Premium tool · Tephra · $399 seat
Tephra — a memory brain that grows itself, shared by every AI you use
Most AI memory is a box you fill by hand: siloed inside one app, and blank again the moment a chat ends. Tephra is the opposite. It is a private, encrypted knowledge brain that pulls in and files new memories on its own — on the order of 5,000 a day — learns from every interaction, and is read and written by every AI you work with, so nothing you work out is ever explained twice. It compounds on its own and gets sharper the more it is used.
What it does
- A brain that grows itself. Tephra is not a static store you have to fill. It autonomously pulls in and files new memories every day — on the order of 5,000 — and generates fresh ones from every interaction, so it compounds without you lifting a finger.
- One memory across every AI. Claude, Onyx, and your local model all read and write the same brain. Ordinary assistants start cold on every prompt; Tephra hands each one your full context, so a decision made once is known everywhere from then on.
- Private, and explorable. Your own side is isolated and encrypted — your goals, facts, decisions, and corrections, kept separate from the shared knowledge. And a living graph lets you see and surf how everything you know connects.
How to get Tephra
Tephra is part of Premium — $19/mo at the member rate through the Obsidian Metrics community, or $29/mo direct from the website. Or buy the seat outright for $399 once: perpetual access with no subscription. Tephra is not metered and there is nothing to top up. See membership and pricing.
Frequently asked questions
What is Tephra?
Tephra is a self-growing memory brain — a private, encrypted knowledge layer that pulls in its own new memories every day, learns from every interaction, and is shared by every AI you use. Instead of re-explaining yourself to each tool, you build one memory that all of them read and write. It is a tool for keeping and connecting what you know, not a source of advice.
What makes Tephra different from other AI memory?
Three things no ordinary memory does at once. It grows itself — filing new memories autonomously, on the order of 5,000 a day, and learning from every interaction. It is shared across every AI you use rather than locked inside one app, so nothing is re-explained. And it keeps a private, per-account side that is isolated and yours, alongside a living graph you can actually see and surf.
How much does Tephra cost?
Two ways to get it. As a subscription, Tephra is part of Premium — $19/mo at the member rate through the community, or $29/mo direct from the website. Or buy the seat outright for $399 once: perpetual access to Tephra with no subscription.
Is Tephra metered?
No. Tephra has no usage metering and nothing to top up. The $399 seat is the whole cost of the tool. That is a real difference from Onyx, whose usage is metered.
How is Tephra different from Onyx?
Tephra is the memory — the self-growing, shared brain where everything you and your systems learn is kept and connected. Onyx is the operator that reaches into that memory to do the work. Tephra is not metered; Onyx is. Many people run both, but each is sold on its own.