All API requests (except the registration endpoints) require a Bearer token in the Authorization header.
Authorization: Bearer mfx_test_abc123...
Key Types
| Prefix | Environment | Traffic |
|---|
mfx_test_ | Sandbox | Routed to sandbox. No real faxes sent. |
mfx_live_ | Live | Routed to production. Real faxes delivered. |
Getting Your First Key
Register a sandbox account to receive your first API key:
# Step 1: Start registration (sends a 6-digit code to your email)
curl -X POST https://api.mintfax.com/v1/account/register \
-H "Content-Type: application/json" \
-d '{"name": "My App", "email": "dev@example.com"}'
# Step 2: Verify the code from your email
curl -X POST https://api.mintfax.com/v1/account/register/verify \
-H "Content-Type: application/json" \
-d '{"email": "dev@example.com", "code": "482901"}'
api_key field in the verification response is your key. It is shown once - store it securely.
Multiple Keys
Each account can have multiple named API keys, managed via the control panel. Use separate keys for different applications or environments to scope access and simplify rotation.
Key Rotation
Generate a new key in the control panel, update your application, then revoke the old key. Both keys work simultaneously during the transition.
Security
- Store keys in environment variables or a secrets manager, not in source code
- Use sandbox keys (
mfx_test_) during development and testing
- Rotate keys immediately if you suspect a leak
- Each key is scoped to a single environment
Last modified on May 10, 2026
