diff --git a/google/pubsub/artman_pubsub.yaml b/google/pubsub/artman_pubsub.yaml
index 5ca885a9..0d354412 100644
--- a/google/pubsub/artman_pubsub.yaml
+++ b/google/pubsub/artman_pubsub.yaml
@@ -2,7 +2,7 @@ common:
   api_name: pubsub
   api_version: v1
   organization_name: google-cloud
-  service_yaml: pubsub.yaml
+  service_yaml: v1/pubsub_v1.yaml
   gapic_yaml: v1/pubsub_gapic.yaml
   src_proto_paths:
   - v1
diff --git a/google/pubsub/pubsub.yaml b/google/pubsub/pubsub.yaml
deleted file mode 100644
index 77cc84c4..00000000
--- a/google/pubsub/pubsub.yaml
+++ /dev/null
@@ -1,67 +0,0 @@
-type: google.api.Service
-config_version: 3
-name: pubsub.googleapis.com
-title: Google Cloud Pub/Sub API
-
-apis:
-- name: google.pubsub.v1.Publisher
-- name: google.pubsub.v1.Subscriber
-
-documentation:
-  summary: |-
-    Provides reliable, many-to-many, asynchronous messaging between
-    applications.
-  rules:
-    - selector: >
-        google.pubsub.v1.Topic.name,
-      description: |
-          The name of the topic. It must have the format
-          `"projects/{project}/topics/{topic}"`. `{topic}` must start with a letter,
-          and contain only letters (`[A-Za-z]`), numbers (`[0-9]`), dashes (`-`),
-          underscores (`_`), periods (`.`), tildes (`~`), plus (`+`) or percent
-          signs (`%`). It must be between 3 and 255 characters in length, and it
-          must not start with `"goog"`.
-    - selector: >
-        google.pubsub.v1.Subscription.name,
-      description: |
-          The name of the subscription. It must have the format
-          `"projects/{project}/subscriptions/{subscription}"`. `{subscription}` must
-          start with a letter, and contain only letters (`[A-Za-z]`), numbers
-          (`[0-9]`), dashes (`-`), underscores (`_`), periods (`.`), tildes (`~`),
-          plus (`+`) or percent signs (`%`). It must be between 3 and 255 characters
-          in length, and it must not start with `"goog"`
-
-http:
-  rules:
-  - selector: google.iam.v1.IAMPolicy.SetIamPolicy
-    post: '/v1/{resource=projects/*/topics/*}:setIamPolicy'
-    body: '*'
-    additional_bindings:
-    - post: '/v1/{resource=projects/*/subscriptions/*}:setIamPolicy'
-      body: '*'
-    - post: '/v1/{resource=projects/*/snapshots/*}:setIamPolicy'
-      body: '*'
-
-  - selector: google.iam.v1.IAMPolicy.GetIamPolicy
-    get: '/v1/{resource=projects/*/topics/*}:getIamPolicy'
-    additional_bindings:
-    - get: '/v1/{resource=projects/*/subscriptions/*}:getIamPolicy'
-    - get: '/v1/{resource=projects/*/snapshots/*}:getIamPolicy'
-
-  - selector: google.iam.v1.IAMPolicy.TestIamPermissions
-    post: '/v1/{resource=projects/*/subscriptions/*}:testIamPermissions'
-    body: '*'
-    additional_bindings:
-    - post: '/v1/{resource=projects/*/topics/*}:testIamPermissions'
-      body: '*'
-    - post: '/v1/{resource=projects/*/snapshots/*}:testIamPermissions'
-      body: '*'
-
-
-authentication:
-  rules:
-  - selector: '*'
-    oauth:
-      canonical_scopes: |-
-        https://www.googleapis.com/auth/cloud-platform,
-        https://www.googleapis.com/auth/pubsub
diff --git a/google/pubsub/v1/BUILD.bazel b/google/pubsub/v1/BUILD.bazel
index 17f44adc..1de8bd5c 100644
--- a/google/pubsub/v1/BUILD.bazel
+++ b/google/pubsub/v1/BUILD.bazel
@@ -14,6 +14,8 @@ proto_library(
     deps = [
         "//google/api:annotations_proto",
         "//google/api:client_proto",
+        "//google/api:field_behavior_proto",
+        "//google/api:resource_proto",
         "@com_google_protobuf//:duration_proto",
         "@com_google_protobuf//:empty_proto",
         "@com_google_protobuf//:field_mask_proto",
@@ -69,7 +71,7 @@ java_gapic_library(
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
     gen_resource_name = False,
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     test_deps = [
         ":pubsub_java_grpc",
         "//google/iam/v1:iam_java_grpc",
@@ -120,6 +122,8 @@ moved_proto_library(
     deps = [
         "//google/api:annotations_proto",
         "//google/api:client_proto",
+        "//google/api:field_behavior_proto",
+        "//google/api:resource_proto",
         "@com_google_protobuf//:duration_proto",
         "@com_google_protobuf//:empty_proto",
         "@com_google_protobuf//:field_mask_proto",
@@ -143,7 +147,7 @@ py_gapic_library(
     name = "pubsub_py_gapic",
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [
         ":pubsub_py_proto",
         ":pubsub_py_grpc"
@@ -183,7 +187,7 @@ go_gapic_library(
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
     importpath = "cloud.google.com/go/pubsub/apiv1",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [":pubsub_go_proto"],
 )
 
