What are some popular backend APIs?

Frontend or backend APIs are mechanisms used to exchange information between different computer programs mutually.

This software-to-software interface involves data sharing, content embedding, app integrations, internal systems, etc. 

That is why utilizing APIs in web and mobile development is snowballing. According to a forecast by Verified Market Research, the market value of APIs will hit 21.06 billion USD by 2030. This figure was 3.76 billion USD in 2023. 

Correspondingly, a survey conducted by MarketsandMarkets anticipates that the value of the API management market will reach 13.7 billion USD by 2027.

It signifies the API management market has a 25.1% compound annual growth rate. Yes, its value was 4.5 billion USD in 2022. 

However, it is crucial to understand that client-side APIs are known for performing superficial tasks. All hefty server-side tasks are linked with backend APIs.

So, this guide will discuss the best APIs for server-side programming in detail. 

What is a backend or a server-side web application?

The backend is a vital part of an application that is only accessed and operated by developers, not end users.

This data access layer sets up servers, databases, operating systems and APIs to collaborate with the frontend. 

Comprehensively, all activities associated with application logic, building APIs, linking servers, authentication, database management and push notifications refer to server-side development.

So, you can say developing a web application without an interactive server-side is pointless. In addition, with several other functionalities, APIs also play a significant role in backend development. 

What is a backend API?

A digital interface that aids developers in smoothly interacting with server-side functionalities of an application is known as backend API.

In simple words, it is a set of tools that permits the backends of applications to communicate with each other. 

Likewise, Fareportal API empowers dev teams with resources to inquire about tickets, flight fares, hotel bookings, etc.

Similarly, MapBox APIs are beneficial for accessing search maps and navigational functionalities for your application. 

Top 10 APIs for Backend

Here are the leading APIs you can use for server-side development:

1. Back4app

Back4app is an open-source BaaS platform that enables developers to create backends with APIs within moments and it’s a popular API for backend development.

Yes, you can build backends of mobile and web applications with these automatically drafted REST and GraphQL APIs.

Also, you need to write minimal lines of code while using these API functionalities of Back4app.

The primary API services that Back4app offers to its users are the following:

REST API 

REST or Representational State Transfer is an approach to get web services in an adaptable manner without processing.

This architectural technology utilizes minimum bandwidth and seems flexible to use. That is why Back4app axiomatically generates and sets up REST APIs to conduct CRUD options on database classes. 

It is seamless for dev teams to access REST features under the ‘REST API Console’ while using Back4app.

Hereof, developers must enable the ‘Get’ and ‘Classes/Articles’ options to send queries. This Parse-powered API also offers cURL commands to deal with complicated programming.

Please read the article How to create a REST API for more information on this subject.

GraphQL API

GraphQL is an open-source data query engine and language to create APIs. It is a modern approach to drafting high-performing web APIs.

In addition, these APIs are beneficial to simplify complicated operations and enhance app efficiency. 

Back4app displays this option with the name of ‘GraphQL API Console.’ This BaaS platform automatically deploys GraphQL APIs when dev teams build database models.

Indeed, developers just need to script the mutations and queries after creating database models. Then, install and turn on the GraphQL client and link it with the API. 

Please read the article How to create a GraphQL API for more information on this subject.

2. Firebase

Firebase is one of the finest backend APIs that comes with the support of Google Inc. This closed-source Backend as a Service (BaaS) platform was founded in 2011.

With products like cloud storage, authentication, database management, notifications and code functions, Firebase is considered an ideal vendor for server-side operations.

In this regard, Firebase confers a significant number of APIs to conduct different backend communication tasks. However, we are going to discuss the significant Firebase APIs below:

Firebase Database REST API

It is one of the most appealing Firebase APIs that utilize the URL of a Realtime Database in the role of REST endpoint. You just have to add. JSON at the edge of the URL.

However, you can only address HTTPS clients using this API. Some other credentials of this API are reading, writing, removing, publishing and updating data.

