diff --git a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequest.java b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequest.java
index 0bf4a8988..7d6bfcad7 100644
--- a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequest.java
+++ b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequest.java
@@ -22,6 +22,8 @@
  *
  *
  * <pre>
+ * ============================================================================
+ * Requests and responses for custom methods.
  * The request to detect user's intent.
  * </pre>
  *
@@ -178,7 +180,9 @@ public static final com.google.protobuf.Descriptors.Descriptor getDescriptor() {
    * ID must not exceed 36 bytes.
    * </pre>
    *
-   * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+   * <code>
+   * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+   * </code>
    *
    * @return The session.
    */
@@ -204,7 +208,9 @@ public java.lang.String getSession() {
    * ID must not exceed 36 bytes.
    * </pre>
    *
-   * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+   * <code>
+   * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+   * </code>
    *
    * @return The bytes for session.
    */
@@ -624,6 +630,8 @@ protected Builder newBuilderForType(com.google.protobuf.GeneratedMessageV3.Build
    *
    *
    * <pre>
+   * ============================================================================
+   * Requests and responses for custom methods.
    * The request to detect user's intent.
    * </pre>
    *
@@ -839,7 +847,9 @@ public Builder mergeFrom(
      * ID must not exceed 36 bytes.
      * </pre>
      *
-     * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+     * <code>
+     * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+     * </code>
      *
      * @return The session.
      */
@@ -865,7 +875,9 @@ public java.lang.String getSession() {
      * ID must not exceed 36 bytes.
      * </pre>
      *
-     * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+     * <code>
+     * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+     * </code>
      *
      * @return The bytes for session.
      */
@@ -891,7 +903,9 @@ public com.google.protobuf.ByteString getSessionBytes() {
      * ID must not exceed 36 bytes.
      * </pre>
      *
-     * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+     * <code>
+     * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+     * </code>
      *
      * @param value The session to set.
      * @return This builder for chaining.
@@ -916,7 +930,9 @@ public Builder setSession(java.lang.String value) {
      * ID must not exceed 36 bytes.
      * </pre>
      *
-     * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+     * <code>
+     * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+     * </code>
      *
      * @return This builder for chaining.
      */
@@ -937,7 +953,9 @@ public Builder clearSession() {
      * ID must not exceed 36 bytes.
      * </pre>
      *
-     * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+     * <code>
+     * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+     * </code>
      *
      * @param value The bytes for session to set.
      * @return This builder for chaining.
diff --git a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequestOrBuilder.java b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequestOrBuilder.java
index 23ff7eda8..5275bb51e 100644
--- a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequestOrBuilder.java
+++ b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/DetectIntentRequestOrBuilder.java
@@ -34,7 +34,9 @@ public interface DetectIntentRequestOrBuilder
    * ID must not exceed 36 bytes.
    * </pre>
    *
-   * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+   * <code>
+   * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+   * </code>
    *
    * @return The session.
    */
@@ -50,7 +52,9 @@ public interface DetectIntentRequestOrBuilder
    * ID must not exceed 36 bytes.
    * </pre>
    *
-   * <code>string session = 1 [(.google.api.field_behavior) = REQUIRED];</code>
+   * <code>
+   * string session = 1 [(.google.api.field_behavior) = REQUIRED, (.google.api.resource_reference) = { ... }
+   * </code>
    *
    * @return The bytes for session.
    */
diff --git a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/SessionProto.java b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/SessionProto.java
index 9513742ec..ff68a0be8 100644
--- a/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/SessionProto.java
+++ b/proto-google-cloud-dialogflow-v2/src/main/java/com/google/cloud/dialogflow/v2/SessionProto.java
@@ -91,113 +91,119 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
       "\n(google/cloud/dialogflow/v2/session.pro"
           + "to\022\032google.cloud.dialogflow.v2\032\034google/a"
           + "pi/annotations.proto\032\027google/api/client."
-          + "proto\032\037google/api/field_behavior.proto\032-"
-          + "google/cloud/dialogflow/v2/audio_config."
