What's new in Azure Communication Services

2025-06-26

This article describes new features and updates related to Azure Communication Services.

June 2025

Teams Phone extensibility

Introducing Teams Phone extensibility in public preview. Teams Phone extensibility (TPE) for Dynamics 365 Contact Center and contact center as a service (CCaaS) ISV solution helps organizations extend their telephony investment with Teams Phone into the contact center.

With generative AI, Contact Center as a Service (CCaaS) providers can easily advise human agents so they’re responsive to customer needs, can automate workflows, and ultimately improve the overall customer experience.

Limitations of previous solutions

Workflows are often divided between Unified Communications as a Service (UCaaS) providers like Microsoft Teams and CCaaS systems. This division limits generative AI's potential to streamline operations and deliver a consolidated view of data. Today, organizations want integrated, customizable solutions from their CCaaS providers that unify telephony infrastructure for a complete view of customer interactions and robust data handling.

Teams Phone extensibility benefits for CCaaS developers

Teams Phone extensibility, which is powered by Azure Communication Services, enables CCaaS vendors to integrate seamlessly with Teams Phone and deliver several benefits to their customers and end-users, including:

Consolidated Telephony for UCaaS and CCaaS: Simplified setup with no need to configure and administer separate phone systems. Customers can use their Teams Phone telephony investment for contact center deployments.
Conversational AI Integration: Developers can use Call Automation APIs to use AI-powered tools, play personalized greeting messages, and recognize conversational voice inputs.
Extend UCaaS Capabilities to CCaaS: Take advantage of Teams Phone enterprise features, including emergency calling and dial plan policies.
Agent Notification handling: Enable data segregation between CCaaS persona and UCaaS persona with the choice of ringing either the Teams standard client or a CCaaS application.
Cost Efficiency: Enable ISVs to build cost-effective solutions using existing Teams Phone plans, without adding Azure Communication Services numbers or Direct Routing.
Broader Geographic Availability: Integration with Teams Calling Plans, Direct Routing, and Operator Connect provides wider telephony options.

A diagram showing separate voice solutions for information workers and contact center agents compared to a more unified solution using Azure Communication Services and Teams Phone extensibility.

Key Features

Provisioning for Seamless Integration: Empower CCaaS providers to connect their Azure Communication Services deployments with customers' Teams tenants. This integration enables the use of Teams telephony features for a cohesive and efficient communication experience.
Call Routing and Mid-Call Controls: Advanced call routing capabilities for efficient call management and escalation to agents. Mid-call controls enable adding participants, redirecting calls, and transferring calls seamlessly.
Convenience Recording: Integrate call recording capabilities into Microsoft Teams for CCaaS scenarios, enabling customized recording processes controlled by CCaaS admins. For more information, see Call Recording overview.
Conversational AI Integration: Developers can use Call Automation APIs to use AI-powered tools, play personalized greeting messages, recognize conversational voice inputs, and use sentiment analysis to improve customer service. Get started today with this Call Automation OpenAI sample.
On-Behalf-Of (OBO): OBO calling enables applications to initiate and manage voice calls on behalf of a Teams Resource Account, enabling seamless integration with enterprise workflows.
Integrate with Call Automation: Azure Communication Services Call Automation APIs provide call control and enable CCaaS providers to build server-based and intelligent call flows.
Use the Client SDK: Azure Communication Services Client SDK provides the means for a CCaaS provider to develop a custom client for CCaaS persona workflows.
Emergency Calling: Powered by Azure Communication Services Calling SDK, we bring enhanced emergency calling support for agents who can dial emergency services, provide their static location, and receive callbacks from public safety answering points with Teams Phone service numbers.
Billing: The Teams Phone extensibility business model charges CCaaS vendors for using Azure Communication Services SDKs, including Calling SDK, VoIP consumption, Audio Insights, and Call Recording, while end users must use Teams Calling Plans and enable necessary Teams licenses for agents and resource accounts. For more information, see Azure Communication Services pricing.
Telemetry: Developers and CCaaS providers can access calling details and logging tools as part of the Teams Phone extensibility. Telemetry enables developers and system admins to monitor call use and debug call quality from the Azure portal either. They can do this by analyzing the Call Summary and Call Diagnostic Logs with a clear Team Phone Extensibility identifier or using the Call Diagnostic Center.

A diagram showing the Azure Communication Services Call automation API enabling your application to integrate Teams Phone and Azure AI Speech.

Join the Azure Communication Services Technology Adoption Program (TAP)

Azure Communication Services Technology Adoption Program Registration.

Next steps

May 2025

Background Blur for Android Mobile browsers

Implement background blur for Android Web mobile using Azure Communication Services Calling SDK. This feature is generally available (GA). By enabling background blur, end users can enjoy calls with increased privacy and confidence, knowing that their background is obscured and doesn’t distract from the call.

Next steps

Add video effects to your video calls

Mobile Browsers support sending 720p resolution video

The Azure Communication Services Calling SDK for Web mobile browser now enables developers to send video by default at a 720p video resolution. This feature is generally available (GA). When you enable a higher video resolution to be sent from mobile browsers, it provides all users with higher quality video and more intimate calling experience.

