validate_node
Read-onlyIdempotent
Validate n8n node configurations to ensure proper setup before workflow execution. Choose full validation for detailed feedback or minimal mode for quick checks.
Instructions
Validate n8n node configuration. Use mode='full' for comprehensive validation with errors/warnings/suggestions, mode='minimal' for quick required fields check. Example: nodeType="nodes-base.slack", config={resource:"channel",operation:"create"}
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| nodeType | Yes | Node type as string. Example: "nodes-base.slack" | |
| config | Yes | Configuration as object. For simple nodes use {}. For complex nodes include fields like {resource:"channel",operation:"create"} | |
| mode | No | Validation mode. full=comprehensive validation with errors/warnings/suggestions, minimal=quick required fields check only. Default is "full" | full |
| profile | No | Profile for mode=full: "minimal", "runtime", "ai-friendly", or "strict". Default is "ai-friendly" | ai-friendly |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| valid | Yes | ||
| errors | No | ||
| summary | No | ||
| nodeType | Yes | ||
| warnings | No | ||
| displayName | Yes | ||
| suggestions | No | ||
| workflowNodeType | No | ||
| missingRequiredFields | No | Only present in mode=minimal |
Implementation Reference
- src/mcp-tools-engine.ts:52-71 (handler)Primary handler function for the 'full' validation mode of validate_node tool. Fetches node definition, handles missing nodes, extracts user-provided config keys to avoid false warnings, and delegates to ConfigValidator for detailed validation including errors, warnings, and suggestions.
async validateNodeOperation(args: any) { // Get node properties and validate const node = await this.repository.getNodeByType(args.nodeType); if (!node) { return { valid: false, errors: [{ type: 'invalid_configuration', property: '', message: 'Node type not found' }], warnings: [], suggestions: [], visibleProperties: [], hiddenProperties: [] }; } // CRITICAL FIX: Extract user-provided keys before validation // This prevents false warnings about default values const userProvidedKeys = new Set(Object.keys(args.config || {})); return ConfigValidator.validate(args.nodeType, args.config, node.properties || [], userProvidedKeys); } - src/mcp-tools-engine.ts:73-90 (handler)Handler function for the 'minimal' validation mode of validate_node tool. Quickly checks only for missing required fields using PropertyFilter.getEssentials.
async validateNodeMinimal(args: any) { // Get node and check minimal requirements const node = await this.repository.getNodeByType(args.nodeType); if (!node) { return { missingFields: [], error: 'Node type not found' }; } const missingFields: string[] = []; const requiredFields = PropertyFilter.getEssentials(node.properties || [], args.nodeType).required; for (const field of requiredFields) { if (!args.config[field.name]) { missingFields.push(field.name); } } return { missingFields }; } - src/mcp/tools.ts:112-191 (schema)Tool schema definition and registration in the main tools array exported for MCP server registration. Includes inputSchema with parameters (nodeType required string, config required object, mode enum full/minimal, profile enum), outputSchema with validation results structure, and description.
{ name: 'validate_node', description: `Validate n8n node configuration. Use mode='full' for comprehensive validation with errors/warnings/suggestions, mode='minimal' for quick required fields check. Example: nodeType="nodes-base.slack", config={resource:"channel",operation:"create"}`, inputSchema: { type: 'object', properties: { nodeType: { type: 'string', description: 'Node type as string. Example: "nodes-base.slack"', }, config: { type: 'object', description: 'Configuration as object. For simple nodes use {}. For complex nodes include fields like {resource:"channel",operation:"create"}', }, mode: { type: 'string', enum: ['full', 'minimal'], description: 'Validation mode. full=comprehensive validation with errors/warnings/suggestions, minimal=quick required fields check only. Default is "full"', default: 'full', }, profile: { type: 'string', enum: ['strict', 'runtime', 'ai-friendly', 'minimal'], description: 'Profile for mode=full: "minimal", "runtime", "ai-friendly", or "strict". Default is "ai-friendly"', default: 'ai-friendly', }, }, required: ['nodeType', 'config'], additionalProperties: false, }, outputSchema: { type: 'object', properties: { nodeType: { type: 'string' }, workflowNodeType: { type: 'string' }, displayName: { type: 'string' }, valid: { type: 'boolean' }, errors: { type: 'array', items: { type: 'object', properties: { type: { type: 'string' }, property: { type: 'string' }, message: { type: 'string' }, fix: { type: 'string' } } } }, warnings: { type: 'array', items: { type: 'object', properties: { type: { type: 'string' }, property: { type: 'string' }, message: { type: 'string' }, suggestion: { type: 'string' } } } }, suggestions: { type: 'array', items: { type: 'string' } }, missingRequiredFields: { type: 'array', items: { type: 'string' }, description: 'Only present in mode=minimal' }, summary: { type: 'object', properties: { hasErrors: { type: 'boolean' }, errorCount: { type: 'number' }, warningCount: { type: 'number' }, suggestionCount: { type: 'number' } } } }, required: ['nodeType', 'displayName', 'valid'] }, }, - Detailed tool documentation including full description, parameters, returns, examples, use cases, performance notes, best practices, pitfalls, and related tools.
