Harbor Freight sells a union with clamps designed to repair an air hose. With that being said, I think any air hose repair is a bad idea. A high quality commercial grade hose will last a lifetime and stay flexible during cold weather.

The way stuff is packaged now, sometimes you wind up with things you'd never buy separately. When I bought my compressor, it came with a 3/8 drive air ratchet - I need that like I need another hole in my head.

I agree that the 3/8 air ratchet is not the most used
tool in my box, but there will come an occasion when
you will be glad you had it. They were 'The Berries'
when taking fan blades off, back when fans were attached
to the water pump. Saved a lot of skin on my knuckles.
Also, the 'butterfly' 3/8 impact gun is rarely used by
me, but there are times when it sure comes in handy.

If it is the Flex Eel style you have 2 good options. One is the compression kit. Or if it is close to an existing end they are assembled with compression clamps so you can cut the hose and move the end back.