Think MCP

Instructions

Implementation Reference

• src/services/thinking.service.ts:186-371 (handler)

  The core handler function processThought in ThinkingService that executes the logic for the 'think' tool. Handles validation, branching, stagnation detection, coaching nudges, quick extensions, dead-end warnings, and returns progress information.

  processThought(input: ThoughtInput): ThinkingResult {
    // Smart auto-reset: if thoughtNumber=1 and history not empty, start fresh session
    // SYNCHRONOUS reset to avoid race conditions
    if (input.thoughtNumber === 1 && this.thoughtHistory.length > 0 && !input.isRevision) {
      console.error('🔄 New session detected (thought #1), clearing previous state...');
      this.reset(); // Synchronous clear
      // Clear persistence file asynchronously (non-blocking)
      this.clearSession().catch((err) => console.error('Failed to clear session:', err));
    }
  
    // Generate new sessionId for first thought of session (v2.11.0)
    if (input.thoughtNumber === 1 && !input.isRevision) {
      this.currentSessionId = new Date().toISOString();
      console.error(`🆔 New session ID: ${this.currentSessionId}`);
    }
  
    // Auto-adjust totalThoughts if exceeded
    if (input.thoughtNumber > input.totalThoughts) {
      input.totalThoughts = input.thoughtNumber;
    }
  
    // EMPTY THOUGHT VALIDATION - reject meaningless input
    if (!input.thought || !input.thought.trim()) {
      return {
        thoughtNumber: input.thoughtNumber,
        totalThoughts: input.totalThoughts,
        nextThoughtNeeded: true,
        branches: Array.from(this.branches.keys()),
        thoughtHistoryLength: this.thoughtHistory.length,
        contextSummary: this.generateContextSummary(),
        thoughtTree: this.generateAsciiTree(),
        isError: true,
        errorMessage: '🚫 REJECTED: Empty thought. Provide meaningful content.',
        warning: '🚫 REJECTED: Empty thought. Provide meaningful content.',
      };
    }
  
    // SESSION GOAL (v2.10.0) - Save goal from first thought
    if (input.goal && input.thoughtNumber === 1) {
      this.sessionGoal = input.goal;
      console.error(`🎯 Session goal set: ${input.goal.substring(0, 50)}...`);
    }
  
    // HARD DUPLICATE REJECTION - reject before adding to history
    const duplicateError = this.checkDuplicateStrict(input);
    if (duplicateError) {
      return {
        thoughtNumber: input.thoughtNumber,
        totalThoughts: input.totalThoughts,
        nextThoughtNeeded: true,
        branches: Array.from(this.branches.keys()),
        thoughtHistoryLength: this.thoughtHistory.length,
        contextSummary: this.generateContextSummary(),
        thoughtTree: this.generateAsciiTree(),
        isError: true,
        errorMessage: duplicateError,
        warning: duplicateError,
      };
    }
  
    // BRANCH VALIDATION - reject if branchFromThought references non-existent thought
    const branchError = this.validateBranchSource(input);
    if (branchError) {
      return {
        thoughtNumber: input.thoughtNumber,
        totalThoughts: input.totalThoughts,
        nextThoughtNeeded: true,
        branches: Array.from(this.branches.keys()),
        thoughtHistoryLength: this.thoughtHistory.length,
        contextSummary: this.generateContextSummary(),
        thoughtTree: this.generateAsciiTree(),
        isError: true,
        errorMessage: branchError,
        warning: branchError,
      };
    }
  
    // Validate sequence (includes shallow/circular revision check)
    const validation = this.validateSequence(input);
    
    // HARD REJECTION for invalid revisions (shallow, circular, non-existent target)
    if (!validation.valid && input.isRevision) {
      return {
        thoughtNumber: input.thoughtNumber,
        totalThoughts: input.totalThoughts,
        nextThoughtNeeded: true,
        branches: Array.from(this.branches.keys()),
        thoughtHistoryLength: this.thoughtHistory.length,
        contextSummary: this.generateContextSummary(),
        thoughtTree: this.generateAsciiTree(),
        isError: true,
        errorMessage: validation.warning,
        warning: validation.warning,
      };
    }
  
