fix: correct misleading Code node documentation based on real-world testing

Critical fixes based on Claude Desktop feedback: 1. Fixed crypto documentation: require('crypto') IS available despite editor warnings - Added clear examples of crypto usage - Updated validation to guide correct require() usage 2. Clarified $helpers vs standalone functions - $getWorkflowStaticData() is standalone, NOT $helpers.getWorkflowStaticData() - Added validation to catch incorrect usage (prevents '$helpers is not defined' errors) - Enhanced examples showing proper $helpers availability checks 3. Fixed JMESPath numeric literal documentation - n8n requires backticks around numbers in filters: [?age >= `18`] - Added multiple examples and validation to detect missing backticks - Prevents 'JMESPath syntax error' that Claude Desktop encountered 4. Fixed webhook data access gotcha - Webhook payload is at items[0].json.body, NOT items[0].json - Added dedicated 'Webhook Data Access' section with clear examples - Created process_webhook_data task template - Added validation to detect incorrect webhook data access patterns All fixes based on production workflows TaNqYoZNNeHC4Hne and JZ9urD7PNClDZ1bm 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>
2025-07-10 09:22:34 +02:00
parent 20f018f8dc
commit 99e74cf22a
14 changed files with 3072 additions and 73 deletions
--- a/README.md
+++ b/README.md
@@ -580,48 +580,7 @@ Current database coverage (n8n v1.100.1):

 ## 🔄 Recent Updates

-### v2.7.10 - Enhanced Authentication Logging
- ✅ **ENHANCED**: Authentication logging for better debugging of client authentication issues
- ✅ **ADDED**: Specific error reasons: `no_auth_header`, `invalid_auth_format`, `invalid_token`
- ✅ **FIXED**: Issue #22 - Improved authentication failure diagnostics
- ✅ **FIXED**: Issue #16 - AUTH_TOKEN_FILE validation for Docker production stacks
- ✅ **SECURITY**: Removed token length from logs, trimmed tokens for whitespace edge cases
-
-### v2.7.8 - npx Support & npm Publishing
- ✅ **NEW**: npx support - Run `npx n8n-mcp` without installation!
- ✅ **OPTIMIZED**: npm package with runtime-only dependencies (8 deps vs 50+ dev deps)
- ✅ **REDUCED**: Package size from 1GB+ to ~50MB by excluding dev dependencies
- ✅ **FIXED**: Issue #15 - Added npx execution support as requested
- ✅ **ENHANCED**: Database path resolution for npx, global, and local installations
-
-### v2.7.5 - AUTH_TOKEN_FILE Support
- ✅ **NEW**: AUTH_TOKEN_FILE support for Docker secrets compatibility
- ✅ **ADDED**: Known Issues section documenting Claude Desktop container duplication
- ✅ **ENHANCED**: Authentication flexibility with both AUTH_TOKEN and AUTH_TOKEN_FILE
- ✅ **FIXED**: Issue #16 - AUTH_TOKEN_FILE now properly implemented as documented
- ✅ **BACKWARD COMPATIBLE**: AUTH_TOKEN continues to work as before
-
-### v2.7.4 - Self-Documenting MCP Tools
- ✅ **RENAMED**: `start_here_workflow_guide` → `tools_documentation` for clarity
- ✅ **NEW**: Depth parameter - Control documentation detail with "essentials" or "full"
- ✅ **NEW**: Per-tool documentation - Get help for any specific MCP tool by name
- ✅ **CONCISE**: Essential info by default, comprehensive docs on demand
- ✅ **LLM-FRIENDLY**: Plain text format instead of JSON for better readability
- ✅ **QUICK HELP**: Call without parameters for immediate quick reference
- ✅ **8 TOOLS DOCUMENTED**: Complete documentation for most commonly used tools
-
-### v2.7.0 - Diff-Based Workflow Editing with Transactional Updates
- ✅ **NEW**: `n8n_update_partial_workflow` tool - Update workflows using diff operations
- ✅ **RENAMED**: `n8n_update_workflow` → `n8n_update_full_workflow` for clarity
- ✅ **80-90% TOKEN SAVINGS**: Only send changes, not entire workflow JSON
- ✅ **13 OPERATIONS**: addNode, removeNode, updateNode, moveNode, enable/disable, connections, settings, tags
- ✅ **TRANSACTIONAL**: Two-pass processing allows adding nodes and connections in any order
- ✅ **5 OPERATION LIMIT**: Ensures reliability and atomic updates
- ✅ **VALIDATION MODE**: Test changes with `validateOnly: true` before applying
- ✅ **IMPROVED DOCS**: Comprehensive parameter documentation and examples
-
-
-See [CHANGELOG.md](./docs/CHANGELOG.md) for full version history.
+See [CHANGELOG.md](./docs/CHANGELOG.md) for full version history and recent changes.

 ## ⚠️ Known Issues

--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -5,6 +5,29 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

+## [Unreleased]
+
+### Fixed
+- **Code Node Documentation**: Corrected information about `$helpers` object and `getWorkflowStaticData` function
+  - `$getWorkflowStaticData()` is a standalone function, NOT `$helpers.getWorkflowStaticData()`
+  - Updated Code node guide to clarify which functions are standalone vs methods on $helpers
+  - Added validation warning when using incorrect `$helpers.getWorkflowStaticData` syntax
+  - Based on n8n community feedback and GitHub issues showing this is a common confusion point
+
+### Added
+- **Expression vs Code Node Clarification**: Added comprehensive documentation about differences between expression and Code node contexts
+  - New section "IMPORTANT: Code Node vs Expression Context" explaining key differences
+  - Lists expression-only functions not available in Code nodes ($now(), $today(), Tournament template functions)
+  - Clarifies different syntax: $('Node Name') vs $node['Node Name']
+  - Documents reversed JMESPath parameter order between contexts
+  - Added "Expression Functions NOT in Code Nodes" section with alternatives
+- **Enhanced Code Node Validation**: Added new validation checks for common expression/Code node confusion
+  - Detects expression syntax {{...}} in Code nodes with clear error message
+  - Warns about using $node[] syntax instead of $() in Code nodes
+  - Identifies expression-only functions with helpful alternatives
+  - Checks for wrong JMESPath parameter order
+  - Test script `test-expression-code-validation.ts` to verify validation works correctly
+
 ## [2.7.11] - 2025-07-09

 ### Fixed
@@ -30,6 +53,58 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Shows all node-level properties in proper configuration
  - Demonstrates common mistakes to avoid
  - Validates workflow configurations
+- **Comprehensive Code Node Documentation** in tools_documentation
+  - New `code_node_guide` topic with complete reference for JavaScript and Python
+  - Covers all built-in variables: $input, $json, $node, $workflow, $execution, $prevNode
+  - Documents helper functions: DateTime (Luxon), JMESPath, $helpers methods
+  - Includes return format requirements with correct/incorrect examples
+  - Security considerations and banned operations
+  - Common patterns: data transformation, filtering, aggregation, error handling
+  - Code node as AI tool examples
+  - Performance best practices and debugging tips
+- **Enhanced Code Node Validation** with n8n-specific patterns
+  - Validates return statement presence and format
+  - Checks for array of objects with json property
+  - Detects common mistakes (returning primitives, missing array wrapper)
+  - Validates n8n variable usage ($input, items, $json context)
+  - Security checks (eval, exec, require, file system access)
+  - Language-specific validation for JavaScript and Python
+  - Mode-specific warnings ($json in wrong mode)
+  - Async/await pattern validation
+  - External library detection with helpful alternatives
+- **Expanded Code Node Examples** in ExampleGenerator
+  - Data transformation, aggregation, and filtering examples
+  - API integration with error handling
+  - Python data processing example
+  - Code node as AI tool pattern
+  - CSV to JSON transformation
+  - All examples include proper return format
+- **New Code Node Task Templates**
+  - `custom_ai_tool`: Create custom tools for AI agents
+  - `aggregate_data`: Summary statistics from multiple items
+  - `batch_process_with_api`: Process items in batches with rate limiting
+  - `error_safe_transform`: Robust data transformation with validation
+  - `async_data_processing`: Concurrent processing with limits
+  - `python_data_analysis`: Statistical analysis using Python
+  - All templates include comprehensive error handling
+- **Fixed Misleading Documentation** based on real-world testing:
+  - **Crypto Module**: Clarified that `require('crypto')` IS available despite editor warnings
+  - **Helper Functions**: Fixed documentation showing `$getWorkflowStaticData()` is standalone, not on $helpers
+  - **JMESPath**: Corrected syntax from `jmespath.search()` to `$jmespath()`
+  - **Node Access**: Fixed from `$node['Node Name']` to `$('Node Name')`
+  - **Python**: Documented `item.json.to_py()` for JsProxy conversion
+  - Added comprehensive "Available Functions and Libraries" section
+  - Created security examples showing proper crypto usage
+  - **JMESPath Numeric Literals**: Added critical documentation about n8n-specific requirement for backticks around numbers in filters
+    - Example: `[?age >= \`18\`]` not `[?age >= 18]`
+    - Added validation to detect and warn about missing backticks
+    - Based on Claude Desktop feedback from workflow testing
+  - **Webhook Data Structure**: Fixed common webhook data access gotcha
+    - Webhook payload is at `items[0].json.body`, NOT `items[0].json` 
+    - Added dedicated "Webhook Data Access" section in Code node documentation
+    - Created webhook processing example showing correct data access
+    - Added validation to detect incorrect webhook data access patterns
+    - New task template `process_webhook_data` with complete example

 ### Enhanced
 - **MCP Tool Documentation** significantly improved:
@@ -41,9 +116,32 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
  - Expanded property checking from 6 to 11 node-level properties
  - Better error messages showing complete correct structure
  - Type validation for all node-level boolean and string properties
+- **Code Node Validation** enhanced with new checks:
+  - Detects incorrect `$helpers.getWorkflowStaticData()` usage
+  - Warns about `$helpers` usage without availability check
+  - Validates crypto usage with proper require statement
+  - All based on common errors found in production workflows
 - **Type Definitions** updated:
  - Added `notesInFlow` to WorkflowNode interface in workflow-validator.ts
  - Fixed credentials type from `Record<string, string>` to `Record<string, unknown>` in n8n-api.ts
+- **NodeSpecificValidators** now includes comprehensive Code node validation
+  - Language-specific syntax checks
+  - Return format validation with detailed error messages
+  - n8n variable usage validation
+  - Security pattern detection
+  - Error handling recommendations
+  - Mode-specific suggestions
+- **Config Validator** improved Code node validation
+  - Better return statement detection
+  - Enhanced syntax checking for both JavaScript and Python
+  - More helpful error messages with examples
+  - Detection of common n8n Code node mistakes
+- **Fixed Documentation Inaccuracies** based on user testing and n8n official docs:
+  - JMESPath: Corrected syntax to `$jmespath()` instead of `jmespath.search()`
+  - Node Access: Fixed to show `$('Node Name')` syntax, not `$node`
+  - Python: Documented `_input.all()` and `item.json.to_py()` for JsProxy conversion
+  - Python: Added underscore prefix documentation for all built-in variables
+  - Validation: Skip property visibility warnings for Code nodes to reduce false positives

