My Ssd disk disappeared there is only macOS base system
Ssd disk not exist anymore
MacBook Pro 13″, macOS 10.13
Question marked as
If you have a non-Retina model laptop, then perhaps the hard drive SATA Cable has failed. You can confirm this by removing the SSD and connecting it externally using a USB to SATA Adapter, drive dock, or enclosure. If you can boot or even see the physical SSD while it is connected externally, then most likely the internal hard drive SATA Cable is bad. OWC sells these cables:
https://eshop.macsales.com/search/?q=hard%20drive%20cable&filter.catidpath=3406/3410
Otherwise it means your SSD has failed. You will need to have the SSD replaced. I hope you have a backup since it is unlikely a professional data recovery service such as Drive Savers will be able to recover any data although you can have them try.