While installing a custom ROM on my OnePlus One, I accidentally wiped the INTERNAL STORAGE of my phone, thus wiping the zip files of the ROM and Gapps. So I'm stuck with only the recovery, but no OS. Upon reboot, the screen is stuck one the OnePlus logo. I've tried using adb push and adb sideload but 'adb devices' does not recognize my device. However, fastboot does recognize it. How do I install a ROM and get my phone to work again?
You've asked the question 15 days ago, did you manage to get your device working again? What steps did you take? I'll give it a go in case anyone needs it.
As I've experienced, having a USB OTG cable laying around can be most useful with this device. You can find them cheap just about anywhere. They convert any USB storage device you have to external memory for your One. Just connect it to your device and mount it in TWRP (or any recovery that supports it). Don't forget to unmount it or you'll run into trouble later on.
It does sound like you didn't get the drivers right if no device popped up with adb. You can install these generic Samsung drivers to make it work.
Another thing, if you're having issues in TWRP, it could be useful to flash a different version via fastboot. I'm using this one on my OnePlus One to flash Resurrection Remix M and it hasn't let me down yet.