 ## [2.7.10] - 2025-07-09

--- a/scripts/test-code-node-enhancements.ts
+++ b/scripts/test-code-node-enhancements.ts
@@ -0,0 +1,203 @@
+#!/usr/bin/env npx tsx
+
+/**
+ * Test script for Code node enhancements
+ * Tests:
+ * 1. Code node documentation in tools_documentation
+ * 2. Enhanced validation for Code nodes
+ * 3. Code node examples
+ * 4. Code node task templates
+ */
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+import { ExampleGenerator } from '../src/services/example-generator.js';
+import { TaskTemplates } from '../src/services/task-templates.js';
+import { getToolDocumentation } from '../src/mcp/tools-documentation.js';
+
+console.log('🧪 Testing Code Node Enhancements\n');
+
+// Test 1: Code node documentation
+console.log('1️⃣ Testing Code Node Documentation');
+console.log('=====================================');
+const codeNodeDocs = getToolDocumentation('code_node_guide', 'essentials');
+console.log('✅ Code node documentation available');
+console.log('First 500 chars:', codeNodeDocs.substring(0, 500) + '...\n');
+
+// Test 2: Code node validation
+console.log('2️⃣ Testing Code Node Validation');
+console.log('=====================================');
+
+// Test cases
+const validationTests = [
+  {
+    name: 'Empty code',
+    config: {
+      language: 'javaScript',
+      jsCode: ''
+    }
+  },
+  {
+    name: 'No return statement',
+    config: {
+      language: 'javaScript',
+      jsCode: 'const data = items;'
+    }
+  },
+  {
+    name: 'Invalid return format',
+    config: {
+      language: 'javaScript',
+      jsCode: 'return "hello";'
+    }
+  },
+  {
+    name: 'Valid code',
+    config: {
+      language: 'javaScript',
+      jsCode: 'return [{json: {result: "success"}}];'
+    }
+  },
+  {
+    name: 'Python with external library',
+    config: {
+      language: 'python',
+      pythonCode: 'import pandas as pd\nreturn [{"json": {"result": "fail"}}]'
+    }
+  },
+  {
+    name: 'Code with $json in wrong mode',
+    config: {
+      language: 'javaScript',
+      jsCode: 'const value = $json.field;\nreturn [{json: {value}}];'
+    }
+  },
+  {
+    name: 'Code with security issue',
+    config: {
+      language: 'javaScript',
+      jsCode: 'const result = eval(item.json.code);\nreturn [{json: {result}}];'
+    }
+  }
+];
+
+for (const test of validationTests) {
+  console.log(`\nTest: ${test.name}`);
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    [
+      { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+      { name: 'jsCode', type: 'string' },
+      { name: 'pythonCode', type: 'string' },
+      { name: 'mode', type: 'options', options: ['runOnceForAllItems', 'runOnceForEachItem'] }
+    ],
+    'operation',
+    'ai-friendly'
+  );
+  
+  console.log(`  Valid: ${result.valid}`);
+  if (result.errors.length > 0) {
+    console.log(`  Errors: ${result.errors.map(e => e.message).join(', ')}`);
+  }
+  if (result.warnings.length > 0) {
+    console.log(`  Warnings: ${result.warnings.map(w => w.message).join(', ')}`);
+  }
+  if (result.suggestions.length > 0) {
+    console.log(`  Suggestions: ${result.suggestions.join(', ')}`);
+  }
+}
+
+// Test 3: Code node examples
+console.log('\n\n3️⃣ Testing Code Node Examples');
+console.log('=====================================');
+
+const codeExamples = ExampleGenerator.getExamples('nodes-base.code');
+console.log('Available examples:', Object.keys(codeExamples));
+console.log('\nMinimal example:');
+console.log(JSON.stringify(codeExamples.minimal, null, 2));
+console.log('\nCommon example preview:');
+console.log(codeExamples.common?.jsCode?.substring(0, 200) + '...');
+
+// Test 4: Code node task templates
+console.log('\n\n4️⃣ Testing Code Node Task Templates');
+console.log('=====================================');
+
+const codeNodeTasks = [
+  'transform_data',
+  'custom_ai_tool',
+  'aggregate_data',
+  'batch_process_with_api',
+  'error_safe_transform',
+  'async_data_processing',
+  'python_data_analysis'
+];
+
+for (const taskName of codeNodeTasks) {
+  const template = TaskTemplates.getTemplate(taskName);
+  if (template) {
+    console.log(`\n✅ ${taskName}:`);
+    console.log(`   Description: ${template.description}`);
+    console.log(`   Language: ${template.configuration.language || 'javaScript'}`);
+    console.log(`   Code preview: ${template.configuration.jsCode?.substring(0, 100) || template.configuration.pythonCode?.substring(0, 100)}...`);
+  } else {
+    console.log(`\n❌ ${taskName}: Template not found`);
+  }
+}
+
+// Test 5: Validate a complex Code node configuration
+console.log('\n\n5️⃣ Testing Complex Code Node Validation');
+console.log('==========================================');
+
+const complexCode = {
+  language: 'javaScript',
+  mode: 'runOnceForEachItem',
+  jsCode: `// Complex validation test
+try {
+  const email = $json.email;
+  const response = await $helpers.httpRequest({
+    method: 'POST',
+    url: 'https://api.example.com/validate',
+    body: { email }
+  });
+  
+  return [{
+    json: {
+      ...response,
+      validated: true
+    }
+  }];
+} catch (error) {
+  return [{
+    json: {
+      error: error.message,
+      validated: false
+    }
+  }];
+}`,
+  onError: 'continueRegularOutput',
+  retryOnFail: true,
+  maxTries: 3
+};
+
+const complexResult = EnhancedConfigValidator.validateWithMode(
+  'nodes-base.code',
+  complexCode,
+  [
+    { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+    { name: 'jsCode', type: 'string' },
+    { name: 'mode', type: 'options', options: ['runOnceForAllItems', 'runOnceForEachItem'] },
+    { name: 'onError', type: 'options' },
+    { name: 'retryOnFail', type: 'boolean' },
+    { name: 'maxTries', type: 'number' }
+  ],
+  'operation',
+  'strict'
+);
+
+console.log('Complex code validation:');
+console.log(`  Valid: ${complexResult.valid}`);
+console.log(`  Errors: ${complexResult.errors.length}`);
+console.log(`  Warnings: ${complexResult.warnings.length}`);
+console.log(`  Suggestions: ${complexResult.suggestions.length}`);
+
+console.log('\n✅ All Code node enhancement tests completed!');
--- a/scripts/test-code-node-fixes.ts
+++ b/scripts/test-code-node-fixes.ts
@@ -0,0 +1,133 @@
+#!/usr/bin/env ts-node
+
+/**
+ * Test script to verify Code node documentation fixes
+ */
+
+import { createDatabaseAdapter } from '../src/database/database-adapter';
+import { NodeDocumentationService } from '../src/services/node-documentation-service';
+import { getToolDocumentation } from '../src/mcp/tools-documentation';
+import { ExampleGenerator } from '../src/services/example-generator';
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator';
+
+const dbPath = process.env.NODE_DB_PATH || './nodes.db';
+
+async function main() {
+  console.log('🧪 Testing Code Node Documentation Fixes\n');
+  
+  const db = await createDatabaseAdapter(dbPath);
+  const service = new NodeDocumentationService(dbPath);
+  
+  // Test 1: Check JMESPath documentation
+  console.log('1️⃣ Testing JMESPath Documentation Fix');
+  console.log('=====================================');
+  const codeNodeGuide = getToolDocumentation('code_node_guide', 'full');
+  
+  // Check for correct JMESPath syntax
+  if (codeNodeGuide.includes('$jmespath(') && !codeNodeGuide.includes('jmespath.search(')) {
+    console.log('✅ JMESPath documentation correctly shows $jmespath() syntax');
+  } else {
+    console.log('❌ JMESPath documentation still shows incorrect syntax');
+  }
+  
+  // Check for Python JMESPath
+  if (codeNodeGuide.includes('_jmespath(')) {
+    console.log('✅ Python JMESPath with underscore prefix documented');
+  } else {
+    console.log('❌ Python JMESPath not properly documented');
+  }
+  
+  // Test 2: Check $node documentation
+  console.log('\n2️⃣ Testing $node Documentation Fix');
+  console.log('===================================');
+  
+  if (codeNodeGuide.includes("$('Previous Node')") && !codeNodeGuide.includes('$node.name')) {
+    console.log('✅ Node access correctly shows $("Node Name") syntax');
+  } else {
+    console.log('❌ Node access documentation still incorrect');
+  }
+  
+  // Test 3: Check Python item.json documentation
+  console.log('\n3️⃣ Testing Python item.json Documentation Fix');
+  console.log('==============================================');
+  
+  if (codeNodeGuide.includes('item.json.to_py()') && codeNodeGuide.includes('JsProxy')) {
+    console.log('✅ Python item.json correctly documented with to_py() method');
+  } else {
+    console.log('❌ Python item.json documentation incomplete');
+  }
+  
+  // Test 4: Check Python examples
+  console.log('\n4️⃣ Testing Python Examples');
+  console.log('===========================');
+  
+  const pythonExample = ExampleGenerator.getExamples('nodes-base.code.pythonExample');
+  if (pythonExample?.minimal?.pythonCode?.includes('_input.all()') && 
+      pythonExample?.minimal?.pythonCode?.includes('to_py()')) {
+    console.log('✅ Python examples use correct _input.all() and to_py()');
+  } else {
+    console.log('❌ Python examples not updated correctly');
+  }
+  
+  // Test 5: Validate Code node without visibility warnings
+  console.log('\n5️⃣ Testing Code Node Validation (No Visibility Warnings)');
+  console.log('=========================================================');
+  
+  const codeNodeInfo = await service.getNodeInfo('n8n-nodes-base.code');
+  if (!codeNodeInfo) {
+    console.log('❌ Could not find Code node info');
+    return;
+  }
+  
+  const testConfig = {
+    language: 'javaScript',
+    jsCode: 'return items.map(item => ({json: {...item.json, processed: true}}))',
+    mode: 'runOnceForAllItems',
+    onError: 'continueRegularOutput'
+  };
+  
+  const nodeProperties = (codeNodeInfo as any).properties || [];
+  const validationResult = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    testConfig,
+    nodeProperties,
+    'full',
+    'ai-friendly'
+  );
+  
+  // Check if there are any visibility warnings
+  const visibilityWarnings = validationResult.warnings.filter(w => 
+    w.message.includes("won't be used due to current settings")
+  );
+  
+  if (visibilityWarnings.length === 0) {
+    console.log('✅ No false positive visibility warnings for Code node');
+  } else {
+    console.log(`❌ Still getting ${visibilityWarnings.length} visibility warnings:`);
+    visibilityWarnings.forEach(w => console.log(`   - ${w.property}: ${w.message}`));
+  }
+  
+  // Test 6: Check Python underscore variables in documentation
+  console.log('\n6️⃣ Testing Python Underscore Variables');
+  console.log('========================================');
+  
+  const pythonVarsDocumented = codeNodeGuide.includes('Variables use underscore prefix') &&
+                               codeNodeGuide.includes('_input') &&
+                               codeNodeGuide.includes('_json') &&
+                               codeNodeGuide.includes('_jmespath');
+  
+  if (pythonVarsDocumented) {
+    console.log('✅ Python underscore variables properly documented');
+  } else {
+    console.log('❌ Python underscore variables not fully documented');
+  }
+  
+  // Summary
+  console.log('\n📊 Test Summary');
+  console.log('===============');
+  console.log('All critical documentation fixes have been verified!');
+  
+  db.close();
+}
+
+main().catch(console.error);
--- a/scripts/test-expression-code-validation.ts
+++ b/scripts/test-expression-code-validation.ts
@@ -0,0 +1,138 @@
+#!/usr/bin/env npx tsx
+
+/**
+ * Test script for Expression vs Code Node validation
+ * Tests that we properly detect and warn about expression syntax in Code nodes
+ */
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+
+console.log('🧪 Testing Expression vs Code Node Validation\n');
+
+// Test cases with expression syntax that shouldn't work in Code nodes
+const testCases = [
+  {
+    name: 'Expression syntax in Code node',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Using expression syntax
+const value = {{$json.field}};
+return [{json: {value}}];`
+    },
+    expectedError: 'Expression syntax {{...}} is not valid in Code nodes'
+  },
+  {
+    name: 'Wrong $node syntax',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Using expression $node syntax
+const data = $node['Previous Node'].json;
+return [{json: data}];`
+    },
+    expectedWarning: 'Use $(\'Node Name\') instead of $node[\'Node Name\'] in Code nodes'
+  },
+  {
+    name: 'Expression-only functions',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Using expression functions
+const now = $now();
+const unique = items.unique();
+return [{json: {now, unique}}];`
+    },
+    expectedWarning: '$now() is an expression-only function'
+  },
+  {
+    name: 'Wrong JMESPath parameter order',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Wrong parameter order
+const result = $jmespath("users[*].name", data);
+return [{json: {result}}];`
+    },
+    expectedWarning: 'Code node $jmespath has reversed parameter order'
+  },
+  {
+    name: 'Correct Code node syntax',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Correct syntax
+const prevData = $('Previous Node').first();
+const now = DateTime.now();
+const result = $jmespath(data, "users[*].name");
+return [{json: {prevData, now, result}}];`
+    },
+    shouldBeValid: true
+  }
+];
+
+// Basic node properties for Code node
+const codeNodeProperties = [
+  { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+  { name: 'jsCode', type: 'string' },
+  { name: 'pythonCode', type: 'string' },
+  { name: 'mode', type: 'options', options: ['runOnceForAllItems', 'runOnceForEachItem'] }
+];
+
+console.log('Running validation tests...\n');
+
+testCases.forEach((test, index) => {
+  console.log(`Test ${index + 1}: ${test.name}`);
+  console.log('─'.repeat(50));
+  
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    codeNodeProperties,
+    'operation',
+    'ai-friendly'
+  );
+  
+  console.log(`Valid: ${result.valid}`);
+  console.log(`Errors: ${result.errors.length}`);
+  console.log(`Warnings: ${result.warnings.length}`);
+  
+  if (test.expectedError) {
+    const hasExpectedError = result.errors.some(e => 
+      e.message.includes(test.expectedError)
+    );
+    console.log(`✅ Expected error found: ${hasExpectedError}`);
+    if (!hasExpectedError) {
+      console.log('❌ Missing expected error:', test.expectedError);
+      console.log('Actual errors:', result.errors.map(e => e.message));
+    }
+  }
+  
+  if (test.expectedWarning) {
+    const hasExpectedWarning = result.warnings.some(w => 
+      w.message.includes(test.expectedWarning)
+    );
+    console.log(`✅ Expected warning found: ${hasExpectedWarning}`);
+    if (!hasExpectedWarning) {
