2. Sending Requests & Body Types

The core action inside Postman is constructing and sending HTTP requests to API servers. An HTTP request consists of a **Method**, a **URL (Endpoint)**, **Headers**, and optionally a **Body (Payload)**.

HTTP Methods Supported by Postman

Postman provides a dropdown list matching all valid HTTP request verbs. The most common are:

• GET: Retrieve data from a server (e.g. fetching a list of users). Does not have a request body.
• POST: Send data to a server to create a new resource (e.g. creating a new user profile).
• PUT: Replace an existing resource entirely with new details.
• PATCH: Apply partial updates to an existing resource.
• DELETE: Remove a resource from the server.

Request Parameters & Headers

When building requests, Postman segments them into easy-to-use tabs:

1. Params (Query Parameters): Key-value pairs appended to the end of a URL after a question mark (e.g., https://api.com/users?status=active&page=2). Postman breaks these down into a visual grid for easy editing.
2. Headers: Custom metadata passed along with the request. Crucial headers include:
   • Content-Type: Instructs the server what format the payload is in (e.g., application/json).
   • Authorization: Holds secure tokens or keys to prove identity.
   • Accept: Tells the server what format the client wants back.

Mastering Request Body Types

When sending data via POST, PUT, or PATCH, you choose how that payload is formatted under the **Body** tab:

Step-by-Step: Sending your First Request

Let’s execute an HTTP GET request against a public test API:

1. Open Postman, click the + button to open a new tab.
2. Select the method as GET in the dropdown.
3. Paste this test URL: https://jsonplaceholder.typicode.com/posts/1
4. Click the blue Send button.
5. Observe the response pane below: You will see a `200 OK` status, latency time in milliseconds, and the corresponding JSON payload containing a mock post object!