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Container Modules

Container modules provide a convenient way to set up Better Auth authentication in your InversifyJS dependency injection container. Each framework has its own specialized container module that automatically configures the necessary services, middleware, and controllers.

Available Container Modules​

BetterAuthExpressContainerModule​

Framework: Express

Sets up Better Auth for Express applications.

const container: Container = new Container();

const options = {
  database: new BetterSqlite3('./path/to/database.db'),
  emailAndPassword: {
    enabled: true,
  },
} as const satisfies BetterAuthOptions;

const betterAuthInstance = betterAuth(options);

const betterAuthExpressContainerModule: BetterAuthExpressContainerModule<
  typeof options,
  () => BetterAuth<typeof options>
> = BetterAuthExpressContainerModule.fromOptions(
  '/api/auth',
  betterAuthInstance,
);

await container.load(betterAuthExpressContainerModule);

const adapter: InversifyExpressHttpAdapter = new InversifyExpressHttpAdapter(
  container,
  {
    logger: true,
    useCookies: true,
  },
);

const application: express.Application = await adapter.build();

application.listen();

BetterAuthExpress4ContainerModule​

Framework: Express v4

Sets up Better Auth for Express v4 applications.

const container: Container = new Container();

const options = {
  database: new BetterSqlite3('./path/to/database.db'),
  emailAndPassword: {
    enabled: true,
  },
} as const satisfies BetterAuthOptions;

const betterAuthInstance = betterAuth(options);

const betterAuthExpress4ContainerModule: BetterAuthExpress4ContainerModule<
  typeof options,
  () => BetterAuth<typeof options>
> = BetterAuthExpress4ContainerModule.fromOptions(
  '/api/auth',
  betterAuthInstance,
);

await container.load(betterAuthExpress4ContainerModule);

const adapter: InversifyExpressHttpAdapter = new InversifyExpressHttpAdapter(
  container,
  {
    logger: true,
    useCookies: true,
  },
);

const application: express.Application = await adapter.build();

application.listen();

BetterAuthFastifyContainerModule​

Framework: Fastify

Sets up Better Auth for Fastify applications.

const container: Container = new Container();

const options = {
  database: new BetterSqlite3('./path/to/database.db'),
  emailAndPassword: {
    enabled: true,
  },
} as const satisfies BetterAuthOptions;

const betterAuthInstance = betterAuth(options);

const betterAuthFastifyContainerModule: BetterAuthFastifyContainerModule<
  typeof options,
  () => BetterAuth<typeof options>
> = BetterAuthFastifyContainerModule.fromOptions(
  '/api/auth',
  betterAuthInstance,
);

await container.load(betterAuthFastifyContainerModule);

const adapter: InversifyFastifyHttpAdapter = new InversifyFastifyHttpAdapter(
  container,
  {
    logger: true,
    useCookies: true,
  },
);

const application = await adapter.build();

await application.listen();

BetterAuthHonoContainerModule​

Framework: Hono

Sets up Better Auth for Hono applications.

const container: Container = new Container();

const options = {
  database: new BetterSqlite3('./path/to/database.db'),
  emailAndPassword: {
    enabled: true,
  },
} as const satisfies BetterAuthOptions;

const betterAuthInstance = betterAuth(options);

const betterAuthHonoContainerModule: BetterAuthHonoContainerModule<
  typeof options,
  () => BetterAuth<typeof options>
> = BetterAuthHonoContainerModule.fromOptions(
  '/api/auth',
  betterAuthInstance,
);

await container.load(betterAuthHonoContainerModule);

const adapter: InversifyHonoHttpAdapter = new InversifyHonoHttpAdapter(
  container,
  {
    logger: true,
  },
);

const application = await adapter.build();

serve(application);

Factory Method: fromOptions()​

All container modules provide a static fromOptions() method for easy instantiation:

public static fromOptions<TOptions extends BetterAuthOptions>(
  basePath: string,
  betterAuth: BetterAuth<TOptions>,
): ContainerModule<TOptions, () => BetterAuth<TOptions>>

Parameters​

  • basePath - The base URL path where Better Auth endpoints will be mounted (e.g., /api/auth)
  • betterAuth - A configured Better Auth instance

Return Value​

Returns a container module instance configured for the specific framework.

What Gets Registered​

When you load a Better Auth container module, it automatically registers the following services in your container:

1. Better Auth Service​

The core Better Auth instance is registered as a singleton service.

Service Identifier: betterAuthServiceIdentifier

2. Better Auth Middleware​

Framework-specific middleware for handling authentication is registered as a singleton.

Service Identifier: betterAuthMiddlewareServiceIdentifier

3. Better Auth Controller​

A framework-specific controller that handles all Better Auth endpoints (sign-in, sign-up, sign-out, etc.) is registered.

Service Identifier: betterAuthControllerServiceIdentifier

Service Identifiers​

You can import service identifiers from '@inversifyjs/http-better-auth'

@Controller('/api')
class UserController {
  @ApplyMiddleware(betterAuthMiddlewareServiceIdentifier)
  @Get('/profile')
  public async getProfile(
    @HonoUserSession() session: UserSession<BetterAuthOptions>,
  ): Promise<UserSession<BetterAuthOptions>> {
    return session;
  }
}

Type Parameters​

All container modules are generic and accept the following type parameters:

TOptions​

Extends BetterAuthOptions - captures your specific Better Auth configuration for type safety.

TFactory​

A factory function type that produces a BetterAuth<TOptions> instance. Usually () => BetterAuth<TOptions> when using fromOptions().

Complete Example​

Here's a complete example showing how to set up a Hono application with Better Auth:

const options = {
  database: new BetterSqlite3('./auth.db'),
  emailAndPassword: {
    enabled: true,
  },
} as const satisfies BetterAuthOptions;

const betterAuthInstance = betterAuth(options);

// 2. Create container and load Better Auth module
const container: Container = new Container();

const betterAuthModule = BetterAuthHonoContainerModule.fromOptions(
  '/api/auth',
  betterAuthInstance,
);

await container.load(betterAuthModule);

// 3. Create a controller that uses authentication
@Controller('/api')
class UserController {
  @ApplyMiddleware(betterAuthMiddlewareServiceIdentifier)
  @Get('/profile')
  public async getProfile(
    @HonoUserSession() session: UserSession<typeof options>,
  ): Promise<UserSession<typeof options>> {
    return session;
  }
}

// 4. Register your controllers
container.bind(UserController).toSelf();

// 5. Build and run the application
const adapter = new InversifyHonoHttpAdapter(container);
const app = await adapter.build();