diff --git a/core/db.py b/core/db.py
index d808011..d35c90a 100644
--- a/core/db.py
+++ b/core/db.py
@@ -719,6 +719,23 @@ def _migrate(conn: sqlite3.Connection):
         )
         conn.commit()
 
+    # Create indexes for project_links (KIN-INFRA-008).
+    # Guard: indexes must be created AFTER the table exists.
+    if "project_links" in existing_tables:
+        existing_indexes = {r[0] for r in conn.execute(
+            "SELECT name FROM sqlite_master WHERE type='index'"
+        ).fetchall()}
+        if "idx_project_links_to" not in existing_indexes:
+            conn.execute(
+                "CREATE INDEX IF NOT EXISTS idx_project_links_to ON project_links(to_project)"
+            )
+            conn.commit()
+        if "idx_project_links_from" not in existing_indexes:
+            conn.execute(
+                "CREATE INDEX IF NOT EXISTS idx_project_links_from ON project_links(from_project)"
+            )
+            conn.commit()
+
 
 def _seed_default_hooks(conn: sqlite3.Connection):
     """Seed default hooks for the kin project (idempotent).