diff --git a/clients/client-transcribe-streaming/TranscribeStreamingClient.ts b/clients/client-transcribe-streaming/TranscribeStreamingClient.ts
index 7b4ea48714e59..8d7955e0d4cb8 100644
--- a/clients/client-transcribe-streaming/TranscribeStreamingClient.ts
+++ b/clients/client-transcribe-streaming/TranscribeStreamingClient.ts
@@ -34,6 +34,12 @@ import {
   getRetryPlugin,
   resolveRetryConfig
 } from "@aws-sdk/middleware-retry";
+import {
+  WebSocketInputConfig,
+  WebSocketResolvedConfig,
+  getWebSocketPlugin,
+  resolveWebSocketConfig
+} from "@aws-sdk/middleware-sdk-transcribe-streaming";
 import {
   AwsAuthInputConfig,
   AwsAuthResolvedConfig,
@@ -176,6 +182,7 @@ export type TranscribeStreamingClientConfig = Partial<
   UserAgentInputConfig &
   HostHeaderInputConfig &
   EventStreamInputConfig &
+  WebSocketInputConfig &
   EventStreamSerdeInputConfig;
 
 export type TranscribeStreamingClientResolvedConfig = __SmithyResolvedConfiguration<
@@ -189,6 +196,7 @@ export type TranscribeStreamingClientResolvedConfig = __SmithyResolvedConfigurat
   UserAgentResolvedConfig &
   HostHeaderResolvedConfig &
   EventStreamResolvedConfig &
+  WebSocketResolvedConfig &
   EventStreamSerdeResolvedConfig;
 
 /**
@@ -214,14 +222,16 @@ export class TranscribeStreamingClient extends __Client<
     let _config_5 = resolveUserAgentConfig(_config_4);
     let _config_6 = resolveHostHeaderConfig(_config_5);
     let _config_7 = resolveEventStreamConfig(_config_6);
-    let _config_8 = resolveEventStreamSerdeConfig(_config_7);
-    super(_config_8);
-    this.config = _config_8;
+    let _config_8 = resolveWebSocketConfig(_config_7);
+    let _config_9 = resolveEventStreamSerdeConfig(_config_8);
+    super(_config_9);
+    this.config = _config_9;
     this.middlewareStack.use(getAwsAuthPlugin(this.config));
     this.middlewareStack.use(getRetryPlugin(this.config));
     this.middlewareStack.use(getUserAgentPlugin(this.config));
     this.middlewareStack.use(getContentLengthPlugin(this.config));
     this.middlewareStack.use(getHostHeaderPlugin(this.config));
+    this.middlewareStack.use(getWebSocketPlugin(this.config));
   }
 
   destroy(): void {
diff --git a/clients/client-transcribe-streaming/package.json b/clients/client-transcribe-streaming/package.json
index 74d26d35cdfea..7349b27afebc0 100644
--- a/clients/client-transcribe-streaming/package.json
+++ b/clients/client-transcribe-streaming/package.json
@@ -45,6 +45,7 @@
     "@aws-sdk/middleware-eventstream": "1.0.0-gamma.0",
     "@aws-sdk/middleware-host-header": "1.0.0-gamma.1",
     "@aws-sdk/middleware-retry": "1.0.0-gamma.1",
+    "@aws-sdk/middleware-sdk-transcribe-streaming": "1.0.0-gamma.0",
     "@aws-sdk/middleware-serde": "1.0.0-gamma.1",
     "@aws-sdk/middleware-signing": "1.0.0-gamma.1",
     "@aws-sdk/middleware-stack": "1.0.0-gamma.1",
@@ -82,4 +83,4 @@
     "url": "https://aws.amazon.com/javascript/"
   },
   "license": "Apache-2.0"
-}
\ No newline at end of file
+}
diff --git a/clients/client-transcribe-streaming/runtimeConfig.browser.ts b/clients/client-transcribe-streaming/runtimeConfig.browser.ts
index b73f3636b86a8..e3789eff50709 100644
--- a/clients/client-transcribe-streaming/runtimeConfig.browser.ts
+++ b/clients/client-transcribe-streaming/runtimeConfig.browser.ts
@@ -1,8 +1,12 @@
 import { name, version } from "./package.json";
 import { Sha256 } from "@aws-crypto/sha256-browser";
 import { eventStreamSerdeProvider } from "@aws-sdk/eventstream-serde-browser";
-import { FetchHttpHandler, streamCollector } from "@aws-sdk/fetch-http-handler";
+import { streamCollector } from "@aws-sdk/fetch-http-handler";
 import { invalidFunction } from "@aws-sdk/invalid-dependency";
+import {
+  WebSocketHandler,
+  eventStreamPayloadHandler
+} from "@aws-sdk/middleware-sdk-transcribe-streaming";
 import { parseUrl } from "@aws-sdk/url-parser-browser";
 import { fromBase64, toBase64 } from "@aws-sdk/util-base64-browser";
 import { calculateBodyLength } from "@aws-sdk/util-body-length-browser";
@@ -19,12 +23,10 @@ export const ClientDefaultValues: Required<ClientDefaults> = {
   bodyLengthChecker: calculateBodyLength,
   credentialDefaultProvider: invalidFunction("Credential is missing") as any,
   defaultUserAgent: defaultUserAgent(name, version),
-  eventStreamPayloadHandlerProvider: () => ({
-    handle: invalidFunction("event stream request is not supported in browser.")
-  }),
+  eventStreamPayloadHandlerProvider: () => eventStreamPayloadHandler,
   eventStreamSerdeProvider,
   regionDefaultProvider: invalidFunction("Region is missing") as any,
-  requestHandler: new FetchHttpHandler(),
+  requestHandler: new WebSocketHandler(),
   sha256: Sha256,
   streamCollector,
   urlParser: parseUrl,
diff --git a/clients/client-transcribe-streaming/runtimeConfig.native.ts b/clients/client-transcribe-streaming/runtimeConfig.native.ts
index 488a2ec132d67..39e6e9ab9d7c1 100644
--- a/clients/client-transcribe-streaming/runtimeConfig.native.ts
+++ b/clients/client-transcribe-streaming/runtimeConfig.native.ts
@@ -1,6 +1,9 @@
 import { name, version } from "./package.json";
 import { Sha256 } from "@aws-crypto/sha256-js";
-import { invalidFunction } from "@aws-sdk/invalid-dependency";
+import {
+  WebSocketHandler,
+  eventStreamPayloadHandler
+} from "@aws-sdk/middleware-sdk-transcribe-streaming";
 import { parseUrl } from "@aws-sdk/url-parser-node";
 import { ClientDefaults } from "./TranscribeStreamingClient";
 import { ClientDefaultValues as BrowserDefaults } from "./runtimeConfig.browser";
@@ -9,17 +12,8 @@ export const ClientDefaultValues: Required<ClientDefaults> = {
   ...BrowserDefaults,
   runtime: "react-native",
   defaultUserAgent: `aws-sdk-js-v3-react-native-${name}/${version}`,
-  eventStreamPayloadHandlerProvider: () => ({
-    handle: invalidFunction(
-      "event stream request is not supported in ReactNative."
-    )
-  }),
-  eventStreamSerdeProvider: () => ({
-    serialize: invalidFunction("event stream is not supported in ReactNative."),
-    deserialize: invalidFunction(
-      "event stream is not supported in ReactNative."
