Sequential Thinking MVP Server

Instructions

Input Schema

Input Schema (JSON Schema)

Implementation Reference

• src/tools/handlers.ts:21-33 (handler)

  Specific handler logic for the 'sequential_thinking' tool call, which invokes SequentialThinkingManager.addThought and returns the result as JSON.
  case 'sequential_thinking': { const input = args as ThoughtInput; const result = thinkingManager.addThought(input); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; }
• src/tools/definitions.ts:8-53 (schema)

  JSON schema definition for the 'sequential_thinking' tool inputs and metadata.
  export const SEQUENTIAL_THINKING_TOOL: Tool = { name: 'sequential_thinking', description: 'Facilitates a detailed, step-by-step thinking process for problem-solving and analysis. Break down complex problems into manageable steps, revise and refine thoughts as understanding deepens, and branch into alternative paths of reasoning.', inputSchema: { type: 'object', properties: { thought: { type: 'string', description: 'The current reasoning step or thought in the sequence', }, nextThoughtNeeded: { type: 'boolean', description: 'Indicates whether additional reasoning steps are required after this one', }, thoughtNumber: { type: 'number', description: 'The sequential number of this thought (e.g., 1, 2, 3...)', }, totalThoughts: { type: 'number', description: 'Estimated total number of thoughts needed to complete the reasoning', }, isRevision: { type: 'boolean', description: 'Marks this thought as a reconsideration or refinement of a previous step', }, revisesThought: { type: 'number', description: 'The thought number being revised (required if isRevision is true)', }, branchFromThought: { type: 'number', description: 'The thought number from which this alternative reasoning path branches', }, branchId: { type: 'string', description: 'Unique identifier for this alternative reasoning branch', }, needsMoreThoughts: { type: 'boolean', description: 'Signals that the total number of thoughts needs to be expanded', }, }, required: ['thought', 'nextThoughtNeeded', 'thoughtNumber', 'totalThoughts'], }, };
• src/index.ts:32-39 (registration)

  MCP server request handler registration for listing tools (includes sequential_thinking via ALL_TOOLS) and handling tool calls.
  server.setRequestHandler(ListToolsRequestSchema, async () => { return { tools: ALL_TOOLS }; }); // Handle tool calls server.setRequestHandler(CallToolRequestSchema, async (request) => { return handleToolCall(request.params, thinkingManager); });
• src/lib.ts:110-160 (helper)

  Core implementation of adding a thought to the sequence, including validation, branching, revisions, session management, and response generation.
  public addThought(input: ThoughtInput, sessionId?: string): ThoughtResponse { // Validate input validateThoughtInput(input); const sid = sessionId || this.currentSessionId; let session = this.sessions.get(sid); if (!session) { this.initializeSession(sid); session = this.sessions.get(sid)!; } const storedThought: StoredThought = { ...input, timestamp: Date.now(), sessionId: sid, }; // Handle branching if (input.branchId && input.branchFromThought !== undefined) { let branchThoughts = session.branches.get(input.branchId); if (!branchThoughts) { branchThoughts = []; session.branches.set(input.branchId, branchThoughts); } branchThoughts.push(storedThought); } else { // Regular thought in main sequence session.thoughts.push(storedThought); } session.updatedAt = Date.now(); // Build response message let message = `Thought ${input.thoughtNumber}`; if (input.isRevision && input.revisesThought !== undefined) { message += ` (revising thought ${input.revisesThought})`; } if (input.branchId) { message += ` [branch: ${input.branchId}]`; } message += `: ${input.thought}`; return { success: true, thoughtNumber: input.thoughtNumber, message, sequence: session.thoughts, totalThoughts: input.totalThoughts, }; }
• src/tools/handlers.ts:13-52 (helper)

  Shared handler function that routes tool calls to the appropriate logic, providing the SequentialThinkingManager instance.
  export async function handleToolCall( params: { name: string; arguments?: unknown }, thinkingManager: SequentialThinkingManager ) { const { name, arguments: args = {} } = params; try { switch (name) { case 'sequential_thinking': { const input = args as ThoughtInput; const result = thinkingManager.addThought(input); return { content: [ { type: 'text', text: JSON.stringify(result, null, 2), }, ], }; } case 'get_thought_sequence': { const { sessionId } = args as { sessionId?: string }; const sequence = thinkingManager.getSequence(sessionId); return { content: [ { type: 'text', text: JSON.stringify( { sessionId: sessionId || thinkingManager.getCurrentSessionId(), thoughtCount: sequence.length, thoughts: sequence, }, null, 2 ), },