-          + "proto\032(google/cloud/dialogflow/v2/contex"
-          + "t.proto\032\'google/cloud/dialogflow/v2/inte"
-          + "nt.proto\0324google/cloud/dialogflow/v2/ses"
-          + "sion_entity_type.proto\032\036google/protobuf/"
-          + "duration.proto\032\034google/protobuf/struct.p"
-          + "roto\032\027google/rpc/status.proto\032\030google/ty"
-          + "pe/latlng.proto\"\240\002\n\023DetectIntentRequest\022"
-          + "\024\n\007session\030\001 \001(\tB\003\340A\002\022F\n\014query_params\030\002 "
-          + "\001(\0132+.google.cloud.dialogflow.v2.QueryPa"
-          + "rametersB\003\340A\001\022@\n\013query_input\030\003 \001(\0132&.goo"
-          + "gle.cloud.dialogflow.v2.QueryInputB\003\340A\002\022"
-          + "O\n\023output_audio_config\030\004 \001(\0132-.google.cl"
-          + "oud.dialogflow.v2.OutputAudioConfigB\003\340A\001"
-          + "\022\030\n\013input_audio\030\005 \001(\014B\003\340A\001\"\370\001\n\024DetectInt"
-          + "entResponse\022\023\n\013response_id\030\001 \001(\t\022=\n\014quer"
-          + "y_result\030\002 \001(\0132\'.google.cloud.dialogflow"
-          + ".v2.QueryResult\022*\n\016webhook_status\030\003 \001(\0132"
-          + "\022.google.rpc.Status\022\024\n\014output_audio\030\004 \001("
-          + "\014\022J\n\023output_audio_config\030\006 \001(\0132-.google."
-          + "cloud.dialogflow.v2.OutputAudioConfig\"\237\003"
-          + "\n\017QueryParameters\022\026\n\ttime_zone\030\001 \001(\tB\003\340A"
-          + "\001\022.\n\014geo_location\030\002 \001(\0132\023.google.type.La"
-          + "tLngB\003\340A\001\022:\n\010contexts\030\003 \003(\0132#.google.clo"
-          + "ud.dialogflow.v2.ContextB\003\340A\001\022\033\n\016reset_c"
-          + "ontexts\030\004 \001(\010B\003\340A\001\022P\n\024session_entity_typ"
-          + "es\030\005 \003(\0132-.google.cloud.dialogflow.v2.Se"
-          + "ssionEntityTypeB\003\340A\001\022-\n\007payload\030\006 \001(\0132\027."
-          + "google.protobuf.StructB\003\340A\001\022j\n!sentiment"
-          + "_analysis_request_config\030\n \001(\0132:.google."
-          + "cloud.dialogflow.v2.SentimentAnalysisReq"
-          + "uestConfigB\003\340A\001\"\313\001\n\nQueryInput\022D\n\014audio_"
-          + "config\030\001 \001(\0132,.google.cloud.dialogflow.v"
-          + "2.InputAudioConfigH\000\0225\n\004text\030\002 \001(\0132%.goo"
-          + "gle.cloud.dialogflow.v2.TextInputH\000\0227\n\005e"
-          + "vent\030\003 \001(\0132&.google.cloud.dialogflow.v2."
-          + "EventInputH\000B\007\n\005input\"\220\005\n\013QueryResult\022\022\n"
-          + "\nquery_text\030\001 \001(\t\022\025\n\rlanguage_code\030\017 \001(\t"
-          + "\022%\n\035speech_recognition_confidence\030\002 \001(\002\022"
-          + "\016\n\006action\030\003 \001(\t\022+\n\nparameters\030\004 \001(\0132\027.go"
-          + "ogle.protobuf.Struct\022#\n\033all_required_par"
-          + "ams_present\030\005 \001(\010\022\030\n\020fulfillment_text\030\006 "
-          + "\001(\t\022H\n\024fulfillment_messages\030\007 \003(\0132*.goog"
-          + "le.cloud.dialogflow.v2.Intent.Message\022\026\n"
-          + "\016webhook_source\030\010 \001(\t\0220\n\017webhook_payload"
-          + "\030\t \001(\0132\027.google.protobuf.Struct\022<\n\017outpu"
-          + "t_contexts\030\n \003(\0132#.google.cloud.dialogfl"
-          + "ow.v2.Context\0222\n\006intent\030\013 \001(\0132\".google.c"
-          + "loud.dialogflow.v2.Intent\022#\n\033intent_dete"
-          + "ction_confidence\030\014 \001(\002\0220\n\017diagnostic_inf"
-          + "o\030\016 \001(\0132\027.google.protobuf.Struct\022V\n\031sent"
-          + "iment_analysis_result\030\021 \001(\01323.google.clo"
-          + "ud.dialogflow.v2.SentimentAnalysisResult"
-          + "\"\312\002\n\034StreamingDetectIntentRequest\022\024\n\007ses"
-          + "sion\030\001 \001(\tB\003\340A\002\022F\n\014query_params\030\002 \001(\0132+."