@@ -232,7 +236,7 @@ php_gapic_library(
     name = "pubsub_php_gapic",
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [
         ":pubsub_php_grpc",
         ":pubsub_php_proto",
@@ -262,7 +266,7 @@ nodejs_gapic_library(
     name = "pubsub_nodejs_gapic",
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [],
 )
 
@@ -300,7 +304,7 @@ ruby_gapic_library(
     name = "pubsub_ruby_gapic",
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [
         ":pubsub_ruby_grpc",
         ":pubsub_ruby_proto",
@@ -343,7 +347,7 @@ csharp_gapic_library(
     name = "pubsub_csharp_gapic",
     src = ":pubsub_proto_with_info",
     gapic_yaml = "pubsub_gapic.yaml",
-    service_yaml = "//google/pubsub:pubsub.yaml",
+    service_yaml = ":pubsub_v1.yaml",
     deps = [
         ":pubsub_csharp_grpc",
         ":pubsub_csharp_proto",
diff --git a/google/pubsub/v1/pubsub.proto b/google/pubsub/v1/pubsub.proto
index da3801df..1a989b5c 100644
--- a/google/pubsub/v1/pubsub.proto
+++ b/google/pubsub/v1/pubsub.proto
@@ -17,12 +17,14 @@ syntax = "proto3";
 
 package google.pubsub.v1;
 
-import "google/api/annotations.proto";
 import "google/api/client.proto";
+import "google/api/field_behavior.proto";
+import "google/api/resource.proto";
 import "google/protobuf/duration.proto";
 import "google/protobuf/empty.proto";
 import "google/protobuf/field_mask.proto";
 import "google/protobuf/timestamp.proto";
+import "google/api/annotations.proto";
 
 option cc_enable_arenas = true;
 option csharp_namespace = "Google.Cloud.PubSub.V1";
@@ -49,6 +51,7 @@ service Publisher {
       put: "/v1/{name=projects/*/topics/*}"
       body: "*"
     };
+    option (google.api.method_signature) = "name";
   }
 
   // Updates an existing topic. Note that certain properties of a
@@ -67,6 +70,7 @@ service Publisher {
       post: "/v1/{topic=projects/*/topics/*}:publish"
       body: "*"
     };
+    option (google.api.method_signature) = "topic,messages";
   }
 
   // Gets the configuration of a topic.
@@ -74,6 +78,7 @@ service Publisher {
     option (google.api.http) = {
       get: "/v1/{topic=projects/*/topics/*}"
     };
+    option (google.api.method_signature) = "topic";
   }
 
   // Lists matching topics.
@@ -81,14 +86,15 @@ service Publisher {
     option (google.api.http) = {
       get: "/v1/{project=projects/*}/topics"
     };
+    option (google.api.method_signature) = "project";
   }
 
   // Lists the names of the subscriptions on this topic.
-  rpc ListTopicSubscriptions(ListTopicSubscriptionsRequest)
-      returns (ListTopicSubscriptionsResponse) {
+  rpc ListTopicSubscriptions(ListTopicSubscriptionsRequest) returns (ListTopicSubscriptionsResponse) {
     option (google.api.http) = {
       get: "/v1/{topic=projects/*/topics/*}/subscriptions"
     };
+    option (google.api.method_signature) = "topic";
   }
 
   // Lists the names of the snapshots on this topic. Snapshots are used in
@@ -97,8 +103,7 @@ service Publisher {
   // you to manage message acknowledgments in bulk. That is, you can set the
   // acknowledgment state of messages in an existing subscription to the state
   // captured by a snapshot.
-  rpc ListTopicSnapshots(ListTopicSnapshotsRequest)
-      returns (ListTopicSnapshotsResponse) {
+  rpc ListTopicSnapshots(ListTopicSnapshotsRequest) returns (ListTopicSnapshotsResponse) {
     option (google.api.http) = {
       get: "/v1/{topic=projects/*/topics/*}/snapshots"
     };
@@ -113,6 +118,7 @@ service Publisher {
     option (google.api.http) = {
       delete: "/v1/{topic=projects/*/topics/*}"
     };
+    option (google.api.method_signature) = "topic";
   }
 }
 
