Do I need carrier integrations for UPS and FedEx, or can one API do it?

You usually can’t rely on just one generic API unless that API is actually a shipping aggregator/label platform that already has UPS and FedEx integrations built in.

Two common cases:

1) You use a shipping platform / aggregator API

Examples: Shippo, EasyPost, ShipStation, etc.

• One API can often handle:
  • rate shopping
  • label generation
  • tracking
  • shipment creation
• Behind the scenes, that platform maintains the carrier integrations with UPS/FedEx for you.

In this case: you typically do not need separate direct integrations with UPS and FedEx.

2) You integrate directly with carriers

If you want to call UPS APIs and FedEx APIs yourself:

• you’ll need separate integrations for each carrier
• each carrier has its own auth, request formats, rate APIs, label APIs, tracking APIs, error handling, etc.

In this case: yes, you need carrier-specific integrations.

Practical rule

• One API can do it if it’s a multi-carrier shipping API
• If it’s your own backend or a custom service, you generally need one integration per carrier

Things to check

When evaluating a provider, confirm it supports:

• UPS rate/label/tracking
• FedEx rate/label/tracking
• your shipping modes (domestic/international, ground/express)
• negotiated rates if you need them
• pickup, address validation, customs docs if relevant

If you want, I can recommend whether to use direct carrier APIs vs a multi-carrier API based on your volume, budget, and tech stack.