-          + "google.cloud.dialogflow.v2.QueryParamete"
-          + "rsB\003\340A\001\022@\n\013query_input\030\003 \001(\0132&.google.cl"
-          + "oud.dialogflow.v2.QueryInputB\003\340A\002\022\037\n\020sin"
-          + "gle_utterance\030\004 \001(\010B\005\030\001\340A\001\022O\n\023output_aud"
-          + "io_config\030\005 \001(\0132-.google.cloud.dialogflo"
-          + "w.v2.OutputAudioConfigB\003\340A\001\022\030\n\013input_aud"
-          + "io\030\006 \001(\014B\003\340A\001\"\325\002\n\035StreamingDetectIntentR"
-          + "esponse\022\023\n\013response_id\030\001 \001(\t\022R\n\022recognit"
-          + "ion_result\030\002 \001(\01326.google.cloud.dialogfl"
-          + "ow.v2.StreamingRecognitionResult\022=\n\014quer"
-          + "y_result\030\003 \001(\0132\'.google.cloud.dialogflow"
-          + ".v2.QueryResult\022*\n\016webhook_status\030\004 \001(\0132"
-          + "\022.google.rpc.Status\022\024\n\014output_audio\030\005 \001("
-          + "\014\022J\n\023output_audio_config\030\006 \001(\0132-.google."
-          + "cloud.dialogflow.v2.OutputAudioConfig\"\206\003"
-          + "\n\032StreamingRecognitionResult\022X\n\014message_"
-          + "type\030\001 \001(\0162B.google.cloud.dialogflow.v2."
-          + "StreamingRecognitionResult.MessageType\022\022"
-          + "\n\ntranscript\030\002 \001(\t\022\020\n\010is_final\030\003 \001(\010\022\022\n\n"
-          + "confidence\030\004 \001(\002\022D\n\020speech_word_info\030\007 \003"
-          + "(\0132*.google.cloud.dialogflow.v2.SpeechWo"
-          + "rdInfo\0224\n\021speech_end_offset\030\010 \001(\0132\031.goog"
-          + "le.protobuf.Duration\"X\n\013MessageType\022\034\n\030M"
-          + "ESSAGE_TYPE_UNSPECIFIED\020\000\022\016\n\nTRANSCRIPT\020"
-          + "\001\022\033\n\027END_OF_SINGLE_UTTERANCE\020\002\":\n\tTextIn"
-          + "put\022\021\n\004text\030\001 \001(\tB\003\340A\002\022\032\n\rlanguage_code\030"
-          + "\002 \001(\tB\003\340A\002\"m\n\nEventInput\022\021\n\004name\030\001 \001(\tB\003"
-          + "\340A\002\0220\n\nparameters\030\002 \001(\0132\027.google.protobu"
-          + "f.StructB\003\340A\001\022\032\n\rlanguage_code\030\003 \001(\tB\003\340A"
-          + "\002\"K\n\036SentimentAnalysisRequestConfig\022)\n\034a"
-          + "nalyze_query_text_sentiment\030\001 \001(\010B\003\340A\001\"^"
-          + "\n\027SentimentAnalysisResult\022C\n\024query_text_"
-          + "sentiment\030\001 \001(\0132%.google.cloud.dialogflo"
-          + "w.v2.Sentiment\"-\n\tSentiment\022\r\n\005score\030\001 \001"
-          + "(\002\022\021\n\tmagnitude\030\002 \001(\0022\346\003\n\010Sessions\022\312\001\n\014D"
-          + "etectIntent\022/.google.cloud.dialogflow.v2"
-          + ".DetectIntentRequest\0320.google.cloud.dial"
-          + "ogflow.v2.DetectIntentResponse\"W\202\323\344\223\002;\"6"
-          + "/v2/{session=projects/*/agent/sessions/*"
-          + "}:detectIntent:\001*\332A\023session,query_input\022"
-          + "\222\001\n\025StreamingDetectIntent\0228.google.cloud"
-          + ".dialogflow.v2.StreamingDetectIntentRequ"
-          + "est\0329.google.cloud.dialogflow.v2.Streami"
-          + "ngDetectIntentResponse\"\000(\0010\001\032x\312A\031dialogf"
-          + "low.googleapis.com\322AYhttps://www.googlea"
-          + "pis.com/auth/cloud-platform,https://www."
