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+// Copyright 2018 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
+//
+// http://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.
+//
+
+syntax = "proto3";
+
+package google.api.expr.v1alpha1;
+
+import "google/api/expr/v1alpha1/conformance_service.proto";
+
+option cc_enable_arenas = true;
+option go_package = "google.golang.org/genproto/googleapis/api/expr/v1alpha1;expr";
+option java_multiple_files = true;
+option java_outer_classname = "CelServiceProto";
+option java_package = "com.google.api.expr.v1alpha1";
+
+// Access a CEL implementation from another process or machine.
+// A CEL implementation is decomposed as a parser, a static checker,
+// and an evaluator. Every CEL implementation is expected to provide
+// a server for this API. The API will be used for conformance testing,
+// utilities, and execution as a service.
+service CelService {
+ // Transforms CEL source text into a parsed representation.
+ rpc Parse(ParseRequest) returns (ParseResponse) {}
+
+ // Runs static checks on a parsed CEL representation and return
+ // an annotated representation, or a set of issues.
+ rpc Check(CheckRequest) returns (CheckResponse) {}
+
+ // Evaluates a parsed or annotation CEL representation given
+ // values of external bindings.
+ rpc Eval(EvalRequest) returns (EvalResponse) {}
+}