The Git-backed Store

This is where anarchie earns its name. Each patient record is its own git repository, and storing a clinical document is an audited git commit. You never have to touch git yourself - anarchie drives it - but everything it does is a plain git operation you can inspect afterwards.

Create an EHR

anarchie ehr new

output

1b4e28ba-2fa1-11d2-883f-0016d3cca427

The command prints the new EHR id (a UUID). Behind it, anarchie created ehrs/<id>/, ran git init inside it, wrote the EHR and EHR_STATUS objects, and made the first commit - the creation audit.

Save the EHR id

The UUID printed here is your EHR id. The rest of this walkthrough uses the shell variable $EHR to refer to it. Set it now so later commands work:

EHR=1b4e28ba-2fa1-11d2-883f-0016d3cca427

Use the id your anarchie ehr new actually printed, not the example value above.

List the EHRs in the deployment at any time:

anarchie ehr list

output

1b4e28ba-2fa1-11d2-883f-0016d3cca427

You can attach an audit identity to the creation:

anarchie ehr new --committer "Dr Ada Lovelace" --email ada@example.org

Commit a Composition

Storing a Composition is a CONTRIBUTION, which anarchie maps onto a single git commit:

anarchie commit "$EHR" vitals.json \
    --committer "Dr Ada Lovelace" --email ada@example.org \
    -m "Admission observations"

output

Committed 9f1c8a3e-7c2b-4e9a-bd11-2a1f6c0e4d55::anarchie.example.org::1
  object_id:       9f1c8a3e-7c2b-4e9a-bd11-2a1f6c0e4d55
  commit:          a1b2c3d4…
  contribution_id: 4d8e…

What just happened:

anarchie assigned a fresh object_id to this Composition.
It built the version_uid as object_id::system_id::version_tree_id. This is the first version, so the version_tree_id is 1.
It wrote the canonical Composition file plus a contribution manifest, then made one git commit whose author, committer, and timestamp are the openEHR AUDIT_DETAILS, and whose trailers (anarchie-contribution-id, anarchie-change-type, anarchie-system-id) tie the commit back to the openEHR model.

Save the object_id

The object_id printed here is used in the next steps. Set a shell variable for it:

OBJECT_ID=9f1c8a3e-7c2b-4e9a-bd11-2a1f6c0e4d55

Use the id your anarchie commit actually printed.

Why the manifest does not contain its own commit

A CONTRIBUTION references the commit that recorded it - but a commit cannot contain its own hash. So the link runs the other way: the commit carries an anarchie-contribution-id trailer, and the manifest stays clean.

Commit a new version

Pass --object-id to create a new version of an existing Composition rather than a brand-new one. Make an edited copy first - correct the diastolic reading (82) to 84:

sed 's/82.0/84.0/' vitals.json > vitals-updated.json

anarchie commit "$EHR" vitals-updated.json \
    --object-id "$OBJECT_ID" \
    --committer "Dr Ada Lovelace" --email ada@example.org \
    -m "Corrected diastolic reading"

output

Committed 9f1c8a3e-7c2b-4e9a-bd11-2a1f6c0e4d55::anarchie.example.org::2

The version_tree_id is now 2. The change is recorded as a Modification rather than a Creation in the audit.

Read it back

anarchie cat prints the head version when given an object_id, or a specific version when given a full version_uid:

# the current head
anarchie cat "$EHR" "$OBJECT_ID"

# version 1, reconstructed from git history
anarchie cat "$EHR" "$OBJECT_ID::anarchie.example.org::1"

The head lives in the working tree; older versions are reconstructed with git show <commit>:<path>. The working file always holds the latest version, and git holds everything before it.

See the history

anarchie log "$EHR" "$OBJECT_ID"

output

9f1c…::anarchie.example.org::2  2026-01-15T09:42:11Z  Corrected diastolic reading
  commit b2c3d4e5…
9f1c…::anarchie.example.org::1  2026-01-15T09:30:00Z  Admission observations
  commit a1b2c3d4…

That is the version history of the Composition, derived directly from git log of its file.

Diff two versions

anarchie diff "$EHR" "$OBJECT_ID" 1 2

from and to are 1-based version_tree_ids. Because the files are canonical, the diff shows exactly what changed clinically - plus the version_uid bump - and nothing else.

Next: Inspecting the Files