Some posts are downloads

A photo in a post is a bare filename in an image line. It always has been:

![A view from the window](window.jpg)

So a file attached to a post is the same line without the exclamation mark:

[Reading notes, 2025](reading-notes.pdf)

A whole line that is nothing but a link, pointing at a bare filename with a known extension, is an attachment. It gets staged through incoming/ like a photo, stored next to the post like a photo, and it never leaves your site.

A line with a URL in it stays what it has always been: a link. The difference is the bare filename — the same rule photos already follow, so there's nothing new to learn.

Rendered as a card, not a link

An attachment renders as a card carrying the label, the extension and the size. The size is there because a download deserves to say what it costs before you commit to it — a 40 MB PDF on a phone on mobile data is a different proposition from a 200 kB one, and the reader should get to make that call.

Over about 50 MB you get a warning when you save. Not a refusal — sometimes a big file is exactly the point — just a note that you're about to ask a lot of somebody.

The extensions that count: .pdf, .zip, .tgz, .epub, .txt, .md, .ics, .gpx, .csv. A whitelist, because the engine should only publish files it can honestly describe.

And a new kind of post

A short line plus a file makes the post a document — the same way a short caption plus a photo makes an image post. Write more than a caption and it's an article that happens to have an attachment.

The first document you publish makes DOCUMENTS appear in the navigation. Nothing to configure: the menu has shown only the types a site actually has since 1.0, so the section arrives with its first tenant and would leave with its last.

Publish and forget. That was the whole brief: a PDF, a GPX track, a calendar file — things worth putting somewhere permanent without writing an essay around them.