Should work

lnbits/extensions/withdraw/crud.py

@@ -98,3 +98,28 @@ async def delete_withdraw_link(link_id: str) -> None:
 def chunks(lst, n):
     for i in range(0, len(lst), n):
         yield lst[i : i + n]
+
+async def create_hash_check(
+    the_hash: str,
+    lnurl_id: str,
+) -> HashCheck:
+    await db.execute(
+        """
+        INSERT INTO hash_check (
+            id,
+            lnurl_id
+        )
+        VALUES (?, ?)
+        """,
+        (
+            the_hash,
+            lnurl_id,
+        ),
+    )
+    hashCheck = await get_hash_check(the_hash, lnurl_id)
+    row = await db.fetchone("SELECT * FROM hash_check WHERE id = ?", (the_hash,))
+    return HashCheck.from_row(row) if row else None
+
+async def get_hash_check(the_hash: str, lnurl_id: str) -> Optional[HashCheck]:
+    row = await db.fetchone("SELECT * FROM hash_check WHERE id = ?", (the_hash,))
+    return HashCheck.from_row(row) if row else None

lnbits/extensions/withdraw/models.py

@@ -63,7 +63,6 @@ class WithdrawLink(NamedTuple):
 class HashCheck(NamedTuple):
     id: str
     lnurl_id: str
-
     @classmethod
     def from_row(cls, row: Row) -> "Hash":
         return cls(**dict(row))

lnbits/extensions/withdraw/views_api.py

@@ -12,6 +12,8 @@ from .crud import (
     get_withdraw_links,
     update_withdraw_link,
     delete_withdraw_link,
+    create_hash_check,
+    get_hash_check,
 )
 
 
@@ -111,3 +113,17 @@ async def api_link_delete(link_id):
     await delete_withdraw_link(link_id)
 
     return "", HTTPStatus.NO_CONTENT
+
+@withdraw_ext.route("/api/v1/links/<the_hash>/<lnurl_id>", methods=["GET"])
+@api_check_wallet_key("invoice")
+async def api_hash_retrieve(the_hash, lnurl_id):
+    hashCheck = await get_hash_check(the_hash, lnurl_id)
+
+    if not hashCheck:
+        hashCheck = await create_hash_check(the_hash, lnurl_id)
+        return jsonify({"status": False}), HTTPStatus.OK
+    
+    if link.wallet != g.wallet.id:
+        return jsonify({"status": True}), HTTPStatus.OK
+
+    return jsonify({"status": True}), HTTPStatus.OK