-    )
-  }),
+  eventStreamPayloadHandlerProvider: () => eventStreamPayloadHandler,
+  requestHandler: new WebSocketHandler(),
   sha256: Sha256,
   urlParser: parseUrl
 };
diff --git a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AddTranscribeStreamingDependency.java b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AddTranscribeStreamingDependency.java
new file mode 100644
index 0000000000000..61139ecf68460
--- /dev/null
+++ b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AddTranscribeStreamingDependency.java
@@ -0,0 +1,81 @@
+package software.amazon.smithy.aws.typescript.codegen;
+
+import static software.amazon.smithy.typescript.codegen.integration.RuntimeClientPlugin.Convention.HAS_CONFIG;
+import static software.amazon.smithy.typescript.codegen.integration.RuntimeClientPlugin.Convention.HAS_MIDDLEWARE;
+
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+import software.amazon.smithy.aws.traits.ServiceTrait;
+import software.amazon.smithy.codegen.core.SymbolProvider;
+import software.amazon.smithy.model.Model;
+import software.amazon.smithy.model.shapes.ServiceShape;
+import software.amazon.smithy.typescript.codegen.LanguageTarget;
+import software.amazon.smithy.typescript.codegen.TypeScriptDependency;
+import software.amazon.smithy.typescript.codegen.TypeScriptSettings;
+import software.amazon.smithy.typescript.codegen.TypeScriptWriter;
+import software.amazon.smithy.typescript.codegen.integration.RuntimeClientPlugin;
+import software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration;
+import software.amazon.smithy.utils.ListUtils;
+import software.amazon.smithy.utils.MapUtils;
+
+/**
+ * Add client plugins and configs to support WebSocket streaming for Transcribe
+ * Streaming service
+ * */
+public class AddTranscribeStreamingDependency implements TypeScriptIntegration {
+    @Override
+    public List<RuntimeClientPlugin> getClientPlugins() {
+        return ListUtils.of(
+                RuntimeClientPlugin.builder()
+                        .withConventions(AwsDependency.TRANSCRIBE_STREAMING_MIDDLEWARE.dependency,
+                                "WebSocket")
+                        .servicePredicate((m, s) -> AddTranscribeStreamingDependency.isTranscribeStreaming(s))
+                        .build()
+        );
+    }
+
+    @Override
+    public Map<String, Consumer<TypeScriptWriter>> getRuntimeConfigWriters(
+            TypeScriptSettings settings,
+            Model model,
+            SymbolProvider symbolProvider,
+            LanguageTarget target
+    ) {
+        ServiceShape service = settings.getService(model);
+        if (!isTranscribeStreaming(service)) {
+            return Collections.emptyMap();
+        }
+
+        Map<String, Consumer<TypeScriptWriter>> transcribeStreamingHandlerConfig = MapUtils.of(
+                "eventStreamPayloadHandlerProvider", writer -> {
+                        writer.addDependency(AwsDependency.TRANSCRIBE_STREAMING_MIDDLEWARE);
+                        writer.addImport("eventStreamPayloadHandler", "eventStreamPayloadHandler",
+                            AwsDependency.TRANSCRIBE_STREAMING_MIDDLEWARE.packageName);
+                        writer.write("eventStreamPayloadHandlerProvider: () => eventStreamPayloadHandler,");
+                },
+                "requestHandler", writer -> {
+                        writer.addDependency(AwsDependency.TRANSCRIBE_STREAMING_MIDDLEWARE);
+                        writer.addImport("WebSocketHandler", "WebSocketHandler",
+                            AwsDependency.TRANSCRIBE_STREAMING_MIDDLEWARE.packageName);
+                        writer.write("requestHandler: new WebSocketHandler(),");
+                });
+
+        switch (target) {
+            case REACT_NATIVE:
+            case BROWSER:
+                return transcribeStreamingHandlerConfig;
+            default:
+                return Collections.emptyMap();
+        }
+    }
+
+    private static boolean isTranscribeStreaming(ServiceShape service) {
+        String serviceId = service.getTrait(ServiceTrait.class).map(ServiceTrait::getSdkId).orElse("");
+        return serviceId.equals("Transcribe Streaming");
+    }
+}
+
+
diff --git a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsDependency.java b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsDependency.java
index e769f6ef80bd7..40ef346bc5c9d 100644
--- a/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsDependency.java
+++ b/codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/AwsDependency.java
@@ -57,7 +57,8 @@ public enum AwsDependency implements SymbolDependencyContainer {
     UUID_GENERATOR(NORMAL_DEPENDENCY, "uuid", "^7.0.0"),
     UUID_GENERATOR_TYPES(DEV_DEPENDENCY, "@types/uuid", "^7.0.0"),
     MIDDLEWARE_EVENTSTREAM(NORMAL_DEPENDENCY, "@aws-sdk/middleware-eventstream", "^1.0.0-beta.0"),
-    AWS_SDK_EVENTSTREAM_HANDLER_NODE(NORMAL_DEPENDENCY, "@aws-sdk/eventstream-handler-node", "^1.0.0-beta.0");
+    AWS_SDK_EVENTSTREAM_HANDLER_NODE(NORMAL_DEPENDENCY, "@aws-sdk/eventstream-handler-node", "^1.0.0-beta.0"),
+    TRANSCRIBE_STREAMING_MIDDLEWARE(NORMAL_DEPENDENCY, "@aws-sdk/middleware-sdk-transcribe-streaming", "^1.0.0-gamma.0");
 
     public final String packageName;
     public final String version;
diff --git a/codegen/smithy-aws-typescript-codegen/src/main/resources/META-INF/services/software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration b/codegen/smithy-aws-typescript-codegen/src/main/resources/META-INF/services/software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration
index 8f0548e82e881..63298334be212 100644
--- a/codegen/smithy-aws-typescript-codegen/src/main/resources/META-INF/services/software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration
+++ b/codegen/smithy-aws-typescript-codegen/src/main/resources/META-INF/services/software.amazon.smithy.typescript.codegen.integration.TypeScriptIntegration
@@ -10,3 +10,4 @@ software.amazon.smithy.aws.typescript.codegen.AddBodyChecksumGeneratorDependency
 software.amazon.smithy.aws.typescript.codegen.AddS3Config
 software.amazon.smithy.aws.typescript.codegen.AddEventStreamHandlingDependency
 software.amazon.smithy.aws.typescript.codegen.AddHttp2Dependency
+software.amazon.smithy.aws.typescript.codegen.AddTranscribeStreamingDependency
diff --git a/packages/eventstream-serde-browser/package.json b/packages/eventstream-serde-browser/package.json
index 1aa96ada56c4b..4cde63709bab7 100644
--- a/packages/eventstream-serde-browser/package.json
+++ b/packages/eventstream-serde-browser/package.json
@@ -16,6 +16,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@aws-sdk/eventstream-marshaller": "1.0.0-gamma.1",
+    "@aws-sdk/eventstream-serde-universal": "1.0.0-gamma.0",
     "@aws-sdk/types": "1.0.0-gamma.1",
     "tslib": "^1.8.0"
   },
diff --git a/packages/eventstream-serde-browser/src/EventStreamMarshaller.ts b/packages/eventstream-serde-browser/src/EventStreamMarshaller.ts
index 861af806f527c..a9214f77b4ba2 100644
--- a/packages/eventstream-serde-browser/src/EventStreamMarshaller.ts
+++ b/packages/eventstream-serde-browser/src/EventStreamMarshaller.ts
@@ -1,3 +1,4 @@
+import { EventStreamMarshaller as UniversalEventStreamMarshaller } from "@aws-sdk/eventstream-serde-universal";
 import { EventStreamMarshaller as EventMarshaller } from "@aws-sdk/eventstream-marshaller";
 import {
   Encoder,
@@ -5,10 +6,7 @@ import {
   Message,
   EventStreamMarshaller as IEventStreamMarshaller
 } from "@aws-sdk/types";
-import { ReadableStreamtoIterable } from "./utils";
-import { getChunkedStream } from "./getChunkedStream";
-import { getEventMessageStream } from "./getEventMessageStream";
-import { getDeserializingStream } from "./getDeserializingStream";
+import { readableStreamtoIterable, iterableToReadableStream } from "./utils";
 
 export interface EventStreamMarshaller extends IEventStreamMarshaller {}
 
@@ -17,35 +15,48 @@ export interface EventStreamMarshallerOptions {
   utf8Decoder: Decoder;
 }
 
+/**
+ * Utility class used to serialize and deserialize event streams in
+ * browsers and ReactNative.