Next steps

Calling SDK overview > Supported video resolutions

April 2025

1080p Web Send

The Azure Communication Services WebJS calling SDK now supports sending video at 1080p resolution, in public preview. Developers can enable this advanced video quality to build solutions that enable their customers to use higher quality and more detailed video presentations.

This enhancement provides developers and participants with improved calling experience. Developers can opt-in to this feature using the Video Constraints API (see the following example), enabling higher quality video streams in their applications.

    const callOptions = {
        videoOptions: {
            localVideoStreams: [...],
            constraints: {
                send: {
                    height: {
                        max: 1080
                    }
                }
            }
        },
        audioOptions: {
            muted: false
        }
    };
    // make a call
    this.callAgent.startCall(identitiesToCall, callOptions);

Next steps

Best practices for subscribing to video feeds

Dual Pin 720p videos

The Azure Communication Services Calling SDK now enables developers to spotlight up to two incoming video streams, in public preview. You can send spotlighted streams at a higher resolution than other incoming streams, providing better quality for highlighted videos. This feature enables developers to deliver a more engaging and visually rich experience for participants.

Next steps

Best practices for subscribing to video feeds

March 2025

Integrate Real Time Text into your apps

Real-Time Text (RTT), now in General Availability, enables participants to transmit and display text in real-time during voice and video calls. Unlike traditional messaging, in which the recipient sees the full message only after sending, RTT ensures that each character appears on the recipient’s screen as it is typed. This creates a dynamic, conversational experience that mirrors spoken communication.

Animated image showing real time text entered into a text box on a mobile device while displayed to all participants in real time.

For developers, integrating RTT into their applications can enhance user engagement and accessibility. By providing immediate and continuous text communication, RTT bridges the gap between spoken and written interactions, making conversations more inclusive and effective. This ability is valuable in scenarios where clarity and real-time feedback are crucial, such as telehealth, remote banking, and customer support.

RTT complies with European accessibility mandates, ensuring that voice and video calling services meet regulatory standards. By incorporating RTT, developers can offer a more inclusive communication experience, catering to users with diverse needs and preferences.

Note

RTT is an accessibility compliance requirement for voice and video platforms in the EU starting June 30, 2025. For more information, see Directive 2019/882.

Next steps

Mobile Numbers for SMS

The Mobile Numbers for SMS feature is now in public preview from Azure Communication Services. This feature is available in 10 countries across Europe including Australia, providing businesses with locally trusted two-way messaging capabilities.

Key Benefits

Dedicated Sender Identity: Supports conversational scenarios across industries like healthcare, retail, public sector, and finance.
Interactive Conversations: Facilitates reply-enabled SMS flows with country-specific mobile numbers.
Improved Deliverability: Uses number types accepted and prioritized by local carriers.

Use Cases

Inbound Communication: Customers can reply to alerts, offers, or initiate conversations, ensuring a seamless and engaging communication experience.

Next steps

Phone number types

February 2025

Calling Native SDKs add calling to Teams call queues and auto attendants

Now in general availability.

Calling Native SDKs can now place calls to a Teams call queue or auto attendant. After answering the call, video calling and screenshare are available to both the Teams and Azure Communication Services users. These features are available in the Calling SDKs for Android, iOS, and Windows.

For more information, see:

Calling Web & Graph Beta SDKs add Teams shared line appearance

Now in public preview.

Microsoft Teams shared line appearance lets a user choose a delegate to answer or handle calls on their behalf. This feature is helpful if a user has an administrative assistant who regularly handles the user's calls. In the context of Teams shared line appearance, a manager is someone who authorizes a delegate to make or receive calls on their behalf. A delegate can make or receive calls on behalf of the delegator.

For more information, see:

Number Lookup API

Now in general availability.

Azure Communication Services Number Lookup API enables you to validate the number format, retrieve insights, and look up a specific phone number using the Communication Services Number Lookup SDK. This new function is part of the Phone Numbers SDK and can be used to support customer service scenarios, appointment reminders, two-factor authentication, and other real-time communication needs. Number Lookup enables you to reliably retrieve number insights (format, type, location, carrier, and so on) before engaging with end users.

For more information, see:

New version of Azure Communication Calling client library for JavaScript

New version release of Calling Web SDK 1.34.1 is now available at https://www.npmjs.com/package/@azure/communication-calling/v/1.34.1.

Calling Web SDK 1.34.1 changes now in general availability:

Supports 720p mobile video send.
Real Time Text (RTT) - Instantly transmit text as you type while in a call, enabling seamless and immediate communication for more accessible and responsive interactions.
Collaborator role support.

Fixed an issue that caused the Web SDK bundle size to increase in versions 1.33 and 1.34.1-beta.

Updated Call.callEndReason subcodes:

Updated message for code 0/5003: "Call was ended by Azure Communication Service as the call has ended."
Added new code 401/71005: "Call failed due to a validation error in Azure Communication Services."

For more information about call end reason codes and subcodes, see Troubleshooting call end response codes for Calling SDK, Call Automation SDK, PSTN, Chat SDK, and SMS SDK.

Live now.

In response to customer feedback and multiple customer interviews, we’re excited to announce an update to the navigational model of our technical documentation. We adjusted the structure of our docs site navigation to make it quicker and simpler than ever to find the information you need when you need it.

For more information, see Azure Communication Services technical documentation table of contents update | Microsoft Community Hub.