-          + "googleapis.com/auth/dialogflowB\233\001\n\036com.g"
-          + "oogle.cloud.dialogflow.v2B\014SessionProtoP"
-          + "\001ZDgoogle.golang.org/genproto/googleapis"
-          + "/cloud/dialogflow/v2;dialogflow\370\001\001\242\002\002DF\252"
-          + "\002\032Google.Cloud.Dialogflow.V2b\006proto3"
+          + "proto\032\037google/api/field_behavior.proto\032\031"
+          + "google/api/resource.proto\032-google/cloud/"
+          + "dialogflow/v2/audio_config.proto\032(google"
+          + "/cloud/dialogflow/v2/context.proto\032\'goog"
+          + "le/cloud/dialogflow/v2/intent.proto\0324goo"
+          + "gle/cloud/dialogflow/v2/session_entity_t"
+          + "ype.proto\032\036google/protobuf/duration.prot"
+          + "o\032\034google/protobuf/struct.proto\032\027google/"
+          + "rpc/status.proto\032\030google/type/latlng.pro"
+          + "to\"\306\002\n\023DetectIntentRequest\022:\n\007session\030\001 "
+          + "\001(\tB)\340A\002\372A#\n!dialogflow.googleapis.com/S"
+          + "ession\022F\n\014query_params\030\002 \001(\0132+.google.cl"
+          + "oud.dialogflow.v2.QueryParametersB\003\340A\001\022@"
+          + "\n\013query_input\030\003 \001(\0132&.google.cloud.dialo"
+          + "gflow.v2.QueryInputB\003\340A\002\022O\n\023output_audio"
+          + "_config\030\004 \001(\0132-.google.cloud.dialogflow."
+          + "v2.OutputAudioConfigB\003\340A\001\022\030\n\013input_audio"
+          + "\030\005 \001(\014B\003\340A\001\"\370\001\n\024DetectIntentResponse\022\023\n\013"
+          + "response_id\030\001 \001(\t\022=\n\014query_result\030\002 \001(\0132"
+          + "\'.google.cloud.dialogflow.v2.QueryResult"
+          + "\022*\n\016webhook_status\030\003 \001(\0132\022.google.rpc.St"
+          + "atus\022\024\n\014output_audio\030\004 \001(\014\022J\n\023output_aud"
+          + "io_config\030\006 \001(\0132-.google.cloud.dialogflo"
+          + "w.v2.OutputAudioConfig\"\237\003\n\017QueryParamete"
+          + "rs\022\026\n\ttime_zone\030\001 \001(\tB\003\340A\001\022.\n\014geo_locati"
+          + "on\030\002 \001(\0132\023.google.type.LatLngB\003\340A\001\022:\n\010co"
+          + "ntexts\030\003 \003(\0132#.google.cloud.dialogflow.v"
+          + "2.ContextB\003\340A\001\022\033\n\016reset_contexts\030\004 \001(\010B\003"
+          + "\340A\001\022P\n\024session_entity_types\030\005 \003(\0132-.goog"
+          + "le.cloud.dialogflow.v2.SessionEntityType"
+          + "B\003\340A\001\022-\n\007payload\030\006 \001(\0132\027.google.protobuf"
+          + ".StructB\003\340A\001\022j\n!sentiment_analysis_reque"
+          + "st_config\030\n \001(\0132:.google.cloud.dialogflo"
+          + "w.v2.SentimentAnalysisRequestConfigB\003\340A\001"
+          + "\"\313\001\n\nQueryInput\022D\n\014audio_config\030\001 \001(\0132,."