+ *
+ * In browsers where ReadableStream API is available:
+ * * deserialize from ReadableStream to an async iterable of output structure
+ * * serialize from async iterable of input structure to ReadableStream
+ * In ReactNative where only async iterable API is available:
+ * * deserialize from async iterable of binaries to async iterable of output structure
+ * * serialize from async iterable of input structure to async iterable of binaries
+ *
+ * We use ReadableStream API in browsers because of the consistency with other
+ * streaming operations, where ReadableStream API is used to denote streaming data.
+ * Whereas in ReactNative, ReadableStream API is not available, we use async iterable
+ * for streaming data although it has lower throughput.
+ */
 export class EventStreamMarshaller {
   private readonly eventMarshaller: EventMarshaller;
+  private readonly universalMarshaller: UniversalEventStreamMarshaller;
   constructor({ utf8Encoder, utf8Decoder }: EventStreamMarshallerOptions) {
     this.eventMarshaller = new EventMarshaller(utf8Encoder, utf8Decoder);
+    this.universalMarshaller = new UniversalEventStreamMarshaller({
+      utf8Decoder,
+      utf8Encoder
+    });
   }
 
   deserialize<T>(
-    body: ReadableStream<Uint8Array>,
+    body: ReadableStream<Uint8Array> | AsyncIterable<Uint8Array>,
     deserializer: (input: { [event: string]: Message }) => Promise<T>
   ): AsyncIterable<T> {
-    const chunkedStream = getChunkedStream(body);
-    const messageStream = getEventMessageStream(
-      chunkedStream,
-      this.eventMarshaller
-    );
-    const deserialingStream = getDeserializingStream(
-      messageStream,
-      deserializer
-    );
-    return ReadableStreamtoIterable(deserialingStream);
+    const bodyIterable = isReadableStream(body)
+      ? readableStreamtoIterable(body)
+      : body;
+    return this.universalMarshaller.deserialize(bodyIterable, deserializer);
   }
 
   /**
-   * Generate a ReadableStream that serialize events
-   * to event stream binary chunks; Use a pull stream
-   * here to support low connection speed.
+   * Generate a stream that serialize events into stream of binary chunks;
    *
-   * This doesn't work on browser currently because
-   * browser doesn't support upload streaming.
+   * Caveat is that streaming request payload doesn't work on browser with native
+   * xhr or fetch handler currently because they don't support upload streaming.
    * reference:
    * * https://bugs.chromium.org/p/chromium/issues/detail?id=688906
    * * https://bugzilla.mozilla.org/show_bug.cgi?id=1387483
@@ -54,8 +65,16 @@ export class EventStreamMarshaller {
   serialize<T>(
     input: AsyncIterable<T>,
     serializer: (event: T) => Message
-  ): ReadableStream {
-    throw new Error(`event stream request in browser is not supported
-Reference: https://bugs.chromium.org/p/chromium/issues/detail?id=688906`);
+  ): ReadableStream | AsyncIterable<Uint8Array> {
+    const serialziedIterable = this.universalMarshaller.serialize(
+      input,
+      serializer
+    );
+    return typeof ReadableStream === "function"
+      ? iterableToReadableStream(serialziedIterable)
+      : serialziedIterable;
   }
 }
+
+const isReadableStream = (body: any): body is ReadableStream =>
+  typeof ReadableStream === "function" && body instanceof ReadableStream;
diff --git a/packages/eventstream-serde-browser/src/getChunkedStream.ts b/packages/eventstream-serde-browser/src/getChunkedStream.ts
deleted file mode 100644
index 45f1a0c08feb9..0000000000000
--- a/packages/eventstream-serde-browser/src/getChunkedStream.ts
+++ /dev/null
@@ -1,111 +0,0 @@
-export function getChunkedStream(
-  source: ReadableStream<Uint8Array>
-): ReadableStream<Uint8Array> {
-  const sourceReader = source.getReader();
-  let currentMessageTotalLength = 0;
-  let currentMessagePendingLength = 0;
-  let currentMessage: Uint8Array | null = null;
-  let messageLengthBuffer: Uint8Array | null = null;
-  const allocateMessage = function (size: number) {
-    if (typeof size !== "number") {
-      throw new Error(
-        "Attempted to allocate an event message where size was not a number: " +
-          size
-      );
-    }
-    currentMessageTotalLength = size;
-    currentMessagePendingLength = 4;
-    currentMessage = new Uint8Array(size);
-    const currentMessageView = new DataView(currentMessage.buffer);
-    currentMessageView.setUint32(0, size, false); //set big-endian Uint32 to 0~3 bytes
-  };
-
-  const chunkedStream = new ReadableStream({
-    start(controller) {
-      function push() {
-        return sourceReader.read().then(({ done, value }) => {
-          if (done) {
-            if (currentMessageTotalLength) {
-              if (currentMessageTotalLength === currentMessagePendingLength) {
-                controller.enqueue(currentMessage);
-              } else {
-                throw new Error("Truncated event message received.");
-              }
-            }
-            controller.close();
-            return;
-          }
-
-          // @ts-ignore error TS2532: Object is possibly 'undefined' for value
-          const chunkLength = value.length;
-          let currentOffset = 0;
-
-          while (currentOffset < chunkLength) {
-            // create new message if necessary
-            if (!currentMessage) {
-              // working on a new message, determine total length
-              const bytesRemaining = chunkLength - currentOffset;
-              // prevent edge case where total length spans 2 chunks
-              if (!messageLengthBuffer) {
-                messageLengthBuffer = new Uint8Array(4);
-              }
-              const numBytesForTotal = Math.min(
-                4 - currentMessagePendingLength, // remaining bytes to fill the messageLengthBuffer
-                bytesRemaining // bytes left in chunk
-              );
-
-              messageLengthBuffer.set(
-                // @ts-ignore error TS2532: Object is possibly 'undefined' for value
-                value.slice(currentOffset, currentOffset + numBytesForTotal),
-                currentMessagePendingLength
-              );
-
-              currentMessagePendingLength += numBytesForTotal;
-              currentOffset += numBytesForTotal;
-
-              if (currentMessagePendingLength < 4) {
-                // not enough information to create the current message
-                break;
-              }
-              allocateMessage(
-                new DataView(messageLengthBuffer.buffer).getUint32(0, false)
-              );
-              messageLengthBuffer = null;
-            }
-
-            // write data into current message
-            const numBytesToWrite = Math.min(
-              currentMessageTotalLength - currentMessagePendingLength, // number of bytes left to complete message
-              chunkLength - currentOffset // number of bytes left in the original chunk
-            );
-            currentMessage!.set(
-              // @ts-ignore error TS2532: Object is possibly 'undefined' for value
-              value.slice(currentOffset, currentOffset + numBytesToWrite),
-              currentMessagePendingLength
-            );
-            currentMessagePendingLength += numBytesToWrite;
-            currentOffset += numBytesToWrite;
-
