CN
By Piotr Jura·
April 29, 2023
·Postman Basics: Guide for API Testing
Learn Postman fundamentals for API testing. Ideal for beginners in API and web development.
Introduction
Postman is a popular HTTP client for API testing. This guide covers Postman basics for developers of all levels.
Download PostmanMaking Your First Request
- Open Postman and create a new tab.
- Select an HTTP Method.
- Enter the API Endpoint URL.
- Click 'Send' to execute.
Example: GET Request
- Select
GET
method. - Enter
https://api.example.com/users
. - Click 'Send'.
- Review the response.
HTTP Methods and Status Codes
Common Methods
GET
: Retrieve dataPOST
: Submit new dataPUT
: Update existing dataDELETE
: Remove data
Status Codes
200 OK
: Successful201 Created
: Resource created400 Bad Request
: Client error401 Unauthorized
: Authentication required404 Not Found
: Resource not found500 Internal Server Error
: Server error
Headers
Key headers:
Content-Type
: Media type of resourceAuthorization
: Authentication credentialsAccept
: Acceptable media typesUser-Agent
: Client software identifier
Query Parameters
Add parameters via the 'Params' button next to the URL bar.
Example: https://api.example.com/users?role=admin
Workspaces, Environments, and Collections
Workspaces
- Personal: Individual projects
- Team: Collaborative projects
Environments
Define variables for different setups (development, staging, production).
Collections
Group related API requests for organization and sharing.
Sharing
Exporting
- Right-click on collection/environment.
- Select 'Export'.
- Choose format and save.
Importing
- Click 'Import'.
- Upload or drag and drop file.
Automation with JavaScript
Use the Tests tab to automate tasks like token extraction.
Example:
JavaScript
const json = JSON.parse(responseBody);
pm.environment.set("TOKEN", json.token);
Advanced Tips
- Use built-in documentation
- Integrate with CI tools
- Set up API monitoring
- Create mock servers
Conclusion
Mastering Postman basics prepares you for advanced API testing and development.
Get Postman