Using HtmlRenderEvent

HtmlRenderEvent(html, last) is the terminal HTML transport value. Use it when another renderer already owns serialization and needs to join Typed’s ordered server output. It is not a raw-HTML escape hatch for application strings.

Mark the terminal chunk

import { Fx } from "@typed/fx";
import { HtmlRenderEvent } from "@typed/template/RenderEvent";

const article = Fx.fromIterable([
  HtmlRenderEvent("<article><h1>Typed</h1>", false),
  HtmlRenderEvent("<p>Cooperative by design.</p></article>", true),
]);

Chunks remain in producer order. Exactly the terminal chunk has last: true. A one-chunk render is HtmlRenderEvent(completeHtml, true), normally produced lazily with Fx.sync when serialization is synchronous.

The marker belongs to the renderer’s protocol. Do not infer it from an index inside Fx.map; an Fx can be empty, asynchronous, unbounded, or interrupted. If a foreign callback reports its terminal event, adapt that callback directly. If an Effect Stream needs one-chunk lookahead, keep that protocol in the adapter and acknowledge Sink delivery in order.

Treat HTML as trusted renderer output

html is inserted verbatim by an HTML consumer. The constructor performs no sanitization because the producing renderer is asserting that it already owns correct escaping and serialization.

Ordinary Typed interpolation is the application-data path:

import { html } from "@typed/template";

const userName = "<script>alert('not markup')</script>";
const safe = html`<p>Hello, ${userName}</p>`;

The HTML renderer escapes userName for its text context. Wrapping the same string in HtmlRenderEvent would make a false trust claim.

DOM and HTML output are not interchangeable

DomRenderEvent transports live browser identity. HtmlRenderEvent transports text, order, and completion. Do not serialize DOM merely to cross a client boundary, and do not parse renderer-owned HTML merely to reconstruct identity it never carried.

Use the public guards when a protocol endpoint accepts either representation. Application templates normally do not branch: the selected RenderTemplate consumes the representation appropriate to that edge.

Connect to Effect HTTP at the response boundary

Typed’s HTML renderer can produce an Fx of chunks. Adapt it to an Effect Stream and pass the encoded bytes to HttpServerResponse.stream, or buffer a finite document and use HttpServerResponse.html. Keep status, headers, cookies, compression, and route composition in Effect’s HTTP ecosystem; HtmlRenderEvent only describes renderer output.

The HTML output recipe shows both response forms with the real Effect v4 HTTP modules. Server rendering and hydration explains when Typed emits hydration markers and when static HTML is the honest result.