-            // check if a message is ready to be pushed
-            if (
-              currentMessageTotalLength &&
-              currentMessageTotalLength === currentMessagePendingLength
-            ) {
-              // push out the message
-              controller.enqueue(currentMessage);
-              // cleanup
-              currentMessage = null;
-              currentMessageTotalLength = 0;
-              currentMessagePendingLength = 0;
-            }
-          }
-          push();
-        });
-      }
-
-      push();
-    }
-  });
-
-  return chunkedStream;
-}
diff --git a/packages/eventstream-serde-browser/src/getDeserializingStream.ts b/packages/eventstream-serde-browser/src/getDeserializingStream.ts
deleted file mode 100644
index 78c050f25eaf4..0000000000000
--- a/packages/eventstream-serde-browser/src/getDeserializingStream.ts
+++ /dev/null
@@ -1,30 +0,0 @@
-import { Message } from "@aws-sdk/types";
-
-export function getDeserializingStream(
-  messageStream: ReadableStream<{ [name: string]: Message }>,
-  deserializer: (input: any) => any
-): ReadableStream<{ [name: string]: any }> {
-  const messageReader = messageStream.getReader();
-  const deserializedStream = new ReadableStream<{ [name: string]: any }>({
-    start(controller) {
-      function push() {
-        messageReader.read().then(async ({ done, value }) => {
-          if (done) {
-            controller.close();
-            return;
-          }
-
-          try {
-            controller.enqueue(await deserializer(value));
-            push();
-          } catch (e) {
-            controller.error(e);
-          }
-        });
-      }
-
-      push();
-    }
-  });
-  return deserializedStream;
-}
diff --git a/packages/eventstream-serde-browser/src/getEventMessageStream.ts b/packages/eventstream-serde-browser/src/getEventMessageStream.ts
deleted file mode 100644
index 13a0bbd236ba4..0000000000000
--- a/packages/eventstream-serde-browser/src/getEventMessageStream.ts
+++ /dev/null
@@ -1,56 +0,0 @@
-import { EventStreamMarshaller as EventMarshaller } from "@aws-sdk/eventstream-marshaller";
-import { Message } from "@aws-sdk/types";
-
-export function getEventMessageStream(
-  chunkedStream: ReadableStream<Uint8Array>,
-  eventMarshaller: EventMarshaller
-): ReadableStream<{ [name: string]: Message }> {
-  const chunkReader = chunkedStream.getReader();
-  const messageStream = new ReadableStream<{ [name: string]: Message }>({
-    start(controller) {
-      function push() {
-        chunkReader.read().then(({ done, value }) => {
-          if (done) {
-            controller.close();
-            return;
-          }
-
-          // @ts-ignore: error TS2345: Argument of type 'Uint8Array | undefined'
-          // is not assignable to parameter of type 'ArrayBufferView'
-          const message = eventMarshaller.unmarshall(value);
-          const { value: messageType } = message.headers[":message-type"];
-          if (messageType === "error") {
-            // Unmodeled exception in event
-            const unmodeledError = new Error(
-              (message.headers[":error-message"].value as string) ||
-                "UnknownError"
-            );
-            unmodeledError.name = message.headers[":error-code"]
-              .value as string;
-            controller.error(unmodeledError);
-          } else if (messageType === "exception") {
-            // throw this.exceptionsDeserializer(message);
-            controller.enqueue({
-              [message.headers[":exception-type"].value as string]: message
-            });
-          } else if (messageType === "event") {
-            controller.enqueue({
-              [message.headers[":event-type"].value as string]: message
-            });
-          } else {
-            controller.error(
-              new Error(
-                `Unrecognizable event type: ${message.headers[":event-type"].value}`
-              )
-            );
-          }
-          push();
-        });
-      }
-
-      push();
-    }
-  });
-
-  return messageStream;
-}
diff --git a/packages/eventstream-serde-browser/src/index.ts b/packages/eventstream-serde-browser/src/index.ts
index 1a8f850f5f8ac..06e0068336085 100644
--- a/packages/eventstream-serde-browser/src/index.ts
+++ b/packages/eventstream-serde-browser/src/index.ts
@@ -1 +1,3 @@
 export * from "./provider";
+export * from "./EventStreamMarshaller";
+export * from "./utils";
diff --git a/packages/eventstream-serde-browser/src/utils.ts b/packages/eventstream-serde-browser/src/utils.ts
index d261672d7c728..53b1d18b71635 100644
--- a/packages/eventstream-serde-browser/src/utils.ts
+++ b/packages/eventstream-serde-browser/src/utils.ts
@@ -1,19 +1,38 @@
 /**
- * Convert ReadableStream into an async iterable.
+ * A util function converting ReadableStream into an async iterable.
+ * Reference: https://jakearchibald.com/2017/async-iterators-and-generators/#making-streams-iterate
  */
-export async function* ReadableStreamtoIterable<T>(
-  readableStream: ReadableStream
-): AsyncIterable<T> {
-  const reader = readableStream.getReader();
-  let done = false;
-  while (!done) {
-    const { done: end, value } = await reader.read();
-    if (end) {
-      done = true;
-      break;
-    }
-    if (value) {
-      yield value;
+export const readableStreamtoIterable = <T>(
+  readableStream: ReadableStream<T>
+): AsyncIterable<T> => ({
+  [Symbol.asyncIterator]: async function* () {
+    const reader = readableStream.getReader();
+    try {
+      while (true) {
+        const { done, value } = await reader.read();
+        if (done) return;
+        yield value as T;
+      }
+    } finally {
+      reader.releaseLock();
     }
   }
-}
+});
+
+/**
+ * A util function converting async iterable to a ReadableStream.
+ */
+export const iterableToReadableStream = <T>(
+  asyncIterable: AsyncIterable<T>
+): ReadableStream<T> => {
+  const iterator = asyncIterable[Symbol.asyncIterator]();
+  return new ReadableStream({
+    async pull(controller) {
+      const { done, value } = await iterator.next();
+      if (done) {
+        return controller.close();
+      }
+      controller.enqueue(value);
+    }
+  });
+};
diff --git a/packages/middleware-sdk-transcribe-streaming/.gitignore b/packages/middleware-sdk-transcribe-streaming/.gitignore
new file mode 100644
index 0000000000000..f30a2ca2cef55
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/.gitignore
@@ -0,0 +1,9 @@
+/node_modules/
+/build/
+/dist/
+/coverage/
+/docs/
+*.tsbuildinfo
+*.tgz
+*.log
+package-lock.json
diff --git a/packages/middleware-sdk-transcribe-streaming/.npmignore b/packages/middleware-sdk-transcribe-streaming/.npmignore
new file mode 100644
index 0000000000000..4b9fe3abf33a6
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/.npmignore
@@ -0,0 +1,13 @@
+/src/
+/coverage/
+/docs/
+tsconfig.test.json
+*.tsbuildinfo
+
+*.spec.js
+*.spec.d.ts
+*.spec.js.map
+
+*.fixture.js
+*.fixture.d.ts
+*.fixture.js.map
diff --git a/packages/middleware-sdk-transcribe-streaming/LICENSE b/packages/middleware-sdk-transcribe-streaming/LICENSE
new file mode 100644
index 0000000000000..e907b58668da3
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/LICENSE
@@ -0,0 +1,201 @@
+                                Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+   1. Definitions.
