Configuration#

A Kyln project is configured by a single kyln.config.ts at its root. Export a config object with defineConfig, which gives you type checking and editor completion over every option.

The config file#

The starter app ships a minimal config:

// kyln.config.ts
import { defineConfig } from "@kyln/core";

export default defineConfig({
  server: {
    port: 2500,
  },
  router: {
    routesDir: "src/routes",
    apiDir: "src/api",
  },
});

Every option is optional and has a sensible default. A config with no fields at all is valid.

Server#

Controls the HTTP server.

server: {
  port: 2500,        // default 2500; applies in every run mode
  host: "0.0.0.0",   // interface to bind
}

server.port is honored across dev, serve, and the baked standalone server (bake writes it into the bundle as its default). In dev and serve, a --port= flag and the PORT environment variable take precedence over it, in that order; the standalone server honors PORT. See the CLI reference for the full resolution.

Router#

Tells Kyln where your routes and API endpoints live. Change these if your project doesn't use the default layout.

router: {
  routesDir: "src/routes",
  apiDir: "src/api",
}

Build#

Controls the production build (kyln bake).

build: {
  outDir: "dist",     // build output directory
  sourcemap: false,   // emit source maps
  minify: true,       // minify the client bundle
}

SSR#

Server-side rendering options.

ssr: {
  enabled: true,      // render on the server for first paint
  streaming: false,   // stream the response
}

Security#

Kyln exposes configuration for CORS, CSRF, rate limiting, security headers, and TLS under security. These are opt-in and each has its own guide; the shape looks like:

security: {
  cors: { origins: ["https://example.com"], credentials: true },
  csrf: { enabled: true },
  rateLimit: { windowMs: 60_000, max: 100 },
}

Refer to the security guide for the full option set before enabling these in production.

Next#

With the framework covered end to end, the CLI reference documents each command: preheat, dev, make, test, bake, and serve.