Square Model Context Protocol Server

Instructions

Implementation Reference

• server.ts:240-288 (registration)

  Registration of the 'get_type_info' MCP tool, including name, description, input schema, and inline handler function.

  server.tool(
    "get_type_info",
    "Get type information for a Square API method. You must call this before calling the make_api_request tool.",
    {
      service: z.string().describe("The Square API service category (e.g., 'catalog', 'payments')"),
      method: z.string().describe("The API method to call (e.g., 'list', 'create')")
    },
    async (params) => {
      try {
        const { service, method } = 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)}`);
        }
  
        if (!methods[method]) {
          throw new Error(`Invalid method ${method} for service ${service}. Available methods: ${JSON.stringify(Object.keys(methods), null, 2)}`);
        }
  
        const methodInfo = methods[method];
        const requestTypeName = methodInfo.requestType;
        
        const typeInfo = typeMap[requestTypeName];
        if (!typeInfo) {
          throw new Error(`Type information not found for ${requestTypeName}`);
        }
  
        return {
          content: [{
            type: "text",
            text: JSON.stringify(typeInfo, 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:247-287 (handler)

  Executes the logic for 'get_type_info': capitalizes service name, retrieves method info from serviceMethodsMap, fetches type info from typeMap using requestType, and returns as JSON text content.

  async (params) => {
    try {
      const { service, method } = 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)}`);
      }
  
      if (!methods[method]) {
        throw new Error(`Invalid method ${method} for service ${service}. Available methods: ${JSON.stringify(Object.keys(methods), null, 2)}`);
      }
  
      const methodInfo = methods[method];
      const requestTypeName = methodInfo.requestType;
      
      const typeInfo = typeMap[requestTypeName];
      if (!typeInfo) {
        throw new Error(`Type information not found for ${requestTypeName}`);
      }
  
      return {
        content: [{
          type: "text",
          text: JSON.stringify(typeInfo, 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:243-246 (schema)

  Zod input schema for the 'get_type_info' tool, requiring 'service' and 'method' strings.

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