website/docs/language/functions/uuid.mdx
uuid Functionuuid generates a unique identifier string.
The result is 16 random bytes formatted in the UUID string layout
(xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx). All 128 bits are
pseudorandom — the function does not set the version or variant
bits described in RFC 4122,
so the output is not a standards-compliant Version 4 UUID.
:::note If you need standards-compliant UUIDs (for example, Version 4 or Version 7), consider using a provider that exposes UUID generation through provider-defined functions. :::
This function produces a new value each time it is called, and so using it
directly in resource arguments will result in spurious diffs. We do not
recommend using the uuid function in resource configurations, but it can
be used with care in conjunction with
the ignore_changes lifecycle meta-argument.
In most cases we recommend using the random provider
instead, since it allows the one-time generation of random values that are
then retained in the OpenTofu state for use by
future operations. In particular,
random_id can generate results with
equivalent randomness to the uuid function.
> uuid()
b5ee72a3-54dd-c4b8-551c-4bdc0204cedb
uuidv5, which generates name-based UUIDs.