diff --git a/graphistry/compute/exceptions.py b/graphistry/compute/exceptions.py
index 3100a78953..8ede4ab41b 100644
--- a/graphistry/compute/exceptions.py
+++ b/graphistry/compute/exceptions.py
@@ -38,6 +38,7 @@ class ErrorCode:
     E303 = "invalid-node-reference"
     E304 = "invalid-edge-reference"
     E305 = "graph-not-bound"
+    E306 = "call-execution-error"
 
     # Remote transport/response errors (E4xx)
     E401 = "remote-request-failed"
@@ -137,6 +138,16 @@ class GFQLSchemaError(GFQLValidationError):
     pass
 
 
+class GFQLCallExecutionError(GFQLTypeError):
+    """A safelisted Call handler raised after parameter validation.
+
+    Distinct E306 subtype of ``GFQLTypeError`` for source compatibility with
+    callers that catch the prior broad class; it identifies engine/handler
+    failures so callers do not rewrite a syntactically valid query.
+    """
+    pass
+
+
 class GFQLRemoteError(GFQLValidationError, ValueError):
     """Remote call failed or returned a response the client cannot use.
 
diff --git a/graphistry/compute/gfql/call/executor.py b/graphistry/compute/gfql/call/executor.py
index e3232bc764..15f3f9c1f9 100644
--- a/graphistry/compute/gfql/call/executor.py
+++ b/graphistry/compute/gfql/call/executor.py
@@ -16,7 +16,7 @@
     execute_row_pipeline_call,
     is_row_pipeline_call,
 )
-from graphistry.compute.exceptions import ErrorCode, GFQLSchemaError, GFQLTypeError
+from graphistry.compute.exceptions import ErrorCode, GFQLCallExecutionError, GFQLSchemaError, GFQLTypeError, GFQLValidationError
 from graphistry.compute.engine_coercion import ensure_engine_match
 from graphistry.compute.gfql.policy import PolicyContext, PolicyException
 from graphistry.compute.gfql.policy.stats import extract_graph_stats
@@ -295,6 +295,17 @@ def execute_call(g: Plottable, function: str, params: Dict[str, Any], engine: En
         if error is not None:
             raise policy_error from error
         raise policy_error
+    engine_name = str(getattr(engine, "value", engine))
+    if error is not None and not isinstance(error, (PolicyException, GFQLValidationError, NotImplementedError)):
+        raise GFQLCallExecutionError(
+            ErrorCode.E306,
+            f"Call execution failed in '{function}': {error}",
+            field="function",
+            value=function,
+            suggestion="The query passed validation; inspect the chained engine error and engine compatibility.",
+            engine=engine_name,
+            original_exception=type(error).__name__,
+        ) from error
     if isinstance(error, TypeError):
         raise GFQLTypeError(
             ErrorCode.E201,
diff --git a/graphistry/tests/compute/gfql/test_alias_scoping_semantics.py b/graphistry/tests/compute/gfql/test_alias_scoping_semantics.py
index bb7aceb4f2..05b5ebab99 100644
--- a/graphistry/tests/compute/gfql/test_alias_scoping_semantics.py
+++ b/graphistry/tests/compute/gfql/test_alias_scoping_semantics.py
@@ -483,7 +483,7 @@ def test_scalar_rebind_stays_an_error(engine: Literal["pandas", "polars"]) -> No
     if engine == "pandas":
         with pytest.raises(GFQLTypeError) as exc_info:
             _run(PEOPLE_NODES, PEOPLE_EDGES, query, engine)
-        assert exc_info.value.code == ErrorCode.E303
+        assert exc_info.value.code == ErrorCode.E306
         assert exc_info.value.context["field"] == "function"
         assert exc_info.value.context["value"] == "select"
     else:
diff --git a/graphistry/tests/compute/gfql/test_row_pipeline_ops.py b/graphistry/tests/compute/gfql/test_row_pipeline_ops.py
index 1e893baad6..ee65717602 100644
--- a/graphistry/tests/compute/gfql/test_row_pipeline_ops.py
+++ b/graphistry/tests/compute/gfql/test_row_pipeline_ops.py
@@ -2135,7 +2135,7 @@ def _assert_runtime_where_rows(
 
         with pytest.raises(GFQLTypeError) as exc_info:
             g.gfql(steps + [return_([("id", "id")])])
-        assert exc_info.value.code == ErrorCode.E303
+        assert exc_info.value.code == ErrorCode.E306
         assert expected_message in exc_info.value.message
 
