diff --git a/bincio/extract/cli.py b/bincio/extract/cli.py
index 4a5fee7..5a5d1ba 100644
--- a/bincio/extract/cli.py
+++ b/bincio/extract/cli.py
@@ -76,8 +76,7 @@ def _process_file(path: Path) -> dict:
 
     try:
         metrics = compute(activity)
-        activity_id = make_activity_id(activity)
-        write_activity(
+        activity_id = write_activity(
             activity, metrics, _output_dir,
             privacy=_privacy,
             rdp_epsilon=_rdp_epsilon,
diff --git a/bincio/extract/writer.py b/bincio/extract/writer.py
index 143e951..ed1c7e0 100644
--- a/bincio/extract/writer.py
+++ b/bincio/extract/writer.py
@@ -90,6 +90,7 @@ def write_activity(
         if existing.get("source_hash") != activity.source_hash:
             activity_id = f"{activity_id}-{activity.source_hash[-6:]}"
             json_path = acts_dir / f"{activity_id}.json"
+            detail["id"] = activity_id
     json_path.write_text(json.dumps(detail, indent=2, ensure_ascii=False))
 
     # ── GeoJSON track ────────────────────────────────────────────────────────
diff --git a/schema/bas-v1.schema.json b/schema/bas-v1.schema.json
index 43c38d8..874322d 100644
--- a/schema/bas-v1.schema.json
+++ b/schema/bas-v1.schema.json
@@ -122,7 +122,8 @@
             "minItems": 2,
             "maxItems": 2
           }
-        }
+        },
+        "custom":            { "type": "object" }
       },
       "additionalProperties": false
     }
diff --git a/site/src/components/EditDrawer.svelte b/site/src/components/EditDrawer.svelte
index 56e1961..e2ba5c5 100644
--- a/site/src/components/EditDrawer.svelte
+++ b/site/src/components/EditDrawer.svelte
@@ -98,7 +98,8 @@
         }
       }
     } catch (e: any) {
-      error = `Upload failed: ${e.message}`;
+      saveStatus = `Upload failed: ${e.message}`;
+      saveOk = false;
     } finally {
       uploading = false;
     }