Models
Model deprecation
Model deprecation is a provider retiring a model version, after which requests to it fail or are silently redirected.
Deprecation notice periods are typically months, not years. Anything built on a specific model version carries a scheduled maintenance cost that most teams do not plan for.
Migration is rarely a rename. Different models tokenize differently, respond differently to the same prompt, and price differently — so a migration needs re-measurement and re-evaluation, not a config change.
In practice
Deprecation notice periods are measured in months, and the migration takes longer than the notice implies because prompts get tuned to a model's quirks. Pin the version explicitly rather than using a floating alias: an alias means the model under your prompt changes on the provider's schedule, and the first sign is a quality regression nobody deployed.
Common questions
How much notice do providers give before retiring a model?
Typically months, published on a deprecation page. The migration usually takes longer than the notice implies, because prompts accumulate tuning specific to a model and that tuning does not transfer cleanly.
Should I use a model alias or a pinned version?
Pin it. An alias means the model under your prompt changes on the provider's schedule rather than yours, and the first sign is a quality regression that nobody deployed.