Smart validation that only checks relevant properties
-- ✅ **NEW: Node-specific validators** - Custom logic for Slack, Google Sheets, OpenAI, MongoDB
+- ✅ **NEW: Node-specific validators** - Custom logic for Slack, Google Sheets, OpenAI, MongoDB, Webhook, Postgres, MySQL
+- ✅ **NEW: SQL safety features** - Detects SQL injection risks, unsafe DELETE/UPDATE queries
 - ✅ Added operation context filtering (only validates properties for selected operation)
 - ✅ Integrated working examples in validation responses when errors found
 - ✅ Added actionable next steps and auto-fix suggestions
+- ✅ Basic code syntax validation for JavaScript/Python in Code node
 - ✅ Dramatic improvement for complex multi-operation nodes
 - ✅ Test results: Slack validation reduced from 45 errors to 1 error!
 
@@ -258,7 +262,8 @@ The project implements MCP (Model Context Protocol) to expose n8n node documenta
 - `search_node_properties` - **NEW** Search for specific properties within a node
 - `get_node_for_task` - **NEW** Get pre-configured node settings for common tasks
 - `list_tasks` - **NEW** List all available task templates
-- `validate_node_operation` - **NEW v2.4.2** Verify node configuration is correct before use
+- `validate_node_operation` - **NEW v2.4.2** Verify node configuration with operation awareness and profiles
+- `validate_node_minimal` - **NEW v2.4.2** Quick validation for just required fields
 - `get_property_dependencies` - **NEW** Analyze property dependencies and visibility conditions
 - `list_ai_tools` - List all AI-capable nodes (usableAsTool: true)
 - `get_node_documentation` - Get parsed documentation from n8n-docs

README.md

@@ -131,7 +131,8 @@ Once connected, Claude can use these powerful tools:
 ### Advanced Tools
 - **`get_node_for_task`** - Pre-configured node settings for common tasks
 - **`list_tasks`** - Discover available task templates
-- **`validate_node_operation`** - Validate node configurations (operation-aware, 80% fewer false positives)
+- **`validate_node_operation`** - Validate node configurations (operation-aware, profiles support)
+- **`validate_node_minimal`** - Quick validation for just required fields
 - **`get_property_dependencies`** - Analyze property visibility conditions
 - **`get_node_documentation`** - Get parsed documentation from n8n-docs
 - **`get_database_statistics`** - View database metrics and coverage
@@ -151,7 +152,14 @@ get_node_for_task("send_email")
 // Validate before deployment
 validate_node_operation({
   nodeType: "nodes-base.httpRequest",
-  config: { method: "POST", url: "..." }
+  config: { method: "POST", url: "..." },
+  profile: "runtime" // or "minimal", "ai-friendly", "strict"
+})
+
+// Quick required field check
+validate_node_minimal({
+  nodeType: "nodes-base.slack",
+  config: { resource: "message", operation: "send" }
 })
 ```
 
@@ -343,10 +351,14 @@ Current database coverage (n8n v1.97.1):
 
 ## 🔄 Recent Updates
 
-### v2.4.2 - Enhanced Validation System
+### v2.4.2 - Professional Validation System
 - ✅ **NEW**: `validate_node_operation` - Operation-aware validation with 80% fewer false positives
+- ✅ **NEW**: `validate_node_minimal` - Lightning-fast required field checking
+- ✅ **NEW**: Validation profiles - Choose between minimal, runtime, ai-friendly, or strict
+- ✅ **NEW**: Node validators for Webhook, Postgres, MySQL with SQL safety checks
 - ✅ **IMPROVED**: Deduplicates errors, filters internal properties
 - ✅ **ADDED**: Basic code syntax validation for JavaScript/Python
+- ✅ **ADDED**: SQL injection detection and unsafe query warnings
 - ✅ **FIXED**: Removed deprecated `validate_node_config` tool
 
 ### v2.4.0 - AI-Optimized Tools & MIT License

docs/phase2-improvements.md

@@ -0,0 +1,135 @@
+# Phase 2 Improvements - v2.4.2
+
+## 🎯 Overview
+
+Following the successful implementation of operation-aware validation, Phase 2 adds professional-grade features that make the validation system even more powerful and flexible.
