Read one file a transcript row carried
The bytes of one picture or converted document a session’s transcript names, addressed by the mediaKey on an Entry.attachments record. This is the ONLY road to them: the transcript read carries what a picture IS and never any of it, so a client that wants to draw one asks here. It serves bytes rather than a path on purpose. The client may be on another machine than the engine, where a path names nothing — and even on one machine a path would invite a client to read a directory the host owns. The key is resolved through the TRANSCRIPT that names it, not by joining it onto a directory. So a key this session’s conversation does not carry is a 404 whether or not a file of that name exists: one conversation’s picture is not another’s, and a home holds every session’s media beside the database. The refusal says nothing else — there is no distinction to draw between “no such file” and “not yours”, and drawing one would answer questions nobody may ask. Immutable once written, so the response may be cached for as long as the client likes. narya session purge destroys a conversation’s media with it, after which its own keys answer 404.
Path Parameters
The session's id.
The name EntryAttachment.mediaKey carries, addressing one stored file inside one session's media directory. It travels as a single path segment and its shape is bounded to what a path segment carries unchanged, for MonitorNameParam's reason: a "/" would address no route, and a "?" or "#" would end the segment early. The host composes these names itself when it stores the bytes, so no key that exists can fail to be addressed here — and a key outside this shape did not come from a transcript this host wrote.
1 - 128^[A-Za-z0-9_][A-Za-z0-9._-]*$Response
The stored file, with the media type the transcript recorded for it.
The response is of type file.

