APIs for Dummies: Everything You Need to Know
Have you ever wondered how the apps on your phone are able to pull in data and functionality from various different sources? How is your social media app able to seamlessly integrate with your phone‘s camera and contact list? The answer lies in APIs.
API stands for "application programming interface". In simple terms, an API allows different software applications to talk to each other and exchange data or functionality, even if they were written by different developers in different programming languages.
APIs provide a standardized way for one piece of software to request data or actions from another independent system, without needing to understand the nitty gritty details of how that other system works under the hood. The API specifies the types of requests that can be made, how they should be made, and the format of the data that will be returned.
Why Are APIs So Important?
APIs play a crucial role in today‘s hyper-connected digital world. They are the unsung heroes that allow data, functionality and value to flow between disparate systems.
Some key benefits of APIs include:
1. They enable automation
APIs allow developers to write a few lines of code that hook together the capabilities of multiple platforms to execute complex automated processes. Actions in one system can automatically trigger appropriate reactions in other connected systems.
2. They allow the creation of powerful solutions
By making it easy to seamlessly combine datasets, features and intelligence from multiple specialized platforms, APIs enable developers to rapidly build powerful applications that are far more than the sum of their parts.
3. They are a business asset
For the companies that offer them, APIs make their platforms more valuable by enabling customers to build an ecosystem of integrations and custom solutions around the core product. A strong API helps drive platform adoption and stickiness.
The Main Types of Web APIs
Web APIs come in several different styles, but some of the most common types you will encounter include:
REST APIs
REST stands for Representational State Transfer, and is an architectural style for building web services. REST APIs expose a set of URL endpoints corresponding to the resources/nouns available in the system (e.g. /users or /products). The actions that can be taken on those resources are mapped to HTTP methods like GET, POST, PUT and DELETE.
For example, making a GET request to /users/123 would retrieve the details of the user with ID 123, while a DELETE request to the same URL would delete that user record from the system. POST requests are generally used to create new records, while PUT requests are used for updating existing records.
SOAP APIs
SOAP stands for Simple Object Access Protocol. It‘s a protocol specification for exchanging structured data between systems. SOAP relies exclusively on XML to encode data, and usually transmits via HTTP.
SOAP APIs tend to be more rigid and complex than REST APIs due to their extensive use of XML schemas to strictly define the structure, data types, and terminology of API requests and responses. However, this rigorous standardization is appealing for some enterprise use cases.
GraphQL APIs
GraphQL is a query language and runtime for APIs. Developed internally by Facebook, it was released publicly in 2015.
The key idea behind GraphQL is to give API clients more control over exactly what data they want to fetch. Instead of working with rigid server-defined endpoints, a GraphQL API exposes a schema describing all the available data types and fields, and lets the client construct its own custom queries to fetch whatever combination of data it needs.
This eliminates the problem of over-fetching data that‘s common with REST APIs. GraphQL also has a handy subscription mechanism for pushing real-time updates to clients.
RPC APIs
RPC APIs model their actions as remote function calls. Instead of accessing resources through URL-encoded parameters, the client simply sends a request to a server-defined function, passing arguments if necessary. The server executes the function and sends a response back.
gRPC is a popular open source framework, developed by Google, that makes it easy to create high-performance RPC APIs in a variety of programming languages.
Synchronous vs Asynchronous APIs
Another important API concept is the distinction between synchronous and asynchronous APIs.
With a synchronous API, when a client makes a request, it will wait for the server to finish processing and return a response before continuing its own execution. The client and server are in lockstep.
In contrast, with an async API the client can fire off a request and then continue doing other things without waiting for the result. The server will process the request in the background and notify the client when it‘s done, perhaps via a callback URL. Asynchronous APIs are more efficient for long-running jobs.
Digging Deeper into REST and GraphQL
Let‘s expand further on two of the most important API paradigms in use today:
REST APIs in Action
Here‘s an example of some data that might be returned from a REST API endpoint like GET /products/123 :
{
"id": 123,
"name": "Widget Pro",
"price": 10.5,
"in_stock": true,
"supplier": {
"id": 42,
"name": "ACME Inc"
}
}
To update the price of that product to $12.75, the client could send a PUT request to the same URL with this request body:
{
"price": 12.75
}
The API would merge those changes into the existing record and return a 200 OK status to indicate success.
