Mike MurphyAI Handyman
Subscribe
Back to tutorials

Beginner’s Guide: How to Test OpenAI API Keys in Postman

September 4, 2025 ·

In this tutorial, I will show you step-by-step how to use Postman to test your OpenAI API keys and make your first API Requests.

Description

You know how to generate OpenAI API Keys, but how exactly do you use them?

Description:
In this tutorial, I will show you step-by-step how to use Postman to test your OpenAI API keys and make your first API Requests.

What you’ll learn:

  • How to set up Postman
  • Where to find your OpenAI API key
  • How to find API Address
  • How to better understand API Documentation
  • How to test and send requests to OpenAI’s AP

**Postman API Platform:
**https://postman.com

OpenAI API Documentation:
https://platform.openai.com/docs/api-reference/chat/create

**How To Get OpenAI API Keys (Tutorial):
**https://youtu.be/Lj43aSwNpog

—————The API Request Recipe———————

**Part 1: The Address
**https://api.openai.com/v1/chat/completions

Part 2: Authorization:
Key:
Authorization
Value: Bearer YOUR_API_KEY

The Message (Body):
{
  "model": "gpt-3.5-turbo",
"messages": [
    {
   "role": "user",
    "content": "Write a 3-sentence story about a lighthouse keeper who finds a message from a sea creature."
  }
 ]
}

————————————

———————

Gear I Use:
https://mikemurphy.co/resources

**To try or buy Adobe After Effects CC 2025:
**https://mikemurphy.co/adobe (affiliate link)

**Terrapin Textures:
**https://terrapintextures.com

⭕️ **Check out my Domestika Course on Adobe Audition:
**https://mikemurphy.co/domestika

——————

✅** Chapters:**
00:00 Intro: About The Tutorial
00:12 What You Will Learn
01:01 Requirements: What You Need
01:40 Set Up Free Postman Account
02:03 Create Postman Workspace
02:24 Workspace Description
02:48 3-Part Recipe (API Requests)
03:17 Confusing API Terminology
03:43 GET Requests
04:04 POST Requests
04:24 Part 1: The Address (URL)
04:40 Open AI API Docs
05:25 Create Chat Completion URL
05:53 Base URL + Endpoint
06:23 Part 2: Authorization
07:19 Part 3: Message (Body)
07:34 Request Body Requirements
08:17 Message: Role & Content
08:45 Postman: New API Request
09:18 Add OpenAI API Key
09:41 Part 3: The Message
10:17 Send API Request!
10:37 Status Code: 200 OK
11:15 Review Response
12:11 Lighthouse Keeper Story Response

🪜How To Use Postman for OpenAI API Requests:

  1. Visit Postman.com and create a Free Account
  2. Click ‘New Workspace’ and enter name for new Workspace
  3. Add Description & Notes
  4. Gather API Request Address (URL)
  5. Gather your OpenAI API (openai.com)
  6. Go to Postman.com
  7. Click (+) to create new API Request
  8. Paste OpenAI Secret (API) Key
  9. Change ‘GET’ to ‘POST’
  10. Go to ‘Authorization’
  11. Click drop-down menu for Auth Type
  12. Select ‘OpenAI Bearer Token’
  13. Go to ‘Body’
  14. Select ‘RAW’
  15. Select ‘JSON’
  16. Paste in Body Snippet of code for message
  17. Click ’SEND’ to send API Request
  18. Look for 200 OK Status Code to determine success or not
  19. Review Response
  20. 20. Save & Create New Collection

AI Unplugged · weekly

Newsletter for AI Builders

One practical email with the news, tools, terms, and tutorials worth remembering. Beehiiv sends it; Astro owns the archive.

No spam. Reply-friendly. Easy to leave.