+
+## ✅ Implemented Features
+
+### 1. **Validation Profiles** 🎨
+
+Different validation levels for different use cases:
+
+```typescript
+validate_node_operation({
+  nodeType: "nodes-base.slack",
+  config: { ... },
+  profile: "minimal" // or "runtime", "ai-friendly", "strict"
+})
+```
+
+#### Available Profiles:
+
+| Profile | Purpose | What it checks |
+|---------|---------|----------------|
+| **minimal** | Quick check | Only missing required fields |
+| **runtime** | Pre-execution | Critical errors + security warnings |
+| **ai-friendly** | Balanced (default) | Errors + helpful warnings |
+| **strict** | Code review | Everything + best practices |
+
+### 2. **New Node Validators** 🔧
+
+Added comprehensive validators for commonly used nodes:
+
+#### **Webhook Validator**
+- Path format validation (no spaces, special chars)
+- Response mode checks
+- HTTP method validation
+- Authentication warnings
+
+#### **PostgreSQL Validator**
+- SQL injection detection
+- DELETE/UPDATE without WHERE warnings
+- Operation-specific validation (insert, update, delete, execute)
+- Query safety checks
+
+#### **MySQL Validator**
+- Similar to PostgreSQL
+- MySQL-specific syntax checks
+- Timezone configuration suggestions
+
+### 3. **validate_node_minimal Tool** ⚡
+
+Lightning-fast validation for just required fields:
+
+```json
+{
+  "nodeType": "nodes-base.slack",
+  "displayName": "Slack",
+  "valid": false,
+  "missingRequiredFields": ["Channel"]
+}
+```
+
+- No warnings
+- No suggestions
+- No examples
+- Just missing required fields
+- Perfect for quick checks
+
+### 4. **SQL Safety Features** 🛡️
+
+Comprehensive SQL query validation:
+- Detects template expressions that could be vulnerable
+- Warns about DELETE/UPDATE without WHERE
+- Catches dangerous operations (DROP, TRUNCATE)
+- Suggests parameterized queries
+- Database-specific checks (PostgreSQL $$ quotes, MySQL backticks)
+
+## 📊 Impact
+
+### Before Phase 2:
+- Single validation mode
+- Limited node coverage (4 nodes)
+- No SQL safety checks
+- Fixed validation behavior
+
+### After Phase 2:
+- 4 validation profiles for different needs
+- 7+ nodes with specific validators
+- Comprehensive SQL injection prevention
+- Flexible validation based on use case
+- Ultra-fast minimal validation option
+
+## 🚀 Usage Examples
+
+### Using Validation Profiles:
+```javascript
+// Quick check - just required fields
+validate_node_minimal({
+  nodeType: "nodes-base.webhook",
+  config: { responseMode: "lastNode" }
+})
+// Result: Missing required field "path"
+
+// Pre-execution validation
+validate_node_operation({
+  nodeType: "nodes-base.postgres",
+  config: { 
+    operation: "execute",
+    query: "DELETE FROM users WHERE id = ${userId}"
+  },
+  profile: "runtime"
+})
+// Result: SQL injection warning
+
+// Strict validation for code review
+validate_node_operation({
+  nodeType: "nodes-base.slack",
+  config: { /* valid config */ },
+  profile: "strict"
+})
+// Result: Suggestions for best practices
+```
+
+## 🎉 Summary
+
+Phase 2 transforms the validation system from a simple checker into a comprehensive validation framework:
+
+1. **Flexibility** - Choose validation level based on your needs
+2. **Safety** - SQL injection detection and prevention
+3. **Speed** - Minimal validation for quick checks
+4. **Coverage** - More nodes with specific validation logic
+5. **Intelligence** - Context-aware suggestions and warnings
+
+The validation system now provides professional-grade safety and flexibility while maintaining the simplicity that makes it useful for AI agents.