January 2025

SMS Opt-Out Management API

The Opt-Out Management API is now available in Public Preview for Azure Communication Services.

The Opt-Out Management API empowers developers to programmatically manage SMS opt-out preferences, enabling businesses to handle opt-out workflows seamlessly and ensure compliance with global messaging regulations.

Unlike static opt-out management processes, where handling preferences is often manual and disconnected, this API introduces automation and flexibility. With endpoints for adding, removing, and checking opt-out entries, developers can centralize management across multiple channels and create smarter workflows that align with customer preferences and regulatory requirements.

For example, a business can manage custom opt-out workflows where customers opt out via SMS and later update their preferences through a web portal. The Opt-Out Management API ensures these changes are synchronized in real time, providing businesses with complete control over compliance and transparency.

Importance of opt-out management

Effective opt-out management is a cornerstone of responsible and compliant SMS communication. The Opt-Out Management API provides the tools to:

Ensure Compliance: By automating opt-out workflows, businesses can meet regulatory requirements, reducing the risk of violations.
Improve Efficiency: Replace manual processes with automation to streamline operations, particularly for large-scale messaging campaigns.
Enhance Customer Trust: Enable customers to manage their preferences across different platforms, ensuring a transparent and consistent experience.

Sample code

string connectionString = "<Your_Connection_String>";
SmsClient smsClient = new SmsClient(connectionString);
smsClient.OptOuts.Add("<from-phone-number>", new List<string> { "<to-phone-number1>", "<to-phone-number2>" });

Get started with opt-Out management

For more information, see:

Real Time Text (RTT)

Real Time Text (RTT) is a system for transmitting text over the internet. RTT enables the recipient to receive and display the text at the same rate as it is being produced without the user pressing send. This ability provides the effect of immediate and continuous communication.

Animated image simulating real time text between people in a meeting and a person using a mobile device.

Unlike traditional chat messaging, in which the recipient sees the full message only after it's completed and sent, RTT provides an immediate and continuous stream of communication.

For example, in a video or voice call, a user typing "Hello, how are you?" sees each character appear on the recipient’s screen as they type: "H," then "He," then "Hel," and so on. This messaging of text creates a dynamic, conversational experience that mirrors spoken communication.

We added new APIs to Azure Communication Services Calling SDKs so that developers can easily and seamlessly integrate RTT into voice and video calls. These APIs also work in tandem with other accessibility features such as closed captions.

Why RTT support is important

RTT is an accessibility feature, and Microsoft is committed to accessibility. This commitment is relevant to Azure Communication Services. The ability to inclusively reach as many humans as possible is an essential value proposition of a developer platform that connects people to people; and people to AI.

Here’s how RTT makes a difference:

Better Accessibility: RTT empowers individuals with speech or hearing impairments to actively participate in conversations. Its real-time functionality ensures their input is received as fluidly and immediately as spoken words, creating equitable and inclusive communication experiences.
Enhancing Clarity: In environments where background noise or technical limitations affect audio quality, RTT serves as a reliable text-based alternative to convey important messages accurately.

As communication moves increasingly to internet-based platforms, features like RTT play a critical role in making digital interactions more inclusive and accessible.

RTT isn't only a valuable feature, it's also essential for meeting global accessibility standards. Under the European Accessibility Act (Directive (EU) 2019/882), voice and video calling services in the European Union are required to support RTT by June 2025.

Azure Communication Services is committed to providing solutions that meet these evolving standards. We want to ensure that all users, regardless of ability, can engage in meaningful and accessible communication.

Next steps

Calling Native iOS SDK enabled picture-in-picture (PiP)

Multitasking is an essential part of how we work and communicate today. With this in mind, Azure Communication Services introduces picture-in-picture (PiP) mode for video calling applications. This powerful feature enhances user experience by enabling a video stream to continue in a floating, movable window while users navigate other applications on their devices.

Why we need picture-in-picture (PiP) mode

PiP mode lets users keep their video calls visible and uninterrupted as they switch between apps or multitask. For example, healthcare professionals can input electronic health records (EHR) in Epic while maintaining video communication with patients. Similarly, users in industries like banking or customer service can seamlessly switch to other tasks without ending the call.

How it works

The Native Calling SDK and UI make it simple to implement PiP in your app. It provides built-in features to:

Join calls: Start and manage calls effortlessly.
Render video streams: Display local and remote video streams within the PiP window.
Manage permissions: The SDK handles user consent and system requirements, ensuring smooth operation of PiP.

PiP keeps calls active in both the foreground and background. This ability ensures uninterrupted communication while users:

Navigate to other apps.
Switch between video streams.
Return to the calling experience instantly via the floating PiP window.

Why PiP matters

A traditional full-screen video UI can limit multitasking, but PiP empowers users to stay productive without sacrificing connectivity. Key benefits include:

Improved workflow in multitasking scenarios.
Continued access to video calls while using other apps.
An intuitive user interface with minimal interruption.

Technical considerations

PiP functions depend on the capabilities of the device, such as CPU performance, RAM, and battery state. Supported devices ensure the PiP window is visible, movable, and easy to use, regardless of the app in focus.

This feature further enhances the Azure Communication Services UI Library, enabling customers like Contoso to maintain active calls, even when navigating between custom activities like chat or task management.

For more information, see Enable picture-in-picture (PIP) in an application.

