Marked seems to quarantine files automatically on my system

Question

Dear Brett,

Find below a clanker generated report of an issue I identified. Installed Marked 3 via App Store on my Macbook, right clicked a markdown file I had just generated minutes before and "Open With: Marked 3"'d it which resulted in a quarantine flag being added to it.

I know very little about Mac apps but trust/hope the clanker added sufficient identifying info for you, but let me know if I can add any more details please, I kept Marked installed and if this gets fixed(or sorted out on my end, if the problem is only there) I'll be extremely happy to buy it.

Thanks!

Marked 3 Adds Quarantine Metadata to Local Markdown Files

Date observed: 2026-07-03

Summary

Opening a local Markdown file with Marked 3 adds the macOS extended attribute
com.apple.quarantine to that file. The quarantine agent recorded in the
attribute is Marked.

After this happens, Finder/LaunchServices/Gatekeeper may show warnings when
opening the file, even though the file is plain local Markdown.

Marked Version

Application path: /Applications/Marked.app
Bundle identifier: com.brettterpstra.marked
Version: 3.1.7
Build: 1184
Mac App Store itemId: 6747497179
Mac App Store softwareVersionExternalIdentifier: 887747611
TeamIdentifier: 47TRS7H4BH

Reproduction Steps

Create a plain local Markdown file:

printf '# Test

Plain local Markdown file.
' > repro.md

Check its extended attributes before opening it:

xattr -l repro.md

Expected at this point: no com.apple.quarantine attribute.

Open the file with Marked.
Check the file's extended attributes again:

xattr -l repro.md

Observed Result

After opening the file with Marked, the file has quarantine metadata:

com.apple.lastuseddate#PS: ...
com.apple.provenance:
com.apple.quarantine: 0082;6a47cc18;Marked;

The timestamp component decodes to:

0x6a47cc18 -> Fri Jul  3 17:50:00 EEST 2026

The important part is that Marked is recorded as the quarantine agent:

com.apple.quarantine: ...;Marked;

Expected Result

Opening a local Markdown file in a Markdown viewer should not add
com.apple.quarantine to that file.

Notes

The tested file was plain local Markdown. It did not contain active HTML,
scripts, images, remote links, javascript: URLs, data: URLs, hidden control
characters, embedded payloads, or secrets.

The warning appears to follow the file metadata, not the Markdown content.

Brett Terpstra · Answer

Hi Anton,

Thanks for the detailed report — the repro steps and xattr output were exactly what I needed.

Short answer: Marked is not deliberately quarantining your files, and it is not changing the Markdown content. This is macOS attaching metadata when a sandboxed App Store app opens a document.

The MAS build runs in Apple’s app sandbox. When it opens a file, macOS often adds com.apple.quarantine (with Marked as the agent), plus things like com.apple.provenance and com.apple.lastuseddate#PS. That matches your output. The 0082-style flag is typical sandbox document tracking, not a sign the file came from the internet or is unsafe.

I checked the codebase and confirmed Marked does not set com.apple.quarantine. It reads your file to render the preview; the system adds the attribute when the sandboxed app accesses the file — including via File → Open inside Marked, which I verified has the same effect as Open With in Finder.

What usually helps:

Clear it if needed: xattr -d com.apple.quarantine /path/to/file.md — though opening the file again in the MAS build may re-add it.
The direct build is not sandboxed and does not do this; see Sandbox Restrictions for MAS limitations, if you haven't purchased yet, I would highly recommend getting the Paddle version instead of MAS, it solves all sandboxing issues and also gets much faster updates and fixes.

There’s no API to opt out — it’s platform behavior. I’m planning a short troubleshooting note so others aren’t surprised.

Your file is fine; this is metadata macOS uses for sandbox tracking, not Marked treating local Markdown as untrusted.