+      console.log('❌ Missing expected warning:', test.expectedWarning);
+      console.log('Actual warnings:', result.warnings.map(w => w.message));
+    }
+  }
+  
+  if (test.shouldBeValid) {
+    console.log(`✅ Should be valid: ${result.valid && result.errors.length === 0}`);
+    if (!result.valid || result.errors.length > 0) {
+      console.log('❌ Unexpected errors:', result.errors);
+    }
+  }
+  
+  // Show actual messages
+  if (result.errors.length > 0) {
+    console.log('\nErrors:');
+    result.errors.forEach(e => console.log(`  - ${e.message}`));
+  }
+  
+  if (result.warnings.length > 0) {
+    console.log('\nWarnings:');
+    result.warnings.forEach(w => console.log(`  - ${w.message}`));
+  }
+  
+  console.log('\n');
+});
+
+console.log('✅ Expression vs Code Node validation tests completed!');
--- a/scripts/test-helpers-validation.ts
+++ b/scripts/test-helpers-validation.ts
@@ -0,0 +1,93 @@
+#!/usr/bin/env npx tsx
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+
+console.log('🧪 Testing $helpers Validation\n');
+
+const testCases = [
+  {
+    name: 'Incorrect $helpers.getWorkflowStaticData',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = $helpers.getWorkflowStaticData('global');
+data.counter = 1;
+return [{json: {counter: data.counter}}];`
+    }
+  },
+  {
+    name: 'Correct $getWorkflowStaticData',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = $getWorkflowStaticData('global');
+data.counter = 1;
+return [{json: {counter: data.counter}}];`
+    }
+  },
+  {
+    name: '$helpers without check',
+    config: {
+      language: 'javaScript',
+      jsCode: `const response = await $helpers.httpRequest({
+  method: 'GET',
+  url: 'https://api.example.com'
+});
+return [{json: response}];`
+    }
+  },
+  {
+    name: '$helpers with proper check',
+    config: {
+      language: 'javaScript',
+      jsCode: `if (typeof $helpers !== 'undefined' && $helpers.httpRequest) {
+  const response = await $helpers.httpRequest({
+    method: 'GET',
+    url: 'https://api.example.com'
+  });
+  return [{json: response}];
+}
+return [{json: {error: 'HTTP not available'}}];`
+    }
+  },
+  {
+    name: 'Crypto without require',
+    config: {
+      language: 'javaScript',
+      jsCode: `const token = crypto.randomBytes(32).toString('hex');
+return [{json: {token}}];`
+    }
+  },
+  {
+    name: 'Crypto with require',
+    config: {
+      language: 'javaScript',
+      jsCode: `const crypto = require('crypto');
+const token = crypto.randomBytes(32).toString('hex');
+return [{json: {token}}];`
+    }
+  }
+];
+
+for (const test of testCases) {
+  console.log(`Test: ${test.name}`);
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    [
+      { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+      { name: 'jsCode', type: 'string' }
+    ],
+    'operation',
+    'ai-friendly'
+  );
+  
+  console.log(`  Valid: ${result.valid}`);
+  if (result.errors.length > 0) {
+    console.log(`  Errors: ${result.errors.map(e => e.message).join(', ')}`);
+  }
+  if (result.warnings.length > 0) {
+    console.log(`  Warnings: ${result.warnings.map(w => w.message).join(', ')}`);
+  }
+  console.log();
+}
+
+console.log('✅ $helpers validation tests completed!');
--- a/scripts/test-jmespath-validation.ts
+++ b/scripts/test-jmespath-validation.ts
@@ -0,0 +1,114 @@
+#!/usr/bin/env npx tsx
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+
+console.log('🧪 Testing JMESPath Validation\n');
+
+const testCases = [
+  {
+    name: 'JMESPath with unquoted numeric literal',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }] };
+const adults = $jmespath(data, 'users[?age >= 18]');
+return [{json: {adults}}];`
+    },
+    expectError: true
+  },
+  {
+    name: 'JMESPath with properly quoted numeric literal',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }] };
+const adults = $jmespath(data, 'users[?age >= \`18\`]');
+return [{json: {adults}}];`
+    },
+    expectError: false
+  },
+  {
+    name: 'Multiple JMESPath filters with unquoted numbers',
+    config: {
+      language: 'javaScript',
+      jsCode: `const products = items.map(item => item.json);
+const expensive = $jmespath(products, '[?price > 100]');
+const lowStock = $jmespath(products, '[?quantity < 10]');
+const highPriority = $jmespath(products, '[?priority == 1]');
+return [{json: {expensive, lowStock, highPriority}}];`
+    },
+    expectError: true
+  },
+  {
+    name: 'JMESPath with string comparison (no backticks needed)',
+    config: {
+      language: 'javaScript',
+      jsCode: `const data = { users: [{ name: 'John', status: 'active' }, { name: 'Jane', status: 'inactive' }] };
+const activeUsers = $jmespath(data, 'users[?status == "active"]');
+return [{json: {activeUsers}}];`
+    },
+    expectError: false
+  },
+  {
+    name: 'Python JMESPath with unquoted numeric literal',
+    config: {
+      language: 'python',
+      pythonCode: `data = { 'users': [{ 'name': 'John', 'age': 30 }, { 'name': 'Jane', 'age': 25 }] }
+adults = _jmespath(data, 'users[?age >= 18]')
+return [{'json': {'adults': adults}}]`
+    },
+    expectError: true
+  },
+  {
+    name: 'Complex filter with decimal numbers',
+    config: {
+      language: 'javaScript',
+      jsCode: `const items = [{ price: 99.99 }, { price: 150.50 }, { price: 200 }];
+const expensive = $jmespath(items, '[?price >= 99.95]');
+return [{json: {expensive}}];`
+    },
+    expectError: true
+  }
+];
+
+let passCount = 0;
+let failCount = 0;
+
+for (const test of testCases) {
+  console.log(`Test: ${test.name}`);
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    [
+      { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+      { name: 'jsCode', type: 'string' },
+      { name: 'pythonCode', type: 'string' }
+    ],
+    'operation',
+    'strict'
+  );
+  
+  const hasJMESPathError = result.errors.some(e => 
+    e.message.includes('JMESPath numeric literal') || 
+    e.message.includes('must be wrapped in backticks')
+  );
+  
+  const passed = hasJMESPathError === test.expectError;
+  
+  console.log(`  Expected error: ${test.expectError}`);
+  console.log(`  Has JMESPath error: ${hasJMESPathError}`);
+  console.log(`  Result: ${passed ? '✅ PASS' : '❌ FAIL'}`);
+  
+  if (result.errors.length > 0) {
+    console.log(`  Errors: ${result.errors.map(e => e.message).join(', ')}`);
+  }
+  if (result.warnings.length > 0) {
+    console.log(`  Warnings: ${result.warnings.slice(0, 2).map(w => w.message).join(', ')}`);
+  }
+  
+  if (passed) passCount++;
+  else failCount++;
+  
+  console.log();
+}
+
+console.log(`\n📊 Results: ${passCount} passed, ${failCount} failed`);
+console.log(failCount === 0 ? '✅ All JMESPath validation tests passed!' : '❌ Some tests failed');
--- a/scripts/test-webhook-validation.ts
+++ b/scripts/test-webhook-validation.ts
@@ -0,0 +1,111 @@
+#!/usr/bin/env npx tsx
+
+import { EnhancedConfigValidator } from '../src/services/enhanced-config-validator.js';
+
+console.log('🧪 Testing Webhook Data Access Validation\n');
+
+const testCases = [
+  {
+    name: 'Direct webhook data access (incorrect)',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Processing data from Webhook node
+const prevWebhook = $('Webhook').first();
+const command = items[0].json.testCommand;
+const data = items[0].json.payload;
+return [{json: {command, data}}];`
+    },
+    expectWarning: true
+  },
+  {
+    name: 'Correct webhook data access through body',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Processing data from Webhook node
+const webhookData = items[0].json.body;
+const command = webhookData.testCommand;
+const data = webhookData.payload;
+return [{json: {command, data}}];`
+    },
+    expectWarning: false
+  },
+  {
+    name: 'Common webhook field names without body',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Processing webhook
+const command = items[0].json.command;
+const action = items[0].json.action;
+const payload = items[0].json.payload;
+return [{json: {command, action, payload}}];`
+    },
+    expectWarning: true
+  },
+  {
+    name: 'Non-webhook data access (should not warn)',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Processing data from HTTP Request node
+const data = items[0].json.results;
+const status = items[0].json.status;
+return [{json: {data, status}}];`
+    },
+    expectWarning: false
+  },
+  {
+    name: 'Mixed correct and incorrect access',
+    config: {
+      language: 'javaScript',
+      jsCode: `// Mixed access patterns
+const webhookBody = items[0].json.body;  // Correct
+const directAccess = items[0].json.command;  // Incorrect if webhook
+return [{json: {webhookBody, directAccess}}];`
+    },
+    expectWarning: false  // If user already uses .body, we assume they know the pattern
+  }
+];
+
+let passCount = 0;
+let failCount = 0;
+
+for (const test of testCases) {
+  console.log(`Test: ${test.name}`);
+  const result = EnhancedConfigValidator.validateWithMode(
+    'nodes-base.code',
+    test.config,
+    [
+      { name: 'language', type: 'options', options: ['javaScript', 'python'] },
+      { name: 'jsCode', type: 'string' }
+    ],
+    'operation',
+    'ai-friendly'
+  );
+  
+  const hasWebhookWarning = result.warnings.some(w => 
+    w.message.includes('Webhook data is nested under .body') ||
+    w.message.includes('webhook data, remember it\'s nested under .body')
+  );
+  
+  const passed = hasWebhookWarning === test.expectWarning;
+  
+  console.log(`  Expected warning: ${test.expectWarning}`);
+  console.log(`  Has webhook warning: ${hasWebhookWarning}`);
+  console.log(`  Result: ${passed ? '✅ PASS' : '❌ FAIL'}`);
+  
+  if (result.warnings.length > 0) {
+    const relevantWarnings = result.warnings
+      .filter(w => w.message.includes('webhook') || w.message.includes('Webhook'))
+      .map(w => w.message);
+    if (relevantWarnings.length > 0) {
+      console.log(`  Webhook warnings: ${relevantWarnings.join(', ')}`);
+    }
+  }
+  
+  if (passed) passCount++;
+  else failCount++;
+  
+  console.log();
+}
+
+console.log(`\n📊 Results: ${passCount} passed, ${failCount} failed`);
+console.log(failCount === 0 ? '✅ All webhook validation tests passed!' : '❌ Some tests failed');
--- a/src/mcp/tools-documentation.ts
+++ b/src/mcp/tools-documentation.ts
@@ -504,6 +504,643 @@ n8n_update_partial_workflow({
      ],
      relatedTools: ['n8n_get_workflow', 'n8n_update_full_workflow', 'validate_workflow']
    }
+  },
+
+  // Code Node specific documentation
+  code_node_guide: {
+    name: 'code_node_guide',
+    category: 'code_node',
+    essentials: {
+      description: 'Comprehensive guide for writing Code node JavaScript and Python',
+      keyParameters: ['topic'],
+      example: 'tools_documentation({topic: "code_node_guide"})',
+      performance: 'Instant - returns documentation',
+      tips: [
+        'Essential reading before writing Code node scripts',
+        'Covers all built-in variables and helpers',
+        'Includes common patterns and error handling'
+      ]
+    },
+    full: {
+      description: `Complete reference for the n8n Code node, covering JavaScript and Python execution environments, built-in variables, helper functions, and best practices.
+
+## Code Node Basics
+
+The Code node allows custom JavaScript or Python code execution within workflows. It runs in a sandboxed environment with access to n8n-specific variables and helpers.
+
+### JavaScript Environment
+- **ES2022 support** with async/await
+- **Built-in libraries**: 
+  - **luxon** (DateTime) - Date/time manipulation
+  - **jmespath** - JSON queries via $jmespath()
+  - **crypto** - Available via require('crypto') despite editor warnings!
+- **Node.js globals**: Buffer, process.env (limited)
+- **require() IS available** for built-in modules only (crypto, util, etc.)
+- **No npm packages** - only Node.js built-ins and n8n-provided libraries
+
+### Python Environment  
+- **Python 3.10+** with standard library (Pyodide runtime)
+- **No pip install** - standard library only
+- **Variables use underscore prefix**: \`_input\`, \`_json\`, \`_jmespath\` (not \`$\`)
+- **item.json is JsProxy**: Use \`.to_py()\` to convert to Python dict
+- **Shared state** between Code nodes in same execution
+
+## Essential Variables
+
+### $input
+Access to all incoming data:
+\`\`\`javascript
+// Get all items from all inputs
+const allItems = $input.all();  // Returns: Item[][]
+
+// Get items from specific input (0-indexed)
+const firstInput = $input.all(0);  // Returns: Item[]
+
+// Get first item from first input
+const firstItem = $input.first();  // Returns: Item
+
+// Get last item from first input  
+const lastItem = $input.last();  // Returns: Item
+
+// Get specific item by index
+const item = $input.item(2);  // Returns: Item at index 2
+\`\`\`
+
+### items
+Direct access to incoming items (legacy, prefer $input):
+\`\`\`javascript
+// items is equivalent to $input.all()[0]
+for (const item of items) {
+  console.log(item.json);  // Access JSON data
+  console.log(item.binary);  // Access binary data
+}
+\`\`\`
+
+### $json
+Shortcut to current item's JSON data (only in "Run Once for Each Item" mode):
+\`\`\`javascript
+// These are equivalent in single-item mode:
+const value1 = $json.fieldName;
+const value2 = items[0].json.fieldName;
+\`\`\`
+
+### Accessing Other Nodes
+Access data from other nodes using $('Node Name') syntax:
+\`\`\`javascript
+// Access another node's output - use $('Node Name') NOT $node
+const prevData = $('Previous Node').all();
+const firstItem = $('Previous Node').first();
+const specificItem = $('Previous Node').item(0);
+
+// Get node parameter
+const webhookUrl = $('Webhook').params.path;
+
+// Python uses underscore prefix
+const pythonData = _('Previous Node').all();
+\`\`\`
+
+⚠️ **Expression vs Code Node Syntax**:
+- **Expressions**: \`{{$node['Previous Node'].json.field}}\`
+- **Code Node**: \`$('Previous Node').first().json.field\`
+- These are NOT interchangeable!
+
+### $workflow
+Workflow metadata:
+\`\`\`javascript
+const workflowId = $workflow.id;
+const workflowName = $workflow.name;
+const isActive = $workflow.active;
+\`\`\`
+
+### $execution
+Execution context:
+\`\`\`javascript
+const executionId = $execution.id;
+const executionMode = $execution.mode;  // 'manual', 'trigger', etc.
+const resumeUrl = $execution.resumeUrl;  // For wait nodes
+\`\`\`
+
+### $prevNode
+Access to the immediate previous node:
+\`\`\`javascript
+const prevOutput = $prevNode.outputIndex;  // Which output triggered this
+const prevData = $prevNode.data;  // Previous node's data
+const prevName = $prevNode.name;  // Previous node's name
+\`\`\`
+
+## Helper Functions
+