     @pytest.mark.parametrize(
@@ -2563,7 +2563,7 @@ def test_row_pipeline_semi_apply_mark_runtime_rejects_blank_join_alias(self):
                     ),
                 ]
             )
-        assert exc_info.value.code == ErrorCode.E303
+        assert exc_info.value.code == ErrorCode.E306
         assert "join_aliases" in exc_info.value.message
 
     def test_row_pipeline_apply_helpers_use_prefixed_join_key_and_payload(self, monkeypatch):
diff --git a/graphistry/tests/compute/test_call_runtime_errors.py b/graphistry/tests/compute/test_call_runtime_errors.py
new file mode 100644
index 0000000000..368c83eb25
--- /dev/null
+++ b/graphistry/tests/compute/test_call_runtime_errors.py
@@ -0,0 +1,38 @@
+from __future__ import annotations
+
+import pandas as pd
+import pytest
+
+import graphistry
+from graphistry.Engine import Engine
+from graphistry.compute.exceptions import ErrorCode, GFQLCallExecutionError, GFQLTypeError
+from graphistry.compute.gfql.call.executor import execute_call
+
+
+@pytest.fixture
+def graph():
+    edges = pd.DataFrame({"src": ["a", "b"], "dst": ["b", "a"]})
+    return graphistry.edges(edges, "src", "dst")
+
+
+def test_handler_exception_is_call_execution_error(graph, monkeypatch):
+    def fail(*args, **kwargs):
+        raise RuntimeError("engine kernel failed")
+
+    monkeypatch.setattr(graph, "get_degrees", fail)
+
+    with pytest.raises(GFQLCallExecutionError) as info:
+        execute_call(graph, "get_degrees", {}, engine=Engine.PANDAS)
+
+    assert info.value.code == ErrorCode.E306
+    assert info.value.context["engine"] == "pandas"
+    assert info.value.context["original_exception"] == "RuntimeError"
+    assert isinstance(info.value.__cause__, RuntimeError)
+
+
+def test_unknown_function_keeps_parameter_validation_error(graph):
+    with pytest.raises(GFQLTypeError) as info:
+        execute_call(graph, "not_safelisted", {}, engine=Engine.PANDAS)
+
+    assert info.value.code == ErrorCode.E303
+    assert not isinstance(info.value, GFQLCallExecutionError)
diff --git a/graphistry/tests/layout/test_circle_entry_guards.py b/graphistry/tests/layout/test_circle_entry_guards.py
index 18c9914c19..ca4d68a1b3 100644
--- a/graphistry/tests/layout/test_circle_entry_guards.py
+++ b/graphistry/tests/layout/test_circle_entry_guards.py
@@ -8,7 +8,7 @@
 
 import graphistry
 from graphistry.Engine import Engine
-from graphistry.compute.exceptions import GFQLTypeError
+from graphistry.compute.exceptions import GFQLCallExecutionError
 from graphistry.compute.gfql.call.executor import execute_call
 
 TRIANGLE_EDGES = pd.DataFrame({'s': [0, 1, 2], 'd': [1, 2, 0]})
@@ -209,7 +209,7 @@ def test_cudf_null_partition_key_names_the_partition_column() -> None:
 def test_gfql_call_surface_reports_the_missing_bounding_box() -> None:
     n = pd.DataFrame({'id': [0, 1, 2]})
     g = graphistry.edges(TRIANGLE_EDGES, 's', 'd').nodes(n, 'id')
-    with pytest.raises(GFQLTypeError, match='requires either bounding_box= or existing x/y node positions'):
+    with pytest.raises(GFQLCallExecutionError, match='requires either bounding_box= or existing x/y node positions'):
         execute_call(g, 'circle_layout', {}, Engine.PANDAS)