If your RESTful web API needs to return the resource representations in different languages depending upon the client locale, use the content negotiation offering in HTTP:
Clients can use the
Accept-Languagerequest header to specify language preferences.While generating a response, the server is expected to translate the messages into the language supported by the client. The server can use the
Content-Languageentity-header field to describe the natural language(s) of the intended audience.