+          + "google.cloud.dialogflow.v2.InputAudioCon"
+          + "figH\000\0225\n\004text\030\002 \001(\0132%.google.cloud.dialo"
+          + "gflow.v2.TextInputH\000\0227\n\005event\030\003 \001(\0132&.go"
+          + "ogle.cloud.dialogflow.v2.EventInputH\000B\007\n"
+          + "\005input\"\220\005\n\013QueryResult\022\022\n\nquery_text\030\001 \001"
+          + "(\t\022\025\n\rlanguage_code\030\017 \001(\t\022%\n\035speech_reco"
+          + "gnition_confidence\030\002 \001(\002\022\016\n\006action\030\003 \001(\t"
+          + "\022+\n\nparameters\030\004 \001(\0132\027.google.protobuf.S"
+          + "truct\022#\n\033all_required_params_present\030\005 \001"
+          + "(\010\022\030\n\020fulfillment_text\030\006 \001(\t\022H\n\024fulfillm"
+          + "ent_messages\030\007 \003(\0132*.google.cloud.dialog"
+          + "flow.v2.Intent.Message\022\026\n\016webhook_source"
+          + "\030\010 \001(\t\0220\n\017webhook_payload\030\t \001(\0132\027.google"
+          + ".protobuf.Struct\022<\n\017output_contexts\030\n \003("
+          + "\0132#.google.cloud.dialogflow.v2.Context\0222"
+          + "\n\006intent\030\013 \001(\0132\".google.cloud.dialogflow"
+          + ".v2.Intent\022#\n\033intent_detection_confidenc"
+          + "e\030\014 \001(\002\0220\n\017diagnostic_info\030\016 \001(\0132\027.googl"
+          + "e.protobuf.Struct\022V\n\031sentiment_analysis_"
+          + "result\030\021 \001(\01323.google.cloud.dialogflow.v"
+          + "2.SentimentAnalysisResult\"\312\002\n\034StreamingD"
+          + "etectIntentRequest\022\024\n\007session\030\001 \001(\tB\003\340A\002"
+          + "\022F\n\014query_params\030\002 \001(\0132+.google.cloud.di"
+          + "alogflow.v2.QueryParametersB\003\340A\001\022@\n\013quer"
+          + "y_input\030\003 \001(\0132&.google.cloud.dialogflow."
+          + "v2.QueryInputB\003\340A\002\022\037\n\020single_utterance\030\004"
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+          + "oConfigB\003\340A\001\022\030\n\013input_audio\030\006 \001(\014B\003\340A\001\"\325"
+          + "\002\n\035StreamingDetectIntentResponse\022\023\n\013resp"
+          + "onse_id\030\001 \001(\t\022R\n\022recognition_result\030\002 \001("
+          + "\01326.google.cloud.dialogflow.v2.Streaming"
+          + "RecognitionResult\022=\n\014query_result\030\003 \001(\0132"
+          + "\'.google.cloud.dialogflow.v2.QueryResult"
+          + "\022*\n\016webhook_status\030\004 \001(\0132\022.google.rpc.St"
+          + "atus\022\024\n\014output_audio\030\005 \001(\014\022J\n\023output_aud"
+          + "io_config\030\006 \001(\0132-.google.cloud.dialogflo"
+          + "w.v2.OutputAudioConfig\"\206\003\n\032StreamingReco"
+          + "gnitionResult\022X\n\014message_type\030\001 \001(\0162B.go"
+          + "ogle.cloud.dialogflow.v2.StreamingRecogn"
+          + "itionResult.MessageType\022\022\n\ntranscript\030\002 "
+          + "\001(\t\022\020\n\010is_final\030\003 \001(\010\022\022\n\nconfidence\030\004 \001("
+          + "\002\022D\n\020speech_word_info\030\007 \003(\0132*.google.clo"
+          + "ud.dialogflow.v2.SpeechWordInfo\0224\n\021speec"
+          + "h_end_offset\030\010 \001(\0132\031.google.protobuf.Dur"
+          + "ation\"X\n\013MessageType\022\034\n\030MESSAGE_TYPE_UNS"
+          + "PECIFIED\020\000\022\016\n\nTRANSCRIPT\020\001\022\033\n\027END_OF_SIN"
+          + "GLE_UTTERANCE\020\002\":\n\tTextInput\022\021\n\004text\030\001 \001"
+          + "(\tB\003\340A\002\022\032\n\rlanguage_code\030\002 \001(\tB\003\340A\002\"m\n\nE"
+          + "ventInput\022\021\n\004name\030\001 \001(\tB\003\340A\002\0220\n\nparamete"
+          + "rs\030\002 \001(\0132\027.google.protobuf.StructB\003\340A\001\022\032"
+          + "\n\rlanguage_code\030\003 \001(\tB\003\340A\002\"K\n\036SentimentA"
+          + "nalysisRequestConfig\022)\n\034analyze_query_te"
+          + "xt_sentiment\030\001 \001(\010B\003\340A\001\"^\n\027SentimentAnal"
+          + "ysisResult\022C\n\024query_text_sentiment\030\001 \001(\013"
+          + "2%.google.cloud.dialogflow.v2.Sentiment\""
+          + "-\n\tSentiment\022\r\n\005score\030\001 \001(\002\022\021\n\tmagnitude"
+          + "\030\002 \001(\0022\346\003\n\010Sessions\022\312\001\n\014DetectIntent\022/.g"
+          + "oogle.cloud.dialogflow.v2.DetectIntentRe"
+          + "quest\0320.google.cloud.dialogflow.v2.Detec"
+          + "tIntentResponse\"W\202\323\344\223\002;\"6/v2/{session=pr"
+          + "ojects/*/agent/sessions/*}:detectIntent:"
+          + "\001*\332A\023session,query_input\022\222\001\n\025StreamingDe"
+          + "tectIntent\0228.google.cloud.dialogflow.v2."