@@ -127,13 +133,19 @@ message MessageStoragePolicy {
 
 // A topic resource.
 message Topic {
-  // The name of the topic. It must have the format
+  option (google.api.resource) = {
+    type: "pubsub.googleapis.com/Topic"
+    pattern: "projects/{project}/topics/{topic}"
+    pattern: "_deleted-topic_"
+  };
+
+  // Required. The name of the topic. It must have the format
   // `"projects/{project}/topics/{topic}"`. `{topic}` must start with a letter,
   // and contain only letters (`[A-Za-z]`), numbers (`[0-9]`), dashes (`-`),
   // underscores (`_`), periods (`.`), tildes (`~`), plus (`+`) or percent
   // signs (`%`). It must be between 3 and 255 characters in length, and it
   // must not start with `"goog"`.
-  string name = 1;
+  string name = 1 [(google.api.field_behavior) = REQUIRED];
 
   // See <a href="https://cloud.google.com/pubsub/docs/labels"> Creating and
   // managing labels</a>.
@@ -193,32 +205,42 @@ message PubsubMessage {
 
 // Request for the GetTopic method.
 message GetTopicRequest {
-  // The name of the topic to get.
+  // Required. The name of the topic to get.
   // Format is `projects/{project}/topics/{topic}`.
-  string topic = 1;
+  string topic = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Topic"
+    }
+  ];
 }
 
 // Request for the UpdateTopic method.
 message UpdateTopicRequest {
-  // The updated topic object.
-  Topic topic = 1;
+  // Required. The updated topic object.
+  Topic topic = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // Indicates which fields in the provided topic to update. Must be specified
+  // Required. Indicates which fields in the provided topic to update. Must be specified
   // and non-empty. Note that if `update_mask` contains
   // "message_storage_policy" then the new value will be determined based on the
   // policy configured at the project or organization level. The
   // `message_storage_policy` must not be set in the `topic` provided above.
-  google.protobuf.FieldMask update_mask = 2;
+  google.protobuf.FieldMask update_mask = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Request for the Publish method.
 message PublishRequest {
-  // The messages in the request will be published on this topic.
+  // Required. The messages in the request will be published on this topic.
   // Format is `projects/{project}/topics/{topic}`.
-  string topic = 1;
+  string topic = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Topic"
+    }
+  ];
 
-  // The messages to publish.
-  repeated PubsubMessage messages = 2;
+  // Required. The messages to publish.
+  repeated PubsubMessage messages = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Response for the `Publish` method.
@@ -231,9 +253,14 @@ message PublishResponse {
 
 // Request for the `ListTopics` method.
 message ListTopicsRequest {
-  // The name of the project in which to list topics.
+  // Required. The name of the project in which to list topics.
   // Format is `projects/{project-id}`.
-  string project = 1;
+  string project = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "cloudresourcemanager.googleapis.com/Project"
+    }
+  ];
 
   // Maximum number of topics to return.
   int32 page_size = 2;
@@ -256,9 +283,14 @@ message ListTopicsResponse {
 
 // Request for the `ListTopicSubscriptions` method.
 message ListTopicSubscriptionsRequest {
-  // The name of the topic that subscriptions are attached to.
+  // Required. The name of the topic that subscriptions are attached to.
   // Format is `projects/{project}/topics/{topic}`.
-  string topic = 1;
+  string topic = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Topic"
+    }
+  ];
 
   // Maximum number of subscription names to return.
   int32 page_size = 2;
@@ -272,7 +304,9 @@ message ListTopicSubscriptionsRequest {
 // Response for the `ListTopicSubscriptions` method.
 message ListTopicSubscriptionsResponse {
   // The names of the subscriptions that match the request.
-  repeated string subscriptions = 1;
+  repeated string subscriptions = 1 [(google.api.resource_reference) = {
+                                       type: "pubsub.googleapis.com/Subscription"
+                                     }];
 
   // If not empty, indicates that there may be more subscriptions that match
   // the request; this value should be passed in a new
@@ -308,9 +342,14 @@ message ListTopicSnapshotsResponse {
 
 // Request for the `DeleteTopic` method.
 message DeleteTopicRequest {
-  // Name of the topic to delete.
+  // Required. Name of the topic to delete.
   // Format is `projects/{project}/topics/{topic}`.
-  string topic = 1;
+  string topic = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Topic"
+    }
+  ];
 }
 
 // The service that an application uses to manipulate subscriptions and to
@@ -340,6 +379,7 @@ service Subscriber {
       put: "/v1/{name=projects/*/subscriptions/*}"
       body: "*"
     };
+    option (google.api.method_signature) = "name,topic,push_config,ack_deadline_seconds";
   }
 
   // Gets the configuration details of a subscription.
@@ -347,6 +387,7 @@ service Subscriber {
     option (google.api.http) = {
       get: "/v1/{subscription=projects/*/subscriptions/*}"
     };
+    option (google.api.method_signature) = "subscription";
   }
 
