Show HN: Robust LLM Extractor for HTML/Markdown in TypeScript (opens in new tab)

While working with LLMs for structured web data extraction, we saw issues with invalid JSON and broken links in the output. This led me to build a library focused on robust extraction and enrichment:

- Clean HTML conversion: transforms HTML into LLM-friendly markdown with an option to extract just the main content - LLM structured output: Uses Gemini 2.5 flash or GPT-4o mini to balance accuracy and cost. Can also also use custom prompt - JSON sanitization: If the LLM structured output fails or doesn't fully match your schema, a sanitization process attempts to recover and fix the data, especially useful for deeply nested objects and arrays - URL validation: all extracted URLs are validated - handling relative URLs, removing invalid ones, and repairing markdown-escaped links

I'd love to hear if anyone else has experimented with LLMs for data extraction or if you have any questions about this approach!