diff --git a/build/repo.targets b/build/repo.targets
index 51077aa751..150d34afcc 100644
--- a/build/repo.targets
+++ b/build/repo.targets
@@ -6,6 +6,6 @@
 
   <Target Name="RunTSClientNodeTests" AfterTargets="Test">
     <Message Text="Running TypeScript client Node tests" Importance="high" />
-    <Exec Command="npm test" WorkingDirectory="$(RepositoryRoot)client-ts" />
+    <Exec Command="npm test" WorkingDirectory="$(RepositoryRoot)client-ts" IgnoreStandardErrorWarningFormat="true" />
   </Target>
 </Project>
diff --git a/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Common.ts b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Common.ts
new file mode 100644
index 0000000000..e40b74eda6
--- /dev/null
+++ b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Common.ts
@@ -0,0 +1,9 @@
+import { ITransport, TransportType } from "../Microsoft.AspNetCore.SignalR.Client.TS/Transports"
+
+export function eachTransport(action: (transport: TransportType) => void) {
+    let transportTypes = [
+        TransportType.WebSockets,
+        TransportType.ServerSentEvents,
+        TransportType.LongPolling ];
+    transportTypes.forEach(t => action(t));
+};
\ No newline at end of file
diff --git a/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Connection.spec.ts b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Connection.spec.ts
index e8348aa0cb..c2c26d7292 100644
--- a/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Connection.spec.ts
+++ b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS.Tests/Connection.spec.ts
@@ -2,7 +2,8 @@ import { IHttpClient } from "../Microsoft.AspNetCore.SignalR.Client.TS/HttpClien
 import { Connection } from "../Microsoft.AspNetCore.SignalR.Client.TS/Connection"
 import { ISignalROptions } from "../Microsoft.AspNetCore.SignalR.Client.TS/ISignalROptions"
 import { DataReceived, TransportClosed } from "../Microsoft.AspNetCore.SignalR.Client.TS/Common"
-import { ITransport } from "../Microsoft.AspNetCore.SignalR.Client.TS/Transports"
+import { ITransport, TransportType } from "../Microsoft.AspNetCore.SignalR.Client.TS/Transports"
+import { eachTransport } from "./Common";
 
 describe("Connection", () => {
 
@@ -102,7 +103,7 @@ describe("Connection", () => {
             httpClient: <IHttpClient>{
                 options(url: string): Promise<string> {
                     connection.stop();
-                    return Promise.resolve("");
+                    return Promise.resolve("{}");
                 },
                 get(url: string): Promise<string> {
                     connection.stop();
@@ -133,7 +134,7 @@ describe("Connection", () => {
         let options: ISignalROptions = {
             httpClient: <IHttpClient>{
                 options(url: string): Promise<string> {
-                    return Promise.resolve("42");
+                    return Promise.resolve("{ \"connectionId\": \"42\" }");
                 },
                 get(url: string): Promise<string> {
                     return Promise.resolve("");
@@ -168,4 +169,54 @@ describe("Connection", () => {
         expect(connectUrl).toBe("http://tempuri.org?q=myData&id=42");
         done();
     });
+
+    eachTransport((requestedTransport: TransportType) => {
+        it(`Connection cannot be started if requested ${TransportType[requestedTransport]} transport not available on server`, async done => {
+            let options: ISignalROptions = {
+                httpClient: <IHttpClient>{
+                    options(url: string): Promise<string> {
+                        return Promise.resolve("{ \"connectionId\": \"42\", \"availableTransports\": [] }");
+                    },
+                    get(url: string): Promise<string> {
+                        return Promise.resolve("");
+                    }
+                }
+            } as ISignalROptions;
+
+            var connection = new Connection("http://tempuri.org", options);
+            try {
+                await connection.start(requestedTransport);
+                fail();
+                done();
+            }
+            catch (e) {
+                expect(e.message).toBe("No available transports found.");
+                done();
+            }
+        });
+    });
+
+    it(`Connection cannot be started if no transport available on server and no transport requested`, async done => {
+        let options: ISignalROptions = {
+            httpClient: <IHttpClient>{
+                options(url: string): Promise<string> {
+                    return Promise.resolve("{ \"connectionId\": \"42\", \"availableTransports\": [] }");
+                },
+                get(url: string): Promise<string> {
+                    return Promise.resolve("");
+                }
+            }
+        } as ISignalROptions;
+
+        var connection = new Connection("http://tempuri.org", options);
+        try {
+            await connection.start();
+            fail();
+            done();
+        }
+        catch (e) {
+            expect(e.message).toBe("No available transports found.");
+            done();
+        }
+    });
 });
diff --git a/client-ts/Microsoft.AspNetCore.SignalR.Client.TS/Connection.ts b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS/Connection.ts
index e4d228131a..b502aca087 100644
--- a/client-ts/Microsoft.AspNetCore.SignalR.Client.TS/Connection.ts
+++ b/client-ts/Microsoft.AspNetCore.SignalR.Client.TS/Connection.ts
@@ -11,6 +11,11 @@ enum ConnectionState {
     Disconnected
 }
 