   // Updates an existing subscription. Note that certain properties of a
@@ -359,11 +400,11 @@ service Subscriber {
   }
 
   // Lists matching subscriptions.
-  rpc ListSubscriptions(ListSubscriptionsRequest)
-      returns (ListSubscriptionsResponse) {
+  rpc ListSubscriptions(ListSubscriptionsRequest) returns (ListSubscriptionsResponse) {
     option (google.api.http) = {
       get: "/v1/{project=projects/*}/subscriptions"
     };
+    option (google.api.method_signature) = "project";
   }
 
   // Deletes an existing subscription. All messages retained in the subscription
@@ -371,11 +412,11 @@ service Subscriber {
   // `NOT_FOUND`. After a subscription is deleted, a new one may be created with
   // the same name, but the new one has no association with the old
   // subscription or its topic unless the same topic is specified.
-  rpc DeleteSubscription(DeleteSubscriptionRequest)
-      returns (google.protobuf.Empty) {
+  rpc DeleteSubscription(DeleteSubscriptionRequest) returns (google.protobuf.Empty) {
     option (google.api.http) = {
       delete: "/v1/{subscription=projects/*/subscriptions/*}"
     };
+    option (google.api.method_signature) = "subscription";
   }
 
   // Modifies the ack deadline for a specific message. This method is useful
@@ -383,12 +424,12 @@ service Subscriber {
   // subscriber, or to make the message available for redelivery if the
   // processing was interrupted. Note that this does not modify the
   // subscription-level `ackDeadlineSeconds` used for subsequent messages.
-  rpc ModifyAckDeadline(ModifyAckDeadlineRequest)
-      returns (google.protobuf.Empty) {
+  rpc ModifyAckDeadline(ModifyAckDeadlineRequest) returns (google.protobuf.Empty) {
     option (google.api.http) = {
       post: "/v1/{subscription=projects/*/subscriptions/*}:modifyAckDeadline"
       body: "*"
     };
+    option (google.api.method_signature) = "subscription,ack_ids,ack_deadline_seconds";
   }
 
   // Acknowledges the messages associated with the `ack_ids` in the
@@ -403,6 +444,7 @@ service Subscriber {
       post: "/v1/{subscription=projects/*/subscriptions/*}:acknowledge"
       body: "*"
     };
+    option (google.api.method_signature) = "subscription,ack_ids";
   }
 
   // Pulls messages from the server. The server may return `UNAVAILABLE` if
@@ -413,6 +455,7 @@ service Subscriber {
       post: "/v1/{subscription=projects/*/subscriptions/*}:pull"
       body: "*"
     };
+    option (google.api.method_signature) = "subscription,return_immediately,max_messages";
   }
 
   // Establishes a stream with the server, which sends messages down to the
@@ -422,8 +465,8 @@ service Subscriber {
   // reassign server-side resources, in which case, the client should
   // re-establish the stream. Flow control can be achieved by configuring the
   // underlying RPC channel.
-  rpc StreamingPull(stream StreamingPullRequest)
-      returns (stream StreamingPullResponse) {}
+  rpc StreamingPull(stream StreamingPullRequest) returns (stream StreamingPullResponse) {
+  }
 
   // Modifies the `PushConfig` for a specified subscription.
   //
@@ -431,12 +474,12 @@ service Subscriber {
   // an empty `PushConfig`) or vice versa, or change the endpoint URL and other
   // attributes of a push subscription. Messages will accumulate for delivery
   // continuously through the call regardless of changes to the `PushConfig`.
-  rpc ModifyPushConfig(ModifyPushConfigRequest)
-      returns (google.protobuf.Empty) {
+  rpc ModifyPushConfig(ModifyPushConfigRequest) returns (google.protobuf.Empty) {
     option (google.api.http) = {
       post: "/v1/{subscription=projects/*/subscriptions/*}:modifyPushConfig"
       body: "*"
     };
+    option (google.api.method_signature) = "subscription,push_config";
   }
 
   // Gets the configuration details of a snapshot. Snapshots are used in
@@ -460,6 +503,7 @@ service Subscriber {
     option (google.api.http) = {
       get: "/v1/{project=projects/*}/snapshots"
     };
+    option (google.api.method_signature) = "project";
   }
 
   // Creates a snapshot from the requested subscription. Snapshots are used in
@@ -485,6 +529,7 @@ service Subscriber {
       put: "/v1/{name=projects/*/snapshots/*}"
       body: "*"
     };
+    option (google.api.method_signature) = "name,subscription";
   }
 
   // Updates an existing snapshot. Snapshots are used in
@@ -514,6 +559,7 @@ service Subscriber {
     option (google.api.http) = {
       delete: "/v1/{snapshot=projects/*/snapshots/*}"
     };
+    option (google.api.method_signature) = "snapshot";
   }
 
