functions-bindings-signalr-service-output.md

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	devx-track-csharp, devx-track-extended-java, devx-track-js, devx-track-python	03/12/2024	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 in a specified group
• Connected clients authenticated to a specific user

The output binding also allows you to manage groups, such as adding a client or user to a group, removing a client or user from a group.

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

Example

Broadcast to all clients

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

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

[!INCLUDE functions-in-process-model-retirement-note]

Isolated worker model

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":::

In-process model

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")]publicstaticTaskSendMessage([HttpTrigger(AuthorizationLevel.Anonymous,"post")]objectmessage,[SignalR(HubName="hubName1")]IAsyncCollector<SignalRMessage>signalROutput){returnsignalROutput.AddAsync(newSignalRMessage{Target="newMessage",Arguments=new[]{message}});}

---

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[!INCLUDE functions-bindings-signalr-output-function-json]

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Model v4

const{ app, output }=require('@azure/functions');constsignalR=output.generic({type: 'signalR',name: 'signalR',hubName: 'hub',connectionStringSetting: 'AzureSignalRConnectionString',});// You can use any other trigger type instead.app.http('broadcast',{methods: ['GET'],authLevel: 'anonymous',extraOutputs: [signalR],handler: (request,context)=>{context.extraOutputs.set(signalR,{"target": "newMessage","arguments": [request.body]});}});

Model v3

[!INCLUDE functions-bindings-signalr-output-function-json]

Here's the JavaScript code:

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

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

Here's the Python code:

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

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@FunctionName("sendMessage") @SignalROutput(name = "$return", HubName = "hubName1") publicSignalRMessagesendMessage( @HttpTrigger( name = "req", methods = { HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) { SignalRMessagemessage = newSignalRMessage(); message.target = "newMessage"; message.arguments.add(req.getBody()); returnmessage; }

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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.

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Isolated worker model

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

In-process model

[FunctionName("SendMessage")]publicstaticTaskSendMessage([HttpTrigger(AuthorizationLevel.Anonymous,"post")]objectmessage,[SignalR(HubName="hubName1")]IAsyncCollector<SignalRMessage>signalROutput){returnsignalROutput.AddAsync(newSignalRMessage{// the message will only be sent to this user IDUserId="userId1",Target="newMessage",Arguments=new[]{message}});}

---

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[!INCLUDE functions-bindings-signalr-output-function-json]

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

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

Here's the Python code:

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

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@FunctionName("sendMessage") @SignalROutput(name = "$return", HubName = "hubName1") publicSignalRMessagesendMessage( @HttpTrigger( name = "req", methods = { HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) { SignalRMessagemessage = newSignalRMessage(); message.userId = "userId1"; message.target = "newMessage"; message.arguments.add(req.getBody()); returnmessage; }

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Model v4

const{ app, output }=require('@azure/functions');constsignalR=output.generic({type: 'signalR',name: 'signalR',hubName: 'hub',connectionStringSetting: 'AzureSignalRConnectionString',});app.http('sendToUser',{methods: ['GET'],authLevel: 'anonymous',extraOutputs: [signalR],handler: (request,context)=>{context.extraOutputs.set(signalR,{"target": "newMessage","arguments": [request.body],"userId": "userId1",});}});

Model v3

[!INCLUDE functions-bindings-signalr-output-function-json]

Here's the JavaScript code:

module.exports=asyncfunction(context,req){context.bindings.signalROutput=[{"target": "newMessage","arguments": [req.body],"userId": "userId1",}];};

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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.

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Isolated worker model

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

In-process model

[FunctionName("SendMessage")]publicstaticTaskSendMessage([HttpTrigger(AuthorizationLevel.Anonymous,"post")]objectmessage,[SignalR(HubName="hubName1")]IAsyncCollector<SignalRMessage>signalROutput){returnsignalROutput.AddAsync(newSignalRMessage{// the message will be sent to the group with this nameGroupName="myGroup",Target="newMessage",Arguments=new[]{message}});}

---

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[!INCLUDE functions-bindings-signalr-output-function-json]

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Model v4

const{ app, output }=require('@azure/functions');constsignalR=output.generic({type: 'signalR',name: 'signalR',hubName: 'hub',connectionStringSetting: 'AzureSignalRConnectionString',});app.http('sendToGroup',{methods: ['GET'],authLevel: 'anonymous',extraOutputs: [signalR],handler: (request,context)=>{context.extraOutputs.set(signalR,{"target": "newMessage","arguments": [request.body],"groupName": "myGroup",});}});

