diff --git a/umap/models.py b/umap/models.py
index 8f12ade7..8c3f4e6a 100644
--- a/umap/models.py
+++ b/umap/models.py
@@ -444,7 +444,7 @@ class DataLayer(NamedModel):
         (OWNER, _("Owner only")),
     )
     uuid = models.UUIDField(
-        unique=True, primary_key=True, default=uuid.uuid4, editable=False
+        unique=True, primary_key=True, default=uuid.uuid4, editable=True
     )
     old_id = models.IntegerField(null=True, blank=True)
     map = models.ForeignKey(Map, on_delete=models.CASCADE)
diff --git a/umap/static/umap/js/modules/data/features.js b/umap/static/umap/js/modules/data/features.js
index 260ed28f..3b39bbe8 100644
--- a/umap/static/umap/js/modules/data/features.js
+++ b/umap/static/umap/js/modules/data/features.js
@@ -139,7 +139,7 @@ class Feature {
       subject: 'feature',
       metadata: {
         id: this.id,
-        layerId: this.datalayer?.umap_id || null,
+        layerId: this.datalayer.umap_id,
         featureType: this.getClassName(),
       },
     }
diff --git a/umap/static/umap/js/modules/data/layer.js b/umap/static/umap/js/modules/data/layer.js
index 795a1f7d..3dc07ad6 100644
--- a/umap/static/umap/js/modules/data/layer.js
+++ b/umap/static/umap/js/modules/data/layer.js
@@ -36,7 +36,7 @@ const LAYER_MAP = LAYER_TYPES.reduce((acc, klass) => {
 }, {})
 
 export class DataLayer {
-  constructor(map, data) {
+  constructor(map, data, sync) {
     this.map = map
     this.sync = map.sync_engine.proxy(this)
     this._index = Array()
@@ -78,7 +78,9 @@ export class DataLayer {
     this.backupOptions()
     this.connectToMap()
     this.permissions = new DataLayerPermissions(this)
-    if (!this.umap_id) {
+
+    if (!this.createdOnServer) {
+      // When importing data, show the layer immediately if applicable
       if (this.showAtLoad()) this.show()
       this.isDirty = true
     }
@@ -89,6 +91,11 @@ export class DataLayer {
     if (this.isVisible()) this.propagateShow()
   }
 
+  get createdOnServer(){
+    console.log("reference version", this._reference_version)
+    return this._reference_version !== undefined
+  }
+
   set isDirty(status) {
     this._isDirty = status
     if (status) {
@@ -119,7 +126,7 @@ export class DataLayer {
     return {
       subject: 'datalayer',
       metadata: {
-        id: this.umap_id || null,
+        id: this.umap_id,
       },
     }
   }
@@ -212,7 +219,7 @@ export class DataLayer {
   }
 
   async fetchData() {
-    if (!this.umap_id) return
+    if (!this.createdOnServer) return
     if (this._loading) return
     this._loading = true
     const [geojson, response, error] = await this.map.server.get(this._dataUrl())
@@ -304,7 +311,7 @@ export class DataLayer {
   }
 
   isLoaded() {
-    return !this.umap_id || this._loaded
+    return !this.createdOnServer || this._loaded
   }
 
   hasDataLoaded() {
@@ -312,8 +319,13 @@ export class DataLayer {
   }
 
   setUmapId(id) {
-    // Datalayer is null when listening creation form
+    // Datalayer ID is null when listening creation form
     if (!this.umap_id && id) this.umap_id = id
+    else {
+      // Generate a random uuid if none is provided
+      this.umap_id = crypto.randomUUID()
+      console.log('Generating random UUID for datalayer', this.umap_id)
+    }
   }
 
   backupOptions() {
@@ -571,7 +583,7 @@ export class DataLayer {
   }
 
   reset() {
-    if (!this.umap_id) this.erase()
+    if (!this.createdOnServer) this.erase()
 
     this.resetOptions()
     this.parentPane.appendChild(this.pane)
@@ -1040,14 +1052,16 @@ export class DataLayer {
     // Filename support is shaky, don't do it for now.
     const blob = new Blob([JSON.stringify(geojson)], { type: 'application/json' })
     formData.append('geojson', blob)
-    const saveUrl = this.map.urls.get('datalayer_save', {
+    const saveURL = this.map.urls.get('datalayer_save', {
       map_id: this.map.options.umap_id,
       pk: this.umap_id,
+      created: this.createdOnServer,
     })
+    console.log("saveUrl", saveURL)
     const headers = this._reference_version
       ? { 'X-Datalayer-Reference': this._reference_version }
       : {}
-    await this._trySave(saveUrl, headers, formData)
+    await this._trySave(saveURL, headers, formData)
     this._geojson = geojson
   }
 
@@ -1076,7 +1090,7 @@ export class DataLayer {
       this._reference_version = response.headers.get('X-Datalayer-Version')
       this.sync.update('_reference_version', this._reference_version)
 
-      this.setUmapId(data.id)
+      // this.setUmapId(data.id)
       this.updateOptions(data)
       this.backupOptions()
       this.connectToMap()
diff --git a/umap/static/umap/js/modules/urls.js b/umap/static/umap/js/modules/urls.js
index c3cb8a2a..1fcb1542 100644
--- a/umap/static/umap/js/modules/urls.js
+++ b/umap/static/umap/js/modules/urls.js
@@ -25,8 +25,8 @@ export default class URLs {
   }
 
   // Update the layer if pk is passed, create otherwise.
-  datalayer_save({ map_id, pk }, ...options) {
-    if (pk) return this.get('datalayer_update', { map_id, pk }, ...options)
+  datalayer_save({ map_id, pk, created}, ...options) {
+    if (created) return this.get('datalayer_update', { map_id, pk }, ...options)
     return this.get('datalayer_create', { map_id, pk }, ...options)
   }
 }
diff --git a/umap/urls.py b/umap/urls.py
index aaab2beb..b3afb557 100644
--- a/umap/urls.py
+++ b/umap/urls.py
@@ -155,8 +155,8 @@ map_urls = [
         views.MapClone.as_view(),
         name="map_clone",
     ),
-    re_path(
-        r"^map/(?P<map_id>[\d]+)/datalayer/create/$",
+    path(
+        "map/<int:map_id>/datalayer/create/<uuid:pk>/",
         views.DataLayerCreate.as_view(),
         name="datalayer_create",
     ),
diff --git a/umap/views.py b/umap/views.py
index 5726a838..2aa418fb 100644
--- a/umap/views.py
+++ b/umap/views.py
@@ -13,6 +13,7 @@ from smtplib import SMTPException
 from urllib.error import HTTPError, URLError
 from urllib.parse import quote_plus, urlparse
 from urllib.request import Request, build_opener
+from uuid import UUID
 
 from django.conf import settings
 from django.contrib import messages
@@ -1181,8 +1182,17 @@ class DataLayerCreate(FormLessEditMixin, GZipMixin, CreateView):
 
     def form_valid(self, form):
         form.instance.map = self.kwargs["map_inst"]
+
+        uuid = self.kwargs["pk"]
+        # Check if UUID already exists
+        if DataLayer.objects.filter(uuid=uuid).exists():
+            return HttpResponseBadRequest("UUID already exists")
+
+        form.instance.uuid = uuid
         self.object = form.save()
-        # Simple response with only metadata (including new id)
+        assert uuid == self.object.uuid
+
+        # Simple response with only metadata
         response = simple_json_response(**self.object.metadata(self.request))
         response["X-Datalayer-Version"] = self.version
         return response