diff --git a/scripts/pb-init.sh b/scripts/pb-init.sh
index 2c02076..30aa97a 100755
--- a/scripts/pb-init.sh
+++ b/scripts/pb-init.sh
@@ -38,7 +38,8 @@ if [ -z "$TOKEN" ] || [ "$TOKEN" = "$AUTH_RESPONSE" ]; then
 fi
 log "auth token obtained"
 
-# ─── 3. Helper: create a collection (ignores 400/422 already-exists) ─────────
+# ─── 3. Helpers ───────────────────────────────────────────────────────────────
+
 create_collection() {
   NAME="$1"
   BODY="$2"
@@ -54,7 +55,60 @@ create_collection() {
   esac
 }
 
-# ─── 4. Create collections ────────────────────────────────────────────────────
+# Patch a collection by name: adds any fields listed in FIELDS_JSON that are
+# missing from the current schema.  This is idempotent and safe to re-run.
+ensure_fields() {
+  NAME="$1"
+  FIELDS_JSON="$2"   # JSON array of field objects to guarantee exist
+
+  # Fetch current schema
+  CURRENT=$(wget -qO- \
+    --header="Authorization: Bearer $TOKEN" \
+    "$PB_URL/api/collections/$NAME" 2>/dev/null)
+
+  COLLECTION_ID=$(echo "$CURRENT" | sed 's/.*"id":"\([^"]*\)".*/\1/')
+  if [ -z "$COLLECTION_ID" ] || [ "$COLLECTION_ID" = "$CURRENT" ]; then
+    log "WARNING: could not get id for collection $NAME — skipping ensure_fields"
+    return
+  fi
+
+  # Build merged fields list via a small python snippet
+  MERGED=$(python3 - "$CURRENT" "$FIELDS_JSON" <<'PYEOF'
+import sys, json
+current = json.loads(sys.argv[1])
+desired = json.loads(sys.argv[2])
+existing_names = {f["name"] for f in current.get("fields", [])}
+all_fields = list(current.get("fields", []))
+added = []
+for f in desired:
+    if f["name"] not in existing_names:
+        all_fields.append(f)
+        added.append(f["name"])
+print(json.dumps({"fields": all_fields, "_added": added}))
+PYEOF
+)
+
+  ADDED=$(echo "$MERGED" | python3 -c 'import sys,json; d=json.load(sys.stdin); print(",".join(d.get("_added",[])))' 2>/dev/null)
+  if [ -z "$ADDED" ]; then
+    log "collection $NAME schema up-to-date"
+    return
+  fi
+
+  PATCH_BODY=$(echo "$MERGED" | python3 -c 'import sys,json; d=json.load(sys.stdin); d.pop("_added",None); print(json.dumps(d))' 2>/dev/null)
+
+  STATUS=$(wget -qSO- \
+    --header="Content-Type: application/json" \
+    --header="Authorization: Bearer $TOKEN" \
+    --body-data="$PATCH_BODY" \
+    --method=PATCH \
+    "$PB_URL/api/collections/$COLLECTION_ID" 2>&1 | grep "HTTP/" | tail -1 | awk '{print $2}')
+  case "$STATUS" in
+    200|201) log "patched collection $NAME — added fields: $ADDED" ;;
+    *)       log "WARNING: patch returned $STATUS for collection $NAME" ;;
+  esac
+}
+
+# ─── 4. Create collections (idempotent — skips if already exist) ─────────────
 
 create_collection "books" '{
   "name": "books",
@@ -134,4 +188,11 @@ create_collection "app_users" '{
   ]
 }'
 
+# ─── 5. Schema migrations (idempotent field additions) ───────────────────────
+# Ensures fields added after initial deploy are present in existing instances.
+
+ensure_fields "progress" '[
+  {"name": "user_id", "type": "text"}
+]'
+
 log "all collections ready"