Explicit consent for Teams meetings recording and transcription is now generally available in the Web calling SDK, enhancing user privacy and security. This feature ensures that participants must explicitly consent to being recorded and transcribed, which is crucial in environments with stringent privacy regulations.

When a Teams meeting recording or transcription is initiated, participants' microphones and cameras are disabled until they provide consent using the new Azure Communication Services API. Once consent is given, participants can unmute and enable their cameras.

If a user joins a meeting already in progress, they follow the same procedure. However, this feature isn't supported in Android, iOS, or Windows calling SDK, nor in the Web and Mobile UI library. Explicit consent is only supported in Teams meetings and Teams group calls, with plans to expand within the broader Azure Communication Services ecosystem.

To implement explicit consent for recording and transcription in your Teams meetings, you can use the following sample code to check if consent is required and to grant consent:

const isConsentRequired = callRecordingApi.isTeamsConsentRequired;
callRecordingApi.grantTeamsConsent();

For more information, see Manage call recording on the client > Explicit consent.

Breakout rooms in the Web Calling SDK

Breakout rooms are now available in the Web Calling SDK, enhancing flexibility and collaboration in online meetings. This feature allows participants to join smaller, focused groups within a larger meeting, boosting productivity and engagement. Whether it's dividing students into small groups for focused discussions, ensuring private and confidential discussions with clients, or conducting virtual consultations with private patient discussions, breakout rooms offer versatile and useful applications.

Breakout rooms enable participants to join another call linked to the main meeting. Users can join and return to the main room as set by the organizers. Participants can view members, engage in chat, and see details of the breakout room. Breakout room managers can access specific room information and join them.

One limitation is that Azure Communication Services doesn't support the creation or management of breakout rooms, and this feature isn't available in Android, iOS, and Windows calling SDK.

For more information, see Breakout rooms.

View Azure Communication Services survey data

Teams admins can now view Azure Communication Services survey data in Teams support tools.

When your Azure Communication Services SDKs submit a survey as part of any Teams interop meeting scenario, the survey data is now available through the Teams meeting organizer's support tools. This capability is in addition to the Azure Communication Services admins access in the Azure Monitor logs.

This update enables Teams admins analyze subjective quality feedback from their Azure Communication Services meeting participants alongside their Teams participants. The specific Teams survey dimensions are referred to as ‘rating’ and can be located here.

The Azure Communication Services survey data is available in the following Teams support tools:

Teams Call Quality Dashboard and Teams Call Analytics: Monitor and improve call quality for Microsoft Teams
Teams Call Quality Connector for Power BI: Use Power BI to analyze CQD data for Microsoft Teams - Microsoft Teams
Teams Graph API: Microsoft Graph overview and userFeedback resource type – Microsoft Graph v1.0

For more information, see Azure Communication Services End of Call Survey overview.

Identify web calling participants with custom data tags

Now developers can add up to three custom data attributes to call participants with the WebJS calling client and view them in Azure Monitor. You can use these customizable attributes to enhance your post-call analysis. Since you have control over the data creation, you can use it for A/B testing, labeling such as west coast, release version, and so on. You can use Call Diagnostics to search for these attributes or create custom queries with Log Analytics.

For more information, see Tutorial on how to attach custom tags to your client telemetry.

December 2024

Teams user interop calling

Our applications can now directly call individual Microsoft Teams users. Those Teams users can be using Microsoft Teams or an authenticated Azure Communication Services Calling SDK endpoint. This feature makes Teams interoperability more complete. You can build custom apps connecting people to:

Individual Teams users
Teams call queues and Auto Attendant
Teams meetings

You can use these features in business-to-coustomer (B2C) contact center and meeting applications to keep external customers in highly tailored websites and app experiences. You can also use this feature to keep all employee and agent communication activity in a single hub: Teams.

For more information, see Capabilities for Microsoft Teams users in Azure Communication Services calls.

SMS support for 10 digit long code

Ten digit long code (10DLC) for SMS is now in public preview. Support for 10DLC enables enterprises with a trusted and scalable messaging solution to connect with their customers efficiently and compliantly.

The 10DLC SMS dedicated messaging channel enables businesses to send messages using local phone numbers. 10DLC offers a unique, registered phone number for your business, enhancing trust and ensuring compliance with carrier regulations. Perfect for transactional alerts, promotional messages, and customer service, 10DLC ensures higher message deliverability while adhering to industry standards.

Benefits of Using 10DLC SMS

Improved Deliverability

A 10-digit number ensures higher message deliverability compared to traditional long codes, making it an effective way to ensure your messages reach your customers.
Local Presence

Using a local 10-digit number provides a more personal and trusted connection with your customers, increasing engagement and response rates.
Cost-effective

Using a 10-digit number offers a more affordable option compared to short codes, providing businesses with an efficient and cost-effective way to send high-volume messages.
Versatility

Perfect for various use cases, including transactional messages, customer support, promotions, and marketing campaigns.

For more information, see:

November 2024

Call Automation troubleshooting improvements

We improved notifications to help developers troubleshoot Call Automation. Now, you receive notifications if the CreateCall or Answer APIs fail asynchronously through the new CreateCallFailed and AnswerFailed events. Along with these events, we provide error codes for various leave and call end scenarios, helping you make informed decisions about what to do next.

