Notes are for what you'd tell someone. Properties are for what you'd put in a column: an owner, a status, a cost, a renewal date. Anything you'd want to read off twenty nodes at a glance rather than go hunting for.
They're optional. A project with no properties at all is a perfectly good project, and plenty of people never add one.
You define a property once for the whole project, and then it's available on every node. Properties sits in Left Panel, under Classifications and Connectors, as the third list the project keeps.
That's deliberate. Defining "Owner" doesn't force an owner on to anything, it just means the box exists when you want it. A node you never fill in stays completely clean: an empty property isn't written to your file at all.
Click ＋ on the Properties section header.
| Kind | What it's for |
|---|---|
| Text | A line of writing. Anything that doesn't fit the others |
| Number | A figure you might want to compare or total |
| Yes / No | A switch. Either it applies or it doesn't |
| Date | A day, picked from a calendar |
| Choice | One option from a list you set |
| Tags | Several options from a list you set |
| Link | A web address, opens in your browser |
| An email address, opens your mail app | |
| Phone | A phone number |
| Rating out of 3 | Three stars, for a rough call: low, middling, high |
| Rating out of 5 | Five stars, when three isn't enough room to be fair |
| Key | A long value you copy rather than read, see below |
Choice and Tags ask you for the options. You don't have to think of them all now, you can add one from the node itself later and it joins the list for everyone.
Open a node and look at Properties in Right Panel (Notepad). Every property the project defines is listed there, filled in or not, so the panel reads as a form rather than as a list of whatever happens to be set.
Type into the one you want. It saves as you go, like your notes do, and it's undoable.
Clear a value and the property goes back to empty. The row stays, because the project still defines it.
Edit a property by clicking it in the sidebar.
Renaming changes only the label you read. Underneath, each property keeps a permanent short key, and that's what's written into your files, so a rename never touches a single node and never loses a value. Rename freely.
Changing the Kind is also allowed. Values you've already entered stay exactly as they are, so switching Text to Choice will leave you with values that aren't yet in the option list. Tidy them or add them as options.
Remove in the property's editor takes it out of the project, and asks first.
Removing it deletes nothing. It disappears from every node you'd left empty, and on the nodes where you'd actually filled it in the value stays exactly where it was, now shown with a small × beside it. So a removal you didn't mean costs you nothing: put the property back and everything returns to normal.
That × is the per-node delete, and it only ever appears on a property the project doesn't define. Besides a removed one, that's usually a property typed straight into the file by hand or by an AI. Clicking it clears that value from that node alone.
Key is for the things you paste rather than read: an API key, a licence code, a long identifier.
It's masked in the panel until you choose to reveal it, it's one click to copy, and its value is held out of Filamental's search so it can't surface when you're looking for something else. The eye-and-slash mark next to it means hidden, nothing more.
It is not encrypted. Nothing in a Filamental project is. The value sits in your markdown file as ordinary text, exactly like every other property, and anyone who can open the folder can read it. Hidden is about keeping a long ugly string out of your way, not about keeping a secret from anyone. If a value would genuinely hurt you if someone read it, it belongs in a password manager, not here.
Properties are the part of a node an AI can use without having to interpret anything.
Your notes are prose, and a model reading them has to work out what you meant. A property is already a fact with a name on it: status: blocked, owner: Maria, renewal: 2027-03-01. That's the difference between asking an AI to read forty pages and asking it a question it can answer by looking.
They sit in the node's file as plain text, so anything reading the file gets them for free. That includes Filamental's own AI, see AI Connections & Prompting, and any assistant connected to the MCP server, which can search on them and read them back.
Two things worth knowing if you're working with AI:
Properties live in the frontmatter at the top of the node's markdown file, which is the same place your node's name and type live, see Graph. Every value is stored as plain text, whatever the Kind, so the file stays readable and hand-editable years from now.
They're yours and they stay put. Properties are not included in a share link or a published page, so filling them in doesn't mean publishing them.
Still stuck? Email [email protected].