Astro MD Editor

Schema-aware editor for Astro content collections. It lets you edit frontmatter and markdown/MDX together, validates on save, and can reuse values from file Git history.

Demo video: https://www.youtube.com/watch?v=-cI6ct8yLHM

https://github.com/user-attachments/assets/7f38b6a4-fe1a-4e30-80c8-19a58aa860f1

Quick start

npx astro-md-editor
# or
pnpm dlx astro-md-editor

By default, it targets the current directory.

Target a specific Astro project:

astro-md-editor /absolute/path/to/astro-project
# or
astro-md-editor --path /absolute/path/to/astro-project

Root resolution order:

1. positional argument (astro-md-editor <astro-project-root>)
2. --path
3. APP_ROOT_PATH
4. current working directory

Port can be set with PORT or NITRO_PORT.

PORT=1234 npx astro-md-editor
# or
NITRO_PORT=1234 npx astro-md-editor

Requirements

• Astro project with collections under src/content
• Generated collection schemas in .astro/collections/*.schema.json

If schema files are missing, run in the target project:

astro sync

Highlights

• Reads collection schemas and content files (.md, .mdx, .markdown)
• Renders schema-aware controls (string, number, boolean, enum, date, arrays)
• Validates frontmatter with AJV before saving
• Infers image fields from src/content.config.* (image() / z.array(image()))
• Supports image pickers for both src assets and public assets
• Shows per-file Git history and applies selected revision values to the current draft safely

Field overrides (optional)

Create astro-md-editor.fields.json at the Astro project root to force specific UI controls.

{
  "blog": {
    "brandColor": { "type": "color" },
    "coverAssetPath": { "type": "image", "mode": "public" },
    "menuIconFiltered": { "type": "icon", "icon_libraries": ["lucide", "mdi"] },
    "menuIconAny": { "type": "icon" }
  },
  "snippet": {
    "galleryPaths": { "type": "image", "multiple": true, "mode": "public" }
  }
}

Supported override types:

• image (mode: "asset" | "public", optional multiple: true)
• color
• icon (optional icon_libraries: string[])

Precedence: astro-md-editor.fields.json > inferred image() fields > schema defaults.

Invalid or schema-incompatible overrides are ignored with startup warnings.

Notes

• Applying Git history updates the in-editor draft only; files are written only on normal Save
• public assets are saved as /path/from/public
• src assets are saved relative to the edited content file (./... or ../...)
• Icon values are saved as Iconify IDs (for example lucide:messages-square)
• Custom controls currently target top-level frontmatter fields

Add a custom UI handler in code

If you are extending the editor itself (not just using astro-md-editor.fields.json), add a new field kind in these places:

1. src/lib/schema-form.ts

   • Extend FieldUiKind, FieldUiConfig, and ResolvedField
   • Update resolveCustomFieldKind to map your override kind to a resolved field

2. scripts/bootstrap-collections.mjs

   • Extend fieldOverrideSchema so config accepts your new type
   • Update getOverrideConfig and resolveSchemaCompatibilityKind

3. src/components/editor/RightSidebar.tsx

   • Add your new field component
   • Render it in the resolvedFields.map(...) switch (field.kind === '<yourKind>')

4. src/lib/frontmatter-history-merge.ts

   • Update isCompatibleValue so Git-history apply validates your new kind correctly

Quick checklist for a new kind (example: slug):

• add slug to schema/field types
• parse type: "slug" in bootstrap overrides
• render <SlugField /> in RightSidebar
• add compatibility logic in history merge

If any part is missing, the field falls back to default/unsupported handling.