We also revamped the error code documentation to offer better guidance for handling issues independently. In addition, you can now view Call Automation callback events in Azure metrics.

For more information, see:

October 2024

Enable advanced noise suppression on web desktop browsers

The WebJS Calling SDK now includes background audio noise suppression. This feature improves call quality by reducing background noise and ensuring that the speaker's voice remains clear and understandable.

This technology is useful in environments with high levels of ambient noise, such as open offices or public spaces, where extra sounds can interfere with communication. By filtering out ambient noise, noise suppression helps participants concentrate on the conversation without interruptions.

Our advanced noise suppression models can manage distracting noises, such as a dog barking and background conversations.

For more information, see Add audio quality enhancements to your audio calling experience.

Extended caller information

Incoming call notifications now include the caller line ID (CLID) and calling party name (CNAM). This information can be used to identify the phone number of an incoming call.

const incomingCallHandler = async (args: { incomingCall: IncomingCall }) => { const incomingCall = args.incomingCall; // Get information about caller console.log(callerInfo.displayName); console.log(callerInfo.identifier); };

For more information, see CallerInfo interface, Manage calls > Receive an incoming call, and Manage calls > Check call properties.

Remote mute VoIP meeting participants

For customers to conduct disruption-free group meetings, virtual appointments, and business-to-consumer (B2C) engagements, they often require controls to manage noise from inattentive participants. A participant might be driving and speaking to their friends without realizing that their noise and conversation is being relayed to participants in the meeting. The ability to remotely mute a VoIP participant comes handy in such situations. It enables another participant to remotely mute one or more VoIP participants in the call. Participants who are muted can unmute themselves when they need to speak.

The ability to remotely mute a participant is now generally available for calls with the following specific functions:

A VoIP user remotely mutes all other VoIP participants in an Azure Communications Services Rooms and group calls using the following API operation:
```
await call.muteAllRemoteParticipants();
```
A VoIP user remotely mutes one or several VoIP participants in an Azure communications services Rooms and group calls using the following API operation:
```
await call.remoteParticipants[0].mute();
```

In Azure Communication Services Rooms calls, only VoIP users with Presenter role can mute other participants to avoid undesired remote mutes.

When a local call participant mutes another participant, it raises the mutedByOthers event. This event causes the client to notify the VoIP participant that they're muted.

For more information, see Remote calls > Mute and unmute a call.

Improved Call Automation bot-to-user voice interactions

In addition to server programmability of Rooms and troubleshooting improvements, we also made an array of other improvements to Call Automation that enable more powerful bots and interactive voice response (IVR).

Hold/Unhold: Provide developers with the ability to play music while putting participants on hold through supported file formats of WAV and MP3.
Play multiple audio files: We enhanced our existing Play and Recognize APIs. Developers now have the ability to provide multiple audio files, text files, and Speech Synthesis Markup Language (SSML) inputs when requesting a Play or Recognize action.
Play barge-in: Developers can provide barge-in capability to the Play action, enabling you to interrupt a current prompt, such as hold music, with a new message such as wait time announcement.
Play started event: We enabled a playStarted event to let developers know that a play prompt started.
VoIP to PSTN transfer: Developers can now transfer VoIP users to PSTN/SIP endpoints. For inbound PSTN calls, the call connection object now contains the PSTN number the user dialed.

For more information, see Call Automation overview.

Enhance email communication with inline attachments

Email service now offers a public preview of inline image attachments.

Email communication is more than just text. It's about creating engaging and visually appealing messages that capture the recipient's attention. One way to engage email recipients is by using inline attachments, which enable you to embed images directly within the email body.

Inline attachments are images or other media files that you embed directly within the email content, rather than sending as separate attachments. Inline attachments let the recipient view the images as part of the email body, enhancing the overall visual appeal and engagement.

Using inline attachments

Some reasons to use inline attachments:

Improved Engagement: Inline images can make your emails more visually appealing and engaging.
Better Branding: Embedding your logo or other brand elements directly in the email can reinforce your brand identity.
Enhanced User Experience: Inline images can help illustrate your message more effectively, making it easier for recipients to understand and act on your content.

Benefits of using CID for inline attachments

We use the HTML attribute content-ID (CID) to embed images directly into the email body. Using CID for inline attachments is considered the best approach for the following reasons:

Reliability: CID embedding references the image data using a unique identifier, rather than embedding the data directly in the email body. CID embedding ensures that the images are reliably displayed across different email clients and platforms.
Efficiency: CID enables you to attach the image to the email and reference it within the HTML content using the unique content-ID. This method is more efficient than base64 encoding, which can significantly increase the size of the email and affect deliverability.
Compatibility: Most email clients support CID, ensuring that your inline images are displayed correctly for most recipients.
Security: Using CID avoids the need to host images on external servers, which can pose security risks. Instead, the images are included as part of the email, reducing the risk of external content being blocked or flagged as suspicious.

For more information, see:

Connect multiple custom domains per email resource

Developers can now connect multiple custom domains with the same Azure Communication Services resource. This feature enables Developers to manage their Azure Communication Services resources more effectively to support various business applications or customers using different custom domains. This feature is currently in public preview.

Some scenarios in which connecting multiple custom domains is useful:

Messaging organizations that need to support multiple custom domains across several applications can use one Azure Communication Services resource to manage and support these applications, reducing resource management efforts.
SaaS service providers can manage many customers with fewer Azure Communication Services resources.