+### Date/Time (Luxon)
+\`\`\`javascript
+// Current time
+const now = DateTime.now();
+const iso = now.toISO();
+
+// Parse dates
+const date = DateTime.fromISO('2024-01-01');
+const formatted = date.toFormat('yyyy-MM-dd');
+
+// Time math
+const tomorrow = now.plus({ days: 1 });
+const hourAgo = now.minus({ hours: 1 });
+\`\`\`
+
+### JSON Queries (JMESPath)
+\`\`\`javascript
+// n8n uses $jmespath() - NOTE: parameter order is reversed from standard JMESPath!
+const data = { users: [{ name: 'John', age: 30 }, { name: 'Jane', age: 25 }] };
+const names = $jmespath(data, 'users[*].name');  // ['John', 'Jane']
+
+// ⚠️ IMPORTANT: Numeric literals in filters need BACKTICKS in n8n!
+const adults = $jmespath(data, 'users[?age >= \`18\`]');  // ✅ CORRECT - backticks around 18
+const seniors = $jmespath(data, 'users[?age >= \`65\`]');  // ✅ CORRECT
+
+// ❌ WRONG - This will cause a syntax error!
+// const adults = $jmespath(data, 'users[?age >= 18]');  // Missing backticks
+
+// More filter examples with proper backticks:
+const expensive = $jmespath(items, '[?price > \`100\`]');
+const inStock = $jmespath(products, '[?quantity >= \`1\`]');
+const highPriority = $jmespath(tasks, '[?priority == \`1\`]');
+
+// String comparisons don't need backticks
+const activeUsers = $jmespath(data, 'users[?status == "active"]');
+
+// Python uses underscore prefix
+const pythonAdults = _jmespath(data, 'users[?age >= \`18\`]');
+\`\`\`
+
+⚠️ **CRITICAL DIFFERENCES** from standard JMESPath:
+1. **Parameter order is REVERSED**:
+   - **Expression**: \`{{$jmespath("query", data)}}\`
+   - **Code Node**: \`$jmespath(data, "query")\`
+2. **Numeric literals in filters MUST use backticks**: \`[?age >= \`18\`]\`
+   - This is n8n-specific and differs from standard JMESPath documentation!
+
+### Available Functions and Libraries
+
+#### Built-in Node.js Modules (via require)
+\`\`\`javascript
+// ✅ These modules ARE available via require():
+const crypto = require('crypto');        // Cryptographic functions
+const util = require('util');            // Utility functions
+const querystring = require('querystring'); // URL query string utilities
+
+// Example: Generate secure random token
+const crypto = require('crypto');
+const token = crypto.randomBytes(32).toString('hex');
+const uuid = crypto.randomUUID();
+\`\`\`
+
+**Note**: The editor may show errors for require() but it WORKS at runtime!
+
+#### Standalone Functions (Global Scope)
+\`\`\`javascript
+// ✅ Workflow static data - persists between executions
+// IMPORTANT: These are standalone functions, NOT methods on $helpers!
+const staticData = $getWorkflowStaticData('global'); // Global static data
+const nodeData = $getWorkflowStaticData('node');    // Node-specific data
+
+// Example: Counter that persists
+const staticData = $getWorkflowStaticData('global');
+staticData.counter = (staticData.counter || 0) + 1;
+
+// ❌ WRONG - This will cause "$helpers is not defined" error:
+// const data = $helpers.getWorkflowStaticData('global');
+
+// JMESPath queries - note the parameter order!
+const result = $jmespath(data, 'users[*].name');
+\`\`\`
+
+#### $helpers Object (When Available)
+\`\`\`javascript
+// Some n8n versions provide $helpers with these methods:
+// (Always test availability in your n8n instance)
+
+// HTTP requests
+const response = await $helpers.httpRequest({
+  method: 'GET',
+  url: 'https://api.example.com/data',
+  headers: { 'Authorization': 'Bearer token' }
+});
+
+// Binary data preparation  
+const binaryData = await $helpers.prepareBinaryData(
+  Buffer.from('content'), 
+  'file.txt',
+  'text/plain'
+);
+
+// Check if $helpers exists before using:
+if (typeof $helpers !== 'undefined' && $helpers.httpRequest) {
+  // Use $helpers.httpRequest
+} else {
+  throw new Error('HTTP requests not available in this n8n version');
+}
+\`\`\`
+
+#### Important Notes:
+- **$getWorkflowStaticData()** is ALWAYS a standalone function
+- **require()** works for built-in Node.js modules despite editor warnings
+- **$helpers** availability varies by n8n version - always check first
+- Python uses underscore prefix: \`_getWorkflowStaticData()\`, \`_jmespath()\`
+- Editor red underlines are often false positives - test at runtime!
+
+## Return Format
+
+Code nodes MUST return an array of objects with 'json' property:
+
+\`\`\`javascript
+// ✅ CORRECT - Array of objects with json property
+return [
+  { json: { id: 1, name: 'Item 1' } },
+  { json: { id: 2, name: 'Item 2' } }
+];
+
+// ✅ CORRECT - Single item (still wrapped in array)
+return [{ json: { result: 'success' } }];
+
+// ✅ CORRECT - With binary data
+return [{
+  json: { filename: 'report.pdf' },
+  binary: {
+    data: {
+      data: base64String,
+      mimeType: 'application/pdf',
+      fileName: 'report.pdf'
+    }
+  }
+}];
+
+// ❌ WRONG - Not an array
+return { json: { result: 'success' } };
+
+// ❌ WRONG - No json property
+return [{ result: 'success' }];
+
+// ❌ WRONG - Not wrapped in object
+return ['item1', 'item2'];
+\`\`\`
+
+## Common Patterns
+
+### Data Transformation
+\`\`\`javascript
+// Transform all items
+const transformedItems = [];
+for (const item of items) {
+  transformedItems.push({
+    json: {
+      ...item.json,
+      processed: true,
+      timestamp: DateTime.now().toISO(),
+      uppercaseName: item.json.name?.toUpperCase()
+    }
+  });
+}
+return transformedItems;
+\`\`\`
+
+### Filtering Items
+\`\`\`javascript
+// Filter items based on condition
+return items
+  .filter(item => item.json.status === 'active')
+  .map(item => ({ json: item.json }));
+\`\`\`
+
+### Aggregation
+\`\`\`javascript
+// Aggregate data from all items
+const total = items.reduce((sum, item) => sum + (item.json.amount || 0), 0);
+const average = total / items.length;
+
+return [{
+  json: {
+    total,
+    average,
+    count: items.length,
+    items: items.map(i => i.json)
+  }
+}];
+\`\`\`
+
+### Error Handling
+\`\`\`javascript
+// Safe data access with defaults
+const results = [];
+for (const item of items) {
+  try {
+    const value = item.json?.nested?.field || 'default';
+    results.push({
+      json: {
+        processed: value,
+        status: 'success'
+      }
+    });
+  } catch (error) {
+    results.push({
+      json: {
+        error: error.message,
+        status: 'failed',
+        originalItem: item.json
+      }
+    });
+  }
+}
+return results;
+\`\`\`
+
+### Working with APIs
+\`\`\`javascript
+// Make HTTP request and process response
+try {
+  const response = await $helpers.httpRequest({
+    method: 'POST',
+    url: 'https://api.example.com/process',
+    body: {
+      data: items.map(item => item.json)
+    },
+    headers: {
+      'Content-Type': 'application/json'
+    }
+  });
+  
+  return [{ json: response }];
+} catch (error) {
+  throw new Error(\`API request failed: \${error.message}\`);
+}
+\`\`\`
+
+### Async Operations
+\`\`\`javascript
+// Process items with async operations
+const results = [];
+for (const item of items) {
+  // Simulate async operation
+  await new Promise(resolve => setTimeout(resolve, 100));
+  
+  results.push({
+    json: {
+      ...item.json,
+      processedAt: new Date().toISOString()
+    }
+  });
+}
+return results;
+\`\`\`
+
+### Webhook Data Access (CRITICAL!)
+\`\`\`javascript
+// ⚠️ WEBHOOK DATA IS NESTED UNDER 'body' PROPERTY!
+// This is a common source of errors in webhook-triggered workflows
+
+// ❌ WRONG - This will be undefined for webhook data:
+const command = items[0].json.testCommand;
+
+// ✅ CORRECT - Webhook data is wrapped in 'body':
+const command = items[0].json.body.testCommand;
+
+// Complete webhook data processing example:
+const webhookData = items[0].json.body; // Get the actual webhook payload
+const headers = items[0].json.headers;   // HTTP headers are separate
+const query = items[0].json.query;       // Query parameters are separate
+
+// Process webhook payload
+return [{
+  json: {
+    command: webhookData.testCommand,
+    user: webhookData.user,
+    timestamp: DateTime.now().toISO(),
+    requestId: headers['x-request-id'],
+    source: query.source || 'unknown'
+  }
+}];
+
+// For other trigger nodes (non-webhook), data is directly under json:
+// - Schedule Trigger: items[0].json contains timestamp
+// - Database Trigger: items[0].json contains row data
+// - File Trigger: items[0].json contains file info
+\`\`\`
+
+## Python Code Examples
+
+### Basic Python Structure
+\`\`\`python
+import json
+from datetime import datetime
+
+# Access items - Python uses underscore prefix for built-in variables
+results = []
+for item in _input.all():
+    # IMPORTANT: item.json is NOT a standard Python dict!
+    # Use to_py() to convert to a proper Python dict
+    processed_item = item.json.to_py()  # Converts JsProxy to Python dict
+    processed_item['timestamp'] = datetime.now().isoformat()
+    results.append({'json': processed_item})
+
+return results
+\`\`\`
+
+### Python Data Processing
+\`\`\`python
+# Aggregate data - use _input.all() to get items
+items = _input.all()
+total = sum(item.json.get('amount', 0) for item in items)
+average = total / len(items) if items else 0
+
+# For safe dict operations, convert JsProxy to Python dict
+safe_items = []
+for item in items:
+    # Convert JsProxy to dict to avoid KeyError with null values
+    safe_dict = item.json.to_py()
+    safe_items.append(safe_dict)
+
+# Return aggregated result
+return [{
+    'json': {
+        'total': total,
+        'average': average,
+        'count': len(items),
+        'processed_at': datetime.now().isoformat(),
+        'items': safe_items  # Now these are proper Python dicts
+    }
+}]
+\`\`\`
+
+## Code Node as AI Tool
+
+Code nodes can be used as custom tools for AI agents:
+
+\`\`\`javascript
+// Code node configured as AI tool
+// Name: "Calculate Discount"
+// Description: "Calculates discount based on quantity"
+
+const quantity = $json.quantity || 1;
+const basePrice = $json.price || 0;
+
+let discount = 0;
+if (quantity >= 100) discount = 0.20;
+else if (quantity >= 50) discount = 0.15;
+else if (quantity >= 20) discount = 0.10;
+else if (quantity >= 10) discount = 0.05;
+
+const discountAmount = basePrice * quantity * discount;
+const finalPrice = (basePrice * quantity) - discountAmount;
+
+return [{
+  json: {
+    quantity,
+    basePrice,
+    discountPercentage: discount * 100,
+    discountAmount,
+    finalPrice,
+    savings: discountAmount
+  }
+}];
+\`\`\`
+
+## Security Considerations
+
+### Available Security Features
+\`\`\`javascript
+// ✅ Crypto IS available despite editor warnings!
+const crypto = require('crypto');
+
+// Generate secure random values
+const randomBytes = crypto.randomBytes(32);
+const randomUUID = crypto.randomUUID();
+
+// Create hashes
+const hash = crypto.createHash('sha256')
+  .update('data to hash')
+  .digest('hex');
+
+// HMAC for signatures
+const hmac = crypto.createHmac('sha256', 'secret-key')
+  .update('data to sign')
+  .digest('hex');
+\`\`\`
+
+### Banned Operations
+- No file system access (fs module) - except read-only for some paths
+- No network requests except via $helpers.httpRequest
+- No child process execution
+- No external npm packages (only built-in Node.js modules)
+- No eval() or Function() constructor
+
+### Safe Practices
+\`\`\`javascript
+// ✅ SAFE - Use crypto for secure operations
+const crypto = require('crypto');
+const token = crypto.randomBytes(32).toString('hex');
+
+// ✅ SAFE - Use built-in JSON parsing
+const parsed = JSON.parse(jsonString);
+
+// ❌ UNSAFE - Never use eval
+const parsed = eval('(' + jsonString + ')');
+
+// ✅ SAFE - Validate input
+if (typeof item.json.userId !== 'string') {
+  throw new Error('userId must be a string');
+}
+
+// ✅ SAFE - Sanitize for logs
+const safeLog = String(userInput).substring(0, 100);
+
+// ✅ SAFE - Time-safe comparison for secrets
+const expectedToken = 'abc123';
+const providedToken = item.json.token;
+const tokensMatch = crypto.timingSafeEqual(
+  Buffer.from(expectedToken),
+  Buffer.from(providedToken || '')
+);
+\`\`\`
+
+## Debugging Tips
+
+### Console Output
+\`\`\`javascript
+// Console.log appears in n8n execution logs
+console.log('Processing item:', item.json.id);
+console.error('Error details:', error);
+
+// Return debug info in development
+return [{
+  json: {
+    result: processedData,
+    debug: {
+      itemCount: items.length,
+      executionId: $execution.id,
+      timestamp: new Date().toISOString()
+    }
+  }
+}];
+\`\`\`
+
+### Error Messages
+\`\`\`javascript
+// Provide helpful error context
+if (!item.json.requiredField) {
+  throw new Error(\`Missing required field 'requiredField' in item \${items.indexOf(item)}\`);
+}
+
+// Include original data in errors
+try {
+  // processing...
+} catch (error) {
+  throw new Error(\`Failed to process item \${item.json.id}: \${error.message}\`);
+}
+\`\`\`
+
+## Performance Best Practices
+
+1. **Avoid nested loops** when possible
+2. **Use array methods** (map, filter, reduce) for clarity
+3. **Limit HTTP requests** - batch when possible
+4. **Return early** for error conditions
+5. **Keep state minimal** - Code nodes are stateless between executions
+
+## Common Mistakes to Avoid
+
+1. **Forgetting to return an array**
+2. **Not wrapping in json property**
+3. **Modifying items array directly**
+4. **Using undefined variables**
+5. **Infinite loops with while statements**
+6. **Not handling missing data gracefully**
+7. **Forgetting await for async operations**`,
+      parameters: {
+        topic: { type: 'string', description: 'Specific Code node topic (optional)', required: false }
+      },
+      returns: 'Comprehensive Code node documentation and examples',
+      examples: [
+        'tools_documentation({topic: "code_node_guide"}) - Full guide',
+        'tools_documentation({topic: "code_node_guide", depth: "full"}) - Complete reference'
+      ],
+      useCases: [
+        'Learning Code node capabilities',
+        'Understanding built-in variables',
+        'Finding the right helper function',
+        'Debugging Code node issues',
+        'Building custom AI tools'
+      ],
+      performance: 'Instant - returns static documentation',
+      bestPractices: [
+        'Read before writing Code nodes',
+        'Reference for variable names',
+        'Copy examples as starting points',
+        'Check security considerations'
+      ],
+      pitfalls: [
+        'Not all Node.js features available',
+        'Python has limited libraries',
+        'State not preserved between executions'
+      ],
+      relatedTools: ['get_node_essentials', 'validate_node_operation', 'get_node_for_task']
+    }
  }
 };

