API REFERENCE

defineConfig

import {
  defineConfig,
  type RasenganServerConfig,
  type BuildConfig,
} from '@rasenganjs/server';

See Config & Build for usage and how config interacts with CLI flags. This page is the flat type reference.

defineConfig()

function defineConfig(config: RasenganServerConfig): RasenganServerConfig;

Typed pass-through helper, returns the same object you pass in, with type-checking. Used in rasengan.server.ts:

rasengan.server.ts

import { defineConfig } from '@rasenganjs/server';
 
export default defineConfig({
  entry: 'src/main.ts',
  port: 4000,
});

RasenganServerConfig

interface RasenganServerConfig {
  entry?: string; // default "src/main.ts"
  port?: number; // default 3000
  host?: string; // default "0.0.0.0"
  preset?: 'node' | 'bun' | 'workerd'; // default "node"
  watchDir?: string | string[]; // default "src/"
  build?: BuildConfig;
}

Field	Description
`entry`	Path to the server entry file.
`port`	Port the server listens on.
`host`	Host address to bind to.
`preset`	Target runtime: `"node"`, `"bun"`, or `"workerd"` (Cloudflare Workers).
`watchDir`	Directory (or directories) watched for file changes in `rasengan-server dev`.
`build`	Production build output configuration, see `BuildConfig`.

Every field the CLI accepts as a flag maps directly to one of these. See CLI for the flag-to-field table.

BuildConfig

interface BuildConfig {
  outDir?: string; // default "dist"
  minify?: boolean; // default true
  formats?: Array<'single-file' | 'directory'>; // default ['single-file', 'directory']
}

Field	Description
`outDir`	Output directory for the production bundle.
`minify`	Whether to minify the bundled output.
`formats`	Which output shapes to produce: `"single-file"` (one `server.bundle.mjs`) and/or `"directory"` (one `.mjs` per source file, preserving structure).

ConfigHolder

class ConfigHolder {
  static set(config: RasenganServerConfig): void;
  static reset(): void;
  static get(
    overrides?: Partial<RasenganServerConfig>
  ): Promise<Readonly<RasenganServerConfig>>;
}

Static, process-wide config cache used by bootstrap() and the CLI. Most apps never call this directly.

Method	Description
`set(config)`	Seed the cache directly (used by the CLI, which resolves config before spawning the app process).
`reset()`	Clear the cached config, useful in tests, so each test loads a fresh config.
`get(overrides?)`	Resolve the config, then shallow-merge `overrides` on top. See resolution order below.

get()'s resolution order, first match wins:

An already-cached instance (set via a prior get() or set() call).
The RASENGAN_SERVER_CONFIG environment variable, parsed as JSON.
dist/config.json, if present (the production build output).
rasengan.server.ts/.js, loaded from disk via the CLI's config loader.

Once resolved, the config is frozen and cached process-wide. Subsequent get() calls only re-apply overrides, they don't re-resolve from scratch.

Logger

CLI

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