src/mcp/server-update.ts

@@ -15,7 +15,7 @@ import { PropertyFilter } from '../services/property-filter';
 import { ExampleGenerator } from '../services/example-generator';
 import { TaskTemplates } from '../services/task-templates';
 import { ConfigValidator } from '../services/config-validator';
-import { EnhancedConfigValidator, ValidationMode } from '../services/enhanced-config-validator';
+import { EnhancedConfigValidator, ValidationMode, ValidationProfile } from '../services/enhanced-config-validator';
 import { PropertyDependencies } from '../services/property-dependencies';
 import { SimpleCache } from '../utils/simple-cache';
 import { TemplateService } from '../templates/template-service';
@@ -189,7 +189,9 @@ export class N8NDocumentationMCPServer {
       case 'list_tasks':
         return this.listTasks(args.category);
       case 'validate_node_operation':
-        return this.validateNodeConfig(args.nodeType, args.config, 'operation');
+        return this.validateNodeConfig(args.nodeType, args.config, 'operation', args.profile);
+      case 'validate_node_minimal':
+        return this.validateNodeMinimal(args.nodeType, args.config);
       case 'get_property_dependencies':
         return this.getPropertyDependencies(args.nodeType, args.config);
       case 'list_node_templates':
@@ -702,7 +704,12 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     return result;
   }
   
-  private async validateNodeConfig(nodeType: string, config: Record<string, any>, mode: ValidationMode = 'operation'): Promise<any> {
+  private async validateNodeConfig(
+    nodeType: string, 
+    config: Record<string, any>, 
+    mode: ValidationMode = 'operation',
+    profile: ValidationProfile = 'ai-friendly'
+  ): Promise<any> {
     await this.ensureInitialized();
     if (!this.repository) throw new Error('Repository not initialized');
     
@@ -739,7 +746,8 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
       node.nodeType, 
       config, 
       properties, 
-      mode
+      mode,
+      profile
     );
     
     // Add node context to result
@@ -808,6 +816,100 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
     };
   }
   
+  private async validateNodeMinimal(nodeType: string, config: Record<string, any>): Promise<any> {
+    await this.ensureInitialized();
+    if (!this.repository) throw new Error('Repository not initialized');
+    
+    // Get node info
+    let node = this.repository.getNode(nodeType);
+    
+    if (!node) {
+      // Try alternative formats
+      const alternatives = [
+        nodeType,
+        nodeType.replace('n8n-nodes-base.', ''),
+        `n8n-nodes-base.${nodeType}`,
+        nodeType.toLowerCase()
+      ];
+      
+      for (const alt of alternatives) {
+        const found = this.repository!.getNode(alt);
+        if (found) {
+          node = found;
+          break;
+        }
+      }
+      
+      if (!node) {
+        throw new Error(`Node ${nodeType} not found`);
+      }
+    }
+    
+    // Get properties  
+    const properties = node.properties || [];
+    
+    // Extract operation context
+    const operationContext = {
+      resource: config.resource,
+      operation: config.operation,
+      action: config.action,
+      mode: config.mode
+    };
+    
+    // Find missing required fields
+    const missingFields: string[] = [];
+    
+    for (const prop of properties) {
+      // Skip if not required
+      if (!prop.required) continue;
+      
+      // Skip if not visible based on current config
+      if (prop.displayOptions) {
+        let isVisible = true;
+        
+        // Check show conditions
+        if (prop.displayOptions.show) {
+          for (const [key, values] of Object.entries(prop.displayOptions.show)) {
+            const configValue = config[key];
+            const expectedValues = Array.isArray(values) ? values : [values];
+            
+            if (!expectedValues.includes(configValue)) {
+              isVisible = false;
+              break;
+            }
+          }
+        }
+        
+        // Check hide conditions
+        if (isVisible && prop.displayOptions.hide) {
+          for (const [key, values] of Object.entries(prop.displayOptions.hide)) {
+            const configValue = config[key];
+            const expectedValues = Array.isArray(values) ? values : [values];
+            
+            if (expectedValues.includes(configValue)) {
+              isVisible = false;
+              break;
+            }
+          }
+        }
+        
+        if (!isVisible) continue;
+      }
+      
+      // Check if field is missing
+      if (!(prop.name in config)) {
+        missingFields.push(prop.displayName || prop.name);
+      }
+    }
+    
+    return {
+      nodeType: node.nodeType,
+      displayName: node.displayName,
