Jun 18, 2024

A Guide to Phone Number Verification APIs, SDKs, & Repos

101 Guide: Here's what you need to know about phone verification APIs, SDKs and Repos

A Guide to Phone Number Verification APIs, SDKs, & Repos

Are you building a product that requires customer verification via phone numbers, or are you working in a brand's marketing department that uses phone number verification?

Either way, you’re probably a little confused about the technical side of SMS/OTP verification. That’s totally fair, especially if you’re from a non-technical background (like me). 

In this article, I’ll give you a 101-style view into the fundamentals of APIs, SDKs, and Repos, as well as how they relate to the “OTP verification” or “SMS verification” part of your website or app. 

Let’s start with the basic terms. 

What is an API?

An API (Application Programming Interface) is a packet of code designed to communicate and exchange data between different programs or software applications.APIs are most commonly used to transmit data, features, and functions. 

This is the best 101 video on YouTube (in my opinion) on APIs:

APIs are essential for software development, as they help developers quickly integrate services, information, and features; developing them from scratch would take infinitely longer. Organizations can also use APIs to disseminate information among different departments or regions. Frequently, app developers use them to share or import data from third parties or technical partners. 

APIs are unique because they let you share information without compromising the security of internal systems. By configuring APIs to share only certain packets of data, devs can guard confidential data without missing out on any third-party functionality. 

What is an SDK?

Think of the SDK as a sort of Lego box for developers. It contains all the necessary parts — tools, libraries, documentation, sample code — required to create applications for specific user bases, platforms, industries, services, etc. Individual SDKs are heavily customized to align with their chosen platform.

Obviously, not all SDKs work the same way. They are configured to facilitate different functions, based on their use case. For instance, the Prelude SDK serves one very specific purpose: allowing devs to call our APIs easily with very little code. 

Here’s a fantastic breakdown of what SDKs are, perfect for you if you (like me) are not a programmer:

SDKs generally come with:

  • Libraries: Pre-written code that lets devs write or “call” specific tasks or functions when integrated with a particular OS or software system quickly. 

  • Documentation: Explanation, tutorials, and references required to use the SDK effectively. 

  • Sample Code: Snippets of code or sample projects that showcase how to integrate the SDK’s features into the developer’s codebase. 

  • Dev Tools: Tools required for developers to build, test, debug and deploy software. Common examples are visual editors and debuggers.

  • APIs: As explained above, APIs are required for software components to interact with each other. Devs need the code libraries and APIs to build full functionalities in their app. 

SDKs are utilized in almost every form of software development — mobile app development, web development, game development, IoT (Internet of Things) development, integration with third-party services or platforms, you name it. They speed up development by providing ready-made components, protocols, and resources that developers can simply integrate into their codebase and get going. 

What is a repo?

Relax, we’re not talking about the repos that the Fed uses. A repo or repository means something entirely different in the context of software development. 

A repo, software repository, or code repository is a “folder on steroids.” Since almost every software development project involves multiple developers, they need a central location to store all the code they are individually writing to build a specific piece of software. This is the repo.

GitHub is the most popular code repo in the world.

The code repository stores a project’s code, files, and resources in a central location, accessible only to developers and stakeholders involved with the project. Any of these individuals can “pull” code from the repository to build new features, fix bugs, and so on. They can also “push” new code they have written to integrate it into the repo. 

Aside from simply being a folder (with many sub-folders) containing all programming folders for a certain project, repos are also equipped with features to add, delete, and modify files. They also include versioning and collecting identifiable data about the creator of each file, the time of creation, and so on. 

Repos provides two fundamental requirements for software development: online storage and codebase management. They can be thought of as GDrive or Notion, but specifically for code. 

APIs, SDKs, and repos for phone verification

As the definitions above have already clarified, APIs, SDKs, and repos vary based on their purpose. Video chat SDKs will be completely different from image hosting SDKs. APIs for building robots are nothing like APIs for integrating Instagram into your photo-editing app. 

Phone verification APIs — What do they do?

Phone verification APIs are generally provided by telecom companies or third-party service providers (like Prelude) to help developers integrate this “verification” functionality into the application they are building. 

The process the API will facilitate looks something like this:

  • The user enters their phone number into an app or site.

  • The application triggers a request to the API, as well as the user’s phone number, 

  • The API generates a unique verification code and sends it to the user’s number via SMS, WhatsApp, voice call, Viber, etc. 

  • The user receives the code and feeds it into the site or app. 

  • If the codes (sent and entered) match, the number is verified.

Instead of having to code the functionality of generating and sending a unique verification code, devs can use an API to integrate and activate this function in minutes. Phone verification APIs are perfect for actions like user verification, account registration, and fraud prevention. 

Bear in mind that an API, even after being integrated, does not reveal any personal user information or company data. It is configured to guard that data and provide only the information required (the unique verification code). 

