HTTP streaming

Mochi does not stream HTML responses. Every page renders to completion via Svelte’s render from svelte/server, then ships as a single text/html Response.

What does stream

• Mochi.sse(handler) — Server-Sent Events. The response body is a ReadableStream and stream.send(...) pushes events as they happen.
• Mochi.ws(handlers) — WebSockets via Bun.serve upgrade. Bidirectional, message-by-message.

Use these for realtime UI on top of an already-rendered page; do NOT reach for them as a replacement for streamed SSR.

Workarounds for slow pages

• Server islands (mochi:defer) load slow or personalized fragments out-of-band after the shell ships. The rest of the page renders immediately; the island fetches itself once the browser sees the placeholder.
• Visible hydration (mochi:hydrate:visible) keeps the initial JS payload small without progressive HTML.
• Shared HTTP cache (Cloudflare, CloudFront, Fastly, Varnish, nginx) in front of the origin makes render time irrelevant for the cacheable common case. Server islands can stay uncached behind a cached shell — see Cache.

Do NOT add an artificial loading screen to mask slow serverProps; instead, move the slow fetch into a mochi:defer island so the rest of the page paints immediately.