This guide explains how to generate your API key, authenticate requests, and use the Lunio Developer API endpoints for GST, HST, PST, and QST calculations.
Getting Started
The Lunio Developer API allows you to integrate Canadian GST, HST, PST, and QST calculations into your application using simple JSON endpoints.
Step 1 — Generate an API Key
To begin:
- Sign in to your Lunio account
- Open the Developer API dashboard
- Navigate to API Keys
- Create your API key
Important: your full API key is only shown once after creation. Make sure to copy and store it securely.
If you lose the key, you can regenerate a new one at any time.
Step 2 — Authenticate Requests
All protected endpoints require Bearer token authentication using your API key.
Your API key should always be stored securely and never exposed publicly.
Step 3 — Make Your First Request
The API currently supports:
- Retrieving Canadian tax rates
- Calculating taxes from a subtotal
- Reverse-calculating the subtotal and tax from a total amount
Supported provinces and territories include:
- Ontario
- Alberta
- British Columbia
- Quebec
- Nova Scotia
- Newfoundland and Labrador
- Prince Edward Island
- Saskatchewan
- Manitoba
- Yukon
- Northwest Territories
- Nunavut
- New Brunswick
API Rate Limits
Your monthly request allowance depends on your plan.
Free
100 requests/month
Starter
5,000 requests/month
Growth
25,000 requests/month
You can monitor your usage directly from the Developer Dashboard.
API Key Security
Treat your API key like a password.
Best practices include:
- Never exposing keys publicly
- Never commit keys to Git repositories
- Regenerating compromised keys immediately
- Storing keys securely in environment variables
Need Help?
If you experience issues with authentication, request formatting, or rate limits, review the Developer Docs or contact support through Lunio.