local-first, encrypted AI memory

Cypher Brain

The brain you offload to AI
should stay unreadable to everyone but you.

An AI second brain, encrypted on your machine — only you hold the key — parked permanently on Arweave, where no platform can read or delete it.

Cypher Brain mascot — a cypherpunk hooded dog in sunglasses
01  Concept

Encrypt your memory locally, park it somewhere durable

Encrypt the notes and chats you feed to AI on your own machine, turn them into a queryable second brain, and park the ciphertext permanently on Arweave — pay once, stored forever. Three layers: Cipher, Brain, Store.

1 · Your data notes · chats memory 2 · Brain AI structures it embed · synthesize 3 · Cipher encrypt with your key 4 · Store push to Arweave pay once · forever 5 · Yours only your key restores it encrypted from here on ON YOUR MACHINE · plaintext never leaves ARWEAVE back to you
Steps 1–3 run on your machine — only encrypted data ever reaches Arweave.
02  Problem

Your brain now lives on someone else’s server

The more you offload to AI, the more your second brain lives inside a platform — deletable, alterable, and readable by whoever runs it. Your most personal data is the one you own least.

BRAIN INSIDE A PLATFORM AI platform holds your data their database plaintext to them ✗ deleted on a policy change ✗ readable by the operator ✗ censorable / subpoenable CYPHER BRAIN encrypted snapshot ciphertext only Arweave pay once · forever ✓ no operator can read it ✓ no host to delete it ✓ only your key restores it
Same second brain, two custody models — only the encrypted-on-Arweave one is truly yours.
03  Solution

Encrypt it, keep the key, and park it somewhere no one can take it down

Three layers in one tool: Cipher encrypts on-device, Brain makes your memory queryable, and Store parks the ciphertext on Arweave — a one-time payment for permanence, beyond any single party's reach.

you key holder CIPHER client-side encryption — only your key decrypts nothing leaves the device as plaintext BRAIN AI second brain — ingest, embed, synthesize, query your memory becomes answerable, not just stored STORE Arweave permanence — pay once, stored forever reads are plain HTTP — no wallet, no SDK
Cipher + Brain run on your machine; Store parks the encrypted result on Arweave.
Cipher
Client-side encryption keyed to you — the network only ever holds ciphertext.
Brain
An AI second brain over your own corpus — memory you can ask, not just store.
Store
Arweave pay-once permanence — no server to babysit; a fresh machine restores with just the locator + your key.
04  Why Arweave

A permanence you pay for once, not uptime you have to maintain

A backup must outlive your attention. Arweave funds perpetual replication from a one-time upload fee — no contracts to renew, no server to keep alive — and getting the bytes back is a plain HTTP fetch from any gateway.

Pay-once permanence
One upload fee funds an endowment that pays for replication — the archive survives your neglect by design.
Recovery = plain HTTP
No wallet, no SDK — a fresh machine restores with just the tx id and your key; any public gateway serves the bytes.
Ciphertext only
The network is public and permanent, but it only ever holds bytes that your key alone can decrypt.
05  Status & Roadmap

The whole loop runs today — encrypt, park, restore

The Cipher layer round-trips against real second-brain data, the Brain layer synthesizes nightly, and real snapshots have been parked on Arweave and pulled back from a public gateway.

STEP 1Cipher layer — a key only you hold
cypher-brain encrypts each snapshot with age (X25519) to your public key; the private identity stays off the always-on machine. The round-trip has been validated end-to-end against real gbrain data, and a different identity cannot restore it.
# encrypt on your machine — storage never sees plaintext $ cypher-brain snapshot --pg "$PG" --dir ~/.gbrain --out brain.age
STEP 2Brain layer — a second brain we already run
We already run a personal second brain (GBrain) nightly on a local machine: it ingests our AI conversations across projects, embeds them, and synthesizes links, then serves hybrid search plus LLM reasoning over the whole corpus.
# the brain we run every night — locally $ gbrain think "what did we decide about X?"
STEP 3Store — park it permanently on Arweave
push uploads the ciphertext via a bundler (payable with ETH/USDC, under 100 KB free); pull is a plain gateway fetch that needs no wallet and no SDK. Proven against the real network: a snapshot slice was uploaded, retrieved from a public gateway, and decrypted.
# pay once — the network keeps it forever $ cypher-brain push --in brain.age --backend turbo