   // Seeks an existing subscription to a point in time or to a given snapshot,
@@ -534,19 +580,29 @@ service Subscriber {
 
 // A subscription resource.
 message Subscription {
-  // The name of the subscription. It must have the format
+  option (google.api.resource) = {
+    type: "pubsub.googleapis.com/Subscription"
+    pattern: "projects/{project}/subscriptions/{subscription}"
+  };
+
+  // Required. The name of the subscription. It must have the format
   // `"projects/{project}/subscriptions/{subscription}"`. `{subscription}` must
   // start with a letter, and contain only letters (`[A-Za-z]`), numbers
   // (`[0-9]`), dashes (`-`), underscores (`_`), periods (`.`), tildes (`~`),
   // plus (`+`) or percent signs (`%`). It must be between 3 and 255 characters
   // in length, and it must not start with `"goog"`.
-  string name = 1;
+  string name = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // The name of the topic from which this subscription is receiving messages.
+  // Required. The name of the topic from which this subscription is receiving messages.
   // Format is `projects/{project}/topics/{topic}`.
   // The value of this field will be `_deleted-topic_` if the topic has been
   // deleted.
-  string topic = 2;
+  string topic = 2 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Topic"
+    }
+  ];
 
   // If push delivery is used with this subscription, this field is
   // used to configure it. An empty `pushConfig` signifies that the subscriber
@@ -762,26 +818,36 @@ message ReceivedMessage {
 
 // Request for the GetSubscription method.
 message GetSubscriptionRequest {
-  // The name of the subscription to get.
+  // Required. The name of the subscription to get.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 }
 
 // Request for the UpdateSubscription method.
 message UpdateSubscriptionRequest {
-  // The updated subscription object.
-  Subscription subscription = 1;
+  // Required. The updated subscription object.
+  Subscription subscription = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // Indicates which fields in the provided subscription to update.
+  // Required. Indicates which fields in the provided subscription to update.
   // Must be specified and non-empty.
-  google.protobuf.FieldMask update_mask = 2;
+  google.protobuf.FieldMask update_mask = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Request for the `ListSubscriptions` method.
 message ListSubscriptionsRequest {
-  // The name of the project in which to list subscriptions.
+  // Required. The name of the project in which to list subscriptions.
   // Format is `projects/{project-id}`.
-  string project = 1;
+  string project = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "cloudresourcemanager.googleapis.com/Project"
+    }
+  ];
 
   // Maximum number of subscriptions to return.
   int32 page_size = 2;
@@ -805,31 +871,46 @@ message ListSubscriptionsResponse {
 
 // Request for the DeleteSubscription method.
 message DeleteSubscriptionRequest {
-  // The subscription to delete.
+  // Required. The subscription to delete.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 }
 
 // Request for the ModifyPushConfig method.
 message ModifyPushConfigRequest {
-  // The name of the subscription.
+  // Required. The name of the subscription.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
-  // The push configuration for future deliveries.
+  // Required. The push configuration for future deliveries.
   //
   // An empty `pushConfig` indicates that the Pub/Sub system should
   // stop pushing messages from the given subscription and allow
   // messages to be pulled and acknowledged - effectively pausing
   // the subscription if `Pull` or `StreamingPull` is not called.
-  PushConfig push_config = 2;
+  PushConfig push_config = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Request for the `Pull` method.
 message PullRequest {
-  // The subscription from which messages should be pulled.
+  // Required. The subscription from which messages should be pulled.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
   // If this field set to true, the system will respond immediately even if
   // it there are no messages available to return in the `Pull` response.
@@ -837,10 +918,10 @@ message PullRequest {
   // least one message is available, rather than returning no messages.
   bool return_immediately = 2;
 
-  // The maximum number of messages to return for this request. Must be a
+  // Required. The maximum number of messages to return for this request. Must be a
   // positive integer. The Pub/Sub system may return fewer than the number
   // specified.
-  int32 max_messages = 3;
+  int32 max_messages = 3 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Response for the `Pull` method.
@@ -854,14 +935,19 @@ message PullResponse {
 
 // Request for the ModifyAckDeadline method.
 message ModifyAckDeadlineRequest {
-  // The name of the subscription.
+  // Required. The name of the subscription.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
-  // List of acknowledgment IDs.
-  repeated string ack_ids = 4;
+  // Required. List of acknowledgment IDs.
+  repeated string ack_ids = 4 [(google.api.field_behavior) = REQUIRED];
 
