Chain of Draft (CoD) MCP Server

Instructions

Implementation Reference

• server.py:82-100 (handler)

  Primary handler for the 'math_solve' MCP tool. Registered via @app.tool() decorator in FastMCP. Delegates to chain_of_draft_solve with domain set to 'math'.

  @app.tool()
  async def math_solve(
      problem: str,
      approach: str = None,
      max_words_per_step: int = None
  ) -> str:
      """Solve a math problem using Chain of Draft reasoning.
      
      Args:
          problem: The math problem to solve
          approach: Force "CoD" or "CoT" approach (default: auto-select)
          max_words_per_step: Maximum words per step (default: adaptive)
      """
      return await chain_of_draft_solve(
          problem=problem,
          domain="math",
          approach=approach,
          max_words_per_step=max_words_per_step
      )

• server.py:36-80 (helper)

  Core helper function implementing the Chain of Draft reasoning logic, used by math_solve and other domain tools.

  @app.tool()
  async def chain_of_draft_solve(
      problem: str,
      domain: str = "general",
      max_words_per_step: int = None,
      approach: str = None,
      enforce_format: bool = True,
      adaptive_word_limit: bool = True
  ) -> str:
      """Solve a reasoning problem using Chain of Draft approach.
      
      Args:
          problem: The problem to solve
          domain: Domain for context (math, logic, code, common-sense, etc.)
          max_words_per_step: Maximum words per reasoning step (default: adaptive)
          approach: Force "CoD" or "CoT" approach (default: auto-select)
          enforce_format: Whether to enforce the word limit (default: True)
          adaptive_word_limit: Adjust word limits based on complexity (default: True)
      """
      # Track execution time
      start_time = time.time()
      
      # Process the request with the client
      result = await cod_client.solve_with_reasoning(
          problem=problem,
          domain=domain,
          max_words_per_step=max_words_per_step,
          approach=approach,
          enforce_format=enforce_format,
          adaptive_word_limit=adaptive_word_limit
      )
      
      # Calculate execution time
      execution_time = (time.time() - start_time) * 1000  # ms
      
      # Format the response
      formatted_response = (
          f"Chain of {result['approach']} reasoning ({result['word_limit']} word limit):\n\n"
          f"{result['reasoning_steps']}\n\n"
          f"Final answer: {result['final_answer']}\n\n"
          f"Stats: {result['token_count']} tokens, {execution_time:.0f}ms, "
          f"complexity score: {result['complexity']}"
      )
      
      return formatted_response

• index.js:459-480 (schema)

  Explicit input schema definition for the math_solve tool in the JavaScript MCP server.

  const MATH_TOOL = {
    name: "math_solve",
    description: "Solve a math problem using Chain of Draft reasoning",
    inputSchema: {
      type: "object",
      properties: {
        problem: {
          type: "string",
          description: "The math problem to solve"
        },
        approach: {
          type: "string",
          description: "Force 'CoD' or 'CoT' approach"
        },
        max_words_per_step: {
          type: "number",
          description: "Maximum words per reasoning step"
        }
      },
      required: ["problem"]
    }
  };

• index.js:618-637 (handler)

  Handler block for 'math_solve' tool execution in the JavaScript MCP server call handler.

  if (name === "math_solve") {
    const result = await chainOfDraftClient.solveWithReasoning({
      ...args,
      domain: "math"
    });
    
    const formattedResponse = 
      `Chain of ${result.approach} reasoning (${result.word_limit} word limit):\n\n` +
      `${result.reasoning_steps}\n\n` +
      `Final answer: ${result.final_answer}\n\n` +
      `Stats: ${result.token_count} tokens, ${result.execution_time_ms.toFixed(0)}ms, ` +
      `complexity score: ${result.complexity}`;
    
    return {
      content: [{
        type: "text",
        text: formattedResponse
      }]
    };
  }

• index.js:581-591 (registration)

  Registration of math_solve tool (as MATH_TOOL) in the ListTools request handler for the JS MCP server.

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools: [
      CHAIN_OF_DRAFT_TOOL,
      MATH_TOOL,
      CODE_TOOL,
      LOGIC_TOOL,
      PERFORMANCE_TOOL,
      TOKEN_TOOL,
      COMPLEXITY_TOOL
    ],
  }));