diff --git a/catopt_query/core.py b/catopt_query/core.py
index c867399..90f5cdc 100644
--- a/catopt_query/core.py
+++ b/catopt_query/core.py
@@ -24,11 +24,12 @@ def map_local_to_canonical(local: LocalProblem) -> CanonicalPlan:
     op = {
         "shard": local.shard_id,
         "predicates": local.predicates,
-        "attributes": local.projected_attributes,
+        "attributes": local.projection,
         "costs": local.costs,
         "constraints": local.constraints,
     }
-    total = sum(local.costs.values()) if local.costs else 0.0
+    # LocalProblem.costs is a float, not a dict; summing over values would be invalid.
+    total = local.costs if local.costs is not None else 0.0
     return CanonicalPlan(plan_id=str(uuid.uuid4()), operations=[op], total_cost=total, details={"shard_alias": local.shard_id})
 
 
@@ -45,4 +46,3 @@ def aggregate_joint_plan(local_plans: List[CanonicalPlan]) -> CanonicalPlan:
 def aggregate_joint_plan_from_locals(locals: List[LocalProblem]) -> CanonicalPlan:
     cans = [map_local_to_canonical(l) for l in locals]
     return aggregate_joint_plan(cans)
-