Square Model Context Protocol Server

Instructions

Implementation Reference

• server.ts:297-333 (handler)

  Handler function that takes a service name, capitalizes it, looks up the methods in serviceMethodsMap, extracts descriptions, and returns them as JSON. Handles errors by returning error content.

  async (params) => {
    try {
      const { service } = params;
      const serviceName = service.charAt(0).toUpperCase() + service.slice(1);
      
      const methods = serviceMethodsMap[serviceName];
      if (!methods) {
        throw new Error(`Invalid service: ${service}. Available services: ${JSON.stringify(Object.keys(serviceMethodsMap), null, 2)}`);
      }
  
      // Create a map of method names to their descriptions
      const methodInfo = Object.entries(methods).reduce((acc, [methodName, info]) => {
        acc[methodName] = {
          description: info.description
        };
        return acc;
      }, {} as Record<string, { description: string }>);
  
      return {
        content: [{
          type: "text",
          text: JSON.stringify(methodInfo, null, 2)
        }]
      };
    } catch (err: any) {
      return {
        content: [{
          type: "text",
          text: JSON.stringify({
            error: err.message,
            details: err.errors || err.stack
          }, null, 2)
        }],
        isError: true
      };
    }
  }

• server.ts:291-334 (registration)

  Registers the 'get_service_info' tool with MCP server, including name, description, input schema (service: string), and handler function.

  server.tool(
    "get_service_info",
    "Get information about a Square API service. Call me before trying to get type info",
    {
      service: z.string().describe("The Square API service category (e.g., 'catalog', 'payments')")
    },
    async (params) => {
      try {
        const { service } = params;
        const serviceName = service.charAt(0).toUpperCase() + service.slice(1);
        
        const methods = serviceMethodsMap[serviceName];
        if (!methods) {
          throw new Error(`Invalid service: ${service}. Available services: ${JSON.stringify(Object.keys(serviceMethodsMap), null, 2)}`);
        }
  
        // Create a map of method names to their descriptions
        const methodInfo = Object.entries(methods).reduce((acc, [methodName, info]) => {
          acc[methodName] = {
            description: info.description
          };
          return acc;
        }, {} as Record<string, { description: string }>);
  
        return {
          content: [{
            type: "text",
            text: JSON.stringify(methodInfo, null, 2)
          }]
        };
      } catch (err: any) {
        return {
          content: [{
            type: "text",
            text: JSON.stringify({
              error: err.message,
              details: err.errors || err.stack
            }, null, 2)
          }],
          isError: true
        };
      }
    }
  );

• server.ts:294-296 (schema)

  Zod schema for the tool input: a single 'service' parameter as string.

  {
    service: z.string().describe("The Square API service category (e.g., 'catalog', 'payments')")
  },