What is a REST API?
How does a RESTful API work?
When a client sends a request using a RESTful API, it transfers the ‘representational state’, i.e., clients and servers communicate with each other over Hypertext Transfer Protocol (HTTP).
HTTP formats used by RESTful APIs
– JSON (JavaScript Object Notation)
– HTML
– XLT
– Python
– PHP
– Plain text
JSON, XML, and HTML are popular data formats for transmitting information in a RESTful context. JSON is the most common programming language because it can represent structured data in a human-readable format that can be easily parsed and generated by machines. In certain settings, RESTful interactions can be implemented using HTTP methods such as HEAD, CONNECT, PATCH, or TRACE. There are various resource methods.
RESTful API – HTTP requests
– GET: request resources online, e.g. when calling up a website
– POST: send data to a server, e.g. via a contact form
– PUT: create and update resources that already exist on a server
– DELETE: delete resources
In specific settings, RESTful interactions can be implemented using HTTP methods such as HEAD, CONNECT, PATCH or TRACE. JSON, XML and HTML are popular data formats for transmitting information in a RESTful context.
How does a REST request work?
With a RESTful API, server resources are defined that encapsulate entities or even just nameable information and thus conceal the type of implementation on the server.
Resources in a RESTful API are identified by Uniform Resource Identifiers (URIs). The server first checks whether the client is authorised to access the resource. Once the client has been successfully authenticated, the server processes the request internally and responds with the result.
Should authentication or processing fail, then the client is notified accordingly by the client, avoiding idle time in the communication between the two systems.
As RESTful APIs use the HTTP protocol and its methods for communication between a client and a server, there’s no need for additional agreements or protocols beyond what HTTP provides.
The six principles of the REST interface
1. Client-server architecture
With a REST interface, the client, i.e. the requesting program, requests a service from the server, triggering a response. What sets the REST client-server model apart is the clear separation of roles between the data requester and the data deliverer.
2. Statelessness
REST is ‘stateless’, meaning each request from a client to the server must contain all the information necessary to understand and fulfil the request. The server doesn’t store any client context between requests. In addition, the client must authenticate itself for each request according to the system’s requirements.
3. Caching
REST also offers the possibility of caching data explicitly labelled as ‘cacheable’ or ‘non-cacheable’. The data is then cached depending on the settings and used again for identical requests. Caching, i.e. storing copies of server responses at various points in the network, improves performance.
4. Standardised interface
To ensure that all components in REST interfaces can communicate with each other and the system without any issues, they must follow identical rules. Therefore, all requests have one standardised format, and all resources are only accessible via one and the same email address.
5. Multi-layered system
In the REST architecture, the programming interface consists of several layers. Each layer/intermediate component recognises only the directly adjacent layers and cannot see beyond them. Therefore, the individual components of the RESTful API are independent of each other and can be extended or exchanged individually.
6. Code on demand
One benefit of programming interfaces is that they do not run on complex code. However, by transferring executable code to the client as part of a response, the server can temporarily extend the client’s functionality, allowing it to dynamically update its behaviour or functionality. This is referred to as code-on-demand and is the only optional constraint in REST.
What else do you need to know when working with RESTful interfaces?
There are hardly any downsides to using REST interfaces. However, if your business is not particularly digitalised, the widespread use of REST APIs to exchange data between systems could impact your API strategy.
Therefore, SMEs would do well to introduce the necessary expertise and infrastructure to address or make REST APIs available, whether as clients or servers, to harness their benefits.
Background and advantages of the REST API
The REST architectural style was published in 2000 by the American computer scientist Roy Fielding as part of his dissertation. Previously, Microsoft’s SOAP (Simple Object Access Protocol) was the most common protocol for client-server interactions.
However, SOAP has two significant disadvantages:
- Users must adhere to strict rules when interacting with the server.
- The protocol is more complex as it is based on XML.
To address these pain points, Roy Fielding developed a better alternative: the REST interface.
REST not only solves SOAP’s problems but offers three additional significant advantages:
- It offers more flexible formatting,
- it’s faster, and
- it requires a lower bandwidth.
Today, the REST API is one of the most common APIs used by major platforms, including Amazon, Facebook, X (formerly Twitter) and Google.
EBay and Amazon were the first to introduce the technology. Ebay introduced a dedicated REST API to enable not just direct visitors to access its online marketplace but also allow any website that wanted to access the Ebay API to do so—marking the beginning of today’s API economy.
Since 2006, Amazon has continued to drive the move towards cloud computing, enabling customers to interact with cloud services via the Amazon RESTful API. The economic benefits are initially similar to those of other programming interfaces.
Economic advantages of REST
- Optimised data exchange across all regions and time zones
- Easy access for external parties to in-house corporate systems
- Improved process efficiency (shorter response times, easier customisation, etc.)
- Enhanced brand awareness through optimised CX & customer acquisition
Advantages during development
– Straightforward API management with a multi-layer approach (individual settings and options to update and delete resources and components) during ongoing business operations
– More flexible API development thanks to the strict separation of the two levels (user/interface and server/data storage) and therefore improved portability, increased scalability and easy migration
– Seamless deployment or testing in new environments thanks to the flexibility to completely adapt to the existing platform type or language/syntax. Languages, mostly XML or JSON, are only specified when responding to requests.
– Shorter development cycles unlock time and cost savings, particularly in terms of ‘programming expertise’, which is in short supply due to the shortage of IT skills.
Straightforward API management – no coding skills needed, thanks to Lobster
With Lobster_data’s API management capabilities, you can set up a REST API client and server in just a few steps without programming knowledge.
The no-code-based data integration platform manages all REST communication channels centrally in its partner management section, so basic connection parameters such as communication endpoints and authentication are made available system-wide as API definitions. This is not only incredibly clear but also straightforward to maintain.
If connection parameters change, they only need to be updated in once. Meta information such as partner contact addresses, certificates, access IDs and protocol options are easy to manage and can be used system-wide.
For example, Lobster_data automatically handles HTTP authentication – regardless of whether the server requires Basic Authentication or Digest Access Authentication. A HTTP channel with the necessary data simply needs to be added to the Lobster_data profile, a highly user-friendly standard software module. The data is collected via a time-controlled input agent and sent for further processing – often data mapping.
With OAuth2 authentication, Lobster_data ensures that a request always receives a current or valid access token. If necessary, it is updated in the background of the actual request.
The integrated simulators offer excellent partner channel testing capabilities. Lobster_data can act as the server or REST endpoint and still share additional data. Monitoring features with automatic system monitoring are available as standard.
Lobster_data rapidly provides automated and error-free API documentation for each interface via a Swagger/OpenAPI interface description (JSON or YAML). Implementing the RESTful APIs with this human- and machine-readable feature accelerates interface development enormously. It also significantly reduces the chance of errors when setting up the communication, as connection parameters are always automatically updated.
Keen to learn more about Lobster_data’s API management capabilities? Contact us for a no-obligation demo. Our specialists will be happy to answer any questions you may have about your particular application. We can’t wait to show you how easy and intuitive API management is with Lobster_data.