@@ -584,6 +1221,7 @@ Welcome! Here's how to efficiently work with n8n nodes:

 ## Get Help
 - tools_documentation({topic: "search_nodes"}) - Get help for specific tool
+- tools_documentation({topic: "code_node_guide"}) - Essential Code node reference
 - tools_documentation({topic: "overview", depth: "full"}) - See complete guide
 - list_tasks() - See available task templates

@@ -652,6 +1290,23 @@ validate_workflow(workflow)
 n8n_create_workflow(workflow)
 \`\`\`

+### Working with Code Nodes
+The Code node is essential for custom logic. Always reference the guide:
+\`\`\`javascript
+// Get comprehensive Code node documentation
+tools_documentation({topic: "code_node_guide"})
+
+// Common Code node pattern
+get_node_essentials("n8n-nodes-base.code")
+// Returns minimal config with JavaScript/Python examples
+
+// Validate Code node configuration
+validate_node_operation("n8n-nodes-base.code", {
+  language: "javaScript",
+  jsCode: "return items.map(item => ({json: {...item.json, processed: true}}))"
+})
+\`\`\`
+
 ### Node-Level Properties Reference
 ⚠️ **CRITICAL**: These properties go at the NODE level, not inside parameters!

--- a/src/services/config-validator.ts
+++ b/src/services/config-validator.ts
@@ -391,12 +391,18 @@ export class ConfigValidator {
   * Check for common configuration issues
   */
  private static checkCommonIssues(
-    _nodeType: string,
+    nodeType: string,
    config: Record<string, any>,
    properties: any[],
    warnings: ValidationWarning[],
    suggestions: string[]
  ): void {
+    // Skip visibility checks for Code nodes as they have simple property structure
+    if (nodeType === 'nodes-base.code') {
+      // Code nodes don't have complex displayOptions, so skip visibility warnings
+      return;
+    }
+    
    // Check for properties that won't be used
    const visibleProps = properties.filter(p => this.isPropertyVisible(p, config));
    const configuredKeys = Object.keys(config);
@@ -562,20 +568,133 @@ export class ConfigValidator {
      warnings.push({
        type: 'missing_common',
        message: 'No return statement found',
-        suggestion: 'Code node should return data for the next node. Add: return items (Python) or return items; (JavaScript)'
+        suggestion: 'Code node must return data. Example: return [{json: {result: "success"}}]'
      });
    }
    
-    // Check for common n8n patterns
+    // Check return format for JavaScript
+    if (language === 'javascript' && hasReturn) {
+      // Check for common incorrect return patterns
+      if (/return\s+items\s*;/.test(code) && !code.includes('.map') && !code.includes('json:')) {
+        warnings.push({
+          type: 'best_practice',
+          message: 'Returning items directly - ensure each item has {json: ...} structure',
+          suggestion: 'If modifying items, use: return items.map(item => ({json: {...item.json, newField: "value"}}))'
+        });
+      }
+      
+      // Check for return without array
+      if (/return\s+{[^}]+}\s*;/.test(code) && !code.includes('[') && !code.includes(']')) {
+        warnings.push({
+          type: 'invalid_value',
+          message: 'Return value must be an array',
+          suggestion: 'Wrap your return object in an array: return [{json: {your: "data"}}]'
+        });
+      }
+      
+      // Check for direct data return without json wrapper
+      if (/return\s+\[['"`]/.test(code) || /return\s+\[\d/.test(code)) {
+        warnings.push({
+          type: 'invalid_value',
+          message: 'Items must be objects with json property',
+          suggestion: 'Use format: return [{json: {value: "data"}}] not return ["data"]'
+        });
+      }
+    }
+    
+    // Check return format for Python
+    if (language === 'python' && hasReturn) {
+      // Check for common incorrect patterns
+      if (/return\s+items\s*$/.test(code) && !code.includes('json') && !code.includes('dict')) {
+        warnings.push({
+          type: 'best_practice',
+          message: 'Returning items directly - ensure each item is a dict with "json" key',
+          suggestion: 'Use: return [{"json": item.json} for item in items]'
+        });
+      }
+      
+      // Check for dict return without list
+      if (/return\s+{['"]/.test(code) && !code.includes('[') && !code.includes(']')) {
+        warnings.push({
+          type: 'invalid_value',
+          message: 'Return value must be a list',
+          suggestion: 'Wrap your return dict in a list: return [{"json": {"your": "data"}}]'
+        });
+      }
+    }
+    
+    // Check for common n8n variables and patterns
    if (language === 'javascript') {
-      if (!code.includes('items') && !code.includes('$input')) {
+      // Check if accessing items/input
+      if (!code.includes('items') && !code.includes('$input') && !code.includes('$json')) {
        warnings.push({
          type: 'missing_common',
-          message: 'Code doesn\'t reference input items',
-          suggestion: 'Access input data with: items or $input.all()'
+          message: 'Code doesn\'t reference input data',
+          suggestion: 'Access input with: items, $input.all(), or $json (in single-item mode)'
+        });
+      }
+      
+      // Check for common mistakes with $json
+      if (code.includes('$json') && !code.includes('mode')) {
+        warnings.push({
+          type: 'best_practice',
+          message: '$json only works in "Run Once for Each Item" mode',
+          suggestion: 'For all items mode, use: items[0].json or loop through items'
+        });
+      }
+      
+      // Check for undefined variable usage
+      const commonVars = ['$node', '$workflow', '$execution', '$prevNode', 'DateTime', 'jmespath'];
+      const usedVars = commonVars.filter(v => code.includes(v));
+      
+      // Check for incorrect $helpers usage patterns
+      if (code.includes('$helpers.getWorkflowStaticData')) {
+        warnings.push({
+          type: 'invalid_value',
+          message: '$helpers.getWorkflowStaticData() is incorrect - causes "$helpers is not defined" error',
+          suggestion: 'Use $getWorkflowStaticData() as a standalone function (no $helpers prefix)'
+        });
+      }
+      
+      // Check for $helpers usage without checking availability
+      if (code.includes('$helpers') && !code.includes('typeof $helpers')) {
+        warnings.push({
+          type: 'best_practice',
+          message: '$helpers availability varies by n8n version',
+          suggestion: 'Check availability first: if (typeof $helpers !== "undefined" && $helpers.httpRequest) { ... }'
+        });
+      }
+      
+      // Check for async without await
+      if (code.includes('async') || code.includes('.then(')) {
+        if (!code.includes('await')) {
+          warnings.push({
+            type: 'best_practice',
+            message: 'Using async operations without await',
+            suggestion: 'Use await for async operations: await $helpers.httpRequest(...)'
+          });
+        }
+      }
+      
+      // Check for crypto usage without require
+      if ((code.includes('crypto.') || code.includes('randomBytes') || code.includes('randomUUID')) && !code.includes('require')) {
+        warnings.push({
+          type: 'invalid_value',
+          message: 'Using crypto without require statement',
+          suggestion: 'Add: const crypto = require("crypto"); at the beginning (ignore editor warnings)'
+        });
+      }
+      
+      // Check for console.log (informational)
+      if (code.includes('console.log')) {
+        warnings.push({
+          type: 'best_practice',
+          message: 'console.log output appears in n8n execution logs',
+          suggestion: 'Remove console.log statements in production or use them sparingly'
        });
      }
    } else if (language === 'python') {
+      // Python-specific checks
      if (!code.includes('items') && !code.includes('_input')) {
        warnings.push({
          type: 'missing_common',
@@ -583,6 +702,44 @@ export class ConfigValidator {
          suggestion: 'Access input data with: items variable'
        });
      }
+      
+      // Check for print statements
+      if (code.includes('print(')) {
+        warnings.push({
+          type: 'best_practice',
+          message: 'print() output appears in n8n execution logs',
+          suggestion: 'Remove print statements in production or use them sparingly'
+        });
+      }
+      
+      // Check for common Python mistakes
+      if (code.includes('import requests') || code.includes('import pandas')) {
+        warnings.push({
+          type: 'invalid_value',
+          message: 'External libraries not available in Code node',
+          suggestion: 'Only Python standard library is available. For HTTP requests, use JavaScript with $helpers.httpRequest'
+        });
+      }
+    }
+    
+    // Check for infinite loops
+    if (/while\s*\(\s*true\s*\)|while\s+True:/.test(code)) {
+      warnings.push({
+        type: 'security',
+        message: 'Infinite loop detected',
+        suggestion: 'Add a break condition or use a for loop with limits'
+      });
+    }
+    
+    // Check for error handling
+    if (!code.includes('try') && !code.includes('catch') && !code.includes('except')) {
+      if (code.length > 200) { // Only suggest for non-trivial code
+        warnings.push({
+          type: 'best_practice',
+          message: 'No error handling found',
+          suggestion: 'Consider adding try/catch (JavaScript) or try/except (Python) for robust error handling'
+        });
+      }
    }
  }
 }
--- a/src/services/enhanced-config-validator.ts
+++ b/src/services/enhanced-config-validator.ts
@@ -213,7 +213,7 @@ export class EnhancedConfigValidator extends ConfigValidator {
        break;
        
      case 'nodes-base.code':
-        // Code node uses base validation which includes syntax checks
+        NodeSpecificValidators.validateCode(context);
        break;
        
      case 'nodes-base.openAi':
--- a/src/services/example-generator.ts
+++ b/src/services/example-generator.ts
@@ -75,50 +75,330 @@ export class ExampleGenerator {
      }
    },
    
+    // Webhook data processing example
+    'nodes-base.code.webhookProcessing': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// ⚠️ CRITICAL: Webhook data is nested under 'body' property!
+// This Code node should be connected after a Webhook node
+
+// ❌ WRONG - This will be undefined:
+// const command = items[0].json.testCommand;
+
+// ✅ CORRECT - Access webhook data through body:
+const webhookData = items[0].json.body;
+const headers = items[0].json.headers;
+const query = items[0].json.query;
+
+// Process webhook payload
+return [{
+  json: {
+    // Extract data from webhook body
+    command: webhookData.testCommand,
+    userId: webhookData.userId,
+    data: webhookData.data,
+    
+    // Add metadata
+    timestamp: DateTime.now().toISO(),
+    requestId: headers['x-request-id'] || crypto.randomUUID(),
+    source: query.source || 'webhook',
+    
+    // Original webhook info
+    httpMethod: items[0].json.httpMethod,
+    webhookPath: items[0].json.webhookPath
+  }
+}];`
+      }
+    },
+    
    // Code - Custom logic
    'nodes-base.code': {
      minimal: {
        language: 'javaScript',
-        jsCode: 'return items;'
+        jsCode: 'return [{json: {result: "success"}}];'
      },
      common: {
        language: 'javaScript',
-        jsCode: `// Access input items
+        jsCode: `// Process each item and add timestamp
+return items.map(item => ({
+  json: {
+    ...item.json,
+    processed: true,
+    timestamp: DateTime.now().toISO()
+  }
+}));`,
+        onError: 'continueRegularOutput'
+      },
+      advanced: {
+        language: 'javaScript',
+        jsCode: `// Advanced data processing with proper helper checks
+const crypto = require('crypto');
 const results = [];

 for (const item of items) {
-  // Process each item
-  results.push({
-    json: {
-      ...item.json,
-      processed: true,
-      timestamp: new Date().toISOString()
+  try {
+    // Validate required fields
+    if (!item.json.email || !item.json.name) {
+      throw new Error('Missing required fields: email or name');
    }
-  });
+    
+    // Generate secure API key
+    const apiKey = crypto.randomBytes(16).toString('hex');
+    
+    // Check if $helpers is available before using
+    let response;
+    if (typeof $helpers !== 'undefined' && $helpers.httpRequest) {
+      response = await $helpers.httpRequest({
+        method: 'POST',
+        url: 'https://api.example.com/process',
+        body: {
+          email: item.json.email,
+          name: item.json.name,
+          apiKey
+        },
+        headers: {
+          'Content-Type': 'application/json'
+        }
+      });
+    } else {
+      // Fallback if $helpers not available
+      response = { message: 'HTTP requests not available in this n8n version' };
+    }
+    
+    // Add to results with response data
+    results.push({
+      json: {
+        ...item.json,
+        apiResponse: response,
+        processedAt: DateTime.now().toISO(),
+        status: 'success'
+      }
+    });
+    
+  } catch (error) {
+    // Include failed items with error info
+    results.push({
+      json: {
+        ...item.json,
+        error: error.message,
+        status: 'failed',
+        processedAt: DateTime.now().toISO()
+      }
+    });
+  }
 }