Note

We enable customers to link up to 100 custom domains to a single communication service resource. All Mail-From addresses configured under these custom domains are accessible for the communication service resource. You can only link verified custom domains.

For more information, see Connect a verified email domain

September 2024

Native UI Library customization and accessibility

We have a suite of new features for the open source Calling Native UI Library that provide enhanced customization options and improved accessibility for developers building communication experiences on Android and iOS. Developers can use these APIs to make video calling better fit their brand identity, provide improved user experiences, and ensure their services are accessible to a wider audience.

Empower brands

You can now use the Native UI Library to:

Change interface colors to match brand themes.
Customize call title and subtitle for personalized interactions.
Configure the button bar by adding, removing, or modifying action buttons to suit specific business workflows.

Use cases

Healthcare Providers

A telemedicine platform can now align in-call interfaces with its brand colors, giving patients a familiar and trustworthy experience. Customizing the call title to display Telemedicine Session and adding subtitles like Dr. Jane Doe help ensure that patients know exactly whom they’re speaking with. Developers can further tailor the call interface by adding or removing buttons, such as a custom End Consultation button.
Custom Workflows for Customer Support

Enterprises providing customer support through calling can now use customized buttons to streamline the user experience. For example, instead of a generic button layout, they can configure buttons like Hold, Transfer to Supervisor, or Open Ticket to match their specific operational workflows. Custom workflows improve agent efficiency and enhance customer satisfaction.

Side-by-side screen capture of mobile phone screens comparing unbranded to branded experiences.

Captions components

Accessibility is a key consideration for businesses aiming to reach diverse audiences. Closed captions for Azure Communication Services and Teams interop calls can improve the communication experience for users with hearing impairments. You can also use closed captions in situations where audio clarity may be compromised such as noisy environments.

For more information, see Native UI Library tutorials:

Call Recording reliability enhancements

We introduced new functions in bring your own storage (BYOS) for call recording. The enhancements provide customers with the option to download their recordings and receive notifications if recording uploads to their storage fail due to misconfiguration.

When the first attempt to upload to a customer’s blob storage fails, status and error codes are provided. These codes address common issues such as:

Managed Identity not enabled
Permissions not set up correctly
Container does not exist
Invalid container name or storage path

These error messages help reduce the loss of recordings by providing timely notifications for manual action (such as direct download) and guiding customers to resolve configuration issues for BYOS.

For more information, see Bring your own Azure storage overview.

August 2024

Enhance custom app experiences with Microsoft Teams

We’re announcing a set of enhancements for developers building custom app and website experiences that connect to users on Microsoft Teams. Azure Communication Services and these new capabilities are especially tailored for business-to-consumer (B2C) interactions where an external user (the consumer) talks to an employee that is using Teams (the business).

In-Teams enhancements:

Breakout Rooms
Together Mode
Enhanced Audio

Joining Teams made easier:

Short URL
Join by Meeting ID

Together mode: Bring everyone into the same room

We now support Microsoft Teams' Together Mode in public preview, enhancing the virtual meeting experience for participants joining through Azure Communication Services. This integration enables Azure Communication Services participants to render the Together Mode stream, creating a shared background that makes it feel like everyone is in the same room. It’s a great way to reduce meeting fatigue and help participants feel more engaged and attentive.

Together Mode is useful for making virtual gatherings more immersive and interactive. Whether you're hosting a team meeting, a virtual event, or a classroom session, this feature can make your meetings feel more connected. Plus, organizations can customize these virtual environments to reflect their brand or meeting context through the Teams Developer Portal. Just a heads-up, Teams users need a Teams Premium license to use custom Together Mode scenes.

For more information, see Together Mode.

Breakout rooms: Enhance virtual collaboration

Continuing our efforts to make virtual meetings a more dynamic and interactive experience, Microsoft Teams introduces breakout rooms integrated with Azure Communication Services for an optimized experience. Currently in public preview, this function enables you to divide your meetings into smaller, more focused groups, enhancing the dynamism and engagement of discussions.

Breakout rooms are perfect for diving into specific areas without the distractions of a larger meeting. Whether you're working on a team project, hosting a classroom session, or conducting group therapy, breakout rooms help facilitate in-depth conversations and active participation. This ability leads to more efficient and productive meetings.

Teams administrators can easily manage the availability of breakout rooms through meeting policies, ensuring they're used effectively. Currently in public preview, this integration offers a glimpse into the future of virtual collaboration, making online meetings more engaging and interactive.

For more information, see Tutorial - Integrate Microsoft Teams breakout rooms.

Enhanced support for audio conferencing: Ensuring reliable connections

Microsoft Teams revolutionized seamless communication during virtual appointments by enabling a single Teams meeting to have multiple audio-conferencing setups. This means that participants can join through the most optimal phone line, ensuring they stay connected even if they face internet issues.

Azure Communication Services now exposes this configuration, enabling developers to provide the most optimal phone line to their customers. This feature not only enhances the reliability of virtual appointments but also ensures that participants can always stay connected, making virtual meetings more efficient and stress-free.

For more information, see Teams Meeting Audio Conferencing.

Short URL support - web and native

Sharing meeting links just got easier with the new short URL format for Microsoft Teams, now supported by Azure Communication Services. This update enables you to share meeting links more conveniently, making the process smoother for everyone involved.

