My API Functions Had No Code Inside Them. So Who Was Actually Fetching the Data? (Interview Prep)

Short summary

Retrofit generates the actual networking code at runtime from your interface declarations when you call retrofit.create()—that's where the 'missing' implementation lives. Functions appear empty because Retrofit auto-generates a hidden class containing the real code: URL building, OkHttp calls, and JSON parsing. Master the distinction: @Path fills placeholders for specific resource identifiers (pokemon/bulbasaur), while @Query appends optional filter parameters (limit, offset).

• •Retrofit.create() generates a hidden implementation class containing actual networking code
• •@Path specifies resource identity in the URL path, @Query adds optional parameters
• •Functions are empty interfaces that Retrofit transforms into working code at runtime

Generated with AI, which can make mistakes.