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+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
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+      the terms of any separate license agreement you may have executed
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+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
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+
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+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
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+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
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+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/packages/middleware-sdk-transcribe-streaming/README.md b/packages/middleware-sdk-transcribe-streaming/README.md
new file mode 100644
index 0000000000000..6aa9abcacdc27
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/README.md
@@ -0,0 +1,4 @@
+# @aws-sdk/@aws-sdk/middleware-sdk-transcribe-streaming
+
+[![NPM version](https://img.shields.io/npm/v/@aws-sdk/@aws-sdk/middleware-sdk-transcribe-streaming/beta.svg)](https://www.npmjs.com/package/@aws-sdk/@aws-sdk/middleware-sdk-transcribe-streaming)
+[![NPM downloads](https://img.shields.io/npm/dm/@aws-sdk/@aws-sdk/middleware-sdk-transcribe-streaming.svg)](https://www.npmjs.com/package/@aws-sdk/@aws-sdk/middleware-sdk-transcribe-streaming)
diff --git a/packages/middleware-sdk-transcribe-streaming/jest.config.js b/packages/middleware-sdk-transcribe-streaming/jest.config.js
new file mode 100644
index 0000000000000..e9c9f9642d5f5
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/jest.config.js
@@ -0,0 +1,7 @@
+const base = require("../../jest.config.base.js");
+
+module.exports = {
+  ...base,
+  //only test cjs dist, avoid testing the package twice
+  testPathIgnorePatterns: ["/node_modules/", "/es/"]
+};
diff --git a/packages/middleware-sdk-transcribe-streaming/package.json b/packages/middleware-sdk-transcribe-streaming/package.json
new file mode 100644
index 0000000000000..e31d35991f9cb
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/package.json
@@ -0,0 +1,38 @@
+{
+  "name": "@aws-sdk/middleware-sdk-transcribe-streaming",
+  "version": "1.0.0-gamma.0",
+  "main": "./dist/cjs/index.js",
+  "module": "./dist/es/index.js",
+  "scripts": {
+    "build:cjs": "tsc -p tsconfig.json",
+    "build:es": "tsc -p tsconfig.es.json",
+    "build": "yarn build:es && yarn build:cjs",
+    "prepublishOnly": "yarn build",
+    "pretest": "yarn build",
+    "test": "jest --passWithNoTests"
+  },
+  "types": "./dist/cjs/index.d.ts",
+  "author": {
+    "name": "AWS SDK for JavaScript Team",
+    "url": "https://aws.amazon.com/javascript/"
+  },
+  "license": "Apache-2.0",
+  "dependencies": {
+    "@aws-sdk/eventstream-serde-browser": "1.0.0-gamma.1",
+    "@aws-sdk/middleware-signing": "1.0.0-gamma.1",
+    "@aws-sdk/protocol-http": "1.0.0-gamma.1",
+    "@aws-sdk/signature-v4": "1.0.0-gamma.1",
+    "@aws-sdk/types": "1.0.0-gamma.1",
+    "@aws-sdk/util-format-url": "1.0.0-gamma.1",
+    "react-native-get-random-values": "^1.4.0",
+    "tslib": "^1.8.0",
+    "uuid": "^8.0.0"
+  },
+  "devDependencies": {
+    "@types/jest": "^25.1.4",
+    "jest": "^25.1.0",
+    "jest-websocket-mock": "^2.0.2",
+    "mock-socket": "^9.0.3",
+    "typescript": "~3.8.3"
+  }
+}
diff --git a/packages/middleware-sdk-transcribe-streaming/src/configuration.ts b/packages/middleware-sdk-transcribe-streaming/src/configuration.ts
new file mode 100644
index 0000000000000..ac876c6f35889
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/configuration.ts
@@ -0,0 +1,38 @@
+import { Provider, RequestSigner, RequestHandler } from "@aws-sdk/types";
+import { SignatureV4 as BaseSignatureV4 } from "@aws-sdk/signature-v4";
+import { SignatureV4 } from "./signer";
+
+export interface WebSocketInputConfig {}
+
+interface PreviouslyResolved {
+  signer: Provider<RequestSigner>;
+  requestHandler: RequestHandler<any, any>;
+}
+
+export interface WebSocketResolvedConfig {
+  signer: Provider<RequestSigner>;
+  requestHandler: RequestHandler<any, any>;
+}
+
+export const resolveWebSocketConfig = <T>(
+  input: T & WebSocketInputConfig & PreviouslyResolved
+): T & WebSocketResolvedConfig =>
+  input.requestHandler.metadata?.handlerProtocol !== "websocket"
+    ? input
+    : {
+        ...input,
+        signer: async () => {
+          const signerObj = await input.signer();
+          if (validateSigner(signerObj)) {
+            return new SignatureV4({ signer: signerObj });
+          }
+          throw new Error(
+            "Expected SignatureV4 signer, please check the client constructor."
+          );
+        }
+      };
+
+const validateSigner = (signer: any): signer is BaseSignatureV4 =>
+  // We cannot use instanceof here. Because we might import the wrong SignatureV4
+  // constructor here as multiple version of packages maybe installed here.
