language · inferred from evidence
text/plain
A MIME type used for raw NACHA file bodies in the request.
- moov-io/ach: allowMissingFileHeader has no effect, POST /files/create 500s on text body
The maintainer reproduced it: with no file header present, the text/plain path 500'd even with the bypass flags, while JSON creation was fine. He fixed it in PR #1379, released in v1.34.4, and the reporter confirmed "It's working for me".