Which is the most reliable way to use a API. integrating/downloading an SDK to your application, or using the URL-HTTP-GET method

I want to know which is the best and most reliable method. I have looked on here for an answer but didn't come across any.

I Want to use multiple API'S in my project so please keep that in mind when answering. Any advice about the best way of doing this and most reliable method will really be appreciated.

Isit possible to download multiple SDK's into an iOS application through Xcode?

Pros of SDK:

• Can be used offline
• Most SDKs are small in file size
• All of the functioning code is visible to you, the SDK developer can't keep many secrets

Cons of SDK:

• Larger binary
• More clutter in your Xcode project

Pros of API:

• Smaller binary
• Less 3rd party frameworks cluttering your Xcode project

Cons of API:

• Can't be used offline
• Tends to be a blackbox
• App will need to be updated every time the API is updated

In terms of reliability, the SDK will always be functional assuming

1. It worked in the first place
2. It doesn't rely on an API in the background