+  (signer.constructor.toString() as string).indexOf("SignatureV4") >= 0;
diff --git a/packages/middleware-sdk-transcribe-streaming/src/eventstream-handler.ts b/packages/middleware-sdk-transcribe-streaming/src/eventstream-handler.ts
new file mode 100644
index 0000000000000..fdf60adc5aae2
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/eventstream-handler.ts
@@ -0,0 +1,10 @@
+import {
+  EventStreamPayloadHandler as IEventStreamPayloadHandler,
+  BuildHandler,
+  BuildHandlerArguments
+} from "@aws-sdk/types";
+
+export const eventStreamPayloadHandler: IEventStreamPayloadHandler = {
+  handle: (next: BuildHandler<any, any>, args: BuildHandlerArguments<any>) =>
+    next(args)
+};
diff --git a/packages/middleware-sdk-transcribe-streaming/src/index.native.ts b/packages/middleware-sdk-transcribe-streaming/src/index.native.ts
new file mode 100644
index 0000000000000..ca4a5e1bd1ef3
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/index.native.ts
@@ -0,0 +1,9 @@
+//reference: https://github.com/uuidjs/uuid#getrandomvalues-not-supported
+import "react-native-get-random-values";
+export * from "./websocket-handler";
+export * from "./eventstream-handler";
+export * from "./signer";
+export * from "./configuration";
+export * from "./middleware-endpoint";
+export * from "./middleware-session-id";
+export * from "./plugin";
diff --git a/packages/middleware-sdk-transcribe-streaming/src/index.ts b/packages/middleware-sdk-transcribe-streaming/src/index.ts
new file mode 100644
index 0000000000000..e2b9dcf968a4b
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/index.ts
@@ -0,0 +1,7 @@
+export * from "./websocket-handler";
+export * from "./eventstream-handler";
+export * from "./signer";
+export * from "./configuration";
+export * from "./middleware-endpoint";
+export * from "./middleware-session-id";
+export * from "./plugin";
diff --git a/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.spec.ts b/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.spec.ts
new file mode 100644
index 0000000000000..9fecfdfaee619
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.spec.ts
@@ -0,0 +1,117 @@
+import { RequestHandler, BuildHandlerArguments } from "@aws-sdk/types";
+import { websocketURLMiddleware } from "./middleware-endpoint";
+import { HttpRequest } from "@aws-sdk/protocol-http";
+
+describe("websocketURLMiddleware", () => {
+  const mockHandler: RequestHandler<any, any> = {
+    metadata: { handlerProtocol: "websocket" },
+    handle: () => ({} as any)
+  };
+  it("should skip non-http request", done => {
+    const nonHttpRequest = {
+      foo: "bar"
+    };
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(args.request).toEqual(nonHttpRequest);
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request: nonHttpRequest, input: {} });
+  });
+
+  it("should skip non WebSocket requests", done => {
+    const mockHandler: RequestHandler<any, any> = {
+      metadata: { handlerProtocol: "some_protocol" },
+      handle: () => ({} as any)
+    };
+    const request = new HttpRequest({});
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(args.request).toEqual(request);
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request, input: {} });
+  });
+
+  it("should update endpoint to websocket url", done => {
+    const request = new HttpRequest({
+      protocol: "https:",
+      hostname: "transcribestreaming.us-east-1.amazonaws.com",
+      path: "/stream-transcription",
+      method: "POST"
+    });
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(HttpRequest.isInstance(args.request)).toBeTruthy();
+      const processed = args.request as HttpRequest;
+      expect(processed.protocol).toEqual("wss:");
+      expect(processed.hostname).toEqual(
+        "transcribestreaming.us-east-1.amazonaws.com:8443"
+      );
+      expect(processed.path).toEqual("/stream-transcription-websocket");
+      expect(processed.method).toEqual("GET");
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request, input: {} });
+  });
+
+  it("should remove content-type and sha256 hash header", done => {
+    const request = new HttpRequest({
+      headers: {
+        "content-type": "application/vnd.amazon.eventstream",
+        "Content-Type": "application/vnd.amazon.eventstream",
+        "x-amz-content-sha256": "STREAMING-AWS4-HMAC-SHA256-EVENTS",
+        "X-Amz-Content-Sha256": "STREAMING-AWS4-HMAC-SHA256-EVENTS"
+      }
+    });
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(HttpRequest.isInstance(args.request)).toBeTruthy();
+      const processed = args.request as HttpRequest;
+      expect(processed.headers["content-type"]).toBeUndefined();
+      expect(processed.headers["Content-Type"]).toBeUndefined();
+      expect(processed.headers["x-amz-content-sha256"]).toBeUndefined();
+      expect(processed.headers["X-Amz-Content-Sha256"]).toBeUndefined();
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request, input: {} });
+  });
+
+  it("should contains host header after adjustment", done => {
+    const request = new HttpRequest({});
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(HttpRequest.isInstance(args.request)).toBeTruthy();
+      const processed = args.request as HttpRequest;
+      expect(processed.headers["host"]).toBeDefined();
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request, input: {} });
+  });
+
+  it("should move API parameters from headers to query", done => {
+    const request = new HttpRequest({
+      headers: {
+        "x-amzn-transcribe-language-code": "en-US",
+        "x-amzn-transcribe-media-encoding": "pmc",
+        "x-amzn-transcribe-session-id": "123",
+        "x-amzn-transcribe-vocabulary-name": "abc",
+        "x-amzn-transcribe-sample-rate": "44100"
+      }
+    });
+    const next = (args: BuildHandlerArguments<any>) => {
+      expect(HttpRequest.isInstance(args.request)).toBeTruthy();
+      const processed = args.request as HttpRequest;
+      expect(processed.query).toEqual({
+        "language-code": "en-US",
+        "media-encoding": "pmc",
+        "session-id": "123",
+        "vocabulary-name": "abc",
+        "sample-rate": "44100"
+      });
+      done();
+    };
+    const mw = websocketURLMiddleware({ requestHandler: mockHandler });
+    mw(next as any, {} as any)({ request, input: {} });
+  });
+});
diff --git a/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.ts b/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.ts
new file mode 100644
index 0000000000000..21ecd40c2336c
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/middleware-endpoint.ts
@@ -0,0 +1,69 @@
+import {
+  BuildMiddleware,
+  BuildHandler,
+  BuildHandlerArguments,
+  RequestHandler,
+  BuildHandlerOptions,
+  RelativeLocation
+} from "@aws-sdk/types";
+import { HttpRequest } from "@aws-sdk/protocol-http";
+
+/**
+ * Middleware that generates WebSocket URL to TranscribeStreaming service
+ * Reference: https://docs.aws.amazon.com/transcribe/latest/dg/websocket.html
+ */
+export const websocketURLMiddleware = (options: {
+  requestHandler: RequestHandler<any, any>;
+}): BuildMiddleware<any, any> => (next: BuildHandler<any, any>) => (
+  args: BuildHandlerArguments<any>
+) => {
+  const { request } = args;
+  if (
+    HttpRequest.isInstance(request) &&
+    options.requestHandler.metadata?.handlerProtocol === "websocket"
+  ) {
+    // Update http/2 endpoint to WebSocket-specific endpoint.
+    request.protocol = "wss:";
+    // Append port to hostname because it needs to be signed together
+    request.hostname = `${request.hostname}:8443`;
+    request.path = `${request.path}-websocket`;
+    request.method = "GET";
+
+    // Move headers to query string. Because the signature is generated with
+    // headers moved to query, the endpoint url needs to tally with the signature.
+    const { headers } = request;
+
+    // 'Content-Type' and 'x-amz-content-sha256' headers are normally set for
+    // event stream, but WebSocket doesn't require it.
+    // See: 'eventStreamHeaderMiddleware' in @aws-sdk/middleware-eventstream
+    delete headers["Content-Type"];
+    delete headers["x-amz-content-sha256"];
+
+    // Serialized header like 'x-amzn-transcribe-sample-rate' should be 'sample-rate'
+    // in WebSocket URL.
+    for (const name of Object.keys(headers)) {
+      if (name.indexOf("x-amzn-transcribe-") === 0) {
+        const chunkedName = name.replace("x-amzn-transcribe-", "");
+        request.query[chunkedName] = headers[name];
+      }
+    }
+
+    // The service perfers Node.js style 'user-agent' over browser-style
+    // 'x-amz-user-agent'
+    if (headers["x-amz-user-agent"]) {
+      request.query["user-agent"] = headers["x-amz-user-agent"];
+    }
+    // Host header is required for signing
+    request.headers = { host: request.hostname };
+  }
+  return next(args);
+};
+
+export const websocketURLMiddlewareOptions: BuildHandlerOptions &
+  RelativeLocation<any, any> = {
+  step: "build",
+  name: "websocketURLMiddleware",
+  tags: ["WEBSOCKET", "EVENT_STREAM"],
+  relation: "after",
+  toMiddleware: "eventStreamHeaderMiddleware"
+};
diff --git a/packages/middleware-sdk-transcribe-streaming/src/middleware-session-id.ts b/packages/middleware-sdk-transcribe-streaming/src/middleware-session-id.ts
new file mode 100644
index 0000000000000..2016836170c45
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/middleware-session-id.ts
@@ -0,0 +1,50 @@
+import {
+  InitializeMiddleware,
+  InitializeHandler,
+  InitializeHandlerArguments,
+  InitializeHandlerOptions,
+  RequestHandler
+} from "@aws-sdk/types";
+import { v4 } from "uuid";
+
+type WithSession = {
+  SessionId?: string;
+  [key: string]: any;
+};
+
+/**
+ * Middleware that inject default sessionId for operations, and inject
+ * the parameters from request to the response metadata. This is
+ * necessary because the SDK cannot access any parameters other than
+ * the result stream. So it copies the parameters from input to the same
+ * parameters in the output.