Cloud Firestore API

Firestore is another advanced database of Firebase that works in the meantime. Cloud Firestore offers two types of APIs to perform distinct interaction tasks: REST and RPC.

First of all, if we talk about REST APIs under Firestore, it is helpful to perform authorization and authentication tasks. Developers also find it beneficial in fetching database metadata and managing databases. 

On the contrary, RPC is an action-based API that backs POST and GET requests. Firebase mainly uses this API type to deal with GetLocations and ListLocations requests.

FCM API

Firebase Cloud Messaging API empowers you to perform cross-platform messaging without paying anything.

Yes, FCM API allows developers to seamlessly deliver and receive messages for iOS, Android and web applications.

By the way, Firebase is not limited to only the mentioned APIs. It grants an extensive range of APIs, including Authentication, Analytics, Hosting and Crashlytics application programming interfaces.

You can robustly find all the details on the documentation page of its official website. 

3. Backendless

Backendless is a visual no-code app development platform which is popular because of its outstanding API services.

Its no-code nature eliminates the need for server-side scripting, so backend development becomes easy with ready-to-use SDKs and APIs.

You can robustly transform an established codeless logic or programming script in the form of API services through REST APIs and native SDKs.

These API services are not only completely safe but also highly extensible. 

The prominent API services that Backendless confers to businesses and developers are here:

Codeless API Services

Backendless empowers dev teams to generate API services, explain business logic and conduct tests in the absence of any source code.

These APIs act upon REST mechanisms. Besides, you can connect them with the Backendless servers with a few clicks only. By the same token, you can also utilize them as dedicated blocks. 

Instant APIs 

On the other hand, if you don’t like codeless APIs, you can choose the Instant APIs functionality of Backendless to create APIs through scripts quickly.

Yes, you can transform your Java or JS script into an API without following any particular framework. 

Service Management

This is an exciting feature of Backendless. It lets the developers present their API services and used methods on a board.

You cannot only examine the REST API operations through the Test Drive feature but also establish documentation for API services. 

REST & GraphQL APIs

Backendless typically depends on REST APIs to develop highly tailored backend logic for mobile and web applications. The core Backendless APIs that practice the REST approach are:

• Database API
• Email API
• Hive API
• Caching API
• Logging API & much more

Similarly, using the GraphQL approach for building APIs is also feasible for single endpoints while using Backendless. 

4. Hasura

Do you want to generate and deploy GraphQL and REST APIs spontaneously? If yes, don’t miss Hasura.

This data API platform was designed in 2018. Now, it has 30.6k repository stars on GitHub. Furthermore, Hasura has delivered 600 million API downloads since the beginning. It also has the ability to handle more than 10 billion API calls daily.

This platform authorizes the programmers to design secure and reusable APIs within a few minutes. You can swiftly integrate these APIs with 100 data sources, including PostgreSQL, MySQL, MariaDB, Oracle and Snowflake. 

Let’s talk about the key traits of Hasura when it comes to the development and deployment of server-side APIs:

Instant API

It is simple to obtain production-level APIs using the GraphQL engine powered by Hasura.

With in-built functionalities like subscriptions, queries and mutations, you can quickly turn your data into REST or GraphQL APIs.

Then, you can connect these APIs with a database of your choice. Also, Hasura provides support for both on-premises and cloud deployments. 

Authorization

This feature computes role-based access control for data APIs. Developers elaborate role-based permission on the sessions and schema.

In this regard, the Hasura API platform releases a unique GraphQL schema. Businesses can also set permissions through this feature according to the designation of different dev teammates. 

API Security

Security is crucial to avoid API attacks and malevolent requests. That is why Hasura permits developers to restrict role-based actions and practice API rate limiting.

Correspondingly, this API platform complies with HIPAA, ISO, GDPR and SOC2 Type II.  

Performance

Hasura is known for shipping high-performing REST and GraphQL APIs. It claims to improve the API performance 10x quicker than competitors.

