Bootstrap & ServerApp

bootstrap() is the recommended entry point for a Rasengan Server app. It creates a ServerApp, hands it to your callback for configuration, then compiles and serves it.

import { bootstrap } from '@rasenganjs/server';
 
bootstrap((app) => {
  app.registerModule(appModule);
  app.enableCors();
});

What bootstrap() Does

1. Creates a ServerApp instance.
2. Loads configuration (rasengan.server.ts, merged with any CLI overrides).
3. Invokes your callback, passing the ServerApp for configuration.
4. Calls app.compile(), turning your modules/controllers into a runtime Futon.
5. Selects the right runtime adapter (Node/Bun/Workerd) and starts serving.
6. Registers SIGTERM/SIGINT handlers for graceful shutdown.

function bootstrap(
  callback: (app: ServerApp) => void | Promise<void>,
  overrides?: Partial<RasenganServerConfig>
): Promise<ServerHandle>;

bootstrap() returns a ServerHandle ({ close(), app }) you can use to shut the server down programmatically — useful in tests.

ServerApp — the Orchestrator

ServerApp is the class your bootstrap() callback configures. It owns module registration, global middleware, error/404 handlers, and compiles everything into a Futon instance.

bootstrap((app) => {
  app.registerModule(appModule);
  app.enableCors({ origin: 'https://myapp.com' });
  app.onError(async (error, ctx) => {
    return ctx.res.status(500).json({ error: error.message });
  });
  app.notFound(async (ctx) => {
    return ctx.res.status(404).json({ error: 'Not Found' });
  });
});

Default Global Middleware

Every ServerApp starts with two middleware pre-registered, in this order: a request logger() and a bodyParser() (storing the parsed body under ctx.state.body). Anything you add via app.use() runs after these.

Middleware Execution Order

Rasengan Server layers middleware in a fixed order, regardless of where each layer is declared:

1. Global — app.use(), app.enableCors(), plus the default logger/body parser
2. Module-level — ModuleConfig.middlewares, scoped to that module's routes
3. Controller-level — Controller.middlewares, scoped to that controller's routes
4. Route-level — passed directly to router.get(path, middleware, handler)
5. Validation — injected automatically for routes with schemas
6. Handler — your route handler function

See Middleware for a worked example of each layer.

Compiling and Serving

app.compile() runs once, internally, as part of bootstrap() — you don't normally call it yourself. It flattens your module tree, registers every provider in a shared DI container, and registers every controller's routes with the correct middleware nesting. bootstrap() then hands the resulting Futon to whichever runtime adapter matches your preset.