Google deprecates the Deep Research agent `deep-research-pro-preview-12-2025`, shutdown October 23

Google's Gemini API changelog of October 8, 2026 says the deep-research-pro-preview-12-2025 agent is deprecated and will be shut down on October 23, 2026.

Google tells developers to move to one of two newer Deep Research agents:

• deep-research-preview-04-2026, designed for speed and efficiency and suited to streaming back to a client UI.
• deep-research-max-preview-04-2026, for maximum comprehensiveness in automated context gathering and synthesis.

To migrate, change the agent parameter in interactions.create requests from deep-research-pro-preview-12-2025 to one of the new names.