Automatic scaling, end-to-end caching and swift response time are also crucial highlights of Hasura. 

5. Django

Django is a server-side web framework that follows a model-view-controller approach.

This open-source framework is typically used to build data-intensive web applications. Yes, it performs very well when it comes to dealing with complicated computing resources. 

However, you have to employ the Django REST framework hereof. Indeed, the use of Django REST Framework is common among the programming community.

Developers use this toolset to create and ship high-performing web APIs. Mainly, if you are familiar with Python and Django and willing to make serialization smoother, you should pick DRF.

Here are the core features of Django Rest Framework:

RESTful Structure

API requests conventionally depend on an endpoint, body, HTTP approach and headers under this structure. The four data types you can use here are GET, DELETE, POST and PUT. 

Model Serializer

It is an appealing feature of DRF that enables you to utilize the ModelSerializer class to switch a prototype to a serialized JSON object.

Automatically creating a set of fields and serialization validators are positive outcomes of this trait. In addition, DRF backs non-ORM and Object-relational mapping data instances. 

Authentication

The use of DRF APIs is beneficial to deal with authentication schema. This REST-based approach can verify every class mentioned in the list. The implementation of Basic and Token authentications is also straightforward here.

6. CakePHP

CakePHP is a popular server-side framework that was made public in 2005. This cross-platform framework acts upon the MVC pattern and is best for building enterprise-grade web applications and elementary projects. 

This framework confers API support for routing, testing, databases, commands, consoles, and much more. Its most recent version is documented under the name of ‘CakePHP 5.0’.

Withal, you can also get API documentation for older versions of this open-source PHP framework. 

Let’s talk about the key offerings of CakePHP hereof:

REST

CakePHP follows a REST mechanism to draft APIs. This is undoubtedly an outstanding way to approach your app’s logic.

In this regard, it relies on HTTP header and XML-centric protocol. To deploy a REST API with CakePHP, you simply need to include a few scripting lines in your config/routes.php file. 

Secure

CakePHP is considered one of the most secure PHP frameworks. Yes, this platform provides excellent protection against SQL injection, data tempering, Cross-Site Request Forgery attacks, etc.  

7. Appery.io

With 500k registered users, Appery.io is a low-code app development platform that helps build and deploy APIs efficiently.

This is basically a Backend as a Service (BaaS) provider that has published around 10k applications in the last 10 years. 

All of its API offerings are available under ‘API Express.’ Let’s talk about the key API functionalities one by one:

Instant APIs

This is an exciting feature that enables you to generate APIs in a robust manner using the REST approach. You just have to transform your enterprise assets in the form of APIs utilizing this feature.

Integration & Management

Converting your mobile app assets into APIs with API Express is seamless. Yes, you don’t have to rescript the mobile application again to generate these interfaces.

Similarly, the API management of Appery will definitely impress you. It constructs a RESTwall for developers to keep an eye on API usage. Also, this feature confines the API access and improves security.

SOAP Services Integration

If you already use SOAP-centric service, you can seamlessly connect it with Appery. Hereof, you don’t have to convert the SOAP into REST.

You must integrate the SOAP with the mobile application through the WSDL file and make some arrangements. Now, you can run the SOAP service as a REST service. 

Cloud & Onsite Deployments

Businesses that pick cloud service from Appery wouldn’t have to spend their engineering hours installing software and hardware resources.

However, if you want more control over your APIs and mobile applications, Appery’s team is ready to assist you.

With limits and clustering, you can also efficiently perform on-premises installations with this BaaS provider. 

Multiple & Existing REST Services

This platform allows the developers to combine multiple REST services into the form of a single API. This collection of REST services could be used for several purposes.

On the contrary, you can renew an existing REST service to meet security needs. You can also establish distinct entries to approach endpoints for different app users. 

8. Spring Boot

Spring Boot is a highly acclaimed open-source framework for RESTful services and enterprise-grade applications.

This Java-based tool was released in 2014 by Rod Johnson. Right now, it has 40k repository forks and 71k stars on GitHub. 

