Your agent re-learns your project every morning.

What it actually does

A session opens. Before the first turn, the brain puts the wall clock, the git state, the rules that bind this project and the way you like to be worked with straight into context. No prompt asked for it. A hook did it.

$ brain recall "why postgres here"
#31 [channel:design/decision] (score 2.114) Postgres, not SQLite: three writers
      Settled 2026-03-04. WAL contention was real at 3 concurrent writers, measured
      at 40ms p99 on the deploy box. Deviates from the house SQLite default.
      (confirmed · 2026-03-04)
      tree unchanged since stored (a41f22c9)

That last line is the part people miss. The memory records the commit it was written against, so a later session can see nothing has moved and skip re-deriving the whole thing from the files. When the tree has moved, it says so instead.

Memory that ages

Not every fact deserves the same shelf life. "The box is rebooting" should be gone in a week. "TLS terminates at nginx, port 8443" should not.

Recall ranks on relevance multiplied by tier weight, age, how often the memory has earned its keep, the stakes you set and how good the source was. Hearsay can't outrank a measured fact by being newer.

Corrections win

Store a correction with --supersedes and the old wording still finds the new fact. Ask about the thing you believed in March and you get what's true today, not both at equal weight.

Try to file the same subject twice in one scope and it refuses, names the memory already there and offers you the three ways out. A brain that quietly grows two answers to one question is worse than one that admits it doesn't know.

$ brain remember --type gotcha --title "staging deploy needs the vault unsealed"
#42 in channel:deploy is already about this (67% title overlap):
  stored:  the staging deploy needs the vault unsealed first
  yours:   staging deploy needs the vault unsealed
Storing both would put two answers to one question in the brain. Pick one:
  the fact CHANGED         --supersedes 42
  same fact, better words  brain update 42 --body ...
  genuinely separate       --allow-duplicate

It fails closed

A recall miss returns nothing. Not the nearest thing, not the whole scope, nothing. That rule exists because a miss once fed a delete loop and destroyed real memories, and the warning that would have stopped it only existed in output nobody was reading.

• forget refuses pinned memories and guardrails, and refuses to delete a memory that other memories were superseded by.
• prune is a dry run, dumps the whole brain before it deletes anything and won't touch the two tiers that never decay.
• Credential-shaped text is rejected on every write path. The store is chmod 600 and gitignored.

Every command, over MCP

All 41 commands are MCP tools, over stdio or HTTP. Not a curated handful. The schemas are generated from the CLI's own flag definitions, so a flag added to one shows up in the other on the next build.

Point your editor at a brain running on a box you own and every machine you work from reads the same memory. That's what the hosted tier automates and what the free one lets you build yourself.

Three ways to run it

The kernel is never the paywall. Ranking, decay, supersession, provenance, the guards and full export ship in Solo exactly as they ship in the paid one. A price multiple should buy a different thing, not the same thing with permissions.