+ */
+export const injectSessionIdMiddleware = (config: {
+  requestHandler: RequestHandler<any, any>;
+}): InitializeMiddleware<any, any> => (
+  next: InitializeHandler<WithSession, WithSession>
+) => async (args: InitializeHandlerArguments<WithSession>) => {
+  if (args.input.SessionId === undefined && isWebSocket(config)) {
+    args.input.SessionId = v4();
+  }
+  const requestParams = {
+    ...args.input
+  };
+  const response = await next(args);
+  const output = response.output;
+  for (const key of Object.keys(output)) {
+    if (output[key] === undefined && requestParams[key]) {
+      output[key] = requestParams[key];
+    }
+  }
+  return response;
+};
+
+const isWebSocket = (config: { requestHandler: RequestHandler<any, any> }) =>
+  config.requestHandler.metadata?.handlerProtocol === "websocket";
+
+export const injectSessionIdMiddlewareOptions: InitializeHandlerOptions = {
+  step: "initialize",
+  name: "injectSessionIdMiddleware",
+  tags: ["WEBSOCKET", "EVENT_STREAM"]
+};
diff --git a/packages/middleware-sdk-transcribe-streaming/src/plugin.ts b/packages/middleware-sdk-transcribe-streaming/src/plugin.ts
new file mode 100644
index 0000000000000..d6585a095ad7c
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/plugin.ts
@@ -0,0 +1,25 @@
+import { Pluggable } from "@aws-sdk/types";
+import {
+  websocketURLMiddleware,
+  websocketURLMiddlewareOptions
+} from "./middleware-endpoint";
+import {
+  injectSessionIdMiddleware,
+  injectSessionIdMiddlewareOptions
+} from "./middleware-session-id";
+import { WebSocketResolvedConfig } from "./configuration";
+
+export const getWebSocketPlugin = (
+  config: WebSocketResolvedConfig
+): Pluggable<any, any> => ({
+  applyToStack: clientStack => {
+    clientStack.addRelativeTo(
+      websocketURLMiddleware(config),
+      websocketURLMiddlewareOptions
+    );
+    clientStack.add(
+      injectSessionIdMiddleware(config),
+      injectSessionIdMiddlewareOptions
+    );
+  }
+});
diff --git a/packages/middleware-sdk-transcribe-streaming/src/signer.ts b/packages/middleware-sdk-transcribe-streaming/src/signer.ts
new file mode 100644
index 0000000000000..ea9849d15a4bd
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/signer.ts
@@ -0,0 +1,42 @@
+import {
+  RequestSigner,
+  HttpRequest as IHttpRequest,
+  RequestSigningArguments,
+  RequestPresigner,
+  RequestPresigningArguments
+} from "@aws-sdk/types";
+import { SignatureV4 as BaseSignatureV4 } from "@aws-sdk/signature-v4";
+import { HttpRequest } from "@aws-sdk/protocol-http";
+
+export class SignatureV4 implements RequestSigner, RequestPresigner {
+  private readonly signer: BaseSignatureV4;
+  constructor(options: { signer: BaseSignatureV4 }) {
+    this.signer = options.signer;
+  }
+
+  public presign(
+    originalRequest: IHttpRequest,
+    options: RequestPresigningArguments = {}
+  ): Promise<IHttpRequest> {
+    return this.signer.presign(originalRequest, options);
+  }
+
+  public async sign(
+    toSign: IHttpRequest,
+    options?: RequestSigningArguments
+  ): Promise<IHttpRequest> {
+    if (HttpRequest.isInstance(toSign)) {
+      // Presign the endpoint url with empty body, otherwise
+      // the payload hash would be UNSINGED_PAYLOAD
+      const signedRequest = await this.signer.presign({ ...toSign, body: "" }, {
+        expiresIn: 5 * 60 // presigned url must be expired within 5 mins
+      } as any);
+      return {
+        ...signedRequest,
+        body: toSign.body
+      };
+    } else {
+      return this.signer.sign(toSign, options);
+    }
+  }
+}
diff --git a/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.spec.ts b/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.spec.ts
new file mode 100644
index 0000000000000..f0216531e7898
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.spec.ts
@@ -0,0 +1,76 @@
+import { WebSocketHandler } from "./websocket-handler";
+import { HttpRequest } from "@aws-sdk/protocol-http";
+import { PassThrough } from "stream";
+import WS from "jest-websocket-mock";
+import { WebSocket } from "mock-socket";
+
+describe("WebSocketHandler", () => {
+  beforeEach(() => {
+    (global as any).WebSocket = WebSocket;
+  });
+  afterEach(() => {
+    WS.clean();
+    jest.clearAllMocks();
+  });
+  it("should contain protocol metadata", () => {
+    const handler = new WebSocketHandler();
+    expect(handler.metadata.handlerProtocol).toEqual("websocket");
+  });
+
+  it("should throw in output stream if input stream throws", async () => {
+    expect.assertions(2);
+    const handler = new WebSocketHandler();
+    //Using Node stream is fine because they are also async iterables.
+    const payload = new PassThrough();
+    const server = new WS("ws://localhost:6789");
+    const {
+      response: { body: responsePayload }
+    } = await handler.handle(
+      new HttpRequest({
+        body: payload,
+        hostname: "localhost:6789",
+        protocol: "ws:"
+      })
+    );
+    await server.connected;
+    payload.emit("error", new Error("FakeError"));
+    try {
+      for await (const chunk of responsePayload) {
+        /** pass */
+      }
+    } catch (err) {
+      expect(err).toBeDefined();
+      expect(err.message).toEqual("FakeError");
+    }
+  });
+
+  it("should return retryable error if cannot setup ws connection", async () => {
+    expect.assertions(4);
+    const originalFn = setTimeout;
+    (global as any).setTimeout = jest.fn().mockImplementation(setTimeout);
+    const connectionTimeout = 1000;
+    const handler = new WebSocketHandler({ connectionTimeout });
+    //Using Node stream is fine because they are also async iterables.
+    const payload = new PassThrough();
+    try {
+      await handler.handle(
+        new HttpRequest({
+          body: payload,
+          hostname: "localhost:9876", //invalid websocket endpoint
+          protocol: "ws:"
+        })
+      );
+    } catch (err) {
+      expect(err).toBeDefined();
+      expect(err.$metadata).toBeDefined();
+      expect(err.$metadata.httpStatusCode >= 500).toBe(true);
+      expect(
+        (global.setTimeout as jest.Mock).mock.calls.filter(args => {
+          //find the 'setTimeout' call from the websocket handler
+          return args[0].toString().indexOf("$metadata") >= 0;
+        })[0][1]
+      ).toBe(connectionTimeout);
+    }
+    (global as any).setTimeout = originalFn;
+  });
+});
diff --git a/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.ts b/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.ts
new file mode 100644
index 0000000000000..6fe86c387fd25
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/src/websocket-handler.ts
@@ -0,0 +1,159 @@
+import { HttpHandlerOptions, RequestHandlerMetadata } from "@aws-sdk/types";
+import { HttpHandler, HttpRequest, HttpResponse } from "@aws-sdk/protocol-http";
+import { formatUrl } from "@aws-sdk/util-format-url";
+import {
+  iterableToReadableStream,
+  readableStreamtoIterable
+} from "@aws-sdk/eventstream-serde-browser";
+
+export interface WebSocketHandlerOptions {
+  /**
+   * The maximum time in milliseconds that the connection phase of a request
+   * may take before the connection attempt is abandoned.
