Sharing a brain in a team

Several people can share one notes folder through git, and each person’s agents then start from the same notes. Sharing is through git only: nothing syncs live, and there are no accounts. This page says what is shared, what stays with each person, and what does not work yet.

In one line: commit the notes and the workspace’s shared files; hippo init already ignores everything that is per person, so git add -A is safe. Each person’s dreaming learns from their own sessions.

What is shared and what is per person

Nothing in $HIPPO_HOME is shared: the configuration, the index and the rollup are per machine. In the workspace:

What init writes

hippo init makes sure of three files, adding only the lines that are missing. It never removes or reorders a line, so your own .gitignore and .gitattributes are kept:

• .hippo/.gitignore: snapshots/, sessions/, reports/, dream-state.json;
• the workspace’s .gitignore: /<log_path>, for example /notes/Session log.md;
• the workspace’s .gitattributes: /<notes_dir>/**/*.md merge=union, so two dreams that append to the end of the same note merge without a conflict. A union merge keeps both appends, each once, in the order the pull meets them; read the note after a merge.

In a workspace set up before these rules, run hippo init with no flags in it: it adds the missing lines and changes nothing else. hippo doctor has a git row that warns when one of these files is not ignored, or when git already tracks one, and names the commands that fix it:

git rm -r --cached -- .hippo/sessions
git commit -m "Stop tracking per-person hippo files"

Only your workspace’s sessions leave a record

hippo ingest indexes every transcript on your machine into your own $HIPPO_HOME, so search, the overview, fleet, incidents and the card see all of your work. It writes a session record into the workspace only for a session that ran inside the workspace’s folder (or one of its git worktrees), read, edited or cited one of its notes, or declared itself there through the hooks. A session of another project leaves nothing in the workspace. A workspace written by an older version is cleaned on the next ingest, which says how many records it removed and why. Session records are ignored as well, so even a workspace session’s task text stays on your machine.

Each person

Once, after cloning:

hippo init        # no flags: reads the workspace's .hippo/, writes your own config
hippo ingest

model_command is per machine: set it with hippo config set model_command … if the claude CLI is not on your PATH, or your first dream fails.

Then, as usual: work with the hooks (hippo hooks install), let dreaming run, and commit:

git pull --rebase
git add -A
git commit -m "notes"
git push

What was tried

Two people, each with their own home folder and $HIPPO_HOME, cloned one workspace from a shared git remote. Each had a session in the workspace and one in another project, ran a session start and end with a handoff linking the same note, wrote the session log, dreamed (a stand-in model, so both appended to the same note), committed with git add -A, pushed, and pulled the other’s commits with git pull --rebase. No per-person file was ever staged, the pull had no conflict, the note held both appends once each, neither person’s dreaming window moved, the other project’s sessions left no record, and hippo doctor stayed quiet. This runs as a test (crates/hippo/tests/team.rs) with every cargo test.

What does not work yet

• Dreaming learns only from your own sessions. Handoffs live in .hippo/sessions/, which stays on your machine, so your dream never sees a teammate’s handoffs, and theirs never sees yours. Each person who wants their sessions folded into the notes runs dreaming themselves.
• hippo revert works only on the machine that dreamed the change. The snapshot it needs is there. On another machine, git is the undo: git log -p -- <note> shows the commit, and git revert or an edit undoes it. revert says so when it refuses.
• A teammate’s evidence is not in your index. hippo show proposal on their proposal prints (not in the index) for each evidence turn, and hippo xray or resume on their session says there is no such session.
• Nothing coordinates two people. There is no owner on a session record, no per-person folder inside .hippo/, no live sync and no lock across machines.