+          + "StreamingDetectIntentRequest\0329.google.cl"
+          + "oud.dialogflow.v2.StreamingDetectIntentR"
+          + "esponse\"\000(\0010\001\032x\312A\031dialogflow.googleapis."
+          + "com\322AYhttps://www.googleapis.com/auth/cl"
+          + "oud-platform,https://www.googleapis.com/"
+          + "auth/dialogflowB\261\002\n\036com.google.cloud.dia"
+          + "logflow.v2B\014SessionProtoP\001ZDgoogle.golan"
+          + "g.org/genproto/googleapis/cloud/dialogfl"
+          + "ow/v2;dialogflow\370\001\001\242\002\002DF\252\002\032Google.Cloud."
+          + "Dialogflow.V2\352A\222\001\n!dialogflow.googleapis"
+          + ".com/Session\022@projects/{project}/locatio"
+          + "ns/{location}/agent/sessions/{session}\022+"
+          + "projects/{project}/agent/sessions/{sessi"
+          + "on}b\006proto3"
     };
     descriptor =
         com.google.protobuf.Descriptors.FileDescriptor.internalBuildGeneratedFileFrom(
@@ -206,6 +212,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
               com.google.api.AnnotationsProto.getDescriptor(),
               com.google.api.ClientProto.getDescriptor(),
               com.google.api.FieldBehaviorProto.getDescriptor(),
+              com.google.api.ResourceProto.getDescriptor(),
               com.google.cloud.dialogflow.v2.AudioConfigProto.getDescriptor(),
               com.google.cloud.dialogflow.v2.ContextProto.getDescriptor(),
               com.google.cloud.dialogflow.v2.IntentProto.getDescriptor(),
@@ -361,11 +368,14 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
     registry.add(com.google.api.AnnotationsProto.http);
     registry.add(com.google.api.ClientProto.methodSignature);
     registry.add(com.google.api.ClientProto.oauthScopes);
+    registry.add(com.google.api.ResourceProto.resourceDefinition);
+    registry.add(com.google.api.ResourceProto.resourceReference);
     com.google.protobuf.Descriptors.FileDescriptor.internalUpdateFileDescriptor(
         descriptor, registry);
     com.google.api.AnnotationsProto.getDescriptor();
     com.google.api.ClientProto.getDescriptor();
     com.google.api.FieldBehaviorProto.getDescriptor();
+    com.google.api.ResourceProto.getDescriptor();
     com.google.cloud.dialogflow.v2.AudioConfigProto.getDescriptor();
     com.google.cloud.dialogflow.v2.ContextProto.getDescriptor();
     com.google.cloud.dialogflow.v2.IntentProto.getDescriptor();
diff --git a/proto-google-cloud-dialogflow-v2/src/main/proto/google/cloud/dialogflow/v2/session.proto b/proto-google-cloud-dialogflow-v2/src/main/proto/google/cloud/dialogflow/v2/session.proto
index 2688d6c4b..225813a34 100644
--- a/proto-google-cloud-dialogflow-v2/src/main/proto/google/cloud/dialogflow/v2/session.proto
+++ b/proto-google-cloud-dialogflow-v2/src/main/proto/google/cloud/dialogflow/v2/session.proto
@@ -20,6 +20,7 @@ package google.cloud.dialogflow.v2;
 import "google/api/annotations.proto";
 import "google/api/client.proto";
 import "google/api/field_behavior.proto";
+import "google/api/resource.proto";
 import "google/cloud/dialogflow/v2/audio_config.proto";
 import "google/cloud/dialogflow/v2/context.proto";
 import "google/cloud/dialogflow/v2/intent.proto";
@@ -36,6 +37,11 @@ option java_multiple_files = true;
 option java_outer_classname = "SessionProto";
 option java_package = "com.google.cloud.dialogflow.v2";
 option objc_class_prefix = "DF";
+option (google.api.resource_definition) = {
+  type: "dialogflow.googleapis.com/Session"
+  pattern: "projects/{project}/locations/{location}/agent/sessions/{session}"
+  pattern: "projects/{project}/agent/sessions/{session}"
+};
 
 // A session represents an interaction with a user. You retrieve user input
 // and pass it to the [DetectIntent][google.cloud.dialogflow.v2.Sessions.DetectIntent] (or
@@ -66,6 +72,8 @@ service Sessions {
   }
 }
 
+// ============================================================================
+// Requests and responses for custom methods.