Looking for a phone verification API? You should try Prelude

Prelude is a powerful and easy-to-use API that lets you send OTP codes worldwide using the most appropriate channel, depending on your user’s context. Businesses typically see a 20-30% increase in conversion compared with their previous provider, while saving 30-40% monthly. Prelude also detects and prevents fraud using algorithms trained on tens of millions of data points.

Behind its minimalist API, Prelude acts as a real-time broker and selects the optimal route based on your user’s context and history. It also prevents fraud transparently without requiring any additional configuration.

Learn more about the Prelude API here. Or, you could explore how to integrate the Prelude API from any language. We’re very proud that we have finally created a set of communication APIs that developers may actually like. 

Phone verification SDKs — what do they do?

Phone verification SDKs provide the necessary tools to integrate phone number verification functionality into applications or software systems. By using an SDK, developers can reduce the time and effort required to build specific features or capabilities in an application. 

SDKs generally provide the following components for developers to use:

  • Libraries and APIs that devs can use to integrate the verification functionality into their app. They contain methods for initiating verification requests, sending verification codes via SMS or voice call, and verifying the entered codes.

  • Documentation to guide the integration process, containing tutorials on available functions, parameters, error handling, and so on.

  • Sample code demonstrating how to use the SDK’s features in the real world. 

  • Customization options allow devs to modify aspects of the phone verification process, such as the content and format of messages. 

  • Security features that devs can implement to prevent unauthorized access to internal data and user information. Common features allotted by SDKs are encryption of communication channels, and rate limiting to prevent abuse.

Every SDK should ideally come with round-the-clock technical support to help developers with integration and resolving issues. Email, voice, messaging support, documentation updates, and community forums for unanswered questions should be mandatory elements of the support package. 

Dev teams can choose from SDKs tailored to different platforms and developer environments, such as iOS, Android, web apps, mobile apps, etc.

The Prelude SDK; try something smarter

You can set up the Prelude SDK to send and verify a code in 2 minutes. We have SDKs for different languages: Node, Go, Python, Ruby, Java, PHP, and C#. 

Use the SDK to call the Prelude API via your language of choice. It's exactly like calling a method and then…an SMS is sent. That’s it! It also allows users to perform retries, to perform phone number lookups and to check whether a code is valid or not.

Look through our Quickstart Guide; you’ll see how simple it is to integrate our SDK and get started with triggering verification messages via SMS, WhatsApp, Viber, etc. 

A Guide to Phone Number Verification APIs, SDKs, & Repos

Are you building a product that requires customer verification via phone numbers, or are you working in a brand's marketing department that uses phone number verification?

Either way, you’re probably a little confused about the technical side of SMS/OTP verification. That’s totally fair, especially if you’re from a non-technical background (like me). 

In this article, I’ll give you a 101-style view into the fundamentals of APIs, SDKs, and Repos, as well as how they relate to the “OTP verification” or “SMS verification” part of your website or app. 

Let’s start with the basic terms. 

What is an API?

An API (Application Programming Interface) is a packet of code designed to communicate and exchange data between different programs or software applications.APIs are most commonly used to transmit data, features, and functions. 

This is the best 101 video on YouTube (in my opinion) on APIs:

APIs are essential for software development, as they help developers quickly integrate services, information, and features; developing them from scratch would take infinitely longer. Organizations can also use APIs to disseminate information among different departments or regions. Frequently, app developers use them to share or import data from third parties or technical partners. 

APIs are unique because they let you share information without compromising the security of internal systems. By configuring APIs to share only certain packets of data, devs can guard confidential data without missing out on any third-party functionality. 

What is an SDK?

Think of the SDK as a sort of Lego box for developers. It contains all the necessary parts — tools, libraries, documentation, sample code — required to create applications for specific user bases, platforms, industries, services, etc. Individual SDKs are heavily customized to align with their chosen platform.

Obviously, not all SDKs work the same way. They are configured to facilitate different functions, based on their use case. For instance, the Prelude SDK serves one very specific purpose: allowing devs to call our APIs easily with very little code. 

Here’s a fantastic breakdown of what SDKs are, perfect for you if you (like me) are not a programmer:

SDKs generally come with:

  • Libraries: Pre-written code that lets devs write or “call” specific tasks or functions when integrated with a particular OS or software system quickly. 

  • Documentation: Explanation, tutorials, and references required to use the SDK effectively. 

  • Sample Code: Snippets of code or sample projects that showcase how to integrate the SDK’s features into the developer’s codebase. 

  • Dev Tools: Tools required for developers to build, test, debug and deploy software. Common examples are visual editors and debuggers.

  • APIs: As explained above, APIs are required for software components to interact with each other. Devs need the code libraries and APIs to build full functionalities in their app. 

