What are Communication APIs?

Communications APIs, or Application Programming Interfaces, are a convenient way for developers to integrate communication features into their applications faster than building integrations from scratch. Developers can use these APIs to embed email, calendar, messaging, voice, video, and other communication tools into their application.

Communication APIs help businesses improve customer service and streamline internal communication processes while freeing up internal resources to focus on strategic initiatives.

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How do communication APIs work?

Communications APIs provide a standard framework for connecting a company’s systems with other business applications like CRMs, IoT devices, and e-commerce platforms. They allow for secure exchanges of data between systems that wouldn’t otherwise be able to communicate without the risk of manual errors or tampering.

Communication APIs can use different technologies, including: 

These APIs can be used in conjunction with cloud solutions like AWS or Azure to provide extra scalability for larger projects. 

Types of communication APIs

Communication APIs enable applications to perform various communication tasks – but not all are created equal. The quality and reliability of a communication API can depend on the features offered, ease of use, and the underlying infrastructure. 

It’s important to evaluate the different communication API vendors to ensure they meet the needs of your application and end-user. 

Here are some of the communication APIs a provider might include.

Email APIs

Email APIs provide a set of protocols and tools that allow developers to rapidly integrate email functionality into their applications. They can be used to send and receive messages as well as create and manage contacts, folders, and messages. Email APIs also allow organizations to access email data from different email providers and protocols such as Gmail, Microsoft Outlook, IMAP, POP3, and SMTP.

Email APIs can help businesses: 

  • Sync, send, and receive email natively in their applications
  • Send automated email notifications or confirmations from an app
  • Build email marketing campaigns with best-in-class deliverability 
  • Synchronize email data with internal tools, CRM systems, customer support platforms, and other business applications
  • Extract and analyze data from email messages to unlock business intelligence and personalize customer experiences

Learn more about email APIs.

Calendar APIs

A calendar API enables developers to integrate calendar functionality into their applications and websites. End users can centralize their workflows by easily creating and managing calendar events, inviting attendees, syncing calendars, setting reminders, and more.

The best calendar APIs like Nylas also offer: 

  • Automated, real-time scheduling features fast with a pre-built, customizable front-end widget
  • A central repository to capture calendar data in applications and unlock valuable insights
  • Automated reminders that send alerts and notifications across Email, Slack, and Microsoft Teams
  • Virtual calendars for people or resources that aren’t associated with an existing calendar account, such as assigning rooms for doctor appointments

Learn more about the Nylas Calendar APIs.

Messaging & chat APIs

Messaging and chat APIs are for developing apps that use SMS, MMS, and chatbots to send and receive messages. These APIs allow businesses to tailor messages to individual profiles and respond to customer inquiries conveniently – helping improve the overall customer experience. 

Video APIs

Video APIs can be used to create and manage video sessions, configure video settings, and retrieve data such as transcripts and video analytics. Additionally, video APIs provide screen sharing, recording, and audio/video quality control features.

Some common uses of video APIs include:

  • Integrating video conferencing functions to a customer service platform or a team collaboration tool
  • Building a custom video conferencing app, such as a virtual meeting platform
  • Creating a video streaming service that allows users to watch and upload videos
  • Adding live video streaming functions to a social media platform or a live event platform

Nylas offers a video conferencing feature within its calendar API that allows users to automatically generate video conferencing links by integrating with Zoom, Google Meet, and Microsoft Teams accounts.

Voice APIs

A voice API allows developers to add telephonic capabilities to their applications. Voice APIs can be used to route voice calls with global reach to phones, browsers, SIP domains, and mobile applications. They help bridge the gap between internet-based applications and the Public Switched Telephone Network (PSTN). 

Benefits of using communication APIs

Cost & time optimization

When your developers spend more time on backend infrastructure and less time on the front-end features your customers are using, you’re risking low engagement, high customer churn, and poor adoption. 

Communication APIs take away the burden of building out communications features on your own. This saves thousands of developer hours and allows you to launch new capabilities in weeks or months. 

Plus, these APIs drastically reduce the ongoing maintenance burden, bug resolution, and unforeseeable customer edge cases that every integration requires.

Improved customer experience

Communication APIs let you reinvest your team’s time and energy into delivering differentiating features that drive customer engagement. 

