Begin by adding the REST Client extension to your Visual Studio Code environment. Once activated, create a new file with the .http extension to start defining requests.

A basic GET request looks like this:

GET https://api.example.com/status HTTP/1.1

Clicking the link above the request sends it, displaying the response in a side panel. To organize multiple tests within a single file, separate distinct requests using ###.

Managing different deployment stages is handled through environment variables. Open settings.json and configure the rest-client.environmentVariables object. Define scopes such as development, staging, and production. Shared values belong in the $shared key.

"rest-client.environmentVariables": {
    "$shared": {
        "apiVersion": "v2"
    },
    "development": {
        "host": "http://localhost:3000",
        "apiKey": "dev-secret-key"
    },
    "staging": {
        "host": "https://stage.example.com",
        "apiKey": "stage-secret-key"
    },
    "production": {
        "host": "https://api.example.com",
        "apiKey": "prod-secret-key"
    }
}

Reference these variables in your requests using double curly braces. For instance, {{host}} resolves based on the currently selected environment. Switch contexts via the status bar indicator at the bottom right.

To chain requests, capture response data using the @name directive. Assign a name to a request, then reference specific JSON paths from that response in subsequent calls.

###
# @name loginRequest
POST {{host}}/auth/login
Content-Type: application/json

{
  "username": "admin",
  "password": "securePass123"
}

For POST operations requiring a body, define the Content-Type header and provide the payload below. File uploads utilize multipart/form-data. Specify the file path relative to the project root.

POST {{host}}/upload
Content-Type: multipart/form-data; boundary=BoundaryString

file=@./documents/report.pdf

The extension also supports generating code snippets from existing requests. Right-click a request block, select the generate option, and choose the target language to retrieve ready-to-use client code.