AGT-2669: Add turn detection and interruption protobufs

protobufs/agent/livekit_agent_turn_detector.proto

@@ -0,0 +1,142 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// 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 livekit.agent;
+
+option go_package = "github.com/livekit/protocol/livekit/agent";
+option csharp_namespace = "LiveKit.Proto";
+option ruby_package = "LiveKit::Proto";
+option optimize_for = SPEED;
+
+import "agent/livekit_agent_session.proto";
+import "google/protobuf/duration.proto";
+import "google/protobuf/timestamp.proto";
+
+enum TdAudioEncoding {
+  TD_AUDIO_ENCODING_OPUS = 0;
+}
+
+message TdSessionSettings {
+  uint32 sample_rate = 1;
+  TdAudioEncoding encoding = 2;
+}
+
+message TdInferenceStats {
+  google.protobuf.Duration e2e_latency = 1;
+  google.protobuf.Duration preprocessing_duration = 2;
+  google.protobuf.Duration inference_duration = 3;
+}
+
+message TdError {
+  string message = 1;
+  // error code follows the HTTP status code convention
+  // 4xx for client errors
+  // 5xx for server errors
+  uint32 code = 2;
+}
+
+// --- Client -> Server ---
+
+message TdSessionCreate {
+  TdSessionSettings settings = 1;
+}
+
+message TdInputAudio {
+  bytes audio = 1;
+  google.protobuf.Timestamp created_at = 2;
+}
+
+message TdInputChatContext {
+  repeated ChatMessage messages = 1;
+}
+
+message TdSessionFlush {}
+
+message TdSessionClose {}
+
+message TdInferenceStart {
+  string request_id = 1;
+}
+
+message TdInferenceStop {
+  string request_id = 1;
+}
+
+message TdClientMessage {
+  oneof message {
+    TdSessionCreate session_create = 1;
+    TdInputAudio input_audio = 2;
+    TdInputChatContext input_chat_context = 3;
+    TdSessionFlush session_flush = 4;
+    TdSessionClose session_close = 5;
+    TdInferenceStart inference_start = 6;
+    TdInferenceStop inference_stop = 7;
+  }
+  google.protobuf.Timestamp created_at = 8;
+}
+
+// --- Server -> Model ---
+
+message TdInferenceRequest {
+  bytes audio = 1;
+  string assistant_text = 2;
+  TdAudioEncoding encoding = 3;
+  uint32 sample_rate = 4;
+}
+
+// --- Model -> Server ---
+
+message TdInferenceResponse {
+  float probability = 1;
+  TdInferenceStats stats = 2;
+}
+
+// --- Server -> Client ---
+
+message TdSessionCreated {}
+
+message TdProcessingStats {
+  google.protobuf.Timestamp earliest_client_created_at = 1;
+  google.protobuf.Timestamp latest_client_created_at = 2;
+  // server-side E2E latency
+  google.protobuf.Duration e2e_latency = 3;
+  // stats including model-side E2E latency
+  TdInferenceStats inference_stats = 4;
+}
+
+message TdEouPrediction {
+  float probability = 1;
+  TdProcessingStats processing_stats = 2;
+}
+
+message TdInferenceStarted {}
+
+message TdInferenceStopped {}
+
+message TdSessionClosed {}
+
+message TdServerMessage {
+  oneof message {
+    TdSessionCreated session_created = 1;
+    TdInferenceStarted inference_started = 2;
+    TdInferenceStopped inference_stopped = 3;
+    TdEouPrediction eou_prediction = 4;
+    TdSessionClosed session_closed = 5;
+    TdError error = 6;
+  }
+  optional string request_id = 7;
+  google.protobuf.Timestamp server_created_at = 8;
+  optional google.protobuf.Timestamp client_created_at = 9;
+}