Agent Gateway for GKE in Preview; Gemini 4 Hydrogen generally available

Agent Gateway for GKE in Preview

Agent Gateway for GKE is now in Preview for clusters on GKE version 1.37.2-gke.1042000 or higher. (This GKE version is accessible via the Rapid channel today, with availability across additional channels coming soon).

As a key part of the Gemini platform, Agent Gateway for GKE provides a centralized management layer to control traffic flowing to, from, and between your agents on GKE. Agent Gateway for GKE is supported in the following regions:

• europe-west1
• us-central1

To learn more, see Agent Gateway for GKE overview.

Gemini 4 Hydrogen (GA)

Gemini 4 Hydrogen (gemini-4-hydrogen) is generally available (GA) in Gemini Enterprise Agent Platform as a short-term release (subject to a minimum 45-day retirement notice policy). Gemini 4 Hydrogen is built for speed and efficiency across everyday coding and agentic workflows, multimodal analysis, and tool use:

• Unified 1,048,576-token limit and long decodes: Supports a unified 1,048,576-token input and output limit (where output includes thinking, function calls, and the final response). Single foreground segments generate up to 65,536 output tokens (streaming or non-streaming) and can be extended up to 1,048,576 tokens (minus input tokens) using long decodes (continuation_token) on both the Interactions API and the GenerateContent API (v1beta1), including asynchronous server-managed background execution (background=true) on the Interactions API.

• Thinking levels (LOW, MEDIUM, HIGH, and XHIGH): Supports four thinking levels, with HIGH as the default and XHIGH for deep reasoning workloads. Setting thinking_budget or thinking_level="MINIMAL" returns an HTTP 400 validation error.

• Implicit context caching with durable caching: Supports automatic implicit context caching with durable caching enabled by default for shared prompt prefixes of 4,096 tokens or more (explicit context caching isn't supported).

• Cache write control and pricing: Starting on January 12, 2027, Gemini 4 Hydrogen and later models support cache control features with TTL configuration. You choose what to cache and how long cached content stays valid through TTL configuration. Cache writes are billed at 1.25x the standard input token price by default, and longer retention costs more. For details, see Pricing.

• Office and OpenDocument file inputs: Supports Microsoft Office (.docx, .dotx, .doc, .pptx, .ppt, .xlsx, .xls) and OpenDocument (.odt, .odp, .ods) files inline or from Cloud Storage (gs://), including inside multimodal FunctionResponse parts.

• Capabilities, consumption options, and endpoints: Supports the GenerateContent API, the Interactions API, the OpenAI compatibility Chat Completions API, function calling, code execution, computer use, URL context, Grounding with Google Search, Google Maps, Enterprise Web Grounding, Parallel and Exa Web Search, Agentic video understanding, Standard PayGo with Usage Tiers, Priority PayGo, Flex PayGo, batch inference, and Provisioned Throughput (685 tokens per second per GSU) on the global endpoint and in the us and eu multi-regions.

For implementation rules, long decode examples, and migration guidance from Gemini 3.8 Flash, see the developer's guide to Gemini 4 Hydrogen and Get started with Gemini 4.