-return results;`
-      },
-      advanced: {
-        language: 'python',
-        pythonCode: `import json
-from datetime import datetime
+return results;`,
+        onError: 'continueRegularOutput',
+        retryOnFail: true,
+        maxTries: 2
+      }
+    },
+    
+    // Additional Code node examples
+    'nodes-base.code.dataTransform': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// Transform CSV-like data to JSON
+return items.map(item => {
+  const lines = item.json.data.split('\\n');
+  const headers = lines[0].split(',');
+  const rows = lines.slice(1).map(line => {
+    const values = line.split(',');
+    return headers.reduce((obj, header, i) => {
+      obj[header.trim()] = values[i]?.trim() || '';
+      return obj;
+    }, {});
+  });
+  
+  return {json: {rows, count: rows.length}};
+});`
+      }
+    },
+    
+    'nodes-base.code.aggregation': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// Aggregate data from all items
+const totals = items.reduce((acc, item) => {
+  acc.count++;
+  acc.sum += item.json.amount || 0;
+  acc.categories[item.json.category] = (acc.categories[item.json.category] || 0) + 1;
+  return acc;
+}, {count: 0, sum: 0, categories: {}});
+
+return [{
+  json: {
+    totalItems: totals.count,
+    totalAmount: totals.sum,
+    averageAmount: totals.sum / totals.count,
+    categoryCounts: totals.categories,
+    processedAt: DateTime.now().toISO()
+  }
+}];`
+      }
+    },
+    
+    'nodes-base.code.filtering': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// Filter items based on conditions
+return items
+  .filter(item => {
+    const amount = item.json.amount || 0;
+    const status = item.json.status || '';
+    return amount > 100 && status === 'active';
+  })
+  .map(item => ({json: item.json}));`
+      }
+    },
+    
+    'nodes-base.code.jmespathFiltering': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// JMESPath filtering - IMPORTANT: Use backticks for numeric literals!
+const allItems = items.map(item => item.json);
+
+// ✅ CORRECT - Filter with numeric literals using backticks
+const expensiveItems = $jmespath(allItems, '[?price >= \`100\`]');
+const lowStock = $jmespath(allItems, '[?inventory < \`10\`]');
+const highPriority = $jmespath(allItems, '[?priority == \`1\`]');
+
+// Combine multiple conditions
+const urgentExpensive = $jmespath(allItems, '[?price >= \`100\` && priority == \`1\`]');
+
+// String comparisons don't need backticks
+const activeItems = $jmespath(allItems, '[?status == "active"]');
+
+// Return filtered results
+return expensiveItems.map(item => ({json: item}));`
+      }
+    },
+    
+    'nodes-base.code.pythonExample': {
+      minimal: {
+        language: 'python',
+        pythonCode: `# Python data processing - use underscore prefix for built-in variables
+import json
+from datetime import datetime
+import re

-# Access input items
 results = []

-for item in items:
-    # Process each item
-    processed_item = item.json.copy()
-    processed_item['processed'] = True
-    processed_item['timestamp'] = datetime.now().isoformat()
+# Use _input.all() to get items in Python
+for item in _input.all():
+    # Convert JsProxy to Python dict to avoid issues with null values
+    item_data = item.json.to_py()
    
-    results.append({'json': processed_item})
+    # Clean email addresses
+    email = item_data.get('email', '')
+    if email and re.match(r'^[\\w\\.-]+@[\\w\\.-]+\\.\\w+$', email):
+        cleaned_data = {
+            'email': email.lower(),
+            'name': item_data.get('name', '').title(),
+            'validated': True,
+            'timestamp': datetime.now().isoformat()
+        }
+    else:
+        # Spread operator doesn't work with JsProxy, use dict()
+        cleaned_data = dict(item_data)
+        cleaned_data['validated'] = False
+        cleaned_data['error'] = 'Invalid email format'
+    
+    results.append({'json': cleaned_data})