To delete the product entirely, the client would send a DELETE request to the URL.
GraphQL APIs in Action
Here‘s an example GraphQL schema that models the same basic product and supplier data:
type Product {
id: ID!
name: String!
price: Float!
inStock: Boolean!
supplier: Supplier
}
type Supplier {
id: ID!
name: String!
}
type Query {
product(id: ID!): Product
products: [Product]
}
This schema defines a Product type with fields for name, price, inStock status, and its related Supplier. It also defines a top-level "Query" type with two available queries: one to look up a specific Product by ID, and one to list all Products.
To fetch just the name and price of Product 123, the client could send this query:
query {
product(id: "123") {
name
price
}
}
And the server would return:
{
"data": {
"product": {
"name": "Widget Pro",
"price": 12.75
}
}
}
How to Integrate an API
When you find an API that you want to use in your application, the typical integration process looks like this:
Sign up for the API provider‘s service and obtain your authentication credentials, usually an API key or OAuth token.
Find the API documentation and example code for your programming language of choice.
Install any helper libraries or SDKs provided by the API vendor to simplify development.
Write code to initialize the API client with your credentials and make your first test request.
Integrate the API calls into your application logic, mapping the returned data into your app‘s data structures and UX.
Add error handling to gracefully deal with any failed requests or unexpected responses.
If the API is asynchronous, decide whether to use callbacks, promises or an event-driven approach to manage the asynchronous flow.
API Security Considerations
When you use a third-party API, you‘re placing trust in an external system and potentially sharing sensitive data. It‘s important to assess the security and reliability of APIs before integrating them.
Make sure the API uses encryption (look for https in the URL) to protect data in transit. Avoid APIs that require you to send authentication secrets like passwords in plain text.
Carefully review the API‘s documentation and terms to understand how it will use and store any data you send to it. Ensure the API provider‘s security standards and practices meet your requirements.
Finally, never expose your API credentials like tokens or API keys in frontend website code that could be viewed by anyone. Call APIs from your backend server where possible, or use secure secret storage solutions.
Real-World API Examples
Still fuzzy on what you can actually do with APIs? Here are a couple of quick real-world examples:
Random Data Generation with the Faker API
Imagine you‘re building a prototype web app and you need realistic-looking test data to populate your UI. Instead of making up fake names and addresses by hand, you could use the Faker API to generate them dynamically.
You just need to make a request to the appropriate URL, specifying how many records you want. For example, to generate 10 fake user profiles, you‘d call:
https://fakerapi.it/api/v1/users?_quantity=10
The API will return an array of randomly generated user objects complete with names, email addresses, phone numbers, profile pictures and more. Easy!
Search Result Scraping with Bright Data APIs
What if you need to pull search results data from Google, Bing or other search engines into your application? Web scraping is notoriously difficult due to CAPTCHAs, bot detection, and other anti-scraping measures.
Rather than building and maintaining your own scraping infrastructure, you can use a ready-made API service like Bright Data‘s SERP API. Just sign up for an account to get an API token, and then you can make requests to their API endpoint with your search parameters:
POST https://api.brightdata.com/dca/dataset?id=_SERP
{
"search_engine": "google",
"q": "keyword",
"num_results": 50
}
The API will return a complete set of scraped search result data matching your query, without you having to worry about the low-level scraping mechanics and proxy management.
Go Forth and API!
We‘ve covered a lot of ground in this API overview, but hopefully you now have a solid foundation to start working with APIs yourself.
Remember, every API is different, so always consult the official documentation for the specific API you want to use. Most API providers offer quickstart guides, code samples and SDKs to help you get up and running quickly.
Don‘t be afraid to experiment and try things out! The best way to cement your API knowledge is to dive in and start making requests. Before long, you‘ll be integrating APIs into your projects like a pro.
Happy API-ing!