We updated our SDKs to accommodate this new format, so developers need to update their SDKs to take advantage of it. The shorter URLs not only simplify the sharing process but also enhance the overall user experience by making links easier to distribute and manage.

For more information, see Quickstart: Join your calling app to a Teams meeting.

Join a Teams Meeting by ID – native

Azure Communication Services now supports joining Microsoft Teams meetings using a meeting ID and passcode. This feature enables developers to build native applications for iOS, Android, and Windows that connect to Teams meetings with simple, manually entered credentials found in the event invite.

We enabled this straightforward method of joining meetings to makes it easier to stay connected and collaborate across various platforms. This update enhances security and convenience, ensuring seamless access to your Teams meetings.

For more information, see Manage calls for Teams users > Join a Teams meeting.

More features and enhancements

Real-time transcription
Real-time audio streaming
Server programmability for Rooms
Rich text support

Real-time transcription: Instant insights from your calls

Azure Communication Services now offers real-time transcription in public preview, providing developers with immediate text output from call audio. This feature is incredibly useful for analyzing conversations and gaining insights that can inform business decisions or assist agents in real-time.

With integration into Azure AI's Speech-to-Text service, real-time transcription supports over 140 languages, making it easy to incorporate speech recognition and transcription into your applications. This capability enables you to capture and transcribe audio seamlessly, providing a valuable resource for various use cases

By combining these transcriptions with large language models (LLMs), you can gain more insights such as suggested next steps, summaries, intent, and sentiment analysis.

For more information, see:

Real-time audio streaming: Capture and analyze conversations

Building on the power of real-time capabilities, developers now have access to real-time audio streams. Access to real-time audio streams enables developers to create server applications that capture and analyze audio for each participant on a call as it happens.

By integrating audio streaming with call automation actions or custom AI models, you can unlock various use cases. These use cases include natural language processing (NLP) for conversation analysis, voice authentication using biometrics, and providing real-time insights and suggestions to agents during active interactions

For more information, see:

Server programmability for Rooms: Enhance virtual appointments

Real-time programming support for Rooms calls through Azure Communication Services is now in public preview, enabled through the Call Automation API. The first feature in preview enables PSTN dial out from Rooms. PSTN dial out enables independent software vendors (ISVs) to integrate multiple third-party professional services over PSTN into virtual appointments.

For example, interpreters, social services representatives, and other professionals can join telehealth appointments or virtual courtrooms over PSTN. With this new capability, developers can manage these scenarios efficiently, providing robust audio-conferencing features for virtual appointments.

This is just the beginning. Over the coming year, we plan to enhance this integration further, adding AI features to support various virtual appointment scenarios, making the process even more streamlined and effective.

For more information, see Virtual Rooms overview > How to conduct calls in Virtual Rooms.

Rich text support

Azure Communication Services Chat now supports Rich Text Editor and inline image upload in both the Chat SDK and Web UI library. With this release, the chat experience is more dynamic and visually appealing. The following features are now available:

Different text styles, including bold, italic, and underline, to make messages stand out.
The ability to create bulleted and numbered lists for better organization.
Options to adjust text indent for improved readability.
The ability to add and update tables to better structure data.

The Web UI library also now supports the Rich Text Editor in both the ChatComposite and the CallWithChatComposite.

ChatComposite

CallWithChatComposite

To get started:

Rich Text Send Box.
Rich Text Editor Support for ChatComposite.
Or check our storybook on aka.ms/acsstorybook.

July 2024

Closed Captions - Native UI Library

Closed Captions are now generally available in the Native UI Library for Android and iOS. This feature applies to a range of scenarios in which closed captions are essential, enhancing the experience for users with hearing impairments and ensuring inclusivity.

Closed Captions in the Native UI library streamline the integration between Azure Communication Services and Microsoft Teams, making it easier for users to connect and collaborate seamlessly. It simplifies the process and enhances the user experience.

For example, a multinational law firm with a diverse workforce can use closed captions during video conferences to ensure that all employees, regardless of language ability or hearing ability, can fully take part. For example, in meetings involving complex legal discussions, closed captions can help non-native speakers follow along more easily. Additionally, the firm can use this feature during interop scenarios with Microsoft Teams, ensuring seamless communication with clients and partners.

For more information, see:

Rooms roles and capabilities - Native UI Library

The Native UI Library for Android and iOS now includes Rooms Integration in general availability, offering enhanced roles and capabilities for call participants. This integration offers customers greater flexibility and control over their calls, keeping the management on the customer side.

Consider a corporation hosting a virtual town hall meeting with employees worldwide. With Rooms Integration, the company can assign roles such as presenter, attendees and, consumer, ensuring a structured and organized meeting environment. This setup is crucial for keeping order in large meetings, allowing for efficient information dissemination and productive Q&A sessions, enhancing organizational communication and engagement.

To understand how to configure a standard Rooms architecture for validating role assignments and creation, see the following diagram.

The Rooms API enables developers to create rooms, manage users, and adjust the lifetime of rooms. The Rooms API is a back-end service separate from the UI Library.

For more information, see:

Now in general availability, share files during a Microsoft Teams meeting with Azure Communication Services Chat service. File sharing enables participants to share documents required for daily business needs such as product information, brochures, or follow-up care instructions.