import { ToolDocumentation } from '../types'; export const validateNodeDoc: ToolDocumentation = { name: 'validate_node', category: 'validation', essentials: { description: 'Validate n8n node configuration. Use mode="full" for comprehensive validation with errors/warnings/suggestions, mode="minimal" for quick required fields check.', keyParameters: ['nodeType', 'config', 'mode', 'profile'], example: 'validate_node({nodeType: "nodes-base.slack", config: {resource: "channel", operation: "create"}})', performance: 'Fast (<100ms)', tips: [ 'Always call get_node({detail:"standard"}) first to see required fields', 'Use mode="minimal" for quick checks during development', 'Use mode="full" with profile="strict" before production deployment', 'Includes automatic structure validation for filter, resourceMapper, etc.' ] }, full: { description: `**Validation Modes:** - full (default): Comprehensive validation with errors, warnings, suggestions, and automatic structure validation - minimal: Quick check for required fields only - fast but less thorough **Validation Profiles (for mode="full"):** - minimal: Very lenient, basic checks only - runtime: Standard validation (default) - ai-friendly: Balanced for AI agent workflows - strict: Most thorough, recommended for production **Automatic Structure Validation:** Validates complex n8n types automatically: - filter (FilterValue): 40+ operations (equals, contains, regex, etc.) - resourceMapper (ResourceMapperValue): Data mapping configuration - assignmentCollection (AssignmentCollectionValue): Variable assignments - resourceLocator (INodeParameterResourceLocator): Resource selection modes`, parameters: { nodeType: { type: 'string', required: true, description: 'Node type with prefix: "nodes-base.slack"' }, config: { type: 'object', required: true, description: 'Configuration object to validate. Use {} for empty config' }, mode: { type: 'string', required: false, description: 'Validation mode: "full" (default) or "minimal"' }, profile: { type: 'string', required: false, description: 'Validation profile for mode=full: "minimal", "runtime" (default), "ai-friendly", "strict"' } }, returns: `Object containing: - nodeType: The validated node type - workflowNodeType: Type to use in workflow JSON - displayName: Human-readable node name - valid: Boolean indicating if configuration is valid - errors: Array of error objects with type, property, message, fix - warnings: Array of warning objects with suggestions - suggestions: Array of improvement suggestions - missingRequiredFields: (mode=minimal only) Array of missing required field names - summary: Object with hasErrors, errorCount, warningCount, suggestionCount`, examples: [ '// Full validation with default profile\nvalidate_node({nodeType: "nodes-base.slack", config: {resource: "channel", operation: "create"}})', '// Quick required fields check\nvalidate_node({nodeType: "nodes-base.webhook", config: {}, mode: "minimal"})', '// Strict validation for production\nvalidate_node({nodeType: "nodes-base.httpRequest", config: {...}, mode: "full", profile: "strict"})', '// Validate IF node with filter\nvalidate_node({nodeType: "nodes-base.if", config: {conditions: {combinator: "and", conditions: [...]}}})' ], useCases: [ 'Validate node configuration before adding to workflow', 'Quick check for required fields during development', 'Pre-production validation with strict profile', 'Validate complex structures (filters, resource mappers)', 'Get suggestions for improving node configuration' ], performance: 'Fast validation: <50ms for minimal mode, <100ms for full mode. Structure validation adds minimal overhead.', bestPractices: [ 'Always call get_node() first to understand required fields', 'Use mode="minimal" for rapid iteration during development', 'Use profile="strict" before deploying to production', 'Pay attention to warnings - they often prevent runtime issues', 'Validate after any configuration changes' ], pitfalls: [ 'Empty config {} is valid for some nodes (e.g., manual trigger)', 'mode="minimal" only checks required fields, not value validity', 'Some warnings may be acceptable for specific use cases', 'Credential validation requires runtime context' ], relatedTools: ['get_node', 'validate_workflow', 'n8n_autofix_workflow'] } };