 return results`
      }
    },
    
+    'nodes-base.code.aiTool': {
+      minimal: {
+        language: 'javaScript',
+        mode: 'runOnceForEachItem',
+        jsCode: `// Code node as AI tool - calculate discount
+const quantity = $json.quantity || 1;
+const price = $json.price || 0;
+
+let discountRate = 0;
+if (quantity >= 100) discountRate = 0.20;
+else if (quantity >= 50) discountRate = 0.15;
+else if (quantity >= 20) discountRate = 0.10;
+else if (quantity >= 10) discountRate = 0.05;
+
+const subtotal = price * quantity;
+const discount = subtotal * discountRate;
+const total = subtotal - discount;
+
+return [{
+  json: {
+    quantity,
+    price,
+    subtotal,
+    discountRate: discountRate * 100,
+    discountAmount: discount,
+    total,
+    savings: discount
+  }
+}];`
+      }
+    },
+    
+    'nodes-base.code.crypto': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// Using crypto in Code nodes - it IS available!
+const crypto = require('crypto');
+
+// Generate secure tokens
+const token = crypto.randomBytes(32).toString('hex');
+const uuid = crypto.randomUUID();
+
+// Create hashes
+const hash = crypto.createHash('sha256')
+  .update(items[0].json.data || 'test')
+  .digest('hex');
+
+return [{
+  json: {
+    token,
+    uuid,
+    hash,
+    timestamp: DateTime.now().toISO()
+  }
+}];`
+      }
+    },
+    
+    'nodes-base.code.staticData': {
+      minimal: {
+        language: 'javaScript',
+        jsCode: `// Using workflow static data correctly
+// IMPORTANT: $getWorkflowStaticData is a standalone function!
+const staticData = $getWorkflowStaticData('global');
+
+// Initialize counter if not exists
+if (!staticData.processCount) {
+  staticData.processCount = 0;
+  staticData.firstRun = DateTime.now().toISO();
+}
+
+// Update counter
+staticData.processCount++;
+staticData.lastRun = DateTime.now().toISO();
+
+// Process items
+const results = items.map(item => ({
+  json: {
+    ...item.json,
+    runNumber: staticData.processCount,
+    processed: true
+  }
+}));
+
+return results;`
+      }
+    },
+    
    // Set - Data manipulation
    'nodes-base.set': {
      minimal: {
--- a/src/services/node-specific-validators.ts
+++ b/src/services/node-specific-validators.ts
@@ -1056,4 +1056,501 @@ export class NodeSpecificValidators {
    suggestions.push('Consider adding webhook validation (HMAC signature verification)');
    suggestions.push('Implement rate limiting for public webhooks');
  }
+  
+  /**
+   * Validate Code node configuration with n8n-specific patterns
+   */
+  static validateCode(context: NodeValidationContext): void {
+    const { config, errors, warnings, suggestions, autofix } = context;
+    const language = config.language || 'javaScript';
+    const codeField = language === 'python' ? 'pythonCode' : 'jsCode';
+    const code = config[codeField] || '';
+    
+    // Check for empty code
+    if (!code || code.trim() === '') {
+      errors.push({
+        type: 'missing_required',
+        property: codeField,
+        message: 'Code cannot be empty',
+        fix: 'Add your code logic. Start with: return [{json: {result: "success"}}]'
+      });
+      return;
+    }
+    
+    // Language-specific validation
+    if (language === 'javaScript') {
+      this.validateJavaScriptCode(code, errors, warnings, suggestions);
+    } else if (language === 'python') {
+      this.validatePythonCode(code, errors, warnings, suggestions);
+    }
+    
+    // Check return statement and format
+    this.validateReturnStatement(code, language, errors, warnings, suggestions);
+    
+    // Check n8n variable usage
+    this.validateN8nVariables(code, language, warnings, suggestions, errors);
+    
+    // Security and best practices
+    this.validateCodeSecurity(code, language, warnings);
+    
+    // Error handling recommendations
+    if (!config.onError && code.length > 100) {
+      warnings.push({
+        type: 'best_practice',
+        property: 'errorHandling',
+        message: 'Code nodes can throw errors - consider error handling',
+        suggestion: 'Add onError: "continueRegularOutput" to handle errors gracefully'
+      });
+      autofix.onError = 'continueRegularOutput';
+    }
+    
+    // Mode-specific suggestions
+    if (config.mode === 'runOnceForEachItem' && code.includes('items')) {
+      warnings.push({
+        type: 'best_practice',
+        message: 'In "Run Once for Each Item" mode, use $json instead of items array',
+        suggestion: 'Access current item data with $json.fieldName'
+      });
+    }
+    
+    if (!config.mode && code.includes('$json')) {
+      warnings.push({
+        type: 'best_practice',
+        message: '$json only works in "Run Once for Each Item" mode',
+        suggestion: 'Either set mode: "runOnceForEachItem" or use items[0].json'
+      });
+    }
+  }
+  
+  private static validateJavaScriptCode(
+    code: string,
+    errors: ValidationError[],
+    warnings: ValidationWarning[],
+    suggestions: string[]
+  ): void {
+    // Check for syntax patterns that might fail
+    const syntaxPatterns = [
+      { pattern: /const\s+const/, message: 'Duplicate const declaration' },
+      { pattern: /let\s+let/, message: 'Duplicate let declaration' },
+      { pattern: /\)\s*\)\s*{/, message: 'Extra closing parenthesis before {' },
+      { pattern: /}\s*}$/, message: 'Extra closing brace at end' }
+    ];
+    
+    syntaxPatterns.forEach(({ pattern, message }) => {
+      if (pattern.test(code)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: `Syntax error: ${message}`,
+          fix: 'Check your JavaScript syntax'
+        });
+      }
+    });
+    
+    // Common async/await issues
+    // Check for await inside a non-async function (but top-level await is fine)
+    const functionWithAwait = /function\s+\w*\s*\([^)]*\)\s*{[^}]*await/;
+    const arrowWithAwait = /\([^)]*\)\s*=>\s*{[^}]*await/;
+    
+    if ((functionWithAwait.test(code) || arrowWithAwait.test(code)) && !code.includes('async')) {
+      warnings.push({
+        type: 'best_practice',
+        message: 'Using await inside a non-async function',
+        suggestion: 'Add async keyword to the function, or use top-level await (Code nodes support it)'
+      });
+    }
+    
+    // Check for common helper usage
+    if (code.includes('$helpers.httpRequest')) {
+      suggestions.push('$helpers.httpRequest is async - use: const response = await $helpers.httpRequest(...)');
+    }
+    
+    if (code.includes('DateTime') && !code.includes('DateTime.')) {
+      warnings.push({
+        type: 'best_practice',
+        message: 'DateTime is from Luxon library',
+        suggestion: 'Use DateTime.now() or DateTime.fromISO() for date operations'
+      });
+    }
+  }
+  
+  private static validatePythonCode(
+    code: string,
+    errors: ValidationError[],
+    warnings: ValidationWarning[],
+    suggestions: string[]
+  ): void {
+    // Python-specific validation
+    const lines = code.split('\n');
+    
+    // Check for tab/space mixing (already done in base validator)
+    
+    // Check for common Python mistakes in n8n context
+    if (code.includes('__name__') && code.includes('__main__')) {
+      warnings.push({
+        type: 'inefficient',
+        message: 'if __name__ == "__main__" is not needed in Code nodes',
+        suggestion: 'Code node Python runs directly - remove the main check'
+      });
+    }
+    
+    // Check for unavailable imports
+    const unavailableImports = [
+      { module: 'requests', suggestion: 'Use JavaScript Code node with $helpers.httpRequest for HTTP requests' },
+      { module: 'pandas', suggestion: 'Use built-in list/dict operations or JavaScript for data manipulation' },
+      { module: 'numpy', suggestion: 'Use standard Python math operations' },
+      { module: 'pip', suggestion: 'External packages cannot be installed in Code nodes' }
+    ];
+    
+    unavailableImports.forEach(({ module, suggestion }) => {
+      if (code.includes(`import ${module}`) || code.includes(`from ${module}`)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'pythonCode',
+          message: `Module '${module}' is not available in Code nodes`,
+          fix: suggestion
+        });
+      }
+    });
+    
+    // Check indentation after colons
+    lines.forEach((line, i) => {
+      if (line.trim().endsWith(':') && i < lines.length - 1) {
+        const nextLine = lines[i + 1];
+        if (nextLine.trim() && !nextLine.startsWith(' ') && !nextLine.startsWith('\t')) {
+          errors.push({
+            type: 'invalid_value',
+            property: 'pythonCode',
+            message: `Missing indentation after line ${i + 1}`,
+            fix: 'Indent the line after the colon'
+          });
+        }
+      }
+    });
+  }
+  
+  private static validateReturnStatement(
+    code: string,
+    language: string,
+    errors: ValidationError[],
+    warnings: ValidationWarning[],
+    suggestions: string[]
+  ): void {
+    const hasReturn = /return\s+/.test(code);
+    
+    if (!hasReturn) {
+      errors.push({
+        type: 'missing_required',
+        property: language === 'python' ? 'pythonCode' : 'jsCode',
+        message: 'Code must return data for the next node',
+        fix: language === 'python' 
+          ? 'Add: return [{"json": {"result": "success"}}]'
+          : 'Add: return [{json: {result: "success"}}]'
+      });
+      return;
+    }
+    
+    // JavaScript return format validation
+    if (language === 'javaScript') {
+      // Check for object return without array
+      if (/return\s+{(?!.*\[).*}\s*;?$/s.test(code) && !code.includes('json:')) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: 'Return value must be an array of objects',
+          fix: 'Wrap in array: return [{json: yourObject}]'
+        });
+      }
+      
+      // Check for primitive return
+      if (/return\s+(true|false|null|undefined|\d+|['"`])/m.test(code)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: 'Cannot return primitive values directly',
+          fix: 'Return array of objects: return [{json: {value: yourData}}]'
+        });
+      }
+      
+      // Check for array of non-objects
+      if (/return\s+\[[\s\n]*['"`\d]/.test(code)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: 'Array items must be objects with json property',
+          fix: 'Use: return [{json: {value: "data"}}] not return ["data"]'
+        });
+      }
+      
+      // Suggest proper return format for items
+      if (/return\s+items\s*;?$/.test(code) && !code.includes('map')) {
+        suggestions.push(
+          'Returning items directly is fine if they already have {json: ...} structure. ' +
+          'To modify: return items.map(item => ({json: {...item.json, newField: "value"}}))'
+        );
+      }
+    }
+    
+    // Python return format validation
+    if (language === 'python') {
+      // Check for dict return without list
+      if (/return\s+{(?!.*\[).*}$/s.test(code)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'pythonCode',
+          message: 'Return value must be a list of dicts',
+          fix: 'Wrap in list: return [{"json": your_dict}]'
+        });
+      }
+      
+      // Check for primitive return
+      if (/return\s+(True|False|None|\d+|['"`])/m.test(code)) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'pythonCode',
+          message: 'Cannot return primitive values directly',
+          fix: 'Return list of dicts: return [{"json": {"value": your_data}}]'
+        });
+      }
+    }
+  }
+  
+  private static validateN8nVariables(
+    code: string,
+    language: string,
+    warnings: ValidationWarning[],
+    suggestions: string[],
+    errors: ValidationError[]
+  ): void {
+    // Check if code accesses input data
+    const inputPatterns = language === 'javaScript'
+      ? ['items', '$input', '$json', '$node', '$prevNode']
+      : ['items', '_input'];
+    
+    const usesInput = inputPatterns.some(pattern => code.includes(pattern));
+    
+    if (!usesInput && code.length > 50) {
+      warnings.push({
+        type: 'missing_common',
+        message: 'Code doesn\'t reference input data',
+        suggestion: language === 'javaScript'
+          ? 'Access input with: items, $input.all(), or $json (single-item mode)'
+          : 'Access input with: items variable'
+      });
+    }
+    
+    // Check for expression syntax in Code nodes
+    if (code.includes('{{') && code.includes('}}')) {
+      errors.push({
+        type: 'invalid_value',
+        property: language === 'python' ? 'pythonCode' : 'jsCode',
+        message: 'Expression syntax {{...}} is not valid in Code nodes',
+        fix: 'Use regular JavaScript/Python syntax without double curly braces'
+      });
+    }
+    
+    // Check for wrong $node syntax
+    if (code.includes('$node[')) {
+      warnings.push({
+        type: 'invalid_value',
+        property: language === 'python' ? 'pythonCode' : 'jsCode',
+        message: 'Use $(\'Node Name\') instead of $node[\'Node Name\'] in Code nodes',
+        suggestion: 'Replace $node[\'NodeName\'] with $(\'NodeName\')'
+      });
+    }
+    
+    // Check for expression-only functions
+    const expressionOnlyFunctions = ['$now()', '$today()', '$tomorrow()', '.unique()', '.pluck(', '.keys()', '.hash('];
+    expressionOnlyFunctions.forEach(func => {
+      if (code.includes(func)) {
+        warnings.push({
+          type: 'invalid_value',
+          property: language === 'python' ? 'pythonCode' : 'jsCode',
+          message: `${func} is an expression-only function not available in Code nodes`,
+          suggestion: 'See Code node documentation for alternatives'
+        });
+      }
+    });
+    
+    // Check for common variable mistakes
+    if (language === 'javaScript') {
+      // Using $ without proper variable
+      if (/\$(?![a-zA-Z])/.test(code) && !code.includes('${')) {
+        warnings.push({
+          type: 'best_practice',
+          message: 'Invalid $ usage detected',
+          suggestion: 'n8n variables start with $: $json, $input, $node, $workflow, $execution'
+        });
+      }
+      
+      // Check for helpers usage
+      if (code.includes('helpers.') && !code.includes('$helpers')) {
+        warnings.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: 'Use $helpers not helpers',
+          suggestion: 'Change helpers. to $helpers.'
+        });
+      }
+      
+      // Check for $helpers usage without availability check
+      if (code.includes('$helpers') && !code.includes('typeof $helpers')) {
+        warnings.push({
+          type: 'best_practice',
+          message: '$helpers availability varies by n8n version',
+          suggestion: 'Check availability first: if (typeof $helpers !== "undefined" && $helpers.httpRequest) { ... }'
+        });
+      }
+      
+      // Suggest available helpers
+      if (code.includes('$helpers')) {
+        suggestions.push(
+          'Common $helpers methods: httpRequest(), prepareBinaryData(). Note: getWorkflowStaticData is a standalone function - use $getWorkflowStaticData() instead'
+        );
+      }
+      
+      // Check for incorrect getWorkflowStaticData usage
+      if (code.includes('$helpers.getWorkflowStaticData')) {
+        errors.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: '$helpers.getWorkflowStaticData() will cause "$helpers is not defined" error',
+          fix: 'Use $getWorkflowStaticData("global") or $getWorkflowStaticData("node") directly'
+        });
+      }
+      
+      // Check for wrong JMESPath parameter order
+      if (code.includes('$jmespath(') && /\$jmespath\s*\(\s*['"`]/.test(code)) {
+        warnings.push({
+          type: 'invalid_value',
+          property: 'jsCode',
+          message: 'Code node $jmespath has reversed parameter order: $jmespath(data, query)',
+          suggestion: 'Use: $jmespath(dataObject, "query.path") not $jmespath("query.path", dataObject)'
+        });
+      }
+      
+      // Check for webhook data access patterns
+      if (code.includes('items[0].json') && !code.includes('.json.body')) {
+        // Check if previous node reference suggests webhook
+        if (code.includes('Webhook') || code.includes('webhook') || 
+            code.includes('$("Webhook")') || code.includes("$('Webhook')")) {
+          warnings.push({
+            type: 'invalid_value',
+            property: 'jsCode',
+            message: 'Webhook data is nested under .body property',
+            suggestion: 'Use items[0].json.body.fieldName instead of items[0].json.fieldName for webhook data'
+          });
+        }
+        // Also check for common webhook field names that suggest webhook data
+        else if (/items\[0\]\.json\.(payload|data|command|action|event|message)\b/.test(code)) {
+          warnings.push({
+            type: 'best_practice',
+            message: 'If processing webhook data, remember it\'s nested under .body',
+            suggestion: 'Webhook payloads are at items[0].json.body, not items[0].json'
+          });
+        }
+      }
+    }
+    
+    // Check for JMESPath filters with unquoted numeric literals (both JS and Python)
+    const jmespathFunction = language === 'javaScript' ? '$jmespath' : '_jmespath';
+    if (code.includes(jmespathFunction + '(')) {
+      // Look for filter expressions with comparison operators and numbers
+      const filterPattern = /\[?\?[^[\]]*(?:>=?|<=?|==|!=)\s*(\d+(?:\.\d+)?)\s*\]/g;
+      let match;
+      
+      while ((match = filterPattern.exec(code)) !== null) {
+        const number = match[1];
+        // Check if the number is NOT wrapped in backticks
+        const beforeNumber = code.substring(match.index, match.index + match[0].indexOf(number));
+        const afterNumber = code.substring(match.index + match[0].indexOf(number) + number.length);
+        
+        if (!beforeNumber.includes('`') || !afterNumber.startsWith('`')) {
+          errors.push({
+            type: 'invalid_value',
+            property: language === 'python' ? 'pythonCode' : 'jsCode',
+            message: `JMESPath numeric literal ${number} must be wrapped in backticks`,
+            fix: `Change [?field >= ${number}] to [?field >= \`${number}\`]`
+          });
+        }
+      }
+      
+      // Also provide a general suggestion if JMESPath is used
+      suggestions.push(
+        'JMESPath in n8n requires backticks around numeric literals in filters: [?age >= `18`]'
+      );
+    }
+  }
+  
+  private static validateCodeSecurity(
+    code: string,
+    language: string,
+    warnings: ValidationWarning[]
+  ): void {
+    // Security checks
+    const dangerousPatterns = [
+      { pattern: /eval\s*\(/, message: 'Avoid eval() - it\'s a security risk' },
+      { pattern: /Function\s*\(/, message: 'Avoid Function constructor - use regular functions' },
+      { pattern: language === 'python' ? /exec\s*\(/ : /exec\s*\(/, message: 'Avoid exec() - it\'s a security risk' },
+      { pattern: /process\.env/, message: 'Limited environment access in Code nodes' },
+      { pattern: /import\s+\*/, message: 'Avoid import * - be specific about imports' }
+    ];
+    
+    dangerousPatterns.forEach(({ pattern, message }) => {
+      if (pattern.test(code)) {
+        warnings.push({
+          type: 'security',
+          message,
+          suggestion: 'Use safer alternatives or built-in functions'
+        });
+      }
+    });
+    
+    // Special handling for require() - it's allowed for built-in modules
+    if (code.includes('require(')) {
+      // Check if it's requiring a built-in module
+      const builtinModules = ['crypto', 'util', 'querystring', 'url', 'buffer'];
+      const requirePattern = /require\s*\(\s*['"`](\w+)['"`]\s*\)/g;
+      let match;
+      
+      while ((match = requirePattern.exec(code)) !== null) {
+        const moduleName = match[1];
+        if (!builtinModules.includes(moduleName)) {
+          warnings.push({
+            type: 'security',
+            message: `Cannot require('${moduleName}') - only built-in Node.js modules are available`,
+            suggestion: `Available modules: ${builtinModules.join(', ')}`
+          });
+        }
+      }
+      
+      // If require is used without quotes, it might be dynamic
+      if (/require\s*\([^'"`]/.test(code)) {
+        warnings.push({
+          type: 'security',
+          message: 'Dynamic require() not supported',
+          suggestion: 'Use static require with string literals: require("crypto")'
+        });
+      }
+    }
+    
+    // Check for crypto usage without require
+    if ((code.includes('crypto.') || code.includes('randomBytes') || code.includes('randomUUID')) && 
+        !code.includes('require') && language === 'javaScript') {
+      warnings.push({
+        type: 'invalid_value',
+        message: 'Using crypto without require statement',
+        suggestion: 'Add: const crypto = require("crypto"); at the beginning (ignore editor warnings)'
+      });
+    }
+    
+    // File system access warning
+    if (/\b(fs|path|child_process)\b/.test(code)) {
+      warnings.push({
+        type: 'security',
+        message: 'File system and process access not available in Code nodes',
+        suggestion: 'Use other n8n nodes for file operations (e.g., Read/Write Files node)'
+      });
+    }
+  }
 }
--- a/src/services/task-templates.ts
+++ b/src/services/task-templates.ts
@@ -227,6 +227,94 @@ export class TaskTemplates {
      ]
    },
    
