Context and state

A route handler or middleware receives a Context. A page, layout, or application document reads a RenderContext through this.ctx. Both refer to the same request, but only the handler context can continue the pipeline or mutate request-local state.

Field	Meaning
request	Web-standard Request.
url	Parsed request URL.
params	Captured route parameters, as strings.
config	Resolved application configuration.
platform	Optional runtime value passed to app.handler().
state	Data shared within this request. Mutable in Context, readonly in RenderContext.
error	The current HttpError in an error boundary, otherwise undefined.

Context also has next(), render(), and redirect(location, status?). next() runs the next handler. render() renders the current page when a page handler is executing. redirect() returns a redirect Response; its default status is 302.

Pass data to a page

// routes/products/[id].ts
import { PageComponent, type RouteHandlers } from "limette";
import { html } from "lit";

type State = { productName?: string };

export const handler: RouteHandlers<State> = {
  async GET(ctx) {
    ctx.state.productName = `Product ${ctx.params.id}`;
    return ctx.render();
  },
};

export default class Product extends PageComponent<State> {
  override render() {
    return html`<h1>${this.ctx.state.productName}</h1>`;
  }
}

State starts as a new object for each request. Render components see it as readonly. Params are also request-local; optional or catch-all params absent from a URL have the empty string value. Invalid percent encoding yields a 400 response.

Platform values

App<State, Platform> lets you describe host-specific information while keeping the request handler runtime-neutral:

import { App } from "limette";

type Platform = { requestId: string };
const app = new App<Record<string, unknown>, Platform>();
app.get("/request-id", (ctx) => new Response(ctx.platform.requestId));

const response = await app.handler()(
  new Request("https://example.com/request-id"),
  { requestId: "req-123" },
);

The Deno adapter supplies Deno's request information; Cloudflare Workers can pass { env, ctx }. Only read platform fields after choosing and typing the host value your application actually receives.