+interface INegotiateResponse {
+    connectionId: string
+    availableTransports: string[]
+}
+
 export class Connection implements IConnection {
     private connectionState: ConnectionState;
     private url: string;
@@ -25,7 +30,7 @@ export class Connection implements IConnection {
         this.connectionState = ConnectionState.Initial;
     }
 
-    async start(transport: TransportType | ITransport = TransportType.WebSockets): Promise<void> {
+    async start(transport?: TransportType | ITransport): Promise<void> {
         if (this.connectionState != ConnectionState.Initial) {
             return Promise.reject(new Error("Cannot start a connection that is not in the 'Initial' state."));
         }
@@ -38,7 +43,9 @@ export class Connection implements IConnection {
 
     private async startInternal(transportType: TransportType | ITransport): Promise<void> {
         try {
-            this.connectionId = await this.httpClient.options(this.url);
+            let negotiatePayload = await this.httpClient.options(this.url);  
+            let negotiateResponse: INegotiateResponse = JSON.parse(negotiatePayload);
+            this.connectionId = negotiateResponse.connectionId;
 
             // the user tries to stop the the connection when it is being started
             if (this.connectionState == ConnectionState.Disconnected) {
@@ -47,7 +54,7 @@ export class Connection implements IConnection {
 
             this.url += (this.url.indexOf("?") == -1 ? "?" : "&") + `id=${this.connectionId}`;
 
-            this.transport = this.createTransport(transportType);
+            this.transport = this.createTransport(transportType, negotiateResponse.availableTransports);
             this.transport.onDataReceived = this.onDataReceived;
             this.transport.onClosed = e => this.stopConnection(true, e);
             await this.transport.connect(this.url);
@@ -56,21 +63,24 @@ export class Connection implements IConnection {
             this.changeState(ConnectionState.Connecting, ConnectionState.Connected);
         }
         catch (e) {
-            console.log("Failed to start the connection. " + e)
+            console.log("Failed to start the connection. " + e);
             this.connectionState = ConnectionState.Disconnected;
             this.transport = null;
             throw e;
         };
     }
 
-    private createTransport(transport: TransportType | ITransport): ITransport {
-        if (transport === TransportType.WebSockets) {
+    private createTransport(transport: TransportType | ITransport, availableTransports: string[]): ITransport {
+        if (!transport && availableTransports.length > 0) {
+            transport = TransportType[availableTransports[0]];
+        }
+        if (transport === TransportType.WebSockets && availableTransports.indexOf(TransportType[transport]) >= 0) {
             return new WebSocketTransport();
         }
-        if (transport === TransportType.ServerSentEvents) {
+        if (transport === TransportType.ServerSentEvents && availableTransports.indexOf(TransportType[transport]) >= 0) {
             return new ServerSentEventsTransport(this.httpClient);
         }
-        if (transport === TransportType.LongPolling) {
+        if (transport === TransportType.LongPolling && availableTransports.indexOf(TransportType[transport]) >= 0) {
             return new LongPollingTransport(this.httpClient);
         }
 
@@ -78,11 +88,11 @@ export class Connection implements IConnection {
             return transport;
         }
 
-        throw new Error("No valid transports requested.");
+        throw new Error("No available transports found.");
     }
 
     private isITransport(transport: any): transport is ITransport {
-        return "connect" in transport;
+        return typeof(transport) === "object" && "connect" in transport;
     }
 
     private changeState(from: ConnectionState, to: ConnectionState): Boolean {
diff --git a/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/connectionTests.js b/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/connectionTests.js
index 88d0f419bf..13a1a21011 100644
--- a/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/connectionTests.js
+++ b/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/connectionTests.js
@@ -1,4 +1,31 @@
 describe('connection', () => {
+    it(`can connect to the server without specifying transport explicitly`, done => {
+        const message = "Hello World!";
+        let connection = new signalR.Connection(ECHOENDPOINT_URL);
+
+        let received = "";
+        connection.onDataReceived = data => {
+            received += data;
+            if (data == message) {
+                connection.stop();
+            }
+        }
+
+        connection.onClosed = error => {
+            expect(error).toBeUndefined();
+            done();
+        }
+
+        connection.start()
+            .then(() => {
+                connection.send(message);
+            })
+            .catch(e => {
+                fail();
+                done();
+            });
+    });
+
     eachTransport(transportType => {
         it(`over ${signalR.TransportType[transportType]} can send and receive messages`, done => {
             const message = "Hello World!";
diff --git a/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/hubConnectionTests.js b/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/hubConnectionTests.js
index eea1907676..6e8df4cbf2 100644
--- a/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/hubConnectionTests.js
+++ b/client-ts/Microsoft.AspNetCore.SignalR.Test.Server/wwwroot/js/hubConnectionTests.js
@@ -47,11 +47,11 @@ describe('hubConnection', () => {
                                 },
                                 error: (err) => {
                                     fail(err);
-                                    done();
+                                    hubConnection.stop();
                                 },
                                 complete: () => {
                                     expect(received).toEqual(["a", "b", "c"]);
-                                    done();
+                                    hubConnection.stop();
                                 }
                             });
                     })
diff --git a/specs/TransportProtocols.md b/specs/TransportProtocols.md
index fdebf8f54d..12bb934513 100644
--- a/specs/TransportProtocols.md
+++ b/specs/TransportProtocols.md
@@ -16,6 +16,17 @@ Throughout this document, the term `[endpoint-base]` is used to refer to the rou
 
 **NOTE on errors:** In all error cases, by default, the detailed exception message is **never** provided; a short description string may be provided. However, an application developer may elect to allow detailed exception messages to be emitted, which should only be used in the `Development` environment. Unexpected errors are communicated by HTTP `500 Server Error` status codes or WebSockets `1008 Policy Violation` close frames; in these cases the connection should be considered to be terminated.
 
+## `OPTIONS [endpoint-base]` request
+
+The `OPTIONS [endpoint-base]` request is used to establish connection between the client and the server. The response to the `OPTIONS [endpoint-base]` request contains the `connectionId` which will be used to identify the connection on the server and the list of the transports supported by the server. The content type of the response is `application/json`. The following is a sample response to the `OPTIONS [endpoint-base]` request 
+
+```
+{
+  "connectionId":"807809a5-31bf-470d-9e23-afaee35d8a0d",
+  "availableTransports":["WebSockets","ServerSentEvents","LongPolling"]
+}
+```
+
 ## WebSockets (Full Duplex)
 
 The WebSockets transport is unique in that it is full duplex, and a persistent connection that can be established in a single operation. As a result, the client is not required to use the `OPTIONS [endpoint-base]` request to establish a connection in advance. It also includes all the necessary metadata in it's own frame metadata.
diff --git a/src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs b/src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs
index 3aeb9f1313..cf46cc503d 100644
--- a/src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs
+++ b/src/Microsoft.AspNetCore.SignalR/HubEndPoint.cs
@@ -4,9 +4,6 @@
 using System;
 using System.Buffers;
 using System.Collections.Generic;
-using System.IO;
-using System.IO.Pipelines;
-using System.IO.Pipelines.Text.Primitives;
 using System.Linq;
 using System.Reflection;
 using System.Text;
diff --git a/src/Microsoft.AspNetCore.Sockets.Client/Connection.cs b/src/Microsoft.AspNetCore.Sockets.Client/Connection.cs
index 52e2aea69b..7fb903393b 100644
--- a/src/Microsoft.AspNetCore.Sockets.Client/Connection.cs
+++ b/src/Microsoft.AspNetCore.Sockets.Client/Connection.cs
@@ -2,6 +2,7 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+using System.IO;
 using System.Net.Http;
 using System.Threading;
 using System.Threading.Tasks;
@@ -10,6 +11,7 @@ using Microsoft.AspNetCore.Sockets.Client.Internal;
 using Microsoft.AspNetCore.Sockets.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
+using Newtonsoft.Json;
 
 namespace Microsoft.AspNetCore.Sockets.Client
 {
@@ -103,7 +105,7 @@ namespace Microsoft.AspNetCore.Sockets.Client
 
             try
             {
-                var connectUrl = await GetConnectUrl(Url, httpClient, _logger);
+                var negotiationResponse = await Negotiate(Url, httpClient, _logger);
 
                 // Connection is being stopped while start was in progress
                 if (_connectionState == ConnectionState.Disconnected)
@@ -112,9 +114,9 @@ namespace Microsoft.AspNetCore.Sockets.Client
                     return;
                 }
 
-                // TODO: Available server transports should be sent by the server in the negotiation response
-                _transport = transportFactory.CreateTransport(TransportType.All);
+                _transport = transportFactory.CreateTransport(GetAvailableServerTransports(negotiationResponse));
 
+                var connectUrl = CreateConnectUrl(Url, negotiationResponse);
                 _logger.LogDebug("Starting transport '{0}' with Url: {1}", _transport.GetType().Name, connectUrl);
                 await StartTransport(connectUrl);
             }
@@ -179,32 +181,75 @@ namespace Microsoft.AspNetCore.Sockets.Client
             }
         }
 
-        private static async Task<Uri> GetConnectUrl(Uri url, HttpClient httpClient, ILogger logger)
-        {
-            var connectionId = await GetConnectionId(url, httpClient, logger);
-            return Utils.AppendQueryString(url, "id=" + connectionId);
-        }
-
-        private static async Task<string> GetConnectionId(Uri url, HttpClient httpClient, ILogger logger)
+        private async static Task<NegotiationResponse> Negotiate(Uri url, HttpClient httpClient, ILogger logger)
         {
             try
             {
                 // Get a connection ID from the server
                 logger.LogDebug("Establishing Connection at: {0}", url);
-                var request = new HttpRequestMessage(HttpMethod.Options, url);
-                var response = await httpClient.SendAsync(request);
-                response.EnsureSuccessStatusCode();
-                var connectionId = await response.Content.ReadAsStringAsync();
-                logger.LogDebug("Connection Id: {0}", connectionId);
-                return connectionId;
+                using (var request = new HttpRequestMessage(HttpMethod.Options, url))
+                using (var response = await httpClient.SendAsync(request))
+                {
+                    response.EnsureSuccessStatusCode();
+                    return await ParseNegotiateResponse(response, logger);
+                }
             }
             catch (Exception ex)
             {
-                logger.LogError("Failed to start connection. Error getting connection id from '{0}': {1}", url, ex);
+                logger.LogError("Failed to start connection. Error getting negotiation response from '{0}': {1}", url, ex);
                 throw;
             }
         }
 
+        private static async Task<NegotiationResponse> ParseNegotiateResponse(HttpResponseMessage response, ILogger logger)
+        {
+            NegotiationResponse negotiationResponse;
+            using (var reader = new JsonTextReader(new StreamReader(await response.Content.ReadAsStreamAsync())))
+            {
+                try
+                {
+                    negotiationResponse = new JsonSerializer().Deserialize<NegotiationResponse>(reader);
+                }
+                catch (Exception ex)
+                {
+                    throw new FormatException("Invalid negotiation response received.", ex);
+                }
+            }
+
+            if (negotiationResponse == null)
+            {
+                throw new FormatException("Invalid negotiation response received.");
+            }
+
+            return negotiationResponse;
+        }
+
+        private TransportType GetAvailableServerTransports(NegotiationResponse negotiationResponse)
+        {
+            if (negotiationResponse.AvailableTransports == null)
+            {
+                throw new FormatException("No transports returned in negotiation response.");
+            }
+
+            var availableServerTransports = (TransportType)0;
+            foreach (var t in negotiationResponse.AvailableTransports)
+            {
+                availableServerTransports |= t;
+            }
+
+            return availableServerTransports;
+        }
+
+        private static Uri CreateConnectUrl(Uri url, NegotiationResponse negotiationResponse)
+        {
+            if (string.IsNullOrWhiteSpace(negotiationResponse.ConnectionId))
+            {
+                throw new FormatException("Invalid connection id returned in negotiation response.");
+            }
+
+            return Utils.AppendQueryString(url, "id=" + negotiationResponse.ConnectionId);
+        }
+
         private async Task StartTransport(Uri connectUrl)
         {
             var applicationToTransport = Channel.CreateUnbounded<SendMessage>();
@@ -352,5 +397,11 @@ namespace Microsoft.AspNetCore.Sockets.Client
             public const int Connected = 2;
             public const int Disconnected = 3;
         }
+
+        private class NegotiationResponse
+        {
+            public string ConnectionId { get; set; }
+            public TransportType[] AvailableTransports { get; set; }
+        }
     }
 }
diff --git a/src/Microsoft.AspNetCore.Sockets.Client/Microsoft.AspNetCore.Sockets.Client.csproj b/src/Microsoft.AspNetCore.Sockets.Client/Microsoft.AspNetCore.Sockets.Client.csproj
index f0812bd108..b58e94a281 100644
--- a/src/Microsoft.AspNetCore.Sockets.Client/Microsoft.AspNetCore.Sockets.Client.csproj
+++ b/src/Microsoft.AspNetCore.Sockets.Client/Microsoft.AspNetCore.Sockets.Client.csproj
@@ -22,6 +22,7 @@
     <PackageReference Include="System.IO.Pipelines" Version="$(CoreFxLabsVersion)" />
     <PackageReference Include="System.IO.Pipelines.Text.Primitives" Version="$(CoreFxLabsVersion)" />
     <PackageReference Include="System.Threading.Tasks.Channels" Version="$(CoreFxLabsVersion)" />
+    <PackageReference Include="Newtonsoft.Json" Version="$(JsonNetVersion)" />
   </ItemGroup>
 
 </Project>
diff --git a/src/Microsoft.AspNetCore.Sockets.Http/HttpConnectionDispatcher.cs b/src/Microsoft.AspNetCore.Sockets.Http/HttpConnectionDispatcher.cs
index 01a8b166f0..a1e3381371 100644
--- a/src/Microsoft.AspNetCore.Sockets.Http/HttpConnectionDispatcher.cs
+++ b/src/Microsoft.AspNetCore.Sockets.Http/HttpConnectionDispatcher.cs
@@ -12,6 +12,7 @@ using Microsoft.AspNetCore.Sockets.Internal;
 using Microsoft.AspNetCore.Sockets.Transports;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
+using Newtonsoft.Json;
 
 namespace Microsoft.AspNetCore.Sockets
 {
@@ -314,17 +315,46 @@ namespace Microsoft.AspNetCore.Sockets
             // Set the allowed headers for this resource
             context.Response.Headers.AppendCommaSeparatedValues("Allow", "GET", "POST", "OPTIONS");
 
-            context.Response.ContentType = "text/plain";
+            context.Response.ContentType = "application/json";
 
             // Establish the connection
             var connection = _manager.CreateConnection();
 
             // Get the bytes for the connection id
-            var connectionIdBuffer = Encoding.UTF8.GetBytes(connection.ConnectionId);
+            var negotiateResponseBuffer = Encoding.UTF8.GetBytes(GetNegotiatePayload(connection.ConnectionId, options));
 
             // Write it out to the response with the right content length
-            context.Response.ContentLength = connectionIdBuffer.Length;
-            return context.Response.Body.WriteAsync(connectionIdBuffer, 0, connectionIdBuffer.Length);
+            context.Response.ContentLength = negotiateResponseBuffer.Length;
+            return context.Response.Body.WriteAsync(negotiateResponseBuffer, 0, negotiateResponseBuffer.Length);
+        }
+
+        private static string GetNegotiatePayload(string connectionId, HttpSocketOptions options)
+        {
+            var sb = new StringBuilder();
+            using (var jsonWriter = new JsonTextWriter(new StringWriter(sb)))
+            {
+                jsonWriter.WriteStartObject();
+                jsonWriter.WritePropertyName("connectionId");
+                jsonWriter.WriteValue(connectionId);
+                jsonWriter.WritePropertyName("availableTransports");
+                jsonWriter.WriteStartArray();
+                if ((options.Transports & TransportType.WebSockets) != 0)
+                {
+                   jsonWriter.WriteValue(nameof(TransportType.WebSockets));
+                }
+                if ((options.Transports & TransportType.ServerSentEvents) != 0)
+                {
+                    jsonWriter.WriteValue(nameof(TransportType.ServerSentEvents));
+                }
+                if ((options.Transports & TransportType.LongPolling) != 0)
+                {
+                    jsonWriter.WriteValue(nameof(TransportType.LongPolling));
+                }
+                jsonWriter.WriteEndArray();
+                jsonWriter.WriteEndObject();
+            }
+
+            return sb.ToString();
         }
 
         private async Task ProcessSend(HttpContext context)
diff --git a/src/Microsoft.AspNetCore.Sockets.Http/Microsoft.AspNetCore.Sockets.Http.csproj b/src/Microsoft.AspNetCore.Sockets.Http/Microsoft.AspNetCore.Sockets.Http.csproj
index e60b0807fd..f3ad26b1df 100644
--- a/src/Microsoft.AspNetCore.Sockets.Http/Microsoft.AspNetCore.Sockets.Http.csproj
+++ b/src/Microsoft.AspNetCore.Sockets.Http/Microsoft.AspNetCore.Sockets.Http.csproj
@@ -25,6 +25,7 @@
     <PackageReference Include="Microsoft.Extensions.SecurityHelper.Sources" Version="$(AspNetCoreVersion)" PrivateAssets="All" />
     <PackageReference Include="System.Threading.Tasks.Channels" Version="$(CoreFxLabsVersion)" />
     <PackageReference Include="System.IO.Pipelines.Text.Primitives" Version="$(CoreFxLabsVersion)" />
+    <PackageReference Include="Newtonsoft.Json" Version="$(JsonNetVersion)" />
   </ItemGroup>
 
 </Project>
diff --git a/test/Microsoft.AspNetCore.SignalR.Client.Tests/ConnectionTests.cs b/test/Microsoft.AspNetCore.SignalR.Client.Tests/ConnectionTests.cs
index 0577fb320e..149504ba0e 100644
--- a/test/Microsoft.AspNetCore.SignalR.Client.Tests/ConnectionTests.cs
+++ b/test/Microsoft.AspNetCore.SignalR.Client.Tests/ConnectionTests.cs
@@ -51,7 +51,10 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -81,7 +84,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -132,7 +137,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                     // allow DisposeAsync to continue once we know we are past the connection state check
                     allowDisposeTcs.SetResult(null);
                     await releaseNegotiateTcs.Task;
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -174,7 +181,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -199,7 +208,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -230,7 +241,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             var mockTransport = new Mock<ITransport>();
@@ -267,7 +280,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(HttpStatusCode.OK);
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -294,11 +309,12 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    if (request.Method == HttpMethod.Get)
-                    {
-                        return new HttpResponseMessage(HttpStatusCode.InternalServerError) { Content = new StringContent(string.Empty) };
-                    }
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+
+                    return request.Method == HttpMethod.Get
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.InternalServerError)
+                        : request.Method == HttpMethod.Options
+                            ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                            : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -328,7 +344,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             var mockTransport = new Mock<ITransport>();
@@ -370,7 +388,9 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             var mockTransport = new Mock<ITransport>();
@@ -438,7 +458,10 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(HttpStatusCode.OK);
+
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -477,7 +500,10 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                     {
                         sendTcs.SetResult(await request.Content.ReadAsByteArrayAsync());
                     }
-                    return ResponseUtils.CreateResponse(HttpStatusCode.OK);
+
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -523,7 +549,10 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                     {
                         content = "T2:T:42;";
                     }
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(content) };
+
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK, content);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -549,11 +578,12 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    if (request.Method == HttpMethod.Post)
-                    {
-                        return ResponseUtils.CreateResponse(HttpStatusCode.InternalServerError);
-                    }
-                    return ResponseUtils.CreateResponse(HttpStatusCode.OK);
+
+                    return request.Method == HttpMethod.Post
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.InternalServerError)
+                        : request.Method == HttpMethod.Options
+                            ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                            : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -585,7 +615,10 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                     {
                         content = "42";
                     }
-                    return ResponseUtils.CreateResponse(HttpStatusCode.OK, content);
+
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(HttpStatusCode.OK, content);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -627,11 +660,12 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    if (request.Method == HttpMethod.Get)
-                    {
-                        return new HttpResponseMessage(HttpStatusCode.InternalServerError) { Content = new StringContent(string.Empty) };
-                    }
-                    return new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(string.Empty) };
+
+                    return request.Method == HttpMethod.Get
+                        ? ResponseUtils.CreateResponse(HttpStatusCode.InternalServerError)
+                        : request.Method == HttpMethod.Options
+                            ? ResponseUtils.CreateResponse(HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                            : ResponseUtils.CreateResponse(HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -658,5 +692,100 @@ namespace Microsoft.AspNetCore.Sockets.Client.Tests
                 }
             }
         }
+
+        [Theory]
+        [InlineData("")]
+        [InlineData("Not Json")]
+        public async Task StartThrowsFormatExceptionIfNegotiationResponseIsInvalid(string negotiatePayload)
+        {
+            var mockHttpHandler = new Mock<HttpMessageHandler>();
+            mockHttpHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
+                .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
+                {
+                    await Task.Yield();
+                    return ResponseUtils.CreateResponse(HttpStatusCode.OK, negotiatePayload);
+                });
+
+            using (var httpClient = new HttpClient(mockHttpHandler.Object))
+            {
+                var connection = new Connection(new Uri("http://fakeuri.org/"));
+                var exception = await Assert.ThrowsAsync<FormatException>(
+                    () => connection.StartAsync(TransportType.LongPolling, httpClient));
+
+                Assert.Equal("Invalid negotiation response received.", exception.Message);
+            }
+        }
+
+        [Fact]
+        public async Task StartThrowsFormatExceptionIfNegotiationResponseHasNoConnectionId()
+        {
+            var mockHttpHandler = new Mock<HttpMessageHandler>();
+            mockHttpHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
+                .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
+                {
+                    await Task.Yield();
+                    return ResponseUtils.CreateResponse(HttpStatusCode.OK,
+                        ResponseUtils.CreateNegotiationResponse(connectionId: null));
+                });
+
+            using (var httpClient = new HttpClient(mockHttpHandler.Object))
+            {
+                var connection = new Connection(new Uri("http://fakeuri.org/"));
+                var exception = await Assert.ThrowsAsync<FormatException>(
+                    () => connection.StartAsync(TransportType.LongPolling, httpClient));
+
+                Assert.Equal("Invalid connection id returned in negotiation response.", exception.Message);
+            }
+        }
+
+        [Fact]
+        public async Task StartThrowsFormatExceptionIfNegotiationResponseHasNoTransports()
+        {
+            var mockHttpHandler = new Mock<HttpMessageHandler>();
+            mockHttpHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
+                .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
+                {
+                    await Task.Yield();
+                    return ResponseUtils.CreateResponse(HttpStatusCode.OK,
+                        ResponseUtils.CreateNegotiationResponse(transportTypes: null));
+                });
+
+            using (var httpClient = new HttpClient(mockHttpHandler.Object))
+            {
+                var connection = new Connection(new Uri("http://fakeuri.org/"));
+                var exception = await Assert.ThrowsAsync<FormatException>(
+                    () => connection.StartAsync(TransportType.LongPolling, httpClient));
+
+                Assert.Equal("No transports returned in negotiation response.", exception.Message);
+            }
+        }
+
+        [Theory]
+        [InlineData((TransportType)0)]
+        [InlineData(TransportType.ServerSentEvents)]
+        public async Task ConnectionCannotBeStartedIfNoCommonTransportsBetweenClientAndServer(TransportType serverTransports)
+        {
+            var mockHttpHandler = new Mock<HttpMessageHandler>();
+            mockHttpHandler.Protected()
+                .Setup<Task<HttpResponseMessage>>("SendAsync", ItExpr.IsAny<HttpRequestMessage>(), ItExpr.IsAny<CancellationToken>())
+                .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
+                {
+                    await Task.Yield();
+                    return ResponseUtils.CreateResponse(HttpStatusCode.OK,
+                        ResponseUtils.CreateNegotiationResponse(transportTypes: serverTransports));
+                });
+
+            using (var httpClient = new HttpClient(mockHttpHandler.Object))
+            {
+                var connection = new Connection(new Uri("http://fakeuri.org/"));
+                var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+                    () => connection.StartAsync(TransportType.LongPolling, httpClient));
+
+                Assert.Equal("No requested transports available on the server.", exception.Message);
+            }
+        }
     }
 }
diff --git a/test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionTests.cs b/test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionTests.cs
index 02889ebf03..5b7d718872 100644
--- a/test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionTests.cs
+++ b/test/Microsoft.AspNetCore.SignalR.Client.Tests/HubConnectionTests.cs
@@ -47,7 +47,9 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -78,7 +80,9 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -139,7 +143,9 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
@@ -170,7 +176,9 @@ namespace Microsoft.AspNetCore.SignalR.Client.Tests
                 .Returns<HttpRequestMessage, CancellationToken>(async (request, cancellationToken) =>
                 {
                     await Task.Yield();
-                    return ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
+                    return request.Method == HttpMethod.Options
+                        ? ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK, ResponseUtils.CreateNegotiationResponse())
+                        : ResponseUtils.CreateResponse(System.Net.HttpStatusCode.OK);
                 });
 
             using (var httpClient = new HttpClient(mockHttpHandler.Object))
diff --git a/test/Microsoft.AspNetCore.SignalR.Client.Tests/ResponseUtils.cs b/test/Microsoft.AspNetCore.SignalR.Client.Tests/ResponseUtils.cs
index 06b3f1f87c..6651cf24bc 100644
--- a/test/Microsoft.AspNetCore.SignalR.Client.Tests/ResponseUtils.cs
+++ b/test/Microsoft.AspNetCore.SignalR.Client.Tests/ResponseUtils.cs
@@ -3,7 +3,9 @@
 
 using System.Net;
 using System.Net.Http;
-using System.Net.Http.Headers;
+using System.Text;
+
+using SocketsTransportType = Microsoft.AspNetCore.Sockets.TransportType;
 
 namespace Microsoft.AspNetCore.Client.Tests
 {
@@ -25,5 +27,37 @@ namespace Microsoft.AspNetCore.Client.Tests
                 Content = payload
             };
         }
+
+        public static string CreateNegotiationResponse(string connectionId = "00000000-0000-0000-0000-000000000000",
+            SocketsTransportType? transportTypes = SocketsTransportType.All)
+        {
+            var sb = new StringBuilder("{ ");
+            if (connectionId != null)
+            {
+                sb.Append($"\"connectionId\": \"{connectionId}\",");
+            }
+            if (transportTypes != null)
+            {
+                sb.Append($"\"availableTransports\": [ ");
+                if ((transportTypes & SocketsTransportType.WebSockets) == SocketsTransportType.WebSockets)
+                {
+                    sb.Append($"\"{nameof(SocketsTransportType.WebSockets)}\",");
+                }
+                if ((transportTypes & SocketsTransportType.ServerSentEvents) == SocketsTransportType.ServerSentEvents)
+                {
+                    sb.Append($"\"{nameof(SocketsTransportType.ServerSentEvents)}\",");
+                }
+                if ((transportTypes & SocketsTransportType.LongPolling) == SocketsTransportType.LongPolling)
+                {
+                    sb.Append($"\"{nameof(SocketsTransportType.LongPolling)}\",");
+                }
+                sb.Length--;
+                sb.Append("],");
+            }
+            sb.Length--;
+            sb.Append("}");
+
+            return sb.ToString();
+        }
     }
 }
diff --git a/test/Microsoft.AspNetCore.SignalR.Tests/Formatters/ServerSentEventsParserTests.cs b/test/Microsoft.AspNetCore.SignalR.Tests/Formatters/ServerSentEventsParserTests.cs
index 7dcc88cade..17c5dc9181 100644
--- a/test/Microsoft.AspNetCore.SignalR.Tests/Formatters/ServerSentEventsParserTests.cs
+++ b/test/Microsoft.AspNetCore.SignalR.Tests/Formatters/ServerSentEventsParserTests.cs
@@ -15,7 +15,6 @@ namespace Microsoft.AspNetCore.Sockets.Common.Tests.Internal.Formatters
     {
         [Theory]
         [InlineData("\r\n", "")]
-        [InlineData("\r\n", "")]
         [InlineData("\r\n:\r\n", "")]
         [InlineData("\r\n:comment\r\n", "")]
         [InlineData("data: \r\r\n\r\n", "\r")]
@@ -99,7 +98,6 @@ namespace Microsoft.AspNetCore.Sockets.Common.Tests.Internal.Formatters
         [InlineData(new[] { "dat", "a: Hello, World\r\n\r\n" }, "Hello, World")]
         [InlineData(new[] { "data", ": Hello, World\r\n\r\n" }, "Hello, World")]
         [InlineData(new[] { "data:", " Hello, World\r\n\r\n" }, "Hello, World")]
-        [InlineData(new[] { "data: ", "Hello, World\r\n\r\n" }, "Hello, World")]
         [InlineData(new[] { "data: Hello, World", "\r\n\r\n" }, "Hello, World")]
         [InlineData(new[] { "data: Hello, World\r\n", "\r\n" }, "Hello, World")]
         [InlineData(new[] { "data: ", "Hello, World\r\n\r\n" }, "Hello, World")]
diff --git a/test/Microsoft.AspNetCore.Sockets.Tests/HttpConnectionDispatcherTests.cs b/test/Microsoft.AspNetCore.Sockets.Tests/HttpConnectionDispatcherTests.cs
index 056db76b9c..a039ede684 100644
--- a/test/Microsoft.AspNetCore.Sockets.Tests/HttpConnectionDispatcherTests.cs
+++ b/test/Microsoft.AspNetCore.Sockets.Tests/HttpConnectionDispatcherTests.cs
@@ -18,6 +18,8 @@ using Microsoft.AspNetCore.SignalR.Tests.Common;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 using Xunit;
 
 namespace Microsoft.AspNetCore.Sockets.Tests
@@ -45,11 +47,41 @@ namespace Microsoft.AspNetCore.Sockets.Tests
             builder.UseEndPoint<TestEndPoint>();
             var app = builder.Build();
             await dispatcher.ExecuteAsync(context, new HttpSocketOptions(), app);
+            var negotiateResponse = JsonConvert.DeserializeObject<JObject>(Encoding.UTF8.GetString(ms.ToArray()));
+            var connectionId = negotiateResponse.Value<string>("connectionId");
+            Assert.True(manager.TryGetConnection(connectionId, out var connectionContext));
+            Assert.Equal(connectionId, connectionContext.ConnectionId);
+        }
 
-            var id = Encoding.UTF8.GetString(ms.ToArray());
+        [Theory]
+        [InlineData(TransportType.All)]
+        [InlineData((TransportType)0)]
+        [InlineData(TransportType.LongPolling | TransportType.WebSockets)]
+        public async Task NegotiateReturnsAvailableTransports(TransportType transports)
+        {
+            var manager = CreateConnectionManager();
+            var dispatcher = new HttpConnectionDispatcher(manager, new LoggerFactory());
+            var context = new DefaultHttpContext();
+            var services = new ServiceCollection();
+            services.AddEndPoint<TestEndPoint>();
+            services.AddOptions();
+            var ms = new MemoryStream();
+            context.Request.Path = "/foo";
+            context.Request.Method = "OPTIONS";
+            context.Response.Body = ms;
+            var builder = new SocketBuilder(services.BuildServiceProvider());
+            builder.UseEndPoint<TestEndPoint>();
+            var app = builder.Build();
+            await dispatcher.ExecuteAsync(context, new HttpSocketOptions { Transports = transports }, app);
 
-            Assert.True(manager.TryGetConnection(id, out var connection));
-            Assert.Equal(id, connection.ConnectionId);
+            var negotiateResponse = JsonConvert.DeserializeObject<JObject>(Encoding.UTF8.GetString(ms.ToArray()));
+            var availableTransports = (TransportType)0;
+            foreach (var transport in negotiateResponse["availableTransports"])
+            {
+                availableTransports |= (TransportType)Enum.Parse(typeof(TransportType), transport.Value<string>());
+            }
+
+            Assert.Equal(transports, availableTransports);
         }
 
         [Theory]
diff --git a/test/Microsoft.AspNetCore.Sockets.Tests/Microsoft.AspNetCore.Sockets.Tests.csproj b/test/Microsoft.AspNetCore.Sockets.Tests/Microsoft.AspNetCore.Sockets.Tests.csproj
index 41d1342cb5..e17e197247 100644
--- a/test/Microsoft.AspNetCore.Sockets.Tests/Microsoft.AspNetCore.Sockets.Tests.csproj
+++ b/test/Microsoft.AspNetCore.Sockets.Tests/Microsoft.AspNetCore.Sockets.Tests.csproj
@@ -20,6 +20,7 @@
     <PackageReference Include="Microsoft.AspNetCore.Server.Kestrel" Version="$(AspNetCoreVersion)" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
     <PackageReference Include="System.IO.Pipelines.Extensions" Version="$(CoreFxLabsVersion)" />
+    <PackageReference Include="Newtonsoft.Json" Version="$(JsonNetVersion)" />
     <PackageReference Include="xunit.runner.visualstudio" Version="$(XunitVersion)" />
     <PackageReference Include="xunit" Version="$(XunitVersion)" />
   </ItemGroup>