Modules, @Provides & @Binds
Tell Hilt how to build your types.
Modules, @Provides & @Binds is a free Jetpack Compose Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Jetpack Compose Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
When Constructor Injection Is Not Enough
You cannot add @Inject to a constructor you do not own, like a Retrofit or OkHttp instance. Hilt needs another way to learn how to build those.
Meet the Module
A module is a class that teaches Hilt how to create types it cannot construct on its own. Mark it with @Module to register it.
@Module
object NetworkModule { }Install Into a Component
Every module declares where it lives with @InstallIn. SingletonComponent makes its bindings available app-wide for the whole process.
@Module
@InstallIn(SingletonComponent::class)
object NetworkModuleProvide a Type With @Provides
@Provides marks a function whose return value Hilt will use as a dependency. The function body shows exactly how to build it.
@Provides
fun provideApi(): ApiService = Retrofit.Builder().build().create(ApiService::class.java)Provides Can Take Parameters
A @Provides function can ask for other dependencies as parameters. Hilt supplies them first, then runs your function to assemble the result.
@Provides
fun provideRepo(api: ApiService): Repo = Repo(api)Binding Interfaces With @Binds
When you just need to map an interface to an implementation, @Binds is leaner than @Provides. It tells Hilt which class satisfies the interface.
@Binds
abstract fun bindRepo(impl: RepoImpl): Repo@Binds Needs an Abstract Module
Because @Binds methods are abstract, their module must be an abstract class, not an object. The implementation must already be injectable.
@Module
@InstallIn(SingletonComponent::class)
abstract class RepoModuleProvides vs Binds
Use @Binds for a simple interface-to-class mapping, and @Provides when you must run code to build the object. Binds generates less code.
Mark Singletons
Add @Singleton to a provider so Hilt creates the object once and reuses it. Perfect for heavy clients like a shared OkHttp instance.
@Provides
@Singleton
fun provideClient(): OkHttpClient = OkHttpClient()Disambiguate With Qualifiers
If two providers return the same type, a @Qualifier annotation tells them apart. Hilt then knows which binding each injection point wants.
@Qualifier
annotation class AuthClientModules Build the Graph
Together your modules form the dependency graph. Hilt reads them at compile time and wires every type into a connected, verified tree.
Quick Check
You need to bind a Repo interface to its single RepoImpl class. Which is the leanest choice?
Recap: Teaching Hilt to Build
You saw that modules teach Hilt how to create types it cannot construct, using @Provides for code and @Binds for interface mappings. 🧩
Frequently asked questions
Is the “Modules, @Provides & @Binds” lesson free?
Yes — the full text of “Modules, @Provides & @Binds” is free to read here on the web, and the Jetpack Compose Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Jetpack Compose Academy course, upgrade to CoddyKit PRO.
What will I learn in “Modules, @Provides & @Binds”?
Tell Hilt how to build your types. You practise Jetpack Compose Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Jetpack Compose Academy?
No prior experience is required. Jetpack Compose Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Modules, @Provides & @Binds” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Jetpack Compose Academy lesson?
Yes. Every Jetpack Compose Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Why DI: Testable, Decoupled Code
- Modules, @Provides & @Binds
- hiltViewModel & @HiltViewModel
- Scopes & Component Lifetimes