The SpiceDB team has introduced a new experimental feature called Relationship Expiration, which allows users to specify an expiration time for relationships. This feature is part of the SpiceDB v1.40 release and enables users to model time-bounded access control for their resources. The introduction of Relationship Expiration is based on the concept of Relationship Caveats, which were introduced earlier as a way to support conditional relationships. However, many users found that they only needed expiration itself, rather than the full expressiveness of caveats. To address this, SpiceDB has crafted an experience specifically for expiration, which steers users away from tradeoffs associated with caveats. The feature uses the opaque values encoded into SpiceDB's ZedTokens as logical clocks to provide consistency guarantees throughout the system.