 // The request to detect user's intent.
 message DetectIntentRequest {
   // Required. The name of the session this query is sent to. Format:
@@ -73,7 +81,12 @@ message DetectIntentRequest {
   // caller to choose an appropriate session ID. It can be a random number or
   // some type of user identifier (preferably hashed). The length of the session
   // ID must not exceed 36 bytes.
-  string session = 1 [(google.api.field_behavior) = REQUIRED];
+  string session = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "dialogflow.googleapis.com/Session"
+    }
+  ];
 
   // Optional. The parameters of this query.
   QueryParameters query_params = 2 [(google.api.field_behavior) = OPTIONAL];
diff --git a/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/DetectIntentRequest.java b/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/DetectIntentRequest.java
index 2d632f397..b5f2b719b 100644
--- a/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/DetectIntentRequest.java
+++ b/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/DetectIntentRequest.java
@@ -22,6 +22,8 @@
  *
  *
  * <pre>
+ * ============================================================================
+ * Requests and responses for custom methods.
  * The request to detect user's intent.
  * </pre>
  *
@@ -618,6 +620,8 @@ protected Builder newBuilderForType(com.google.protobuf.GeneratedMessageV3.Build
    *
    *
    * <pre>
+   * ============================================================================
+   * Requests and responses for custom methods.
    * The request to detect user's intent.
    * </pre>
    *
diff --git a/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/SessionProto.java b/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/SessionProto.java
index 7413f9c7b..a072f499e 100644
--- a/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/SessionProto.java
+++ b/proto-google-cloud-dialogflow-v2beta1/src/main/java/com/google/cloud/dialogflow/v2beta1/SessionProto.java
@@ -237,12 +237,16 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
           + "treamingDetectIntentResponse\"\000(\0010\001\032x\312A\031d"
           + "ialogflow.googleapis.com\322AYhttps://www.g"
           + "oogleapis.com/auth/cloud-platform,https:"
-          + "//www.googleapis.com/auth/dialogflowB\252\001\n"
+          + "//www.googleapis.com/auth/dialogflowB\300\002\n"
           + "#com.google.cloud.dialogflow.v2beta1B\014Se"
           + "ssionProtoP\001ZIgoogle.golang.org/genproto"
           + "/googleapis/cloud/dialogflow/v2beta1;dia"
           + "logflow\370\001\001\242\002\002DF\252\002\037Google.Cloud.Dialogflo"
-          + "w.V2beta1b\006proto3"
+          + "w.V2beta1\352A\222\001\n!dialogflow.googleapis.com"
+          + "/Session\022@projects/{project}/locations/{"
+          + "location}/agent/sessions/{session}\022+proj"
+          + "ects/{project}/agent/sessions/{session}b"
+          + "\006proto3"
     };
     descriptor =
         com.google.protobuf.Descriptors.FileDescriptor.internalBuildGeneratedFileFrom(
@@ -444,6 +448,7 @@ public static com.google.protobuf.Descriptors.FileDescriptor getDescriptor() {
     registry.add(com.google.api.ClientProto.defaultHost);
     registry.add(com.google.api.AnnotationsProto.http);
     registry.add(com.google.api.ClientProto.oauthScopes);
+    registry.add(com.google.api.ResourceProto.resourceDefinition);
     registry.add(com.google.api.ResourceProto.resourceReference);
     com.google.protobuf.Descriptors.FileDescriptor.internalUpdateFileDescriptor(
