Service Constraints

This chapter lists constraints to keep in mind when creating a service.

Use Async Methods#

Medusa wraps service method executions to inject useful context or transactions. However, since Medusa can't detect whether the method is asynchronous, it always executes methods in the wrapper with the await keyword.

For example, if you have a synchronous getMessage method, and you use it in other resources like workflows, Medusa executes it as an async method:

Code
await helloModuleService.getMessage()

So, make sure your service's methods are always async to avoid unexpected errors or behavior.

Code
1import { MedusaService } from "@medusajs/framework/utils"2import MyCustom from "./models/my-custom"3
4class HelloModuleService extends MedusaService({5  MyCustom,6}){7  // Don't8  getMessage(): string {9    return "Hello, World!"10  }11
12  // Do13  async getMessage(): Promise<string> {14    return "Hello, World!"15  }16}17
18export default HelloModuleService