SDKs are utilized in almost every form of software development — mobile app development, web development, game development, IoT (Internet of Things) development, integration with third-party services or platforms, you name it. They speed up development by providing ready-made components, protocols, and resources that developers can simply integrate into their codebase and get going. 

What is a repo?

Relax, we’re not talking about the repos that the Fed uses. A repo or repository means something entirely different in the context of software development. 

A repo, software repository, or code repository is a “folder on steroids.” Since almost every software development project involves multiple developers, they need a central location to store all the code they are individually writing to build a specific piece of software. This is the repo.

GitHub is the most popular code repo in the world.

The code repository stores a project’s code, files, and resources in a central location, accessible only to developers and stakeholders involved with the project. Any of these individuals can “pull” code from the repository to build new features, fix bugs, and so on. They can also “push” new code they have written to integrate it into the repo. 

Aside from simply being a folder (with many sub-folders) containing all programming folders for a certain project, repos are also equipped with features to add, delete, and modify files. They also include versioning and collecting identifiable data about the creator of each file, the time of creation, and so on. 

Repos provides two fundamental requirements for software development: online storage and codebase management. They can be thought of as GDrive or Notion, but specifically for code. 

APIs, SDKs, and repos for phone verification

As the definitions above have already clarified, APIs, SDKs, and repos vary based on their purpose. Video chat SDKs will be completely different from image hosting SDKs. APIs for building robots are nothing like APIs for integrating Instagram into your photo-editing app. 

Phone verification APIs — What do they do?

Phone verification APIs are generally provided by telecom companies or third-party service providers (like Prelude) to help developers integrate this “verification” functionality into the application they are building. 

The process the API will facilitate looks something like this:

  • The user enters their phone number into an app or site.

  • The application triggers a request to the API, as well as the user’s phone number, 

  • The API generates a unique verification code and sends it to the user’s number via SMS, WhatsApp, voice call, Viber, etc. 

  • The user receives the code and feeds it into the site or app. 

  • If the codes (sent and entered) match, the number is verified.

Instead of having to code the functionality of generating and sending a unique verification code, devs can use an API to integrate and activate this function in minutes. Phone verification APIs are perfect for actions like user verification, account registration, and fraud prevention. 

Bear in mind that an API, even after being integrated, does not reveal any personal user information or company data. It is configured to guard that data and provide only the information required (the unique verification code). 

Looking for a phone verification API? You should try Prelude

Prelude is a powerful and easy-to-use API that lets you send OTP codes worldwide using the most appropriate channel, depending on your user’s context. Businesses typically see a 20-30% increase in conversion compared with their previous provider, while saving 30-40% monthly. Prelude also detects and prevents fraud using algorithms trained on tens of millions of data points.

Behind its minimalist API, Prelude acts as a real-time broker and selects the optimal route based on your user’s context and history. It also prevents fraud transparently without requiring any additional configuration.

Learn more about the Prelude API here. Or, you could explore how to integrate the Prelude API from any language. We’re very proud that we have finally created a set of communication APIs that developers may actually like. 

Phone verification SDKs — what do they do?

Phone verification SDKs provide the necessary tools to integrate phone number verification functionality into applications or software systems. By using an SDK, developers can reduce the time and effort required to build specific features or capabilities in an application. 

SDKs generally provide the following components for developers to use:

  • Libraries and APIs that devs can use to integrate the verification functionality into their app. They contain methods for initiating verification requests, sending verification codes via SMS or voice call, and verifying the entered codes.

  • Documentation to guide the integration process, containing tutorials on available functions, parameters, error handling, and so on.

  • Sample code demonstrating how to use the SDK’s features in the real world. 

  • Customization options allow devs to modify aspects of the phone verification process, such as the content and format of messages. 

  • Security features that devs can implement to prevent unauthorized access to internal data and user information. Common features allotted by SDKs are encryption of communication channels, and rate limiting to prevent abuse.

Every SDK should ideally come with round-the-clock technical support to help developers with integration and resolving issues. Email, voice, messaging support, documentation updates, and community forums for unanswered questions should be mandatory elements of the support package. 

Dev teams can choose from SDKs tailored to different platforms and developer environments, such as iOS, Android, web apps, mobile apps, etc.

The Prelude SDK; try something smarter

You can set up the Prelude SDK to send and verify a code in 2 minutes. We have SDKs for different languages: Node, Go, Python, Ruby, Java, PHP, and C#. 

Use the SDK to call the Prelude API via your language of choice. It's exactly like calling a method and then…an SMS is sent. That’s it! It also allows users to perform retries, to perform phone number lookups and to check whether a code is valid or not.

Look through our Quickstart Guide; you’ll see how simple it is to integrate our SDK and get started with triggering verification messages via SMS, WhatsApp, Viber, etc. 

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