markstream-custom-components

name: markstream-custom-components description: Override built-in Markstream node renderers and add trusted custom tags. Use when Codex needs to apply setCustomComponents, install VueRendererMarkdown with scoped Vue app components, keep overrides scoped with customId, map override keys like image, code_block, mermaid, or link, or wire customHtmlTags and nested renderers for tags such as thinking.

Markstream Custom Components

Use this skill when the task is to change how Markstream renders specific nodes or custom tags.

Read references/patterns.md before choosing an override strategy.

Workflow

1. Classify the request.
   • built-in override: replace an existing renderer such as image, link, code_block, mermaid, d2, or inline_code.
   • custom tag: support trusted HTML-like tags such as thinking.
   • parser-level: requires token transforms or AST reshaping. Only then should you leave this skill and use low-level parser hooks.
2. Prefer scoped mappings.
   • Use setCustomComponents(customId, mapping) instead of global mappings whenever practical.
   • Pass the same customId or custom-id to the renderer instance.
   • In Vue 3 app/plugin setup, import { VueRendererMarkdown } from markstream-vue and install it with { components } when the override should be scoped to the Vue app instance.
3. Start with the smallest safe override.
   • Leaf-like nodes (image, link, inline_code, mermaid) are easier than container nodes (heading, paragraph, list_item).
   • If the request only changes Mermaid, use mermaid, not code_block.
4. Preserve nested Markdown when needed.
   • For trusted custom tags with inner Markdown, render node.content with a nested renderer.
   • Pass the same custom-tag allowlist to nested renderers.
   • Nested renderers inside a smooth-streaming parent are automatically suppressed from double pacing — do not add smooth-streaming to child renderers.
5. Keep props and cleanup intact.
   • Preserve node, loading, indexKey, customId, and isDark.
   • For mermaid and infographic overrides, preserve estimatedPreviewHeightPx so async preview shells keep stable height during remounts.
   • Remove temporary scoped mappings with removeCustomComponents(customId) when the scope is no longer needed.
6. Validate with the smallest useful check.
   • Prefer a local demo, targeted test, or docs build.
   • Call out whether the implementation is safe for repeated and nested custom tags.

Default Decisions

• Scoped overrides first, global overrides only when the whole app truly needs them.
• Leaf-node overrides before container-node overrides.
• customHtmlTags plus scoped custom components before parser hooks.
• Nested renderers for tag bodies that contain Markdown.

Useful Doc Targets

• docs/guide/component-overrides.md
• docs/guide/custom-components.md
• docs/guide/components.md
• docs/guide/advanced.md