diff --git a/passerelle/contrib/toulouse_foederis/models.py b/passerelle/contrib/toulouse_foederis/models.py
index 11a87c97..7bd00001 100644
--- a/passerelle/contrib/toulouse_foederis/models.py
+++ b/passerelle/contrib/toulouse_foederis/models.py
@@ -29,6 +29,51 @@ from passerelle.base.models import BaseResource, HTTPResource
 from passerelle.utils.api import endpoint
 from passerelle.utils.json import datasource_array_schema, datasource_schema, response_schema
 
+ATTACHMENT_SCHEMA = {
+    '$schema': 'http://json-schema.org/draft-04/schema#',
+    'title': _('Attachment data.'),
+    'description': '',
+    'required': ['application_id', 'name', 'file'],
+    'type': 'object',
+    'properties': {
+        'application_id': {
+            'description': _('ID of the application to which to attach the file.'),
+            'oneOf': [
+                {
+                    'type': 'string',
+                    'pattern': '^[0-9]+$',
+                },
+                {
+                    'type': 'integer',
+                },
+            ],
+        },
+        'name': {
+            'description': _('Name of the attachment.'),
+            'type': 'string',
+        },
+        'file': {
+            'description': _('File to attach.'),
+            'type': 'object',
+            'required': ['filename', 'content_type', 'content'],
+            'properties': {
+                'filename': {
+                    'description': _("File name"),
+                    'type': 'string',
+                },
+                'content_type': {
+                    'description': _("MIME type"),
+                    'type': 'string',
+                },
+                'content': {
+                    'description': _("Content"),
+                    'type': 'string',
+                },
+            },
+        },
+    },
+}
+
 
 def boolean_field(description):
     return {
@@ -590,6 +635,31 @@ class Resource(BaseResource, HTTPResource):
             'data': {'application_id': results[0]['id']},
         }
 
+    @endpoint(
+        name='attach-file',
+        perm='can_access',
+        post={
+            "description": _("Attach a file to an application."),
+            "request_body": {"schema": {"application/json": ATTACHMENT_SCHEMA}},
+        },
+    )
+    def attach_file(self, request, post_data):
+        application_id = post_data["application_id"]
+        attachment_name = post_data["name"]
+        file = post_data["file"]
+
+        self.http_request(
+            'POST',
+            f'data/candidature/{application_id}/fields/{attachment_name}?viewIntegrationName=api_publik',
+            json={
+                "contentType": file["content_type"],
+                "value": file["content"],
+                "fileName": file["filename"],
+            },
+        )
+
+        return {'err': 0}
+
     @endpoint(
         description=_('List announces'),
         long_description=_(
diff --git a/tests/test_toulouse_foederis.py b/tests/test_toulouse_foederis.py
index f71d1531..dc458b7e 100644
--- a/tests/test_toulouse_foederis.py
+++ b/tests/test_toulouse_foederis.py
@@ -513,6 +513,40 @@ class TestEndpoints:
 
         assert response.json["data"]["application_id"] == 42
 
+    def test_attach_file(self, resource, app):
+        @httmock.urlmatch(path=r'^.*/data/candidature/424242/fields/cv$')
+        def handler(url, request):
+            assert request.headers['content-type'] == 'application/json'
+            assert request.headers['api-key'] == APIKEY
+            payload = json.loads(request.body)
+            assert payload == {
+                "contentType": "application/pdf",
+                "value": "base 64 content",
+                "fileName": "cv.pdf",
+            }
+
+            return httmock.response(200, json.dumps({"code": 200, "results": ['Field updated']}))
+
+        @httmock.urlmatch()
+        def error_handler(url, request):
+            assert False, 'should not be reached'
+
+        with httmock.HTTMock(handler, error_handler):
+            response = app.post_json(
+                '/toulouse-foederis/foederis/attach-file',
+                params={
+                    "application_id": "424242",
+                    "name": "cv",
+                    "file": {
+                        "content_type": "application/pdf",
+                        "content": "base 64 content",
+                        "filename": "cv.pdf",
+                    },
+                },
+            )
+
+        assert response.json["err"] == 0
+
 
 def test_migration_0003_no_null_no_charfield(migration):
     with connection.cursor() as cur: