title	description	author	ms.topic	ms.devlang	ms.custom	ms.date	ms.author	zone_pivot_groups
Azure Functions SignalR Service output binding	Learn about the SignalR Service output binding for Azure Functions.	Y-Sindo	reference	csharp, java, javascript, python	devx-track-csharp, devx-track-extended-java, devx-track-js, devx-track-python	01/13/2023	zityang	programming-languages-set-functions-lang-workers

SignalR Service output binding for Azure Functions

Use the SignalR output binding to send one or more messages using Azure SignalR Service. You can broadcast a message to:

All connected clients
Connected clients authenticated to a specific user

The output binding also allows you to manage groups.

For information on setup and configuration details, see the overview.

Example

::: zone pivot="programming-language-csharp"

[!INCLUDE functions-bindings-csharp-intro-with-csx]

Broadcast to all clients

In-process

The following example shows a function that sends a message using the output binding to all connected clients. The target is the name of the method to be invoked on each client. The Arguments property is an array of zero or more objects to be passed to the client method.

[FunctionName("SendMessage")]
public static Task SendMessage(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post")]object message,
    [SignalR(HubName = "chat")]IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

Isolated process

The following example shows a function that sends a message using the output binding to all connected clients. The newMessage is the name of the method to be invoked on each client.

:::code language="csharp" source="~/azure-functions-dotnet-worker/samples/Extensions/SignalR/SignalROutputBindingFunctions2.cs" id="snippet_broadcast_to_all":::

C# Script

Here's binding data in the function.json file:

Example function.json:

{
  "type": "signalR",
  "name": "signalRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

Here's the C# Script code:

#r "Microsoft.Azure.WebJobs.Extensions.SignalRService"
using Microsoft.Azure.WebJobs.Extensions.SignalRService;

public static Task Run(
    object message,
    IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

::: zone-end ::: zone pivot="programming-language-javascript,programming-language-python,programming-language-powershell"

Broadcast to all clients

Here's binding data in the function.json file:

Example function.json:

{
  "type": "signalR",
  "name": "signalRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

::: zone-end ::: zone pivot="programming-language-javascript"

Here's the JavaScript code:

module.exports = async function (context, req) {
    context.bindings.signalRMessages = [{
        "target": "newMessage",
        "arguments": [ req.body ]
    }];
};

::: zone-end ::: zone pivot="programming-language-powershell"

Complete PowerShell examples are pending. ::: zone-end ::: zone pivot="programming-language-python"

Here's the Python code:

def main(req: func.HttpRequest, outMessage: func.Out[str]) -> func.HttpResponse:
    message = req.get_json()
    outMessage.set(json.dumps({
        'target': 'newMessage',
        'arguments': [ message ]
    }))

::: zone-end ::: zone pivot="programming-language-java"

Broadcast to all clients

@FunctionName("sendMessage")
@SignalROutput(name = "$return", hubName = "chat")
public SignalRMessage sendMessage(
        @HttpTrigger(
            name = "req",
            methods = { HttpMethod.POST },
            authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) {

    SignalRMessage message = new SignalRMessage();
    message.target = "newMessage";
    message.arguments.add(req.getBody());
    return message;
}

::: zone-end ::: zone pivot="programming-language-csharp"

Send to a user

You can send a message only to connections that have been authenticated to a user by setting the user ID in the SignalR message.

In-process

[FunctionName("SendMessage")]
public static Task SendMessage(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post")]object message,
    [SignalR(HubName = "chat")]IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            // the message will only be sent to this user ID
            UserId = "userId1",
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

Isolated process

:::code language="csharp" source="~/azure-functions-dotnet-worker/samples/Extensions/SignalR/SignalROutputBindingFunctions2.cs" id="snippet_send_to_user":::

C# Script

Example function.json:

{
  "type": "signalR",
  "name": "signalRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

Here's the C# script code:

#r "Microsoft.Azure.WebJobs.Extensions.SignalRService"
using Microsoft.Azure.WebJobs.Extensions.SignalRService;

public static Task Run(
    object message,
    IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            // the message will only be sent to this user ID
            UserId = "userId1",
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

::: zone-end ::: zone pivot="programming-language-javascript,programming-language-python,programming-language-powershell"

Send to a user

You can send a message only to connections that have been authenticated to a user by setting the user ID in the SignalR message.

Example function.json:

{
  "type": "signalR",
  "name": "outRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

::: zone-end ::: zone pivot="programming-language-javascript" Here's the JavaScript code:

module.exports = async function (context, req) {
    context.bindings.signalRMessages  = [{
        // message will only be sent to this user ID
        "userId": "userId1",
        "target": "newMessage",
        "arguments": [ req.body ]
    }];
};

::: zone-end ::: zone pivot="programming-language-powershell"

Complete PowerShell examples are pending. ::: zone-end ::: zone pivot="programming-language-python"

Here's the Python code:

def main(req: func.HttpRequest, outMessages: func.Out[str]) -> func.HttpResponse:
    message = req.get_json()
    outMessage.set(json.dumps({
        #message will only be sent to this user ID
        'userId': 'userId1',
        'target': 'newMessage',
        'arguments': [ message ]
    }))

::: zone-end ::: zone pivot="programming-language-java"

Send to a user

You can send a message only to connections that have been authenticated to a user by setting the user ID in the SignalR message.

@FunctionName("sendMessage")
@SignalROutput(name = "$return", hubName = "chat")
public SignalRMessage sendMessage(
        @HttpTrigger(
            name = "req",
            methods = { HttpMethod.POST },
            authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) {

    SignalRMessage message = new SignalRMessage();
    message.userId = "userId1";
    message.target = "newMessage";
    message.arguments.add(req.getBody());
    return message;
}

::: zone-end ::: zone pivot="programming-language-csharp"

Send to a group

You can send a message only to connections that have been added to a group by setting the group name in the SignalR message.

In-process

[FunctionName("SendMessage")]
public static Task SendMessage(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post")]object message,
    [SignalR(HubName = "chat")]IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            // the message will be sent to the group with this name
            GroupName = "myGroup",
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

Isolated process

:::code language="csharp" source="~/azure-functions-dotnet-worker/samples/Extensions/SignalR/SignalROutputBindingFunctions2.cs" id="snippet_send_to_group":::

C# Script

Example function.json:

{
  "type": "signalR",
  "name": "signalRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

Here's the C# Script code:

#r "Microsoft.Azure.WebJobs.Extensions.SignalRService"
using Microsoft.Azure.WebJobs.Extensions.SignalRService;

public static Task Run(
    object message,
    IAsyncCollector<SignalRMessage> signalRMessages)
{
    return signalRMessages.AddAsync(
        new SignalRMessage
        {
            // the message will be sent to the group with this name
            GroupName = "myGroup",
            Target = "newMessage",
            Arguments = new [] { message }
        });
}

::: zone-end ::: zone pivot="programming-language-javascript,programming-language-python,programming-language-powershell"

Send to a group

You can send a message only to connections that have been added to a group by setting the group name in the SignalR message.

Example function.json:

{
  "type": "signalR",
  "name": "signalRMessages",
  "hubName": "<hub_name>",
  "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
  "direction": "out"
}

::: zone-end ::: zone pivot="programming-language-javascript" Here's the JavaScript code:

module.exports = async function (context, req) {
    context.bindings.signalRMessages = [{
        // message will only be sent to this group
        "groupName": "myGroup",
        "target": "newMessage",
        "arguments": [ req.body ]
    }];
};

::: zone-end ::: zone pivot="programming-language-powershell"

Complete PowerShell examples are pending. ::: zone-end ::: zone pivot="programming-language-python"

Here's the Python code:

def main(req: func.HttpRequest, outMessage: func.Out[str]) -> func.HttpResponse:
    message = req.get_json()
    outMessage.set(json.dumps({
        #message will only be sent to this group
        'groupName': 'myGroup',
        'target': 'newMessage',
        'arguments': [ message ]
    }))

::: zone-end ::: zone pivot="programming-language-java"

Send to a group

You can send a message only to connections that have been added to a group by setting the group name in the SignalR message.

@FunctionName("sendMessage")
@SignalROutput(name = "$return", hubName = "chat")
public SignalRMessage sendMessage(
        @HttpTrigger(
            name = "req",
            methods = { HttpMethod.POST },
            authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) {

    SignalRMessage message = new SignalRMessage();
    message.groupName = "myGroup";
    message.target = "newMessage";
    message.arguments.add(req.getBody());
    return message;
}

::: zone-end ::: zone pivot="programming-language-csharp"

Group management

SignalR Service allows users or connections to be added to groups. Messages can then be sent to a group. You can use the SignalR output binding to manage groups.

In-process

Specify GroupAction to add or remove a member. The following example adds a user to a group.

[FunctionName("addToGroup")]
public static Task AddToGroup(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post")]HttpRequest req,
    ClaimsPrincipal claimsPrincipal,
    [SignalR(HubName = "chat")]
        IAsyncCollector<SignalRGroupAction> signalRGroupActions)
{
    var userIdClaim = claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);
    return signalRGroupActions.AddAsync(
        new SignalRGroupAction
        {
            UserId = userIdClaim.Value,
            GroupName = "myGroup",
            Action = GroupAction.Add
        });
}

Isolated process

Specify SignalRGroupActionType to add or remove a member. The following example removes a user from a group.

:::code language="csharp" source="~/azure-functions-dotnet-worker/samples/Extensions/SignalR/SignalROutputBindingFunctions2.cs" id="snippet_remove_from_group":::

C# Script

The following example adds a user to a group.

Example function.json

{
    "type": "signalR",
    "name": "signalRGroupActions",
    "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
    "hubName": "chat",
    "direction": "out"
}

Run.csx

#r "Microsoft.Azure.WebJobs.Extensions.SignalRService"
using Microsoft.Azure.WebJobs.Extensions.SignalRService;

public static Task Run(
    HttpRequest req,
    ClaimsPrincipal claimsPrincipal,
    IAsyncCollector<SignalRGroupAction> signalRGroupActions)
{
    var userIdClaim = claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);
    return signalRGroupActions.AddAsync(
        new SignalRGroupAction
        {
            UserId = userIdClaim.Value,
            GroupName = "myGroup",
            Action = GroupAction.Add
        });
}

The following example removes a user from a group.

Example function.json

{
    "type": "signalR",
    "name": "signalRGroupActions",
    "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
    "hubName": "chat",
    "direction": "out"
}

Run.csx

#r "Microsoft.Azure.WebJobs.Extensions.SignalRService"
using Microsoft.Azure.WebJobs.Extensions.SignalRService;

public static Task Run(
    HttpRequest req,
    ClaimsPrincipal claimsPrincipal,
    IAsyncCollector<SignalRGroupAction> signalRGroupActions)
{
    var userIdClaim = claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);
    return signalRGroupActions.AddAsync(
        new SignalRGroupAction
        {
            UserId = userIdClaim.Value,
            GroupName = "myGroup",
            Action = GroupAction.Remove
        });
}

Note

In order to get the ClaimsPrincipal correctly bound, you must have configured the authentication settings in Azure Functions.

::: zone-end ::: zone pivot="programming-language-javascript,programming-language-python,programming-language-powershell"

Group management

SignalR Service allows users or connections to be added to groups. Messages can then be sent to a group. You can use the SignalR output binding to manage groups.

Example function.json that defines the output binding:

{
    "type": "signalR",
    "name": "signalRGroupActions",
    "connectionStringSetting": "<name of setting containing SignalR Service connection string>",
    "hubName": "chat",
    "direction": "out"
}

::: zone-end ::: zone pivot="programming-language-javascript"

The following example adds a user to a group.

module.exports = async function (context, req) {
  context.bindings.signalRGroupActions = [{
    "userId": req.query.userId,
    "groupName": "myGroup",
    "action": "add"
  }];
};

The following example removes a user from a group.

module.exports = async function (context, req) {
  context.bindings.signalRGroupActions = [{
    "userId": req.query.userId,
    "groupName": "myGroup",
    "action": "remove"
  }];
};

::: zone-end ::: zone pivot="programming-language-powershell"

Complete PowerShell examples are pending. ::: zone-end ::: zone pivot="programming-language-python"

The following example adds a user to a group.

def main(req: func.HttpRequest, action: func.Out[str]) -> func.HttpResponse:
    action.set(json.dumps({
        'userId': 'userId1',
        'groupName': 'myGroup',
        'action': 'add'
    }))

The following example removes a user from a group.

def main(req: func.HttpRequest, action: func.Out[str]) -> func.HttpResponse:
    action.set(json.dumps({
        'userId': 'userId1',
        'groupName': 'myGroup',
        'action': 'remove'
    }))

::: zone-end ::: zone pivot="programming-language-java"

Group management

SignalR Service allows users or connections to be added to groups. Messages can then be sent to a group. You can use the SignalR output binding to manage groups.

The following example adds a user to a group.

@FunctionName("addToGroup")
@SignalROutput(name = "$return", hubName = "chat")
public SignalRGroupAction addToGroup(
        @HttpTrigger(
            name = "req",
            methods = { HttpMethod.POST },
            authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req,
        @BindingName("userId") String userId) {

    SignalRGroupAction groupAction = new SignalRGroupAction();
    groupAction.action = "add";
    groupAction.userId = userId;
    groupAction.groupName = "myGroup";
    return action;
}

The following example removes a user from a group.

@FunctionName("removeFromGroup")
@SignalROutput(name = "$return", hubName = "chat")
public SignalRGroupAction removeFromGroup(
        @HttpTrigger(
            name = "req",
            methods = { HttpMethod.POST },
            authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req,
        @BindingName("userId") String userId) {

    SignalRGroupAction groupAction = new SignalRGroupAction();
    groupAction.action = "remove";
    groupAction.userId = userId;
    groupAction.groupName = "myGroup";
    return action;
}

::: zone-end ::: zone pivot="programming-language-csharp"

Attributes

Both in-process and isolated worker process C# libraries use attribute to define the function. C# script instead uses a function.json configuration file.

In-process

The following table explains the properties of the SignalR output attribute.

Attribute property	Description
HubName	This value must be set to the name of the SignalR hub for which the connection information is generated.
ConnectionStringSetting	The name of the app setting that contains the SignalR Service connection string, which defaults to `AzureSignalRConnectionString`.

Isolated process

The following table explains the properties of the SignalROutput attribute.

Attribute property	Description
HubName	This value must be set to the name of the SignalR hub for which the connection information is generated.
ConnectionStringSetting	The name of the app setting that contains the SignalR Service connection string, which defaults to `AzureSignalRConnectionString`.

C# Script

The following table explains the binding configuration properties that you set in the function.json file.

function.json property	Description
type	Must be set to `signalR`.
direction	Must be set to `out`.
name	Variable name used in function code for connection info object.
hubName	This value must be set to the name of the SignalR hub for which the connection information is generated.
connectionStringSetting	The name of the app setting that contains the SignalR Service connection string, which defaults to `AzureSignalRConnectionString`.

::: zone-end ::: zone pivot="programming-language-java"

Annotations

The following table explains the supported settings for the SignalROutput annotation.

Setting	Description
name	Variable name used in function code for connection info object.
hubName	This value must be set to the name of the SignalR hub for which the connection information is generated.
connectionStringSetting	The name of the app setting that contains the SignalR Service connection string, which defaults to `AzureSignalRConnectionString`.

::: zone-end ::: zone pivot="programming-language-javascript,programming-language-powershell,programming-language-python"

Configuration

The following table explains the binding configuration properties that you set in the function.json file.

function.json property	Description
type	Must be set to `signalR`.
direction	Must be set to `out`.
name	Variable name used in function code for connection info object.
hubName	This value must be set to the name of the SignalR hub for which the connection information is generated.
connectionStringSetting	The name of the app setting that contains the SignalR Service connection string, which defaults to `AzureSignalRConnectionString`.

::: zone-end

[!INCLUDE app settings to local.settings.json]

Next steps

Handle messages from SignalR Service (Trigger binding)
Return the service endpoint URL and access token (Input binding)

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functions-bindings-signalr-service-output.md

functions-bindings-signalr-service-output.md

SignalR Service output binding for Azure Functions

Example

Broadcast to all clients

In-process

Isolated process

C# Script

Broadcast to all clients

Broadcast to all clients

Send to a user

In-process

Isolated process

C# Script

Send to a user

Send to a user

Send to a group

In-process

Isolated process

C# Script

Send to a group

Send to a group

Group management

In-process

Isolated process

C# Script

Group management

Group management

Attributes

In-process

Isolated process

C# Script

Annotations

Configuration

Next steps

Files

functions-bindings-signalr-service-output.md

Latest commit

History

functions-bindings-signalr-service-output.md

File metadata and controls

SignalR Service output binding for Azure Functions

Example

Broadcast to all clients

Broadcast to all clients

Broadcast to all clients

Send to a user

Send to a user

Send to a user

Send to a group

Send to a group

Send to a group

Group management

Group management

Group management

Attributes

Annotations

Configuration

Next steps