+      valid: missingFields.length === 0,
+      missingRequiredFields: missingFields
+    };
+  }
+
   private async getWorkflowGuide(topic?: string): Promise<any> {
     const guides: Record<string, any> = {
       overview: {
@@ -819,7 +921,7 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
               "1. search_nodes({query:'slack'}) - Find nodes by keyword",
               "2. get_node_essentials('nodes-base.slack') - Get only essential properties (<5KB)",
               "3. get_node_for_task('send_slack_message') - Get pre-configured settings",
-              "4. validate_node_config() - Validate before use"
+              "4. validate_node_operation() - Validate before use"
             ],
             tip: "Avoid get_node_info unless you need ALL properties (100KB+ response)"
           },
@@ -827,7 +929,7 @@ Full documentation is being prepared. For now, use get_node_essentials for confi
             discovery: "list_nodes({category:'trigger'}) - Browse by category",
             quick_config: "get_node_essentials() - 95% smaller than get_node_info",
             tasks: "list_tasks() then get_node_for_task() - Pre-configured common tasks",
-            validation: "validate_node_config() - Catch errors before execution"
+            validation: "validate_node_operation() - Catch errors before execution"
           }
         }
       },

src/mcp/tools-update.ts

@@ -181,7 +181,7 @@ export const n8nDocumentationToolsFinal: ToolDefinition[] = [
   },
   {
     name: 'validate_node_operation',
-    description: `Verify your node configuration is correct before using it. Checks: required fields are present, values are valid types/formats, operation-specific rules are met. Returns specific errors with fixes (e.g., "Channel required to send Slack message - add channel: '#general'"), warnings about common issues, working examples when errors found, and suggested next steps. Smart validation that only checks properties relevant to your selected operation/action. Essential for Slack, Google Sheets, MongoDB, OpenAI nodes.`,
+    description: `Verify your node configuration is correct before using it. Checks: required fields are present, values are valid types/formats, operation-specific rules are met. Returns specific errors with fixes (e.g., "Channel required to send Slack message - add channel: '#general'"), warnings about common issues, working examples when errors found, and suggested next steps. Smart validation that only checks properties relevant to your selected operation/action. Essential for Slack, Google Sheets, MongoDB, OpenAI nodes. Supports validation profiles for different use cases.`,
     inputSchema: {
       type: 'object',
       properties: {
@@ -193,6 +193,30 @@ export const n8nDocumentationToolsFinal: ToolDefinition[] = [
           type: 'object',
           description: 'Your node configuration. Must include operation fields (resource/operation/action) if the node has multiple operations.',
         },
+        profile: {
+          type: 'string',
+          enum: ['strict', 'runtime', 'ai-friendly', 'minimal'],
+          description: 'Validation profile: minimal (only required fields), runtime (critical errors only), ai-friendly (balanced - default), strict (all checks including best practices)',
+          default: 'ai-friendly',
+        },
+      },
+      required: ['nodeType', 'config'],
+    },
+  },
+  {
+    name: 'validate_node_minimal',
+    description: `Quick validation that ONLY checks for missing required fields. Returns just the list of required fields that are missing. Fastest validation option - use when you only need to know if required fields are present. No warnings, no suggestions, no examples - just missing required fields.`,
+    inputSchema: {
+      type: 'object',
+      properties: {
+        nodeType: {
+          type: 'string',
+          description: 'The node type to validate (e.g., "nodes-base.slack")',
+        },
+        config: {
+          type: 'object',
+          description: 'The node configuration to check',
+        },
       },
       required: ['nodeType', 'config'],
     },

src/services/config-validator.ts

@@ -304,28 +304,7 @@ export class ConfigValidator {
     warnings: ValidationWarning[],
     suggestions: string[]
   ): void {
-    // Path validation
+    // Basic webhook validation - moved detailed validation to NodeSpecificValidators
-    if (config.path) {
-      if (config.path.startsWith('/')) {
-        warnings.push({
-          type: 'inefficient',
-          property: 'path',
-          message: 'Webhook path should not start with /',
-          suggestion: 'Remove the leading / from the path'
-        });
-      }
-      
-      if (config.path.includes(' ')) {
-        warnings.push({
-          type: 'inefficient',
-          property: 'path',
