diff --git a/app/api/formsemestres.py b/app/api/formsemestres.py
index e7ca242f8c..18b987387a 100644
--- a/app/api/formsemestres.py
+++ b/app/api/formsemestres.py
@@ -9,11 +9,12 @@
 """
 from operator import attrgetter, itemgetter
 
-from flask import g, request
+from flask import g, make_response, request
 from flask_json import as_json
 from flask_login import login_required
 
 import app
+from app import db
 from app.api import api_bp as bp, api_web_bp, API_CLIENT_ERROR
 from app.decorators import scodoc, permission_required
 from app.scodoc.sco_utils import json_error
@@ -30,6 +31,7 @@ from app.models import (
     ModuleImpl,
     NotesNotes,
 )
+from app.models.formsemestre import GROUPS_AUTO_ASSIGNMENT_DATA_MAX
 from app.scodoc.sco_bulletins import get_formsemestre_bulletin_etud_json
 from app.scodoc import sco_groups
 from app.scodoc.sco_permissions import Permission
@@ -496,3 +498,44 @@ def formsemestre_resultat(formsemestre_id: int):
         row["partitions"] = etud_groups.get(row["etudid"], {})
 
     return rows
+
+
+@bp.route("/formsemestre/<int:formsemestre_id>/get_groups_auto_assignment")
+@api_web_bp.route("/formsemestre/<int:formsemestre_id>/get_groups_auto_assignment")
+@login_required
+@scodoc
+@permission_required(Permission.ScoView)
+@as_json
+def get_groups_auto_assignment(formsemestre_id: int):
+    """rend les données"""
+    query = FormSemestre.query.filter_by(id=formsemestre_id)
+    if g.scodoc_dept:
+        query = query.filter_by(dept_id=g.scodoc_dept_id)
+    formsemestre: FormSemestre = query.first_or_404(formsemestre_id)
+    response = make_response(formsemestre.groups_auto_assignment_data or b"")
+    response.headers["Content-Type"] = scu.JSON_MIMETYPE
+    return response
+
+
+@bp.route(
+    "/formsemestre/<int:formsemestre_id>/save_groups_auto_assignment", methods=["POST"]
+)
+@api_web_bp.route(
+    "/formsemestre/<int:formsemestre_id>/save_groups_auto_assignment", methods=["POST"]
+)
+@login_required
+@scodoc
+@permission_required(Permission.ScoView)
+@as_json
+def save_groups_auto_assignment(formsemestre_id: int):
+    """enregistre les données"""
+    query = FormSemestre.query.filter_by(id=formsemestre_id)
+    if g.scodoc_dept:
+        query = query.filter_by(dept_id=g.scodoc_dept_id)
+    formsemestre: FormSemestre = query.first_or_404(formsemestre_id)
+
+    if len(request.data) > GROUPS_AUTO_ASSIGNMENT_DATA_MAX:
+        return json_error(413, "data too large")
+    formsemestre.groups_auto_assignment_data = request.data
+    db.session.add(formsemestre)
+    db.session.commit()
diff --git a/app/models/formsemestre.py b/app/models/formsemestre.py
index 26bb5ac408..68399262b6 100644
--- a/app/models/formsemestre.py
+++ b/app/models/formsemestre.py
@@ -42,6 +42,8 @@ from app.scodoc.sco_permissions import Permission
 from app.scodoc.sco_utils import MONTH_NAMES_ABBREV
 from app.scodoc.sco_vdi import ApoEtapeVDI
 
+GROUPS_AUTO_ASSIGNMENT_DATA_MAX = 1024 * 1024  # bytes
+
 
 class FormSemestre(db.Model):
     """Mise en oeuvre d'un semestre de formation"""
@@ -108,6 +110,10 @@ class FormSemestre(db.Model):
     elt_annee_apo = db.Column(db.Text())
     "code element annee Apogee, eg 'VRT1A' ou 'V2INLA,V2INCA,...'"
 