-  // The new ack deadline with respect to the time this request was sent to
+  // Required. The new ack deadline with respect to the time this request was sent to
   // the Pub/Sub system. For example, if the value is 10, the new
   // ack deadline will expire 10 seconds after the `ModifyAckDeadline` call
   // was made. Specifying zero might immediately make the message available for
@@ -869,29 +955,39 @@ message ModifyAckDeadlineRequest {
   // increase in the rate of message redeliveries (that is, duplicates).
   // The minimum deadline you can specify is 0 seconds.
   // The maximum deadline you can specify is 600 seconds (10 minutes).
-  int32 ack_deadline_seconds = 3;
+  int32 ack_deadline_seconds = 3 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Request for the Acknowledge method.
 message AcknowledgeRequest {
-  // The subscription whose message is being acknowledged.
+  // Required. The subscription whose message is being acknowledged.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
-  // The acknowledgment ID for the messages being acknowledged that was returned
+  // Required. The acknowledgment ID for the messages being acknowledged that was returned
   // by the Pub/Sub system in the `Pull` response. Must not be empty.
-  repeated string ack_ids = 2;
+  repeated string ack_ids = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // Request for the `StreamingPull` streaming RPC method. This request is used to
 // establish the initial stream as well as to stream acknowledgements and ack
 // deadline modifications from the client to the server.
 message StreamingPullRequest {
-  // The subscription for which to initialize the new stream. This must be
+  // Required. The subscription for which to initialize the new stream. This must be
   // provided in the first request on the stream, and must not be set in
   // subsequent requests from client to server.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 1;
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
   // List of acknowledgement IDs for acknowledging previously received messages
   // (received on this stream or a different stream). If an ack ID has expired,
@@ -920,11 +1016,11 @@ message StreamingPullRequest {
   // processing was interrupted.
   repeated string modify_deadline_ack_ids = 4;
 
-  // The ack deadline to use for the stream. This must be provided in the
+  // Required. The ack deadline to use for the stream. This must be provided in the
   // first request on the stream, but it can also be updated on subsequent
   // requests from client to server. The minimum deadline you can specify is 10
   // seconds. The maximum deadline you can specify is 600 seconds (10 minutes).
-  int32 stream_ack_deadline_seconds = 5;
+  int32 stream_ack_deadline_seconds = 5 [(google.api.field_behavior) = REQUIRED];
 
   // A unique identifier that is used to distinguish client instances from each
   // other. Only needs to be provided on the initial request. When a stream
@@ -944,15 +1040,20 @@ message StreamingPullResponse {
 
 // Request for the `CreateSnapshot` method.
 message CreateSnapshotRequest {
-  // User-provided name for this snapshot. If the name is not provided in the
+  // Required. User-provided name for this snapshot. If the name is not provided in the
   // request, the server will assign a random name for this snapshot on the same
   // project as the subscription. Note that for REST API requests, you must
   // specify a name.  See the <a
   // href="https://cloud.google.com/pubsub/docs/admin#resource_names"> resource
   // name rules</a>. Format is `projects/{project}/snapshots/{snap}`.
-  string name = 1;
+  string name = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Snapshot"
+    }
+  ];
 
-  // The subscription whose backlog the snapshot retains.
+  // Required. The subscription whose backlog the snapshot retains.
   // Specifically, the created snapshot is guaranteed to retain:
   //  (a) The existing backlog on the subscription. More precisely, this is
   //      defined as the messages in the subscription's backlog that are
@@ -961,7 +1062,12 @@ message CreateSnapshotRequest {
   //  (b) Any messages published to the subscription's topic following the
   //      successful completion of the CreateSnapshot request.
   // Format is `projects/{project}/subscriptions/{sub}`.
-  string subscription = 2;
+  string subscription = 2 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
   // See <a href="https://cloud.google.com/pubsub/docs/labels"> Creating and
   // managing labels</a>.
@@ -970,12 +1076,12 @@ message CreateSnapshotRequest {
 
 // Request for the UpdateSnapshot method.
 message UpdateSnapshotRequest {
-  // The updated snapshot object.
-  Snapshot snapshot = 1;
+  // Required. The updated snapshot object.
+  Snapshot snapshot = 1 [(google.api.field_behavior) = REQUIRED];
 
-  // Indicates which fields in the provided snapshot to update.
+  // Required. Indicates which fields in the provided snapshot to update.
   // Must be specified and non-empty.
-  google.protobuf.FieldMask update_mask = 2;
+  google.protobuf.FieldMask update_mask = 2 [(google.api.field_behavior) = REQUIRED];
 }
 
 // A snapshot resource. Snapshots are used in
@@ -985,11 +1091,18 @@ message UpdateSnapshotRequest {
 // acknowledgment state of messages in an existing subscription to the state
 // captured by a snapshot.
 message Snapshot {
+  option (google.api.resource) = {
+    type: "pubsub.googleapis.com/Snapshot"
+    pattern: "projects/{project}/snapshots/{snapshot}"
+  };
+
   // The name of the snapshot.
   string name = 1;
 
   // The name of the topic from which this snapshot is retaining messages.
-  string topic = 2;
+  string topic = 2 [(google.api.resource_reference) = {
+                      type: "pubsub.googleapis.com/Topic"
+                    }];
 
