What a board does that a chat window can't.
What's on the desk is what the chat reads.
Drop a PDF, a link or a note beside a question and that chat reads those — nothing from the other desks — so answers stay on topic and each question sends fewer tokens.
Branch from any answer.
Ask the same desk a different question, or add one source and see what changes. The string thickens toward the question it grew from.
Open any card big.
Long answers get a full page, with the questions that led there on the left. Esc puts you back on the board.
Ask the next question on another AI.
Each branch picks its own model — Claude, GPT, Gemini and more — and the desk and the trail come with it. You pay the provider directly; we add nothing on top.
This desk is empty on purpose.
Context Tree V3 is new. When the first people using it have something to say, their words get pinned here — with their names and their permission. No logo wall until there’s something true to put on it.
Why this exists.
One person builds Context Tree. This is the note pinned to the first board.
I started this in 2025 because my best questions kept getting lost. I'd ask something good, the chat would wander, and forty messages later the model had half-forgotten the paper I'd given it at the start.
I wanted a board instead of a scroll. Each question gets a desk. Whatever sits on the desk is what that chat reads. When I want a second angle I branch, and the branch remembers where it came from.
It runs in your browser and it's free with your own API keys, because I'd rather you pay the people who make the models than pay me a markup. If something breaks or feels wrong, write to me. I read every message.
— [Founder's name] · building Context Tree
Free while you bring your own keys.
Everything on the board. You pay each AI provider for what you use, at their price.
- Unlimited boards, up to 50 cards on each
- Seven providers: Anthropic, OpenAI, Google, Groq, DeepSeek, Mistral, Moonshot
- PDFs, documents, links and notes as sources
Models included, for people who'd rather not manage API keys. Priced when it's ready — not before.
- Everything in Free
- Video and audio reading
- Share a board with a link
Do I need an API key?
Yes, for now. Paste one from any of the seven providers in Settings; it takes about a minute. You can add more later.
Where is my key kept?
Encrypted on our server. It's never sent back to your browser after you save it, and you can remove it at any time.
Do I have to install anything?
No. Context Tree runs in your browser, on any computer you sign in from.