Google is shutting down deep-research-pro-preview-12-2025, the older preview version of its Deep Research agent in the Gemini API, on October 23, 2026. The October 8 changelog entry for the Gemini API says the agent is deprecated and asks developers to move their requests to one of the newer Deep Research agent versions. The entry gives a date but not a time of day.
What Google says to switch to
Google lists two newer versions. It describes deep-research-preview-04-2026 as "Designed for speed and efficiency, ideal to be streamed back to a client UI," and deep-research-max-preview-04-2026 as offering "Maximum comprehensiveness for automated context gathering and synthesis." Google's Deep Research guide calls the two versions Deep Research and Deep Research Max and uses the same descriptions.
On Google's deprecations page, the recommended replacement listed for deep-research-pro-preview-12-2025 is deep-research-preview-04-2026. Both newer versions are listed as preview agents with no shutdown date announced.
How to migrate
According to the Gemini API changelog, the change is in the agent parameter. In your interactions.create requests, Google says to replace deep-research-pro-preview-12-2025 with deep-research-preview-04-2026, or with deep-research-max-preview-04-2026.
Two Flash models are also deprecated
The same changelog entry deprecates two Gemini models. Google says gemini-3.7-flash has been replaced by gemini-3.8-flash and gemini-3.5-flash by gemini-3.6-flash. Neither can be selected in Google AI Studio anymore, and API requests to them are automatically routed to gemini-3.8-flash and gemini-3.6-flash respectively. Google asks developers to update their model strings, and for gemini-3.5-flash it also gives gemini-3.8-flash as an option. The deprecations page says neither endpoint is shutting down.