Businesses can quickly add various communication channels to their customer-facing applications, making it easier for customers to reach out for support and customer service teams to resolve queries quickly. Personalized messaging capabilities (such as through mail merge) also mean customers receive a more engaging, streamlined customer experience. 

Plus, real-time analytics and omnichannel engagement also give businesses greater flexibility and control in customer interactions. Businesses can track conversations and use this data to gain insights into what drives customer satisfaction. 


The flexibility of communication APIs means businesses can quickly and easily scale their communication infrastructure up or down with minimal disruption. This is ideal for rapidly scaling companies since they can expand their communication capabilities without investing in additional hardware, software, and personnel costs.

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Unlock Digital Innovation With Nylas’ Communication APIs

Nylas is the only existing platform that provides businesses of all sizes with an integrated email, contact, and calendar API solution in one place. We save developers thousands of hoursby taking most of the building off their hands. This frees up their time to focus on other priority product enhancements and better meeting customers’ needs. 

Nylas Email API

The Nylas Email API is the fastest and easiest way to connect to your users’ inboxes and stand up engaging email capabilities. It provides companies with industry-leading 99.9% deliverability, ensuring your users’ messages land in the inbox – not SPAM. Nylas is known for its highly secure, scalable architecture and highly responsive customer support team.

Nylas Calendar API 

The Nylas Calendar API is an ideal solution for developers looking to connect their applications with major calendar providers. With a single point of integration, it offers developers the flexibility to create customizable workflows for their users, providing an end-to-end scheduling experience. It also helps streamline scheduling for users by automating workflows, resulting in a seamless user experience within your app.

Nylas Scheduler

The Nylas Scheduler helps organizations easily embed automated, real-time scheduling features into their platform using pre-built front-end widgets. With no custom coding required, businesses can launch scheduling features in minutes versus thousands of hours.

The Scheduler allows end-users to simplify workflow management and offers a variety of scheduling capabilities, including schedule editors, instant booking, round-robin scheduling, group meetings, and collective scheduling capabilities. Nylas also offers virtual calendars for scheduling events for people or resources that aren’t associated with an existing calendar account. 

Nylas Contact API

The Nylas Contact API enables the access and management of contacts across other Nylas tools so you can always keep your users engaged. You can access user contacts without using any custom code, carry out bi-directional sync, and gain access to full CRUD capabilities. By helping you launch products faster through seamless integrations, Nylas maximizes user engagement and drives user efficiency across your business. 

Experience the Nylas communication APIs

Discover why Nylas is trusted by over 200,000 developers and global brands such as Upwork, Wix, Dialpad, and many more. 

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Frequently Asked Questions

What is an API?

An API (Application Programming Interface) is a set of rules and protocols that allows different software programs to communicate with each other. It acts as an intermediary between different systems, allowing them to share data. 

APIs allow developers to access the functionality of different software programs, such as web services or mobile apps. This makes it possible to integrate their own software with others without having to build an entire system themselves.

Learn more in this review of the Build vs Buy debate. 

What are APIs used for?

APIs are used in a variety of industries including e-commerce, healthcare, finance, and social media, among others. They’ve become essential in the creation of integrated and connected systems.

Some of the main uses of APIs include:

  • Enabling IoT
  • Enhancing user experience
  • Integrating with other systems and services
  • Building third-party applications
  • Automating processes and workflows

What is a REST-based communication API?

REST is an acronym that stands for REpresentational State Transfer. First presented in a dissertation from Roy Fielding in 2000, it’s an architecture style ideal for designing loosely coupled applications that communicate over HTTP.  RESTful APIs, like most communications APIs, uses HTTP requests to POST (create), PUT (update), GET (read), and DELETE data.

A REST API defines a set of functions to which developers can perform requests and receive responses, usually in JSON (JavaScript Object Notation) or XML (Extensible Markup Language) format. These functions are called endpoints, and they are the specific locations at which the API can be accessed by apps.

RESTful APIs are typically easier to work with and understand compared to other types of APIs, such as SOAP APIs. They also tend to be more scalable since they do not rely on a specific protocol or technology and can be easily consumed by a wide range of clients and systems.

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Additional Resources

Communication API Vendors
Communication API Vendors: What to Look for in 2023
best cpaas companies
11+ Best CPaaS Companies for 2023: CPaaS Providers Comparison
Build vs Buy Software Analysis
Building vs. Buying Software Debate: Email, Calendar, Contacts, and More [2023]

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