Claude Desktop API MCP

Instructions

Implementation Reference

• src/index.ts:51-78 (handler)

  Handler for the 'send-message' tool: checks the tool name, calls the Anthropic Claude API with the message from arguments, extracts the text response, and returns it as content.

  if (request.params.name === "send-message" && request.params.arguments?.message) {
    try {
      const msg = await client.messages.create({
        model: "claude-3-opus-20240229",
        max_tokens: 1024,
        messages: [
          { 
            role: "user", 
            content: String(request.params.arguments.message)
          }
        ]
      });
  
      const responseText = msg.content[0].type === 'text' ? msg.content[0].text : 'No text response available';
  
      return {
        content: [
          {
            type: "text",
            text: responseText
          }
        ]
      };
    } catch (error) {
      log(`Error calling Claude API: ${error}`);
      throw error;
    }
  }

• src/index.ts:30-43 (registration)

  Registration of the 'send-message' tool in the ListTools response, specifying name, description, and input schema.

  {
    name: "send-message",
    description: "Send a message to Claude",
    inputSchema: {
      type: "object",
      properties: {
        message: {
          type: "string",
          description: "Message to send to Claude"
        }
      },
      required: ["message"]
    }
  }

• src/index.ts:33-42 (schema)

  Input schema definition for the 'send-message' tool, requiring a 'message' string.

  inputSchema: {
    type: "object",
    properties: {
      message: {
        type: "string",
        description: "Message to send to Claude"
      }
    },
    required: ["message"]
  }