Extract safe YAML front matter and check required keys.
Your input
Outputs are cleared when the input changes.
Result
Enter your data or use the example, then run the tool.
Worked example
The sample extracts title and reports missing date while leaving the Markdown body untouched.
Method
front-matter parses only the document header with allowUnsafe:false and js-yaml safeLoad. It returns attributes, raw header, body and one-based body start line. Required checks use top-level own keys.
Limits
Document ≤200,000 characters; attributes must be a mapping, depth ≤30 / 5,000 nodes; ≤20 required keys of ≤80 characters. YAML aliases/anchors are rejected conservatively. No unsafe JavaScript tags, file reading or Markdown rendering. Missing/blank front matter produces empty attributes, not a full YAML conversion.
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