OpenAI Agents SDK 0.17 Breaks Three Things – Here's the Fix

OpenAI's Agents SDK jumped from v0.13 to v0.17 in five weeks, introducing three breaking changes. Two are silent: model refusals now raise exceptions instead of returning empty strings, and the default model switched from gpt-4.1 to gpt-5.4-mini. Developers must add refusal handlers and explicitly set models to avoid crashes.