   // The snapshot is guaranteed to exist up until this time.
   // A newly-created snapshot expires no later than 7 days from the time of its
@@ -1010,16 +1123,26 @@ message Snapshot {
 
 // Request for the GetSnapshot method.
 message GetSnapshotRequest {
-  // The name of the snapshot to get.
+  // Required. The name of the snapshot to get.
   // Format is `projects/{project}/snapshots/{snap}`.
-  string snapshot = 1;
+  string snapshot = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Snapshot"
+    }
+  ];
 }
 
 // Request for the `ListSnapshots` method.
 message ListSnapshotsRequest {
-  // The name of the project in which to list snapshots.
+  // Required. The name of the project in which to list snapshots.
   // Format is `projects/{project-id}`.
-  string project = 1;
+  string project = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "cloudresourcemanager.googleapis.com/Project"
+    }
+  ];
 
   // Maximum number of snapshots to return.
   int32 page_size = 2;
@@ -1042,15 +1165,25 @@ message ListSnapshotsResponse {
 
 // Request for the `DeleteSnapshot` method.
 message DeleteSnapshotRequest {
-  // The name of the snapshot to delete.
+  // Required. The name of the snapshot to delete.
   // Format is `projects/{project}/snapshots/{snap}`.
-  string snapshot = 1;
+  string snapshot = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Snapshot"
+    }
+  ];
 }
 
 // Request for the `Seek` method.
 message SeekRequest {
-  // The subscription to affect.
-  string subscription = 1;
+  // Required. The subscription to affect.
+  string subscription = 1 [
+    (google.api.field_behavior) = REQUIRED,
+    (google.api.resource_reference) = {
+      type: "pubsub.googleapis.com/Subscription"
+    }
+  ];
 
   oneof target {
     // The time to seek to.
@@ -1069,9 +1202,13 @@ message SeekRequest {
     // The snapshot to seek to. The snapshot's topic must be the same as that of
     // the provided subscription.
     // Format is `projects/{project}/snapshots/{snap}`.
-    string snapshot = 3;
+    string snapshot = 3 [(google.api.resource_reference) = {
+                           type: "pubsub.googleapis.com/Snapshot"
+                         }];
   }
 }
 
