Wrap the "lists" extension library

cel_expr_python/BUILD

@@ -172,6 +172,7 @@ py_test(
     data = [
         ":cel",
         "//cel_expr_python/ext:ext_bindings",
+        "//cel_expr_python/ext:ext_lists",
         "//cel_expr_python/ext:ext_math",
         "//cel_expr_python/ext:ext_optional",
         "//cel_expr_python/ext:ext_strings",
@@ -184,6 +185,7 @@ py_test(
         "//conditions:default": [
             ":cel",
             "//cel_expr_python/ext:ext_bindings",
+            "//cel_expr_python/ext:ext_lists",
             "//cel_expr_python/ext:ext_math",
             "//cel_expr_python/ext:ext_optional",
             "//cel_expr_python/ext:ext_strings",

cel_expr_python/ext/BUILD

@@ -39,6 +39,27 @@ pybind_extension(
     ],
 )
 
+pybind_extension(
+    name = "ext_lists",
+    srcs = [
+        "ext_lists.cc",
+    ],
+    data = [
+        "ext_lists.pyi",
+        "//cel_expr_python:cel",
+    ],
+    visibility = ["//visibility:public"],
+    deps = [
+        "//cel_expr_python:cel_extension",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/strings",
+        "@com_google_cel_cpp//compiler",
+        "@com_google_cel_cpp//extensions:lists_functions",
+        "@com_google_cel_cpp//runtime:runtime_builder",
+        "@com_google_cel_cpp//runtime:runtime_options",
+    ],
+)
+
 pybind_extension(
     name = "ext_math",
     srcs = [

cel_expr_python/ext/ext_lists.cc

@@ -0,0 +1,54 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/status/status.h"
+#include "absl/strings/str_cat.h"
+#include "compiler/compiler.h"
+#include "extensions/lists_functions.h"
+#include "runtime/runtime_builder.h"
+#include "runtime/runtime_options.h"
+#include "cel_expr_python/cel_extension.h"
+#include "cel_expr_python/py_error_status.h"
+
+namespace cel_python {
+
+class ExtLists : public CelExtension {
+ public:
+  explicit ExtLists(int version)
+      : CelExtension("cel.lib.ext.lists", "lists", version) {
+    if (version < 0 ||
+        version > cel::extensions::kListsExtensionLatestVersion) {
+      throw StatusToException(absl::InvalidArgumentError(absl::StrCat(
+          "'lists' extension version: ", version, " not in range [0, ",
+          cel::extensions::kListsExtensionLatestVersion, "]")));
+    }
+  }
+
+  ExtLists() : ExtLists(cel::extensions::kListsExtensionLatestVersion) {}
+
+  cel::CompilerLibrary GetCompilerLibrary() override {
+    return cel::extensions::ListsCompilerLibrary(version());
+  }
+
+  absl::Status ConfigureRuntime(cel::RuntimeBuilder& runtime_builder,
+                                const cel::RuntimeOptions& opts) override {
+    return cel::extensions::RegisterListsFunctions(
+        runtime_builder.function_registry(), opts,
+        cel::extensions::ListsExtensionOptions{.version = version()});
+  }
+};
+
+CEL_VERSIONED_EXTENSION_MODULE(ext_lists, ExtLists);
+
+}  // namespace cel_python

cel_expr_python/ext/ext_lists.pyi

@@ -0,0 +1,4 @@
+from cel_expr_python import cel
+
+class ExtLists(cel.CelExtensionBase):
+  def __init__(self, version: int = ...) -> None: ...

conformance/BUILD

@@ -40,6 +40,7 @@ py_test(
         "//cel_expr_python:cel",
         "//cel_expr_python/ext:ext_bindings",
         "//cel_expr_python/ext:ext_encoders",
+        "//cel_expr_python/ext:ext_lists",
         "//cel_expr_python/ext:ext_math",
         "//cel_expr_python/ext:ext_optional",
         "//cel_expr_python/ext:ext_proto",
@@ -63,6 +64,7 @@ py_test(
             "//cel_expr_python:cel",
             "//cel_expr_python/ext:ext_bindings",
             "//cel_expr_python/ext:ext_encoders",
+            "//cel_expr_python/ext:ext_lists",
             "//cel_expr_python/ext:ext_math",
             "//cel_expr_python/ext:ext_optional",
             "//cel_expr_python/ext:ext_proto",

conformance/conformance_test.py

@@ -32,6 +32,7 @@
 from cel_expr_python import cel
 from cel_expr_python.ext import ext_bindings
 from cel_expr_python.ext import ext_encoders
+from cel_expr_python.ext import ext_lists
 from cel_expr_python.ext import ext_math
 from cel_expr_python.ext import ext_optional
 from cel_expr_python.ext import ext_proto
@@ -73,8 +74,6 @@ class ConformanceTestSuite(unittest.TestSuite):
       "proto3/set_null/map_timestamp_null_pruned",
       "proto3/set_null/map_duration_null_pruned",
       "proto3/set_null/map_wrapper_null_pruned",
-      # TODO(b/548571767): add lists_ext support
-      "lists_ext/.*",
   ]
 
   if sys.platform == "win32":
@@ -147,6 +146,7 @@ class ConformanceTest(absltest.TestCase):
   EXTENSIONS_PER_TESTFILE = {
       "bindings_ext": [ext_bindings.ExtBindings()],
       "encoders_ext": [ext_encoders.ExtEncoders()],
+      "lists_ext": [ext_lists.ExtLists()],
       "math_ext": [ext_math.ExtMath()],
       "optionals": [ext_optional.ExtOptional()],
       "proto2_ext": [ext_proto.ExtProto()],

release/setup.py

@@ -207,6 +207,10 @@ def platform_config_macos(self, cmd):
             'cel_expr_python.ext.ext_encoders',
             '//cel_expr_python/ext:ext_encoders',
         ),
+        BazelExtension(
+            'cel_expr_python.ext.ext_lists',
+            '//cel_expr_python/ext:ext_lists',
+        ),
         BazelExtension(
             'cel_expr_python.ext.ext_math',
             '//cel_expr_python/ext:ext_math',