diff --git a/projekt-matching/deploy/build_flows.py b/projekt-matching/deploy/build_flows.py
index 391e488..bcd190c 100644
--- a/projekt-matching/deploy/build_flows.py
+++ b/projekt-matching/deploy/build_flows.py
@@ -79,6 +79,20 @@ def upsert_variable(hdr, name, value, vtype):
 
 
 def get_api_key(hdr):
+    # Idempotent delete+recreate: the key VALUE is only returned at creation
+    # time, so reuse is impossible -- instead remove any previous
+    # "projekt-matching" keys (each earlier run left one behind otherwise)
+    # and mint a fresh one. Callers then refresh both the env file and the
+    # PM_LANGFLOW_API_KEY Credential variable, so nothing still references
+    # the deleted keys. Live API shape (Langflow 1.10.0): GET /api_key/
+    # returns {"total_count", "user_id", "api_keys": [{"id", "name", ...}]};
+    # DELETE /api_key/{id} removes one key.
+    r = requests.get(f"{BASE}/api_key/", headers=hdr, timeout=15)
+    r.raise_for_status()
+    for key in r.json().get("api_keys", []):
+        if key["name"] == "projekt-matching":
+            requests.delete(f"{BASE}/api_key/{key['id']}", headers=hdr,
+                            timeout=15).raise_for_status()
     r = requests.post(f"{BASE}/api_key/", headers=hdr,
                       json={"name": "projekt-matching"}, timeout=15)
     r.raise_for_status()