 // Response for the `Seek` method (this response is empty).
-message SeekResponse {}
+message SeekResponse {
+
+}
diff --git a/google/pubsub/v1/pubsub_grpc_service_config.json b/google/pubsub/v1/pubsub_grpc_service_config.json
new file mode 100755
index 00000000..0a2702cd
--- /dev/null
+++ b/google/pubsub/v1/pubsub_grpc_service_config.json
@@ -0,0 +1,214 @@
+{
+  "methodConfig": [
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "CreateTopic"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "UpdateTopic"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "DeleteTopic"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "SetIamPolicy"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "TestIamPermissions"
+        }
+      ],
+      "timeout": "60s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "UNAVAILABLE"
+        ]
+      }
+    },
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "Publish"
+        }
+      ],
+      "timeout": "60s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "ABORTED",
+          "CANCELLED",
+          "INTERNAL",
+          "RESOURCE_EXHAUSTED",
+          "UNKNOWN",
+          "UNAVAILABLE",
+          "DEADLINE_EXCEEDED"
+        ]
+      }
+    },
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "GetTopic"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "ListTopics"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "ListTopicSubscriptions"
+        },
+        {
+          "service": "google.pubsub.v1.Publisher",
+          "method": "GetIamPolicy"
+        }
+      ],
+      "timeout": "60s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "UNKNOWN",
+          "ABORTED",
+          "UNAVAILABLE"
+        ]
+      }
+    },
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "StreamingPull"
+        }
+      ],
+      "timeout": "900s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "DEADLINE_EXCEEDED",
+          "RESOURCE_EXHAUSTED",
+          "ABORTED",
+          "INTERNAL",
+          "UNAVAILABLE"
+        ]
+      }
+    },
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "CreateSubscription"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "GetSubscription"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "ListSubscriptions"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "ListSnapshots"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "Seek"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "Pull"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "GetIamPolicy"
+        }
+      ],
+      "timeout": "60s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "UNKNOWN",
+          "ABORTED",
+          "UNAVAILABLE"
+        ]
+      }
+    },
+    {
+      "name": [
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "UpdateSubscription"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "DeleteSubscription"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "ModifyAckDeadline"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "ModifyPushConfig"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "CreateSnapshot"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "UpdateSnapshot"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "DeleteSnapshot"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "Acknowledge"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "SetIamPolicy"
+        },
+        {
+          "service": "google.pubsub.v1.Subscriber",
+          "method": "TestIamPermissions"
+        }
+      ],
+      "timeout": "60s",
+      "retryPolicy": {
+        "maxAttempts": 5,
+        "initialBackoff": "0.100s",
+        "maxBackoff": "60s",
+        "backoffMultiplier": 1.3,
+        "retryableStatusCodes": [
+          "UNAVAILABLE"
+        ]
+      }
+    }
+  ]
+}
diff --git a/google/pubsub/v1/pubsub_v1.yaml b/google/pubsub/v1/pubsub_v1.yaml
new file mode 100644
index 00000000..db0ea659
--- /dev/null
+++ b/google/pubsub/v1/pubsub_v1.yaml
@@ -0,0 +1,97 @@
+type: google.api.Service
+config_version: 3
+name: pubsub.googleapis.com
+title: Cloud Pub/Sub API
+
+apis:
+- name: google.pubsub.v1.Publisher
+- name: google.pubsub.v1.Subscriber
+
+documentation:
+  summary: |-
+    Provides reliable, many-to-many, asynchronous messaging between
+    applications.
+  rules:
+  - selector: google.iam.v1.IAMPolicy.GetIamPolicy
+    description: |-
+      Gets the access control policy for a resource. Returns an empty policy
+      if the resource exists and does not have a policy set.
+
+  - selector: google.iam.v1.IAMPolicy.SetIamPolicy
+    description: |-
+      Sets the access control policy on the specified resource. Replaces
+      any existing policy.
+
+      Can return Public Errors: NOT_FOUND, INVALID_ARGUMENT and
+      PERMISSION_DENIED
+
+  - selector: google.iam.v1.IAMPolicy.TestIamPermissions
+    description: |-
+      Returns permissions that a caller has on the specified resource. If the
+      resource does not exist, this will return an empty set of
+      permissions, not a NOT_FOUND error.
+
+      Note: This operation is designed to be used for building
+      permission-aware UIs and command-line tools, not for authorization
+      checking. This operation may "fail open" without warning.
+
+backend:
+  rules:
+  - selector: 'google.pubsub.v1.Publisher.*'
+    deadline: 120.0
+  - selector: google.pubsub.v1.Publisher.Publish
+    deadline: 20.0
+  - selector: 'google.pubsub.v1.Subscriber.*'
+    deadline: 120.0
+
+http:
+  rules:
+  - selector: google.iam.v1.IAMPolicy.GetIamPolicy
+    get: '/v1beta2/{resource=projects/*/topics/*}:getIamPolicy'
+    additional_bindings:
+    - get: '/v1beta2/{resource=projects/*/subscriptions/*}:getIamPolicy'
+    - get: '/v1/{resource=projects/*/topics/*}:getIamPolicy'
+    - get: '/v1/{resource=projects/*/subscriptions/*}:getIamPolicy'
+    - get: '/v1/{resource=projects/*/snapshots/*}:getIamPolicy'
+  - selector: google.iam.v1.IAMPolicy.SetIamPolicy
+    post: '/v1beta2/{resource=projects/*/topics/*}:setIamPolicy'
+    body: '*'
+    additional_bindings:
+    - post: '/v1beta2/{resource=projects/*/subscriptions/*}:setIamPolicy'
+      body: '*'
+    - post: '/v1/{resource=projects/*/topics/*}:setIamPolicy'
+      body: '*'
+    - post: '/v1/{resource=projects/*/subscriptions/*}:setIamPolicy'
+      body: '*'
+    - post: '/v1/{resource=projects/*/snapshots/*}:setIamPolicy'
+      body: '*'
+  - selector: google.iam.v1.IAMPolicy.TestIamPermissions
+    post: '/v1beta2/{resource=projects/*/subscriptions/*}:testIamPermissions'
+    body: '*'
+    additional_bindings:
+    - post: '/v1beta2/{resource=projects/*/topics/*}:testIamPermissions'
+      body: '*'
+    - post: '/v1/{resource=projects/*/subscriptions/*}:testIamPermissions'
+      body: '*'
+    - post: '/v1/{resource=projects/*/topics/*}:testIamPermissions'
+      body: '*'
+    - post: '/v1/{resource=projects/*/snapshots/*}:testIamPermissions'
+      body: '*'
+
+authentication:
+  rules:
+  - selector: 'google.iam.v1.IAMPolicy.*'
+    oauth:
+      canonical_scopes: |-
+        https://www.googleapis.com/auth/cloud-platform,
+        https://www.googleapis.com/auth/pubsub
+  - selector: 'google.pubsub.v1.Publisher.*'
+    oauth:
+      canonical_scopes: |-
+        https://www.googleapis.com/auth/cloud-platform,
+        https://www.googleapis.com/auth/pubsub
+  - selector: 'google.pubsub.v1.Subscriber.*'
+    oauth:
+      canonical_scopes: |-
+        https://www.googleapis.com/auth/cloud-platform,
+        https://www.googleapis.com/auth/pubsub