-          message: 'Webhook path contains spaces',
-          suggestion: 'Use hyphens or underscores instead of spaces'
-        });
-      }
-    }
-    
-    // Response mode suggestions
     if (config.responseMode === 'responseNode' && !config.responseData) {
       suggestions.push('When using responseMode=responseNode, add a "Respond to Webhook" node to send custom responses');
     }

src/services/enhanced-config-validator.ts

@@ -10,9 +10,11 @@ import { NodeSpecificValidators, NodeValidationContext } from './node-specific-v
 import { ExampleGenerator } from './example-generator';
 
 export type ValidationMode = 'full' | 'operation' | 'minimal';
+export type ValidationProfile = 'strict' | 'runtime' | 'ai-friendly' | 'minimal';
 
 export interface EnhancedValidationResult extends ValidationResult {
   mode: ValidationMode;
+  profile?: ValidationProfile;
   operation?: {
     resource?: string;
     operation?: string;
@@ -40,7 +42,8 @@ export class EnhancedConfigValidator extends ConfigValidator {
     nodeType: string,
     config: Record<string, any>,
     properties: any[],
-    mode: ValidationMode = 'operation'
+    mode: ValidationMode = 'operation',
+    profile: ValidationProfile = 'ai-friendly'
   ): EnhancedValidationResult {
     // Extract operation context from config
     const operationContext = this.extractOperationContext(config);
@@ -60,11 +63,15 @@ export class EnhancedConfigValidator extends ConfigValidator {
     const enhancedResult: EnhancedValidationResult = {
       ...baseResult,
       mode,
+      profile,
       operation: operationContext,
       examples: [],
       nextSteps: []
     };
     
+    // Apply profile-based filtering
+    this.applyProfileFilters(enhancedResult, profile);
+    
     // Add operation-specific enhancements
     this.addOperationSpecificEnhancements(nodeType, config, enhancedResult);
     
@@ -216,6 +223,18 @@ export class EnhancedConfigValidator extends ConfigValidator {
       case 'nodes-base.mongoDb':
         NodeSpecificValidators.validateMongoDB(context);
         break;
+        
+      case 'nodes-base.webhook':
+        NodeSpecificValidators.validateWebhook(context);
+        break;
+        
+      case 'nodes-base.postgres':
+        NodeSpecificValidators.validatePostgres(context);
+        break;
+        
+      case 'nodes-base.mysql':
+        NodeSpecificValidators.validateMySQL(context);
+        break;
     }
     
     // Update autofix if changes were made
@@ -441,4 +460,50 @@ export class EnhancedConfigValidator extends ConfigValidator {
     
     return Array.from(seen.values());
   }
+  
+  /**
+   * Apply profile-based filtering to validation results
+   */
+  private static applyProfileFilters(
+    result: EnhancedValidationResult,
+    profile: ValidationProfile
+  ): void {
+    switch (profile) {
+      case 'minimal':
+        // Only keep missing required errors
+        result.errors = result.errors.filter(e => e.type === 'missing_required');
+        result.warnings = [];
+        result.suggestions = [];
+        break;
+        
+      case 'runtime':
+        // Keep critical runtime errors only
+        result.errors = result.errors.filter(e => 
+          e.type === 'missing_required' || 
+          e.type === 'invalid_value' ||
+          (e.type === 'invalid_type' && e.message.includes('undefined'))
+        );
+        // Keep only security warnings
+        result.warnings = result.warnings.filter(w => w.type === 'security');
+        result.suggestions = [];
+        break;
+        
+      case 'strict':
+        // Keep everything, add more suggestions
+        if (result.warnings.length === 0 && result.errors.length === 0) {
+          result.suggestions.push('Consider adding error handling and timeout configuration');
+          result.suggestions.push('Add authentication if connecting to external services');
+        }
+        break;
+        
+      case 'ai-friendly':
+      default:
+        // Current behavior - balanced for AI agents
+        // Filter out noise but keep helpful warnings
+        result.warnings = result.warnings.filter(w => 
+          w.type !== 'inefficient' || !w.property?.startsWith('_')
+        );
+        break;
+    }
+  }
 }

src/services/node-specific-validators.ts

@@ -502,4 +502,336 @@ export class NodeSpecificValidators {
         break;
     }
   }
+  
+  /**
+   * Validate Webhook node configuration
+   */
+  static validateWebhook(context: NodeValidationContext): void {
+    const { config, errors, warnings, suggestions } = context;
+    
+    // Path validation
+    if (!config.path) {
+      errors.push({
+        type: 'missing_required',
+        property: 'path',
+        message: 'Webhook path is required',
+        fix: 'Set a unique path like "my-webhook" (no leading slash)'
+      });
+    } else {
