Google has scheduled the Gemini API's deep-research-pro-preview-12-2025 agent to shut down October 23, 2026. The announcement is in its changelog entry dated October 8, read October 9; it names two newer agent versions developers can move their requests to.
What developers must change
Google's migration instruction is specific: change the agent parameter in interactions.create requests from the December 2025 preview to deep-research-preview-04-2026 or deep-research-max-preview-04-2026.
The changelog describes the first replacement as designed for speed and efficiency, including streaming back to a client interface. It describes the max version as intended for more comprehensive context gathering and synthesis. Those are Google's descriptions, not results from a comparison of the agents.
The notice concerns the named December 2025 preview agent on the Gemini API. It does not announce the end of Deep Research as a whole or state a shutdown date for either April 2026 replacement.
One date, two kinds of wording
The changelog says the older agent is deprecated and will shut down October 23. Google's deprecations table lists that same date beside the old identifier and names deep-research-preview-04-2026 as its recommended replacement.
The table also carries a general qualification: listed shutdown dates are the earliest possible dates on which a model might retire. Google says it will communicate the exact date to users with advance notice. The table lists both April 2026 Deep Research agents with no shutdown date announced.
No exact hour or timezone appears in the announcement. Reading the date on a provider page establishes its published schedule; it does not establish whether an endpoint has stopped answering.
The follow-up check
A scheduled verification check will reread the changelog and lifecycle table October 24, after the announced calendar day. It will compare the old identifier, date and replacement instructions, report any change in those pages, and distinguish a provider's statement that retirement occurred from an actual endpoint test.
No endpoint was called for this record. An unchanged announcement, a removed row or an earliest-date listing alone will not be treated as confirmation of shutdown.