    // Check for stagnation before adding new thought
    const stagnationWarning = this.detectStagnation(input.thought);
  
    // Create record with timestamp and sessionId (v2.11.0)
    const record: ThoughtRecord = {
      ...input,
      timestamp: Date.now(),
      sessionId: this.currentSessionId,
    };
  
    this.thoughtHistory.push(record);
    this.lastThoughtNumber = input.thoughtNumber;
  
    // Invalidate Fuse index for recall_thought (v3.4.0)
    this.invalidateFuseIndex();
  
    // Handle branching
    if (input.branchFromThought && input.branchId) {
      const branchHistory = this.branches.get(input.branchId) ?? [];
      branchHistory.push(record);
      this.branches.set(input.branchId, branchHistory);
    }
  
    // Log to stderr for debugging
    const prefix = input.isRevision
      ? '🔄 Revision'
      : input.branchFromThought
        ? '🌿 Branch'
        : '💭 Thought';
    const confidenceStr = input.confidence ? ` [conf: ${input.confidence}/10]` : '';
    console.error(
      `${prefix} ${input.thoughtNumber}/${input.totalThoughts}${confidenceStr}: ${input.thought.substring(0, 80)}...`
    );
  
    // Save session asynchronously (fire and forget)
    this.saveSession().catch((err) => console.error('Failed to save session:', err));
  
    // Combine warnings
    const warning = [validation.warning, stagnationWarning].filter(Boolean).join('\n');
  
    // QUICK EXTENSION (v3.1.0) - Process inline extension if provided
    if (input.quickExtension) {
      this.processQuickExtension(input.thoughtNumber, input.quickExtension);
    }
  
    // LATERAL THINKING TRIGGER - check for overly linear thinking
    // v5.0.1: Pass isFinishing flag to show subSteps check only at end
    let systemAdvice = this.checkLateralThinking(!input.nextThoughtNeeded);
  
    // DEAD ENDS CHECK (v3.3.0) - Warn if heading towards rejected path
    const deadEndWarning = this.checkDeadEnds(input.thoughtNumber);
    if (deadEndWarning) {
      systemAdvice = systemAdvice ? `${systemAdvice}\n${deadEndWarning}` : deadEndWarning;
    }
  
    // PROACTIVE COACH v3.1.0 - Enhanced nudges for thought quality
    const coachNudges = this.generateProactiveNudges(input);
    if (coachNudges) {
      systemAdvice = systemAdvice ? `${systemAdvice}\n${coachNudges}` : coachNudges;
    }
  
    // PRE-CONSOLIDATION AUDIT (v2.9.2) - Quality gate before finishing
    if (!input.nextThoughtNeeded) {
      const auditAdvice = this.performPreConsolidationAudit();
      if (auditAdvice) {
        systemAdvice = systemAdvice ? `${systemAdvice}\n${auditAdvice}` : auditAdvice;
      }
    }
  
    // v4.6.0: Generate nudge only if no other warnings/advice (avoid noise)
    const shouldSkipNudge = !!(warning || systemAdvice);
    const nudge = this.nudgeService.generateNudge(input, this.getCurrentSessionThoughts(), shouldSkipNudge);
  
    return {
      thoughtNumber: input.thoughtNumber,
      totalThoughts: input.totalThoughts,
      nextThoughtNeeded: input.nextThoughtNeeded,
      branches: Array.from(this.branches.keys()),
      thoughtHistoryLength: this.thoughtHistory.length,
      contextSummary: this.generateContextSummary(),
      thoughtTree: this.generateAsciiTree(),
      // v4.2.0: Lazy Mermaid - removed from hot path, use export_session for diagrams
      thoughtTreeMermaid: undefined,
      warning: warning || undefined,
      averageConfidence: this.calculateAverageConfidence(),
      systemAdvice,
      sessionGoal: this.sessionGoal,
      nudge,
    };
  }

• src/index.ts:68-127 (registration)

  Registration of the 'think' tool using McpServer.registerTool, including title, description, inputSchema, and the handler callback.

