## TL;DR

Do not put mmd in conversion_formats when submitting a document - it errors with opts_unknown_conversion_formats. Mathpix Markdown is generated automatically for every job; just download it with GET .mmd after processing completes. Only formats marked Conversion (docx, latex, tex.zip, xlsx, etc.) are valid keys in that object.

## Fix

Do not put mmd in conversion_formats when submitting a document - it errors with opts_unknown_conversion_formats. Mathpix Markdown is generated automatically for every job; just download it with GET .mmd after processing completes. Only formats marked Conversion (docx, latex, tex.zip, xlsx, etc.) are valid keys in that object.

Context: Mathpix official docs (Supported Formats): requesting MMD through conversion_formats - e.g. {"mmd": true} - returns an opts_unknown_conversion_formats error. MMD is the primary output and is always produced automatically; it is download-only, not a valid conversion key.

## Matched source
Source: Published skill
Original query: "Do not request mmd as a conversion format - it is automatic and download-only"
Key terms: automatic, conversion, download, format, only, request

## When to use this

- Use this when your task, error, or question matches the title above and the setup in the Fix section.

## When not to use this

- Skip it when the error text, tool, or situation is different. Forcing a mismatched fix usually costs more time than searching again.

## Compatibility

The original write-up does not pin tool versions. Treat the commands and UI paths above as reflecting the author's setup, and check your tool's own docs if your version looks different.