What is a REST API?
Quick answer
A REST API is a web API that follows a common, simple style. Each kind of record, such as clients or invoices, has its own web address, and you use standard HTTP methods on it: GET to read, POST to create, PUT or PATCH to change and DELETE to remove. Answers usually come back as JSON.
Last updated
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Updated · By Robert Breen
Why it matters for a small business
REST stands for Representational State Transfer, a style described by Roy Fielding in his 2000 doctoral dissertation. You never need the theory, but you will see the words "REST API" in almost every app's developer docs. Because most apps follow the same style, once you can call one REST API you can call nearly any of them.
That matters in automation tools. When n8n, Make or Zapier has no ready-made connector for an app, you can still reach it with a general HTTP step, as long as the app has a REST API. The docs tell you three things: the address for each kind of record, which method to use, and how to log in, usually an API key or OAuth.
In a real lesson: n8n: Call Any API with the HTTP Request Node
In Call Any API with the HTTP Request Node, you help Harbor Lane Marketing pull clients from a CRM. The practice API is JSONPlaceholder, a free test service built in the REST style. The lesson calls it simply an API, but every step follows the REST pattern: the client list lives at its own address ending in /users, and a GET to it returns 10 items, one per client.
Next you add the query parameter username=Samantha and get back 1 item, Clementine Bauch. Then a second HTTP Request node sends a POST to the /posts address with the client's email in the body, filled by the expression {{ $json.email }}. The API answers with a new id, 101, which is how a REST API confirms it created a record.
Try this lesson free or read the step-by-step guide.
Common confusions
REST API vs API
API is the general idea of software talking to software. A REST API is one popular style of web API. Others include SOAP and GraphQL.
REST API vs webhook
With a REST API, your workflow asks for data when it wants it. With a webhook, the other app sends data to you the moment something happens.
Tips
- Start with a GET request: it only reads, so it can't change anything while you learn.
- Copy the exact address and method from the app's API docs instead of guessing.
- Save the login as a credential in your automation tool, never pasted into the URL.
Related terms
More n8n and automation terms
Where you use it: free lessons
- n8n: Call Any API with the HTTP Request Node (n8n, 9 min)
- What Is a Webhook? Send a Test and Watch the Data Arrive (Webhook.site, 6 min)
Frequently asked questions
- What does REST stand for?
- Representational State Transfer. It is a set of design rules for web APIs, described by Roy Fielding in 2000.
- What is the difference between REST and RESTful?
- People use them the same way. A RESTful API is one that follows the REST style.
- Do I need to code to use a REST API?
- No. In n8n the HTTP Request node lets you fill in the address, method and body in boxes, and Make and Zapier have similar steps.