         descriptor, registry);
diff --git a/proto-google-cloud-dialogflow-v2beta1/src/main/proto/google/cloud/dialogflow/v2beta1/session.proto b/proto-google-cloud-dialogflow-v2beta1/src/main/proto/google/cloud/dialogflow/v2beta1/session.proto
index 1fec1af14..c558e7ad7 100644
--- a/proto-google-cloud-dialogflow-v2beta1/src/main/proto/google/cloud/dialogflow/v2beta1/session.proto
+++ b/proto-google-cloud-dialogflow-v2beta1/src/main/proto/google/cloud/dialogflow/v2beta1/session.proto
@@ -38,6 +38,11 @@ option java_multiple_files = true;
 option java_outer_classname = "SessionProto";
 option java_package = "com.google.cloud.dialogflow.v2beta1";
 option objc_class_prefix = "DF";
+option (google.api.resource_definition) = {
+  type: "dialogflow.googleapis.com/Session"
+  pattern: "projects/{project}/locations/{location}/agent/sessions/{session}"
+  pattern: "projects/{project}/agent/sessions/{session}"
+};
 
 // A session represents an interaction with a user. You retrieve user input
 // and pass it to the [DetectIntent][google.cloud.dialogflow.v2beta1.Sessions.DetectIntent] (or
@@ -79,6 +84,8 @@ service Sessions {
   }
 }
 
+// ============================================================================
+// Requests and responses for custom methods.
 // The request to detect user's intent.
 message DetectIntentRequest {
   // Required. The name of the session this query is sent to. Format:
diff --git a/synth.metadata b/synth.metadata
index 63da3a891..310de1afa 100644
--- a/synth.metadata
+++ b/synth.metadata
@@ -1,5 +1,5 @@
 {
-  "updateTime": "2020-02-01T08:47:10.504450Z",
+  "updateTime": "2020-02-04T08:47:20.781325Z",
   "sources": [
     {
       "generator": {
@@ -12,9 +12,9 @@
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "b5cbe4a4ba64ab19e6627573ff52057a1657773d",
-        "internalRef": "292647187",
-        "log": "b5cbe4a4ba64ab19e6627573ff52057a1657773d\nSecurityCenter v1p1beta1: move file-level option on top to workaround protobuf.js bug.\n\nPiperOrigin-RevId: 292647187\n\nb224b317bf20c6a4fbc5030b4a969c3147f27ad3\nAdds API definitions for bigqueryreservation v1beta1.\n\nPiperOrigin-RevId: 292634722\n\nc1468702f9b17e20dd59007c0804a089b83197d2\nSynchronize new proto/yaml changes.\n\nPiperOrigin-RevId: 292626173\n\nffdfa4f55ab2f0afc11d0eb68f125ccbd5e404bd\nvision: v1p3beta1 publish annotations and retry config\n\nPiperOrigin-RevId: 292605599\n\n78f61482cd028fc1d9892aa5d89d768666a954cd\nvision: v1p1beta1 publish annotations and retry config\n\nPiperOrigin-RevId: 292605125\n\n60bb5a294a604fd1778c7ec87b265d13a7106171\nvision: v1p2beta1 publish annotations and retry config\n\nPiperOrigin-RevId: 292604980\n\n3bcf7aa79d45eb9ec29ab9036e9359ea325a7fc3\nvision: v1p4beta1 publish annotations and retry config\n\nPiperOrigin-RevId: 292604656\n\n2717b8a1c762b26911b45ecc2e4ee01d98401b28\nFix dataproc artman client library generation.\n\nPiperOrigin-RevId: 292555664\n\n"
+        "sha": "69d9945330a5721cd679f17331a78850e2618226",
+        "internalRef": "293080182",
+        "log": "69d9945330a5721cd679f17331a78850e2618226\nAdd file-level `Session` resource definition\n\nPiperOrigin-RevId: 293080182\n\nf6a1a6b417f39694275ca286110bc3c1ca4db0dc\nAdd file-level `Session` resource definition\n\nPiperOrigin-RevId: 293080178\n\n29d40b78e3dc1579b0b209463fbcb76e5767f72a\nExpose managedidentities/v1beta1/ API for client library usage.\n\nPiperOrigin-RevId: 292979741\n\na22129a1fb6e18056d576dfb7717aef74b63734a\nExpose managedidentities/v1/ API for client library usage.\n\nPiperOrigin-RevId: 292968186\n\n"
       }
     },
     {