+   */
+  connectionTimeout?: number;
+}
+
+/**
+ * Base handler for websocket requests. By default, the request input and output
+ * body will be in a ReadableStream, because of interface consistency among middleware.
+ * If ReadableStream is not available, like in React-Native, the response body
+ * will be an async iterable.
+ */
+export class WebSocketHandler implements HttpHandler {
+  public readonly metadata: RequestHandlerMetadata = {
+    handlerProtocol: "websocket"
+  };
+  private readonly connectionTimeout: number;
+  constructor({ connectionTimeout }: WebSocketHandlerOptions = {}) {
+    this.connectionTimeout = connectionTimeout || 2000;
+  }
+
+  destroy(): void {}
+
+  async handle(
+    request: HttpRequest,
+    options: HttpHandlerOptions = {}
+  ): Promise<{ response: HttpResponse }> {
+    const url = formatUrl(request);
+    const socket: WebSocket = new WebSocket(url);
+    socket.binaryType = "arraybuffer";
+    await waitForReady(socket, this.connectionTimeout);
+    const { body } = request;
+    const bodyStream = getIterator(body);
+    const asyncIterable = connect(socket, bodyStream);
+    const outputPayload = toReadableStream(asyncIterable);
+    return {
+      response: new HttpResponse({
+        statusCode: 200, // indicates connection success
+        body: outputPayload
+      })
+    };
+  }
+}
+
+const waitForReady = (socket: WebSocket, connectionTimeout: number) =>
+  new Promise((resolve, reject) => {
+    const timeout = setTimeout(() => {
+      reject({
+        $metadata: {
+          httpStatusCode: 500
+        }
+      });
+    }, connectionTimeout);
+    socket.onopen = () => {
+      clearTimeout(timeout);
+      resolve();
+    };
+  });
+
+const connect = (
+  socket: WebSocket,
+  data: AsyncIterable<Uint8Array>
+): AsyncIterable<Uint8Array> => {
+  // To notify output stream any error thrown after response
+  // is returned while data keeps streaming.
+  let streamError: Error | undefined = undefined;
+  const outputStream: AsyncIterable<Uint8Array> = {
+    [Symbol.asyncIterator]: () => ({
+      next: () => {
+        return new Promise((resolve, reject) => {
+          socket.onerror = error => {
+            socket.onclose = null;
+            socket.close();
+            reject(error);
+          };
+          socket.onclose = () => {
+            if (streamError) {
+              reject(streamError);
+            } else {
+              resolve({
+                done: true,
+                value: undefined
+              });
+            }
+          };
+          socket.onmessage = event => {
+            resolve({
+              done: false,
+              value: new Uint8Array(event.data)
+            });
+          };
+        });
+      }
+    })
+  };
+
+  const send = async (): Promise<void> => {
+    try {
+      for await (const inputChunk of data) {
+        socket.send(inputChunk);
+      }
+    } catch (err) {
+      // We don't throw the error here because the send()'s returned
+      // would already be settled by the time sending chunk throws error.
+      // Instead, the notify the output stream to throw if there's
+      // exceptions
+      streamError = err;
+    } finally {
+      // WS status code: https://tools.ietf.org/html/rfc6455#section-7.4
+      socket.close(1000);
+    }
+  };
+  send();
+  return outputStream;
+};
+
+/**
+ * Transfer payload data to an AsyncIterable.
+ * When the ReadableStream API is available in the runtime(e.g. browser), and
+ * the request body is ReadableStream, so we need to transfer it to AsyncIterable
+ * to make the stream consumable by WebSocket.
+ */
+const getIterator = (stream: any): AsyncIterable<any> => {
+  // Noop if stream is already an async iterable
+  if (stream[Symbol.asyncIterator]) return stream;
+  else if (isReadableStream(stream)) {
+    //If stream is a ReadableStream, transfer the ReadableStream to async iterable.
+    return readableStreamtoIterable(stream);
+  } else {
+    //For other types, just wrap them with an async iterable.
+    return {
+      [Symbol.asyncIterator]: async function* () {
+        yield stream;
+      }
+    };
+  }
+};
+
+/**
+ * Convert async iterable to a ReadableStream when ReadableStream API
+ * is available(browsers). Otherwise, leave as it is(ReactNative).
+ */
+const toReadableStream = <T>(asyncIterable: AsyncIterable<T>) =>
+  typeof ReadableStream === "function"
+    ? iterableToReadableStream(asyncIterable)
+    : asyncIterable;
+
+const isReadableStream = (payload: any): payload is ReadableStream =>
+  typeof ReadableStream === "function" && payload instanceof ReadableStream;
diff --git a/packages/middleware-sdk-transcribe-streaming/tsconfig.es.json b/packages/middleware-sdk-transcribe-streaming/tsconfig.es.json
new file mode 100644
index 0000000000000..8bacf65d673d4
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/tsconfig.es.json
@@ -0,0 +1,18 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "target": "ES2015",
+    "module": "esNext",
+    "moduleResolution": "node",
+    "lib": ["es5", "es2015.promise", "es2015.collection", "DOM"],
+    "declaration": true,
+    "sourceMap": true,
+    "strict": true,
+    "stripInternal": true,
+    "rootDir": "./src",
+    "outDir": "./dist/es",
+    "importHelpers": true,
+    "noEmitHelpers": true,
+    "incremental": true
+  }
+}
diff --git a/packages/middleware-sdk-transcribe-streaming/tsconfig.json b/packages/middleware-sdk-transcribe-streaming/tsconfig.json
new file mode 100644
index 0000000000000..551f36accf08b
--- /dev/null
+++ b/packages/middleware-sdk-transcribe-streaming/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "es2017",
+    "module": "commonjs",
+    "declaration": true,
+    "lib": ["DOM"],
+    "sourceMap": true,
+    "strict": true,
+    "stripInternal": true,
+    "rootDir": "./src",
+    "outDir": "./dist/cjs",
+    "importHelpers": true,
+    "noEmitHelpers": true,
+    "incremental": true
+  }
+}
diff --git a/scripts/generate-clients/code-gen.js b/scripts/generate-clients/code-gen.js
index 649e47b1d84bf..e3b9092b9434e 100644
--- a/scripts/generate-clients/code-gen.js
+++ b/scripts/generate-clients/code-gen.js
@@ -41,9 +41,7 @@ const generateClients = async models => {
         if (!lstatSync(file).isFile()) return;
         const name = path.basename(file);
         console.log(`copying model ${name}...`);
-        copyFileSync(file, path.join(TEMP_CODE_GEN_INPUT_DIR, name), {
-          overwrite: true
-        });
+        copyFileSync(file, path.join(TEMP_CODE_GEN_INPUT_DIR, name));
       });
     });
   } else {