Model v3

[!INCLUDE functions-bindings-signalr-output-function-json]

Here's the JavaScript code:

module.exports=asyncfunction(context,req){context.bindings.signalROutput=[{"target": "newMessage","arguments": [req.body],"groupName": "myGroup",}];};

::: zone-end

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

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

Here's the Python code:

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

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@FunctionName("sendMessage") @SignalROutput(name = "$return", HubName = "hubName1") publicSignalRMessagesendMessage( @HttpTrigger( name = "req", methods = { HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req) { SignalRMessagemessage = newSignalRMessage(); message.groupName = "myGroup"; message.target = "newMessage"; message.arguments.add(req.getBody()); returnmessage; }

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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.

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Isolated worker model

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":::

In-process model

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

[FunctionName("addToGroup")]publicstaticTaskAddToGroup([HttpTrigger(AuthorizationLevel.Anonymous,"post")]HttpRequestreq,ClaimsPrincipalclaimsPrincipal,[SignalR(HubName="hubName1")]IAsyncCollector<SignalRGroupAction>signalRGroupActions){varuserIdClaim=claimsPrincipal.FindFirst(ClaimTypes.NameIdentifier);returnsignalRGroupActions.AddAsync(newSignalRGroupAction{UserId=userIdClaim.Value,GroupName="myGroup",Action=GroupAction.Add});}

---

Note

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

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[!INCLUDE functions-bindings-signalr-output-function-json]

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Model v4

const{ app, output }=require('@azure/functions');constsignalR=output.generic({type: 'signalR',name: 'signalR',hubName: 'hub',connectionStringSetting: 'AzureSignalRConnectionString',});// The following function adds a user to a groupapp.http('addUserToGroup',{methods: ['POST'],authLevel: 'anonymous',extraOutputs: [signalR],handler: (request,context)=>{context.extraOutputs.set(signalR,{"userId": req.query.userId,"groupName": "myGroup","action": "add"});}});// The following function removes a user from a groupapp.http('removeUserFromGroup',{methods: ['POST'],authLevel: 'anonymous',extraOutputs: [signalR],handler: (request,context)=>{context.extraOutputs.set(signalR,{"userId": req.query.userId,"groupName": "myGroup","action": "remove"});}});

Model v3

[!INCLUDE functions-bindings-signalr-output-function-json]

Here's the JavaScript code:

The following example adds a user to a group.

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

The following example removes a user from a group.

module.exports=asyncfunction(context,req){context.bindings.signalROutput=[{"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.

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

The following example removes a user from a group.

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

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The following example adds a user to a group.

@FunctionName("addToGroup") @SignalROutput(name = "$return", HubName = "hubName1") publicSignalRGroupActionaddToGroup( @HttpTrigger( name = "req", methods = { HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req, @BindingName("userId") StringuserId) { SignalRGroupActiongroupAction = newSignalRGroupAction(); groupAction.action = "add"; groupAction.userId = userId; groupAction.groupName = "myGroup"; returnaction; }

The following example removes a user from a group.

@FunctionName("removeFromGroup") @SignalROutput(name = "$return", HubName = "hubName1") publicSignalRGroupActionremoveFromGroup( @HttpTrigger( name = "req", methods = { HttpMethod.POST }, authLevel = AuthorizationLevel.ANONYMOUS) HttpRequestMessage<Object> req, @BindingName("userId") StringuserId) { SignalRGroupActiongroupAction = newSignalRGroupAction(); groupAction.action = "remove"; groupAction.userId = userId; groupAction.groupName = "myGroup"; returnaction; }

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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.

Isolated worker model

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 or settings collection that contains the SignalR Service connection string, which defaults to AzureSignalRConnectionString.

In-process model

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 or settings collection that contains the SignalR Service connection string, which defaults to AzureSignalRConnectionString.

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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 or settings collection that contains the SignalR Service connection string, which defaults to AzureSignalRConnectionString.

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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 or settings collection that contains the SignalR Service connection string, which defaults to AzureSignalRConnectionString.

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

Usage

[!INCLUDE functions-azure-signalr-authorization-note]

Next steps

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