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name: markstream-svelte description: "Integrate the beta markstream-svelte renderer into Svelte 5 or SvelteKit with runes, explicit CSS, smooth streaming, workers, and SSR-safe boundaries." category: frontend risk: critical source: https://github.com/Simon-He95/markstream-vue/tree/main/.agents/skills/markstream-svelte source_repo: Simon-He95/markstream-vue source_type: official date_added: "2026-07-21" author: Simon-He95 tags: [svelte, sveltekit, markdown, streaming, ssr] tools: [claude, cursor, gemini, codex] license: MIT license_source: https://github.com/Simon-He95/markstream-vue/blob/main/license

Markstream Svelte

Overview

Integrate Markstream using Svelte 5 runes and SvelteKit-safe browser boundaries.

When to Use

Use for Svelte 5 or SvelteKit package setup, streaming state, workers, or scoped custom components. Svelte 4 is unsupported.

Workflow

Before changing dependencies or source files, inspect the existing package manager and project conventions, preview the intended edits, and obtain explicit user approval.

1. Confirm Svelte 5 and acceptance of a beta package.
2. Install only requested peers; import package CSS after resets and KaTeX CSS only for math.
3. Start with <MarkdownRender {content} /> and smooth streaming auto.
4. For live chat disable fade and opt into the cursor; on completion set final, disable pacing/cursor, and enable fade only if desired.
5. Use nodes only for worker-owned parsing or shared AST state.
6. Use $props() and callbacks. Configure KaTeX or Mermaid workers only when requested.
7. Prefer renderer-local customComponents; use scoped registration only when sharing is intentional.
8. Keep browser-only workers behind SvelteKit client boundaries; validate with svelte-check, build, or e2e.

Example

<script lang="ts">
  import MarkdownRender from 'markstream-svelte'
  import 'markstream-svelte/index.css'

  let { content, isDone }: { content: string; isDone: boolean } = $props()
</script>

<MarkdownRender
  {content}
  final={isDone}
  fade={isDone}
  typewriter={!isDone}
  smoothStreaming={isDone ? false : 'auto'}
  htmlPolicy="safe"
/>

Limitations

• Svelte 4 is unsupported and the package is beta.
• Workers and heavy peers require client-side bundler support.
• This skill does not migrate unrelated Svelte architecture.

Security & Safety Notes

Keep safe HTML and strict Mermaid defaults. Review dependencies and never run browser-only peers during SSR.