+    'process_webhook_data': {
+      task: 'process_webhook_data',
+      description: 'Process incoming webhook data with Code node (shows correct data access)',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        jsCode: `// ⚠️ CRITICAL: Webhook data is nested under 'body' property!
+// Connect this Code node after a Webhook node
+
+// Access webhook payload data - it's under .body, not directly under .json
+const webhookData = items[0].json.body;  // ✅ CORRECT
+const headers = items[0].json.headers;   // HTTP headers
+const query = items[0].json.query;       // Query parameters
+
+// Common mistake to avoid:
+// const command = items[0].json.testCommand;  // ❌ WRONG - will be undefined!
+// const command = items[0].json.body.testCommand;  // ✅ CORRECT
+
+// Process the webhook data
+try {
+  // Validate required fields
+  if (!webhookData.command) {
+    throw new Error('Missing required field: command');
+  }
+  
+  // Process based on command
+  let result = {};
+  switch (webhookData.command) {
+    case 'process':
+      result = {
+        status: 'processed',
+        data: webhookData.data,
+        processedAt: DateTime.now().toISO()
+      };
+      break;
+      
+    case 'validate':
+      result = {
+        status: 'validated',
+        isValid: true,
+        validatedFields: Object.keys(webhookData.data || {})
+      };
+      break;
+      
+    default:
+      result = {
+        status: 'unknown_command',
+        command: webhookData.command
+      };
+  }
+  
+  // Return processed data
+  return [{
+    json: {
+      ...result,
+      requestId: headers['x-request-id'] || crypto.randomUUID(),
+      source: query.source || 'webhook',
+      originalCommand: webhookData.command,
+      metadata: {
+        httpMethod: items[0].json.httpMethod,
+        webhookPath: items[0].json.webhookPath,
+        timestamp: DateTime.now().toISO()
+      }
+    }
+  }];
+  
+} catch (error) {
+  // Return error response
+  return [{
+    json: {
+      status: 'error',
+      error: error.message,
+      timestamp: DateTime.now().toISO()
+    }
+  }];
+}`,
+        onError: 'continueRegularOutput'
+      },
+      userMustProvide: [],
+      notes: [
+        '⚠️ WEBHOOK DATA IS AT items[0].json.body, NOT items[0].json',
+        'This is the most common webhook processing mistake',
+        'Headers are at items[0].json.headers',
+        'Query parameters are at items[0].json.query',
+        'Connect this Code node directly after a Webhook node'
+      ]
+    },
+    
    // Database Tasks
    'query_postgres': {
      task: 'query_postgres',
@@ -873,6 +961,479 @@ return results;`,
        'Consider implementing exponential backoff in Code node',
        'Monitor usage to stay within quotas'
      ]
+    },
+    
+    // Code Node Tasks
+    'custom_ai_tool': {
+      task: 'custom_ai_tool',
+      description: 'Create a custom tool for AI agents using Code node',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        mode: 'runOnceForEachItem',
+        jsCode: `// Custom AI Tool - Example: Text Analysis
+// This code will be called by AI agents with $json containing the input
+
+// Access the input from the AI agent
+const text = $json.text || '';
+const operation = $json.operation || 'analyze';
+
+// Perform the requested operation
+let result = {};
+
+switch (operation) {
+  case 'wordCount':
+    result = {
+      wordCount: text.split(/\\s+/).filter(word => word.length > 0).length,
+      characterCount: text.length,
+      lineCount: text.split('\\n').length
+    };
+    break;
+    
+  case 'extract':
+    // Extract specific patterns (emails, URLs, etc.)
+    result = {
+      emails: text.match(/[\\w.-]+@[\\w.-]+\\.\\w+/g) || [],
+      urls: text.match(/https?:\\/\\/[^\\s]+/g) || [],
+      numbers: text.match(/\\b\\d+\\b/g) || []
+    };
+    break;
+    
+  default:
+    result = {
+      error: 'Unknown operation',
+      availableOperations: ['wordCount', 'extract']
+    };
+}
+
+return [{
+  json: {
+    ...result,
+    originalText: text,
+    operation: operation,
+    processedAt: DateTime.now().toISO()
+  }
+}];`,
+        onError: 'continueRegularOutput'
+      },
+      userMustProvide: [],
+      notes: [
+        'Connect this to AI Agent node\'s tool input',
+        'AI will pass data in $json',
+        'Use "Run Once for Each Item" mode for AI tools',
+        'Return structured data the AI can understand'
+      ]
+    },
+    
+    'aggregate_data': {
+      task: 'aggregate_data',
+      description: 'Aggregate data from multiple items into summary statistics',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        jsCode: `// Aggregate data from all items
+const stats = {
+  count: 0,
+  sum: 0,
+  min: Infinity,
+  max: -Infinity,
+  values: [],
+  categories: {},
+  errors: []
+};
+
+// Process each item
+for (const item of items) {
+  try {
+    const value = item.json.value || item.json.amount || 0;
+    const category = item.json.category || 'uncategorized';
+    
+    stats.count++;
+    stats.sum += value;
+    stats.min = Math.min(stats.min, value);
+    stats.max = Math.max(stats.max, value);
+    stats.values.push(value);
+    
+    // Count by category
+    stats.categories[category] = (stats.categories[category] || 0) + 1;
+    
+  } catch (error) {
+    stats.errors.push({
+      item: item.json,
+      error: error.message
+    });
+  }
+}
+
+// Calculate additional statistics
+const average = stats.count > 0 ? stats.sum / stats.count : 0;
+const sorted = [...stats.values].sort((a, b) => a - b);
+const median = sorted.length > 0 
+  ? sorted[Math.floor(sorted.length / 2)] 
+  : 0;
+
+return [{
+  json: {
+    totalItems: stats.count,
+    sum: stats.sum,
+    average: average,
+    median: median,
+    min: stats.min === Infinity ? 0 : stats.min,
+    max: stats.max === -Infinity ? 0 : stats.max,
+    categoryCounts: stats.categories,
+    errorCount: stats.errors.length,
+    errors: stats.errors,
+    processedAt: DateTime.now().toISO()
+  }
+}];`,
+        onError: 'continueRegularOutput'
+      },
+      userMustProvide: [],
+      notes: [
+        'Assumes items have "value" or "amount" field',
+        'Groups by "category" field if present',
+        'Returns single item with all statistics',
+        'Handles errors gracefully'
+      ]
+    },
+    
+    'batch_process_with_api': {
+      task: 'batch_process_with_api',
+      description: 'Process items in batches with API calls',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        jsCode: `// Batch process items with API calls
+const BATCH_SIZE = 10;
+const API_URL = 'https://api.example.com/batch-process'; // USER MUST UPDATE
+const results = [];
+
+// Process items in batches
+for (let i = 0; i < items.length; i += BATCH_SIZE) {
+  const batch = items.slice(i, i + BATCH_SIZE);
+  
+  try {
+    // Prepare batch data
+    const batchData = batch.map(item => ({
+      id: item.json.id,
+      data: item.json
+    }));
+    
+    // Make API request for batch
+    const response = await $helpers.httpRequest({
+      method: 'POST',
+      url: API_URL,
+      body: {
+        items: batchData
+      },
+      headers: {
+        'Content-Type': 'application/json'
+      }
+    });
+    
+    // Add results
+    if (response.results && Array.isArray(response.results)) {
+      response.results.forEach((result, index) => {
+        results.push({
+          json: {
+            ...batch[index].json,
+            ...result,
+            batchNumber: Math.floor(i / BATCH_SIZE) + 1,
+            processedAt: DateTime.now().toISO()
+          }
+        });
+      });
+    }
+    
+    // Add delay between batches to avoid rate limits
+    if (i + BATCH_SIZE < items.length) {
+      await new Promise(resolve => setTimeout(resolve, 1000));
+    }
+    
+  } catch (error) {
+    // Add failed batch items with error
+    batch.forEach(item => {
+      results.push({
+        json: {
+          ...item.json,
+          error: error.message,
+          status: 'failed',
+          batchNumber: Math.floor(i / BATCH_SIZE) + 1
+        }
+      });
+    });
+  }
+}
+
+return results;`,
+        onError: 'continueRegularOutput',
+        retryOnFail: true,
+        maxTries: 2
+      },
+      userMustProvide: [
+        {
+          property: 'jsCode',
+          description: 'Update API_URL in the code',
+          example: 'https://your-api.com/batch'
+        }
+      ],
+      notes: [
+        'Processes items in batches of 10',
+        'Includes delay between batches',
+        'Handles batch failures gracefully',
+        'Update API_URL and adjust BATCH_SIZE as needed'
+      ]
+    },
+    
+    'error_safe_transform': {
+      task: 'error_safe_transform',
+      description: 'Transform data with comprehensive error handling',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        jsCode: `// Safe data transformation with validation
+const results = [];
+const errors = [];
+
+for (const item of items) {
+  try {
+    // Validate required fields
+    const required = ['id', 'name']; // USER SHOULD UPDATE
+    const missing = required.filter(field => !item.json[field]);
+    
+    if (missing.length > 0) {
+      throw new Error(\`Missing required fields: \${missing.join(', ')}\`);
+    }
+    
+    // Transform data with type checking
+    const transformed = {
+      // Ensure ID is string
+      id: String(item.json.id),
+      
+      // Clean and validate name
+      name: String(item.json.name).trim(),
+      
+      // Parse numbers safely
+      amount: parseFloat(item.json.amount) || 0,
+      
+      // Parse dates safely
+      date: item.json.date 
+        ? DateTime.fromISO(item.json.date).isValid 
+          ? DateTime.fromISO(item.json.date).toISO()
+          : null
+        : null,
+      
+      // Boolean conversion
+      isActive: Boolean(item.json.active || item.json.isActive),
+      
+      // Array handling
+      tags: Array.isArray(item.json.tags) 
+        ? item.json.tags.filter(tag => typeof tag === 'string')
+        : [],
+      
+      // Nested object handling
+      metadata: typeof item.json.metadata === 'object' 
+        ? item.json.metadata 
+        : {},
+      
+      // Add processing info
+      processedAt: DateTime.now().toISO(),
+      originalIndex: items.indexOf(item)
+    };
+    
+    results.push({
+      json: transformed
+    });
+    
+  } catch (error) {
+    errors.push({
+      json: {
+        error: error.message,
+        originalData: item.json,
+        index: items.indexOf(item),
+        status: 'failed'
+      }
+    });
+  }
+}
+
+// Add summary at the end
+results.push({
+  json: {
+    _summary: {
+      totalProcessed: results.length - errors.length,
+      totalErrors: errors.length,
+      successRate: ((results.length - errors.length) / items.length * 100).toFixed(2) + '%',
+      timestamp: DateTime.now().toISO()
+    }
+  }
+});
+
+// Include errors at the end
+return [...results, ...errors];`,
+        onError: 'continueRegularOutput'
+      },
+      userMustProvide: [
+        {
+          property: 'jsCode',
+          description: 'Update required fields array',
+          example: "const required = ['id', 'email', 'name'];"
+        }
+      ],
+      notes: [
+        'Validates all data types',
+        'Handles missing/invalid data gracefully',
+        'Returns both successful and failed items',
+        'Includes processing summary'
+      ]
+    },
+    
+    'async_data_processing': {
+      task: 'async_data_processing',
+      description: 'Process data with async operations and proper error handling',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'javaScript',
+        jsCode: `// Async processing with concurrent limits
+const CONCURRENT_LIMIT = 5;
+const results = [];
+
+// Process items with concurrency control
+async function processItem(item, index) {
+  try {
+    // Simulate async operation (replace with actual logic)
+    // Example: API call, database query, file operation
+    await new Promise(resolve => setTimeout(resolve, 100));
+    
+    // Actual processing logic here
+    const processed = {
+      ...item.json,
+      processed: true,
+      index: index,
+      timestamp: DateTime.now().toISO()
+    };
+    
+    // Example async operation - external API call
+    if (item.json.needsEnrichment) {
+      const enrichment = await $helpers.httpRequest({
+        method: 'GET',
+        url: \`https://api.example.com/enrich/\${item.json.id}\`
+      });
+      processed.enrichment = enrichment;
+    }
+    
+    return { json: processed };
+    
+  } catch (error) {
+    return {
+      json: {
+        ...item.json,
+        error: error.message,
+        status: 'failed',
+        index: index
+      }
+    };
+  }
+}
+
+// Process in batches with concurrency limit
+for (let i = 0; i < items.length; i += CONCURRENT_LIMIT) {
+  const batch = items.slice(i, i + CONCURRENT_LIMIT);
+  const batchPromises = batch.map((item, batchIndex) => 
+    processItem(item, i + batchIndex)
+  );
+  
+  const batchResults = await Promise.all(batchPromises);
+  results.push(...batchResults);
+}
+
+return results;`,
+        onError: 'continueRegularOutput',
+        retryOnFail: true,
+        maxTries: 2
+      },
+      userMustProvide: [],
+      notes: [
+        'Processes 5 items concurrently',
+        'Prevents overwhelming external services',
+        'Each item processed independently',
+        'Errors don\'t affect other items'
+      ]
+    },
+    
+    'python_data_analysis': {
+      task: 'python_data_analysis',
+      description: 'Analyze data using Python with statistics',
+      nodeType: 'nodes-base.code',
+      configuration: {
+        language: 'python',
+        pythonCode: `# Python data analysis - use underscore prefix for built-in variables
+import json
+from datetime import datetime
+import statistics
+
+# Collect data for analysis
+values = []
+categories = {}
+dates = []
+
+# Use _input.all() to get items in Python
+for item in _input.all():
+    # Convert JsProxy to Python dict for safe access
+    item_data = item.json.to_py()
+    
+    # Extract numeric values
+    if 'value' in item_data or 'amount' in item_data:
+        value = item_data.get('value', item_data.get('amount', 0))
+        if isinstance(value, (int, float)):
+            values.append(value)
+    
+    # Count categories
+    category = item_data.get('category', 'uncategorized')
+    categories[category] = categories.get(category, 0) + 1
+    
+    # Collect dates
+    if 'date' in item_data:
+        dates.append(item_data['date'])
+
+# Calculate statistics
+result = {
+    'itemCount': len(_input.all()),
+    'values': {
+        'count': len(values),
+        'sum': sum(values) if values else 0,
+        'mean': statistics.mean(values) if values else 0,
+        'median': statistics.median(values) if values else 0,
+        'min': min(values) if values else 0,
+        'max': max(values) if values else 0,
+        'stdev': statistics.stdev(values) if len(values) > 1 else 0
+    },
+    'categories': categories,
+    'dateRange': {
+        'earliest': min(dates) if dates else None,
+        'latest': max(dates) if dates else None,
+        'count': len(dates)
+    },
+    'analysis': {
+        'hasNumericData': len(values) > 0,
+        'hasCategoricalData': len(categories) > 0,
+        'hasTemporalData': len(dates) > 0,
+        'dataQuality': 'good' if len(values) > len(items) * 0.8 else 'partial'
+    },
+    'processedAt': datetime.now().isoformat()
+}
+
+# Return single summary item
+return [{'json': result}]`,
+        onError: 'continueRegularOutput'
+      },
+      userMustProvide: [],
+      notes: [
+        'Uses Python statistics module',
+        'Analyzes numeric, categorical, and date data',
+        'Returns comprehensive summary',
+        'Handles missing data gracefully'
+      ]
    }
  };
  
@@ -926,10 +1487,10 @@ return results;`,
  static getTaskCategories(): Record<string, string[]> {
    return {
      'HTTP/API': ['get_api_data', 'post_json_request', 'call_api_with_auth', 'api_call_with_retry'],
-      'Webhooks': ['receive_webhook', 'webhook_with_response', 'webhook_with_error_handling'],
+      'Webhooks': ['receive_webhook', 'webhook_with_response', 'webhook_with_error_handling', 'process_webhook_data'],
      'Database': ['query_postgres', 'insert_postgres_data', 'database_transaction_safety'],
      'AI/LangChain': ['chat_with_ai', 'ai_agent_workflow', 'multi_tool_ai_agent', 'ai_rate_limit_handling'],
-      'Data Processing': ['transform_data', 'filter_data', 'fault_tolerant_processing'],
+      'Data Processing': ['transform_data', 'filter_data', 'fault_tolerant_processing', 'process_webhook_data'],
      'Communication': ['send_slack_message', 'send_email'],
      'AI Tool Usage': ['use_google_sheets_as_tool', 'use_slack_as_tool', 'multi_tool_ai_agent'],
      'Error Handling': ['modern_error_handling_patterns', 'api_call_with_retry', 'fault_tolerant_processing', 'webhook_with_error_handling', 'database_transaction_safety', 'ai_rate_limit_handling']