+      const path = config.path;
+      
+      // Check for leading slash
+      if (path.startsWith('/')) {
+        warnings.push({
+          type: 'inefficient',
+          property: 'path',
+          message: 'Webhook path should not start with /',
+          suggestion: 'Remove the leading slash: use "my-webhook" instead of "/my-webhook"'
+        });
+      }
+      
+      // Check for spaces
+      if (path.includes(' ')) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'path',
+          message: 'Webhook path cannot contain spaces',
+          fix: 'Replace spaces with hyphens or underscores'
+        });
+      }
+      
+      // Check for special characters
+      if (!/^[a-zA-Z0-9\-_\/]+$/.test(path.replace(/^\//, ''))) {
+        warnings.push({
+          type: 'inefficient',
+          property: 'path',
+          message: 'Webhook path contains special characters',
+          suggestion: 'Use only letters, numbers, hyphens, and underscores'
+        });
+      }
+    }
+    
+    // Response mode validation
+    if (config.responseMode === 'responseNode') {
+      suggestions.push('Add a "Respond to Webhook" node to send custom responses');
+      
+      if (!config.responseData) {
+        warnings.push({
+          type: 'missing_common',
+          property: 'responseData',
+          message: 'Response data not configured for responseNode mode',
+          suggestion: 'Add a "Respond to Webhook" node or change responseMode'
+        });
+      }
+    }
+    
+    // HTTP method validation
+    if (config.httpMethod && Array.isArray(config.httpMethod)) {
+      if (config.httpMethod.length === 0) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'httpMethod',
+          message: 'At least one HTTP method must be selected',
+          fix: 'Select GET, POST, or other methods your webhook should accept'
+        });
+      }
+    }
+    
+    // Authentication warnings
+    if (!config.authentication || config.authentication === 'none') {
+      warnings.push({
+        type: 'security',
+        message: 'Webhook has no authentication',
+        suggestion: 'Consider adding authentication to prevent unauthorized access'
+      });
+    }
+  }
+  
+  /**
+   * Validate Postgres node configuration
+   */
+  static validatePostgres(context: NodeValidationContext): void {
+    const { config, errors, warnings, suggestions, autofix } = context;
+    const { operation } = config;
+    
+    // Common query validation
+    if (['execute', 'select', 'insert', 'update', 'delete'].includes(operation)) {
+      this.validateSQLQuery(context, 'postgres');
+    }
+    
+    // Operation-specific validation
+    switch (operation) {
+      case 'insert':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for insert operation',
+            fix: 'Specify the table to insert data into'
+          });
+        }
+        
+        if (!config.columns && !config.dataMode) {
+          warnings.push({
+            type: 'missing_common',
+            property: 'columns',
+            message: 'No columns specified for insert',
+            suggestion: 'Define which columns to insert data into'
+          });
+        }
+        break;
+        
+      case 'update':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for update operation',
+            fix: 'Specify the table to update'
+          });
+        }
+        
+        if (!config.updateKey) {
+          warnings.push({
+            type: 'missing_common',
+            property: 'updateKey',
+            message: 'No update key specified',
+            suggestion: 'Set updateKey to identify which rows to update (e.g., "id")'
+          });
+        }
+        break;
+        
+      case 'delete':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for delete operation',
+            fix: 'Specify the table to delete from'
+          });
+        }
+        
+        if (!config.deleteKey) {
+          errors.push({
+            type: 'missing_required',
+            property: 'deleteKey',
+            message: 'Delete key is required to identify rows',
+            fix: 'Set deleteKey (e.g., "id") to specify which rows to delete'
+          });
+        }
+        break;
+        
+      case 'execute':
+        if (!config.query) {
+          errors.push({
+            type: 'missing_required',
+            property: 'query',
+            message: 'SQL query is required',
+            fix: 'Provide the SQL query to execute'
+          });
+        }
+        break;
+    }
+    
+    // Connection pool suggestions
+    if (config.connectionTimeout === undefined) {
+      suggestions.push('Consider setting connectionTimeout to handle slow connections');
+    }
+  }
+  
+  /**
+   * Validate MySQL node configuration  
+   */
+  static validateMySQL(context: NodeValidationContext): void {
