Vibe Check MCP

Instructions

Implementation Reference

• src/tools/vibeLearn.ts:33-89 (handler)

  Primary handler function executing the core logic of the vibe_learn tool: validates input, enforces single-sentence format, checks for duplicates, stores learning entry, and returns category summary.

  export async function vibeLearnTool(input: VibeLearnInput): Promise<VibeLearnOutput> {
    try {
      // Validate input
      if (!input.mistake) {
        throw new Error('Mistake description is required');
      }
      if (!input.category) {
        throw new Error('Mistake category is required');
      }
      const entryType: LearningType = input.type ?? 'mistake';
      if (entryType !== 'preference' && !input.solution) {
        throw new Error('Solution is required for this entry type');
      }
      
      // Enforce single-sentence constraints
      const mistake = enforceOneSentence(input.mistake);
      const solution = input.solution ? enforceOneSentence(input.solution) : undefined;
      
      // Normalize category to one of our standard categories if possible
      const category = normalizeCategory(input.category);
      
      // Check for similar mistake
      const existing = getLearningEntries()[category] || [];
      const alreadyKnown = existing.some(e => isSimilar(e.mistake, mistake));
  
      // Add mistake to log if new
      let entry: LearningEntry | undefined;
      if (!alreadyKnown) {
        entry = addLearningEntry(mistake, category, solution, entryType);
      }
      
      // Get category summaries
      const categorySummary = getLearningCategorySummary();
      
      // Find current tally for this category
      const categoryData = categorySummary.find(m => m.category === category);
      const currentTally = categoryData?.count || 1;
      
      // Get top 3 categories
      const topCategories = categorySummary.slice(0, 3);
  
      return {
        added: !alreadyKnown,
        alreadyKnown,
        currentTally,
        topCategories
      };
    } catch (error) {
      console.error('Error in vibe_learn tool:', error);
      return {
        added: false,
        alreadyKnown: false,
        currentTally: 0,
        topCategories: []
      };
    }
  }

• src/tools/vibeLearn.ts:10-27 (schema)

  TypeScript interfaces defining input and output schemas for the vibe_learn tool.

  export interface VibeLearnInput {
    mistake: string;
    category: string;
    solution?: string;
    type?: LearningType;
    sessionId?: string;
  }
  
  export interface VibeLearnOutput {
    added: boolean;
    currentTally: number;
    alreadyKnown?: boolean;
    topCategories: Array<{
      category: string;
      count: number;
      recentExample: LearningEntry;
    }>;
  }

• src/index.ts:131-167 (registration)

  Tool registration in the MCP listTools handler, including name, description, and JSON schema for input validation.

    name: 'vibe_learn',
    description: 'Pattern recognition system that tracks common errors and solutions to prevent recurring issues',
    inputSchema: {
      type: 'object',
      properties: {
        mistake: {
          type: 'string',
          description: 'One-sentence description of the learning entry',
          examples: ['Skipped writing tests']
        },
        category: {
          type: 'string',
          description: `Category (standard categories: ${STANDARD_CATEGORIES.join(', ')})`,
          enum: STANDARD_CATEGORIES,
          examples: ['Premature Implementation']
        },
        solution: {
          type: 'string',
          description: 'How it was corrected (if applicable)',
          examples: ['Added regression tests']
        },
        type: {
          type: 'string',
          enum: ['mistake', 'preference', 'success'],
          description: 'Type of learning entry',
          examples: ['mistake']
        },
        sessionId: {
          type: 'string',
          description: 'Optional session ID for state management',
          examples: ['session-123']
        }
      },
      required: ['mistake', 'category'],
      additionalProperties: false
    }
  },

• src/index.ts:243-265 (handler)

  MCP protocol handler for callTool requests to 'vibe_learn': parses arguments, validates, calls vibeLearnTool, formats output.

  case 'vibe_learn': {
    const missing: string[] = [];
    if (!args || typeof args.mistake !== 'string') missing.push('mistake');
    if (!args || typeof args.category !== 'string') missing.push('category');
    if (missing.length) {
      const example = '{"mistake":"Skipped tests","category":"Feature Creep"}';
      const message = IS_DISCOVERY
        ? `discovery: missing [${missing.join(', ')}]; example: ${example}`
        : `Missing: ${missing.join(', ')}. Example: ${example}`;
      throw new McpError(ErrorCode.InvalidParams, message);
    }
    const input: VibeLearnInput = {
      mistake: args.mistake,
      category: args.category,
      solution: typeof args.solution === 'string' ? args.solution : undefined,
      type: ['mistake', 'preference', 'success'].includes(args.type as string)
        ? (args.type as LearningType)
        : undefined,
      sessionId: typeof args.sessionId === 'string' ? args.sessionId : undefined
    };
    const result = await vibeLearnTool(input);
    return { content: [{ type: 'text', text: formatVibeLearnOutput(result) }] };
  }

• src/tools/vibeLearn.ts:89-94 (helper)

  Supporting helper functions used by the handler: enforceOneSentence for input normalization, isSimilar for duplicate detection, normalizeCategory for standardization.

  }
  
  /**
   * Ensure text is a single sentence
   */
  function enforceOneSentence(text: string): string {