Filamental has no AI of its own to sell you. It is the whole product with all of it switched off, and it costs exactly the same either way. If you do want one, five routes in are already built, and you bring whichever model you already trust.
There is no assistant in the corner of the window. Nothing suggests, nothing completes a sentence you were still thinking about, and nothing is quietly reading over your shoulder to get better at doing so. Open Filamental with no key, no connection and no plugin and you have everything the rest of this site describes.
That is not restraint on our part, it is how the thing is built. There is no account, and there is no telemetry of any kind, so there is no channel for your work to leave by even if somebody wanted one. Your files sit in a folder on your disk in plain Markdown, exactly as they did before you installed anything.
None of what follows is a paid feature either. The line we charge at is drawn around handing your work to somebody else, not around thinking. So if you skip this entire page you are not on a lesser plan, you are not being nudged, and nothing is being withheld from you until you reconsider.
You are already paying for a very good model, you have already learned how to talk to it, and you have already bent it to the way you work. Building a worse one, charging you again for it and asking you to make friends with it would be an odd way to repay that. “This is my AI. There are many like it, but this one is mine.”
No branded agent
We could have shipped a chatbot with our name on it. We both know what that is: somebody else’s model, marked up and sold back to you as a unique selling point, with the U doing a great deal of heavy lifting.
Model agnostic, and staying that way
Frontier or open weights, cloud or running on your own machine. Every model vendor makes commercial decisions, and some of those decisions are geopolitical. We would rather not be tied to any of them. We would rather you were not either.
Every other product in this category bills AI use by the tier and reserves the good model for the good plan. We cannot meter what we do not sit in the middle of, and we would not want to.
Talk a subject through in whatever chat window you already use. Ask for the shape of it back, import that, and a structure is standing in front of you a minute later with everything named and connected. The blank canvas problem, which is the reason most tools like this get opened twice and then never again, simply does not arise.
Point it at a structure you built by hand and ask it to finish the parts you did not. Notes on the nodes you created and moved on from. The connector type you kept meaning to define. The relationship between two things that was obvious to you and written down nowhere. It works inside the space rather than producing a document about it.
Hand the whole thing over and the model receives an arrangement, not a folder. What depends on what, which way round, and how strongly. That is the difference between an AI that has your files and an AI that has your reasoning, and it is why the same question asked twice gets a markedly better answer the second time.
None of that needs a translation layer, because there is nothing to translate. A node is a Markdown file with its relationships written down in the front matter, which is a format every current model has read a great deal of. The structure is the prompt, and you did not have to write it.
You will recognise your own on sight. If none of these words mean anything to you, that is a sign this section is not for you rather than a sign you are behind.
MCP
Claude Desktop, Claude Code, Cursor, LM Studio. A live local connection to the space you have open, with nothing new to learn and no new window to work in.
Your own API key. Any model.
Paste a key from whoever you already pay and it works out the rest. It says at the top which model you are talking to, always, because that is the only honest way to run one. We never see the key or the conversation.
Point it at the folder
Anything that can read files can read a space, because a space is files. No connector, no permission dialog, no intermediate format. The second brain route, for people who already built one.
Copy World
The entire structure onto the clipboard, ready to drop into any chat box on earth, including the locked-down one your employer gives you. There is nothing to set up and nothing to install, and it works months later when you want to pick the thread back up.
Mermaid
Build it in conversation, paste the code, and it becomes a real space with types you can assign as it imports. If you know the word, you already know exactly what this does and roughly how long it will take.
Every one of these is free, on every plan, permanently. The full mechanics live in AI Connections & Prompting, where they belong.
Filamental’s own documentation is a Filamental space. One node per topic, connected where the topics genuinely relate, built and kept up to date using the routes described above rather than in spite of them. We did not think it might be useful for this. We reached for it because writing the documentation any other way had become the slower option.
That same space is what generates the Help section you are two clicks away from, and the help inside the application, from one source. They cannot drift apart, because there is only one of them. Go and read it: what you are looking at is the output.
Every route needs the model to understand what a Filamental file is before it can be useful with one. That briefing is two plain text files, and both are published here in full, word for word as they are sent: the skill file and the file format reference.
Not a summary of them, and not a friendly description of what they roughly say. The actual text, with nothing else running underneath it telling your model something different. If you are going to let software brief an AI on your behalf, you are entitled to read what it says.
Download it, never press the AI button, and nothing about the thing you are using is diminished. It will be there if you change your mind, and it will still be free when you do.