This framework has the ability to build applications and API services with minimum configuration and depends on Java Virtual Machine (JVM).

Moreover, some prominent attributes of Spring Boot are innate support for data binding, validation, event management, and type conversion. 

Let’s talk about the key features of Spring Boot:

Convention Over Configuration

Spring Boot follows a convention over the configuration approach. This is a programming concept that frameworks utilize to decrease the number of decisions coders would have to make.

In this regard, developers have to pen the source code once, and then, they can use these scripts anywhere.

Yes, you can say convention over configuration acts upon the rule of DRY or don’t repeat yourself. 

RESTful Services

Although it is still debatable whether REST fits in the category of microservices but, it is good to know Spring Boot aids in building RESTful services.

Yes, the Java framework facilitates dev teams in constructing highly scalable backend REST APIs. These interfaces have attributes like caching, redirections, GET, POST, DELETE and PUT.  

Spring Dependency Injection

DI is another appealing feature of Spring Boot used to obtain inversion of control (IoC). In OOP models, the objects that rely on other objects are known as dependencies.

Hereof, the reliant object is named the client, and the other object is called the service. Therefore, you can say DI supplies the service to clients. 

Easy code maintenance, better testing and concurrent development are significant advantages of using dependency injections. 

9. Amazon S3 API

Amazon Simple Storage Service or S3 offers credible object storage offerings using the WS interface.

AWS introduced this product in 2006 to backlog any object. This storage deals with backups, hybrid cloud storage, disaster recovery, etc.

More than 99.99% data availability and scalability dominate this service among rivals. However, the communication approach that developers use to collaborate with this storage approach is Amazon S3 API.

This application programming interface enables developers to handle metadata, encryption, storage, retrieval, logging, and atomic updates.

Here are the key capabilities of Amazon S3 API:

Amazon S3 REST API

S3 goes with REST APIs to authenticate the requests. Indeed, the use of REST APIs is common to validate authentication appeals. Instead of writing REST API codes, it is better to utilize AWS CLI or AWS SDKs. 

Common Request Headers

Authorization, content-length, date, content-type, expect, host, and content-MD5 are the most common request headers.

First of all, if we talk about authorization, it avoids the tampering probabilities by verifying the API calls. Similarly, content-length should be in accordance with RFC 2616. 

On the other hand, MD5 examines the integrity of content and content-type classifies the resource.  

Common API Actions

The following are the common S3 API Actions:

PutObject: It authorizes the developers to include an object in the bucket. However, APIs need permission before conducting this action. 

ListObject: It is about transferring an object to a specific bucket. Don’t forget to set parameters before this action. 

CreateBucket: Simply use this API command to backlog objects in a newly constructed bucket. Withal, you must ask for authentication in this regard.  

GetBucketPolicy: It permits the users to change the policy of the chosen bucket. 

10. Socket.io

With 59.5k repository stars on GitHub, Socket.io is another trusted solution in this list. It is basically a scalable event-driven library that empowers the dev teams to build client and server APIs.

In this regard, you can run it on browsers and use Node.js for servers. This cross-platform solution follows WebSocket protocol to offer real-time interactions between the backend and the client. 

Let’s discuss the major attributes of Socket.io:

WebSocket API 

It is a modern application programming interface that promises the feasibility of bidirectional interactions between client and server. The core interfaces this API uses are CloseEvent, WebSocket and MessageEvent. 

Engine.IO Protocol

This protocol is responsible for economical and full-duplex interactions between servers and clients.

Furthermore, Engine.IO consists of packet type and payload protocols. Withal, it depends on HTTP long-polling and WebSocket frame to perform a packet encoding function. 

Conclusion

Nowadays, the digital presence of businesses through websites and mobile applications has become crucial.

Hereof, backend APIs play a significant role in developing these mobile and web applications. So, this article presents one of the finest server-side APIs.

You can choose any of the application programming interfaces according to the needs of your projects.