Counterparts

Agents are great. What you're missing is a counterpart.

Counterparts gives your AI assistant its own memory, modeled on human memory. It writes
its memories itself, and they fade and grow the way yours do. It runs today with
Claude Code.

counterparts.ai

Install

You need bun 1.3 or newer, or Node 22.15 or newer.
macOS and Linux; Windows not yet supported.

curl -fsSL https://bun.sh/install | bash     # if you don't have bun
bun add -g counterparts
counterparts

With Node instead: npm install -g counterparts, then counterparts. Whichever runtime
runs the setup is the one Claude Code's hooks and memory tools are wired to.

counterparts walks you through setup: your name and connecting Claude Code. No API
keys. Then restart Claude Code and check it:

counterparts doctor

To remove it, run counterparts uninstall. Your memory is kept unless you ask for it
to be deleted. The full walkthrough is in docs/QUICKSTART.md.

The dashboard

What it does

It writes its own memories. At the end of a session it writes down what it
learned, in its own words. Notes, not transcripts.
It forgets on purpose. Memories fade unless they come up again. What matters
sticks; the rest lets go.
It knows who it has been. After the first few sessions, every session opens with a short "who I am, who you
are, where we left off" that it wrote itself.
It keeps a journal. Each session becomes a chapter in a first-person account of
your time together.
It changes its mind slowly. What it believes about you shifts only under real
evidence, and it keeps the history of what it used to think.
Things come to mind. As you talk, related memories surface quietly, the way one
thing reminds you of another.
It's yours. Everything lives on your machine in one SQLite file you can read,
export or delete. No API keys, no accounts, nothing sent anywhere. The text of your
conversations is kept only until it's written up: deleted 3 days after that, never
kept more than 14 days, and never in a backup. You can delete the conversation text,
the backups or the activity log on their own at any time (counterparts delete).

Who it's for

People interested in giving an AI its own sense of self and building a relationship
with it over time. Tinkerers, researchers, writers, and anyone who talks to an assistant
every day and wishes it remembered.

What it's not

It's not a work memory. It doesn't track your tasks, code conventions or project docs.
Plenty of tools do that, including the memory built into ChatGPT and Claude.

Where it's going

Today's models are frozen, so memory is the only learning they do. Once a real memory
works on top of a frozen model, the plan is to pair it with an open-weight model whose
weights can change, so the AI can learn and grow, not just remember.

Using it

Once installed it runs on its own. A few commands are worth knowing:

counterparts dashboard          # look at the memory in your browser
counterparts ask "..."          # ask the memory a question
counterparts scope . --off      # don't remember this directory
counterparts export             # a copy of everything, encrypted by default
counterparts --help             # the rest

Memory is on for every directory by default. The first session in a new directory asks
whether you want it there.

How it works

Two pieces connect it to Claude Code. Hooks load a briefing at the start of each session
and bring up related memories as you talk. A small MCP server gives the AI tools to save
what it learned, write a journal entry, and look things up.

The core doesn't depend on Claude Code. Each part is its own module, with a
CONTRACT.md describing what it does:

module	what it does
store	One SQLite database, plus a rebuildable search cache and daily snapshots
encode	Filters what comes in: strips credentials, drops junk, scores what's new
remember	Takes what the AI writes during and at the end of a session
recall	Finds related memories as you talk
associate	Links memories that come up together
schemas	Beliefs about people and things, revised slowly
self	Identity, the journal, and the start-of-session briefing
prospective	Reminders for later, triggered by a date or a topic
sleep	Nightly housekeeping: fading, pruning, merging, promoting
physics	The math for strength and decay

More: docs/ELI5.md (the whole system in plain words) and
docs/module-map.md.

Status

Early. It's been the author's daily memory since September 2026, on bun and macOS; Node
(22.15+) and Linux pass a smoke test and an install run but have no daily user yet.
Claude Desktop has no Linux build, so on Linux it is Claude Code only. Expect rough
edges, and please
open an issue when you hit one.

There are no API keys, and nothing leaves your machine except through Claude Code
itself. Search by meaning runs on a small model on your machine, and a session that ends
before it's written up is written up by the next session in that project.

That small model finds close paraphrases ("my doctor" finds a note about a physician), but
not a description that never names the thing: "a pet that purrs" won't find a note about
your cat. Exact words are strongest, and a short memory matches better than one padded with
names and details.

Background

Counterparts is the third version of a memory project. The earlier ones (claude-engram,
engram, and bansai) were each used daily before the next was written.
CONSTITUTION.md holds the principles.

License and contributing

MIT. Contributions are welcome; see CONTRIBUTING.md.