diff --git a/solve.py b/solve.py
index 4b3c0ee..f598df5 100644
--- a/solve.py
+++ b/solve.py
@@ -1015,8 +1015,18 @@ def solve(
     verbose=True,
     fixed_choices=FIXED_CHOICES,
     resource_constraints=None,
+    objective_factors=None,
+    objective_mode=None,
 ):
 
+    if objective_factors is None:
+        objective_factors = OBJECTIVE_FACTORS
+    if objective_mode is None:
+        objective_mode = OBJECTIVE_MODE
+    _validate_objective(objective_factors, objective_mode)
+    # Normalized copy: every key present, missing keys = 0.
+    obj_factors = {k: objective_factors.get(k, 0) for k in "EBSC"}
+
     # ---- build the city list -----------------------------------------
     # cities: list[tuple[int, dict]] where the dict has keys "type" and
     # "adjacent_to". TODO: adjacency unused; for Industrialist agent.