An engram is the physical trace a memory leaves in the brain, and Engram gives your agents one: every fact they keep is sealed with your wallet, hash-chained, notarized on a public chain, and mirrored off-site. It holds up as evidence.
the science
A memory lives as a physical change in the brain: the trace itself.
When an agent remembers, the fact becomes a sealed checkpoint on its own chain, AES‑256 under your wallet key, its position fixed by a keccak hash of everything before it. The memory is the trace.
Fire together, wire together. Use strengthens a synapse; disuse prunes it.
Retrieval works the same way: the search index over an agent's memories is itself sealed memory on the chain, rebuilt as the corpus grows, portable to any machine that holds the wallet.
The hippocampus holds today; sleep moves what matters into cortex, for good.
Every six hours an anchor epoch notarizes each chain's head on a public blockchain and mirrors the ciphertext off‑site. After that, the past is fixed.
the chain of custody
The agent chooses to keep a fact; its tool call is the only writer.
Encrypted client‑side with a per‑entry key, so the store only ever sees ciphertext.
Every append signs its position. Rewrite anything, anywhere, and the head breaks where everyone can see it.
The head lands on a public chain each epoch. Anyone can verify. No one can revise.
Ciphertext replicates off‑site, and a wallet plus a mirror is enough to rebuild the whole chain, byte for byte.
in the product
Then the hard part: wipe the agent's database. It still remembers. The chain heals the store, decrypts with the wallet, and picks up where it left off. We test this by deleting its memory on purpose.
self-host
Apache‑2.0. It runs on one Postgres and one daemon, one command per service, with any model key or a single Hero Run key for the whole catalog.
pnpm install && pnpm db:migrate
pnpm --filter api dev # the app
memoryd --data-dir ./data # the memory chain