  server.registerTool('think', { title: 'Think', description: THINK_DESCRIPTION, inputSchema: thinkSchema },
    async (args) => {
      try {
        const result = thinkingService.processThought({
          thought: args.thought as string,
          nextThoughtNeeded: args.nextThoughtNeeded as boolean,
          thoughtNumber: args.thoughtNumber as number,
          totalThoughts: args.totalThoughts as number,
          isRevision: args.isRevision as boolean | undefined,
          revisesThought: args.revisesThought as number | undefined,
          branchFromThought: args.branchFromThought as number | undefined,
          branchId: args.branchId as string | undefined,
          confidence: args.confidence as number | undefined,
          subSteps: args.subSteps as string[] | undefined,
          alternatives: args.alternatives as string[] | undefined,
          goal: args.goal as string | undefined,
          quickExtension: args.quickExtension as QuickExtension | undefined,
        });
  
        if (result.isError) {
          return { content: [{ type: 'text' as const, text: `Error: ${result.errorMessage}` }], isError: true };
        }
  
        // Progress bar
        const current = result.thoughtNumber;
        const total = result.totalThoughts;
        const filled = Math.round((current / total) * 10);
        const progressBar = '█'.repeat(filled) + '░'.repeat(10 - filled);
  
        // Status detection
        const hasBlocker = result.warning?.includes('BLOCKER') || result.warning?.includes('STAGNATION');
        const status = hasBlocker ? 'BLOCKED' : result.warning ? 'WARNING' : 'OK';
        const nearEnd = current >= total - 1;
        const nextAction = hasBlocker ? 'revise' : nearEnd ? 'think_done' : 'continue';
  
        // Conditional tree - ONLY when explicitly requested
        const showTree = args.showTree === true;
  
        // v5.0.1: Show systemAdvice ONLY when there are real issues
        const conf = result.averageConfidence ?? 10;
        const hasRealIssue = status !== 'OK' || conf < 7;
        const showAdvice = hasRealIssue && result.systemAdvice;
  
        const text = [
          result.sessionGoal ? `🎯 ${result.sessionGoal}\n` : '',
          `[${progressBar}] ${current}/${total}`,
          result.averageConfidence ? ` | conf: ${result.averageConfidence}/10` : '',
          result.warning ? `\n⚠️ ${result.warning}` : '',
          showTree ? `\n\n${result.thoughtTree}` : '',
          showAdvice ? `\n${result.systemAdvice}` : '',
          result.nudge ? `\n💡 ${result.nudge}` : '',
          `\n[${status}|next:${nextAction}]`,
        ].filter(Boolean).join('');
  
        return { content: [{ type: 'text' as const, text }] };
      } catch (error) {
        return { content: [{ type: 'text' as const, text: `Error: ${error instanceof Error ? error.message : 'Unknown'}` }], isError: true };
      }
    }
  );

• src/index.ts:47-66 (schema)

  Zod input schema definition for the 'think' tool parameters.

  const thinkSchema = {
    thought: z.string().describe('Your thinking step'),
    nextThoughtNeeded: z.boolean().describe('More thinking needed?'),
    thoughtNumber: z.number().int().min(1).describe('Current number'),
    totalThoughts: z.number().int().min(1).describe('Estimated total'),
    confidence: z.number().min(1).max(10).optional().describe('Confidence 1-10'),
    subSteps: z.array(z.string()).max(5).optional().describe('Micro-actions (max 5)'),
    alternatives: z.array(z.string()).max(5).optional().describe('Options to compare'),
    goal: z.string().optional().describe('Session goal (set on first thought)'),
    quickExtension: z.object({
      type: z.enum(['critique', 'elaboration', 'correction', 'alternative_scenario', 'assumption_testing', 'innovation', 'optimization', 'polish']),
      content: z.string(),
      impact: z.enum(['low', 'medium', 'high', 'blocker']).optional(),
    }).optional().describe('Inline extension (replaces extend_thought)'),
    isRevision: z.boolean().optional().describe('Revising previous thought?'),
    revisesThought: z.number().int().min(1).optional().describe('Which thought to revise'),
    branchFromThought: z.number().int().min(1).optional().describe('Branch point'),
    branchId: z.string().optional().describe('Branch identifier'),
    showTree: z.boolean().optional().describe('Show ASCII tree'),
  };