It’s a validation tool. In the example @stucork gave at the top of this thread, he has a string which should be a valid email address.
He first defines the zod schema for a valid email address:
from anvil_labs import zod as z
email_schema = z.string().strip().email()
and then uses that to check three strings:
email_schema.parse("foo@bar.com")
which returns foo@bar.com because it passes the validation
email_schema.parse(" foo@bar.com ")
which also returns foo@bar.com because the scheme strips the whitespace before running the check, and,
email_schema.parse("foo@")
which raises an error because the string isn’t a valid email address.
There are lots of other ways to create a schema described in the docs. This one is a simple string validation schema.
Also, because it’s not tied to anvil components, it can be used anywhere - both client and server side.