Use this function to enhance the experience in Teams meetings. File sharing makes it easier for users to collaborate over documents and ask clarifying questions as needed to finish business processes. Business processes can include opening an account, going over results, providing prescriptions or follow up care instructions, and many other scenarios.

For more information, see:

Support for Teams Breakout rooms

The JavaScript Calling SDK now supports Microsoft Teams Breakout rooms in public preview. Azure Communication Services native participants and Microsoft 365 participants using the Calling SDK can participate in Teams meetings breakout rooms. Support for Teams Breakout rooms brings more flexibility and collaboration opportunities to your virtual meetings.

What are Breakout Rooms

Teams Breakout rooms enable meeting facilitators to create separate, smaller sessions within a larger Teams meeting. This feature is useful for various scenarios, such as:

Healthcare: During a group virtual visit with healthcare providers, the meeting organizer can assign patients to breakout rooms to discuss specific areas before reconvening in the larger group session. Healthcare providers can visit each breakout room to check in with patients individually.
Legal: In a virtual courtroom hearing, a defendant and their attorney can join a breakout room for a private side-bar conversation.
Conferences: During a virtual industry conference, the meeting organizer can place attendees into separate discussion groups with focused subjects, before coming back to the larger meeting to share insights with the broader audience.

How does it work

Microsoft Teams users can create breakout rooms for scheduled meetings. Meeting organizers can assign Calling SDK participants to individual breakout rooms. Participants can seamlessly join and move between breakout rooms and the main meeting, just like any other Teams user.

Why is this important

The ability to include Azure Communication Services users in Teams breakout rooms enhances the collaborative experience, making it more inclusive and versatile. Whether you're conducting a training session, hosting a workshop, or facilitating a brainstorming session, breakout rooms provide the structure needed to foster meaningful interactions and productive discussions.

Get started today

To start using this feature, ensure that you have the latest version of the Calling SDK. For more information about implementing and using Teams Breakout rooms, see Tutorial - Integrate Microsoft Teams breakout rooms.

End of call survey - native

The End of Call Survey enables developers to customize questions to collect feedback at the end of a call. This feature is in general availability. By gathering valuable insights directly from users, developers can make informed decisions to enhance their services effectively. This feature is now generally available for Android, iOS, and Windows platforms.

Imagine a healthcare provider using this feature to gather feedback after telemedicine consultations. By customizing questions to inquire about the clarity of communication, ease of access, and satisfaction with medical advice, the provider can quickly identify areas needing improvement. This immediate, specific feedback helps the provider enhance patient care quality, streamline operations, and increase patient satisfaction.

For more information, see:

End of Call Survey Tutorial: End of Call Survey

Transfer to voicemail

Now in general availability, Microsoft Teams organizers can configure call participants to transferred directly into a Teams user’s voicemail, bypassing ringing the Teams user. This is useful when the transferor knows the transferee is unavailable to take the call.

For more information, see Transfer calls.

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What's new in Azure Communication Services

June 2025

Teams Phone extensibility

Limitations of previous solutions

Teams Phone extensibility benefits for CCaaS developers

Key Features

Join the Azure Communication Services Technology Adoption Program (TAP)

Next steps

May 2025

Background Blur for Android Mobile browsers

Next steps

Mobile Browsers support sending 720p resolution video

Next steps

April 2025

1080p Web Send

Next steps

Dual Pin 720p videos

Next steps

March 2025

Integrate Real Time Text into your apps

Next steps

Mobile Numbers for SMS

Key Benefits

Use Cases

Next steps

February 2025

Calling Native SDKs add calling to Teams call queues and auto attendants

Calling Web & Graph Beta SDKs add Teams shared line appearance

Number Lookup API

New version of Azure Communication Calling client library for JavaScript

Updated navigation for technical documentation

January 2025

SMS Opt-Out Management API

Importance of opt-out management

Sample code

Get started with opt-Out management

Real Time Text (RTT)

Why RTT support is important

Next steps

Calling Native iOS SDK enabled picture-in-picture (PiP)

Why we need picture-in-picture (PiP) mode

How it works

Why PiP matters

Technical considerations

Explicit consent for Teams meetings recording and transcription

Breakout rooms in the Web Calling SDK

View Azure Communication Services survey data

Identify web calling participants with custom data tags

December 2024

Teams user interop calling

SMS support for 10 digit long code

Benefits of Using 10DLC SMS

November 2024

Call Automation troubleshooting improvements

October 2024

Enable advanced noise suppression on web desktop browsers

Extended caller information

Remote mute VoIP meeting participants

Improved Call Automation bot-to-user voice interactions

Enhance email communication with inline attachments

Using inline attachments

Benefits of using CID for inline attachments

Connect multiple custom domains per email resource

September 2024

Native UI Library customization and accessibility

Empower brands

Use cases

Captions components

Call Recording reliability enhancements

August 2024

Enhance custom app experiences with Microsoft Teams

Together mode: Bring everyone into the same room

Breakout rooms: Enhance virtual collaboration

Enhanced support for audio conferencing: Ensuring reliable connections

Short URL support - web and native

Join a Teams Meeting by ID – native

More features and enhancements

Real-time transcription: Instant insights from your calls

Real-time audio streaming: Capture and analyze conversations