Does auto generated Firestore Document ID have character restriction?

[_ resun]

Hello!

I was wondering is there any character restriction for the auto generated Firestore Document IDs. Are they always alphanumerics  or could they also contain symbols?

Thank you!

[Joe Spiro]

Hello,

As discussed in Usage and limits::Collections, documents, and fields the restrictions are as follows:

1. Must be valid UTF-8 characters
2. Must be no longer than 1,500 bytes
3. Cannot contain a forward slash (/)
4. Cannot solely consist of a single period (.) or double periods (..)
5. Cannot match the regular expression __.*__
6. If you import Datastore entities into a Firestore database, numeric entity IDs are exposed as __id[0-9]+__