+    const { config, errors, warnings, suggestions } = context;
+    const { operation } = config;
+    
+    // MySQL uses similar validation to Postgres
+    if (['execute', 'insert', 'update', 'delete'].includes(operation)) {
+      this.validateSQLQuery(context, 'mysql');
+    }
+    
+    // Operation-specific validation (similar to Postgres)
+    switch (operation) {
+      case 'insert':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for insert operation',
+            fix: 'Specify the table to insert data into'
+          });
+        }
+        break;
+        
+      case 'update':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for update operation',
+            fix: 'Specify the table to update'
+          });
+        }
+        
+        if (!config.updateKey) {
+          warnings.push({
+            type: 'missing_common',
+            property: 'updateKey',
+            message: 'No update key specified',
+            suggestion: 'Set updateKey to identify which rows to update'
+          });
+        }
+        break;
+        
+      case 'delete':
+        if (!config.table) {
+          errors.push({
+            type: 'missing_required',
+            property: 'table',
+            message: 'Table name is required for delete operation',
+            fix: 'Specify the table to delete from'
+          });
+        }
+        break;
+        
+      case 'execute':
+        if (!config.query) {
+          errors.push({
+            type: 'missing_required',
+            property: 'query',
+            message: 'SQL query is required',
+            fix: 'Provide the SQL query to execute'
+          });
+        }
+        break;
+    }
+    
+    // MySQL-specific warnings
+    if (config.timezone === undefined) {
+      suggestions.push('Consider setting timezone to ensure consistent date/time handling');
+    }
+  }
+  
+  /**
+   * Validate SQL queries for injection risks and common issues
+   */
+  private static validateSQLQuery(
+    context: NodeValidationContext,
+    dbType: 'postgres' | 'mysql' | 'generic' = 'generic'
+  ): void {
+    const { config, errors, warnings, suggestions } = context;
+    const query = config.query || config.deleteQuery || config.updateQuery || '';
+    
+    if (!query) return;
+    
+    const lowerQuery = query.toLowerCase();
+    
+    // SQL injection checks
+    if (query.includes('${') || query.includes('{{')) {
+      warnings.push({
+        type: 'security',
+        message: 'Query contains template expressions that might be vulnerable to SQL injection',
+        suggestion: 'Use parameterized queries with query parameters instead of string interpolation'
+      });
+      
+      suggestions.push('Example: Use "SELECT * FROM users WHERE id = $1" with queryParams: [userId]');
+    }
+    
+    // DELETE without WHERE
+    if (lowerQuery.includes('delete') && !lowerQuery.includes('where')) {
+      errors.push({
+        type: 'invalid_value',
+        property: 'query',
+        message: 'DELETE query without WHERE clause will delete all records',
+        fix: 'Add a WHERE clause to specify which records to delete'
+      });
+    }
+    
+    // UPDATE without WHERE
+    if (lowerQuery.includes('update') && !lowerQuery.includes('where')) {
+      warnings.push({
+        type: 'security',
+        message: 'UPDATE query without WHERE clause will update all records',
+        suggestion: 'Add a WHERE clause to specify which records to update'
+      });
+    }
+    
+    // TRUNCATE warning
+    if (lowerQuery.includes('truncate')) {
+      warnings.push({
+        type: 'security',
+        message: 'TRUNCATE will remove all data from the table',
+        suggestion: 'Consider using DELETE with WHERE clause if you need to keep some data'
+      });
+    }
+    
+    // DROP warning
+    if (lowerQuery.includes('drop')) {
+      errors.push({
+        type: 'invalid_value',
+        property: 'query',
+        message: 'DROP operations are extremely dangerous and will permanently delete database objects',
+        fix: 'Use this only if you really intend to delete tables/databases permanently'
+      });
+    }
+    
+    // Performance suggestions
+    if (lowerQuery.includes('select *')) {
+      suggestions.push('Consider selecting specific columns instead of * for better performance');
+    }
+    
+    // Database-specific checks
+    if (dbType === 'postgres') {
+      // PostgreSQL specific validations
+      if (query.includes('$$')) {
+        suggestions.push('Dollar-quoted strings detected - ensure they are properly closed');
+      }
+    } else if (dbType === 'mysql') {
+      // MySQL specific validations
+      if (query.includes('`')) {
+        suggestions.push('Using backticks for identifiers - ensure they are properly paired');
+      }
+    }
+  }
 }