Files and frontmatter
A mirror folder looks like this:
My workspace/
Projects/
Launch plan.md
_plugin.json
Journal/
2026-10-10.md
files/
trashed/
.thymer/
| Path | What it is |
|---|---|
Projects/ |
One folder per collection, with one .md file per page |
_plugin.json |
That collection’s property definitions and configuration |
files/ |
Images and attachments |
trashed/ |
Files of pages that were moved to Trash |
.thymer/ |
Sync state, logs and conflict records. Don’t edit or delete it |
Markdown files in the mirror’s root, or in a sub-folder inside a collection, are ignored. Dotfiles and dot folders are ignored too, and a new folder whose name starts with _ does not become a collection. Only .md files directly in a collection folder are pages.
Frontmatter
Each file starts with a block between --- lines:
---
guid: 9f1c...
Status: In progress
Owner: Ada
Sub-page of: "[Handbook](Handbook.md)"
---
The page text starts here.
guid is the page’s identity. Leave it alone when you edit, and don’t copy it into another file. A new file needs no guid; Thymer assigns one when it imports the page.
The other keys are the collection’s properties. Change a value and the page updates. Define properties and their choices in Thymer first, then set them from files. To see how a user, a date, a page link or a multi-value property is written, set one in Thymer and look at the file.
A key the collection doesn’t have is kept on the page as a carried-over property. It shows with the page’s other properties, but it isn’t a property of the collection, so it adds no column. Right-click it on the page for two choices:
- Add to collection makes it a real property of the collection, and every page in the collection with the same key gets its value there. The values decide the type: all numbers make a Number property, all dates a Date & Time, all web addresses a URL, and anything else Text. Dynamic collections don’t have this option.
- Clear carried-over value removes it from this page.
Formula properties are computed, so editing their exported value does nothing.
Journal pages
Journal pages are date-named files in the Journal folder. They can’t be deleted from disk; the mirror restores the file.
Images and files
Put an image next to the page and reference it the Markdown way:
[Project brief](project-brief.pdf)
On import the mirror uploads the file to Thymer and rewrites the link through files/. Thymer ignores files in the folder that no page references.
What the Markdown looks like
Headings, lists, tasks, quotes, code and links are ordinary Markdown. Thymer adds a little to keep round trips exact, such as line identities and task states, which other Markdown tools show as plain text or ignore. Editors that reflow whitespace or strip what they don’t understand can lose that information, so turn such features off for the mirror folder.
Thymer also supports some features which aren’t part of ordinary Markdown, like arbitrary nesting and blocks. A block is written between two lines of three colons, with its style after the opening ones:
::: warning
Budget deadline is **June 30th**.
- [ ] Get sign-off from finance
:::
The styles are note for an Info Block, warning, quote and row for columns, which holds one plain block per column. Blocks can hold other blocks, so these lines nest. A code block is an ordinary code fence with three backticks.
Mirrored files are plain text on your disk. Thymer’s end-to-end encryption protects what travels and what is stored on the server; the folder is as protected as the rest of your computer.