+    # Data pour groups_auto_assignment
+    # (ce champ est utilisé uniquement via l'API par le front js)
+    groups_auto_assignment_data = db.Column(db.LargeBinary(), nullable=True)
+
     # Relations:
     etapes = db.relationship(
         "FormSemestreEtape", cascade="all,delete", backref="formsemestre"
diff --git a/migrations/versions/b8df1b913c79_add_data_for_groups_auto_assignment.py b/migrations/versions/b8df1b913c79_add_data_for_groups_auto_assignment.py
new file mode 100644
index 0000000000..54e9db27e9
--- /dev/null
+++ b/migrations/versions/b8df1b913c79_add_data_for_groups_auto_assignment.py
@@ -0,0 +1,34 @@
+"""Add data for groups_auto_assignment
+
+Revision ID: b8df1b913c79
+Revises: 054dd6133b9c
+Create Date: 2023-05-15 23:12:58.257709
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "b8df1b913c79"
+down_revision = "054dd6133b9c"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("notes_formsemestre", schema=None) as batch_op:
+        batch_op.add_column(
+            sa.Column("groups_auto_assignment_data", sa.LargeBinary(), nullable=True)
+        )
+
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    with op.batch_alter_table("notes_formsemestre", schema=None) as batch_op:
+        batch_op.drop_column("groups_auto_assignment_data")
+
+    # ### end Alembic commands ###
diff --git a/tests/api/test_api_formsemestre_data.py b/tests/api/test_api_formsemestre_data.py
new file mode 100644
index 0000000000..fd9b94707c
--- /dev/null
+++ b/tests/api/test_api_formsemestre_data.py
@@ -0,0 +1,71 @@
+"""Test formsemestre
+
+Utilisation :
+    créer les variables d'environnement: (indiquer les valeurs
+    pour le serveur ScoDoc que vous voulez interroger)
+
+    export SCODOC_URL="https://scodoc.xxx.net/"
+    export SCODOC_USER="xxx"
+    export SCODOC_PASSWD="xxx"
+    export CHECK_CERTIFICATE=0 # ou 1 si serveur de production avec certif SSL valide
+
+    (on peut aussi placer ces valeurs dans un fichier .env du répertoire tests/api).
+
+    Lancer :
+        pytest tests/api/test_api_formsemestre.py
+"""
+import requests
+
+from app.scodoc import sco_utils as scu
+
+from tests.api.setup_test_api import (
+    API_URL,
+    CHECK_CERTIFICATE,
+    api_headers,
+)
+
+
+def test_save_groups_auto_assignment(api_headers):
+    """
+    Routes:
+        /formsemestre/<id>/save_groups_auto_assignment
+        /formsemestre/<id>/get_groups_auto_assignment
+    """
+    formsemestre_id = 1
+    r = requests.get(
+        f"{API_URL}/formsemestre/{formsemestre_id}",
+        headers=api_headers,
+        verify=CHECK_CERTIFICATE,
+        timeout=scu.SCO_TEST_API_TIMEOUT,
+    )
+    assert r.status_code == 200
+    # On stocke une chaine quelconque
+    data_orig = (
+        """{ "attribute" : "Un paquet de json", "valide": pas nécessairement +}--"""
+    )
+    r = requests.post(
+        f"{API_URL}/formsemestre/{formsemestre_id}/save_groups_auto_assignment",
+        data=data_orig.encode("utf-8"),
+        headers=api_headers,
+        verify=CHECK_CERTIFICATE,
+        timeout=scu.SCO_TEST_API_TIMEOUT,
+    )
+    assert r.status_code == 200
+    # GET
+    r = requests.get(
+        f"{API_URL}/formsemestre/{formsemestre_id}/get_groups_auto_assignment",
+        headers=api_headers,
+        verify=CHECK_CERTIFICATE,
+        timeout=scu.SCO_TEST_API_TIMEOUT,
+    )
+    assert r.status_code == 200
+    assert r.text == data_orig
+    # Tente d'envoyer trop de données
+    r = requests.post(
+        f"{API_URL}/formsemestre/{formsemestre_id}/save_groups_auto_assignment",
+        data="F*CK" * 1000000,  # environ 4MB
+        headers=api_headers,
+        verify=CHECK_CERTIFICATE,
+        timeout=scu.SCO_TEST_API_TIMEOUT,
+    )
+    assert r.status_code == 413