Model alias
A stable logical name like code.fast that resolves through an immutable release to a concrete provider model.
Aliases let applications request a capability (fast coding, best reasoning) instead of a specific model string. Each alias points to an immutable release that records exactly which model it resolved to and why.
That makes routing reproducible: a replay can pin an alias release and get the same decision later, even after the live alias has moved on.
See it in practice.
Definitions are useful; measurement is better. Run a diagnostic on your own workload.