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Model detail

Gemini 3.8 Flash

Provided by Google
Pay-as-you-go

Gemini 3.8 Flash is Google's most intelligent Flash model with significant gains from 3.7 Flash across software engineering, agentic tasks, and multi-step reasoning.

Model specs

Model ID
gemini-3.8-flash
Context length
1.048576M
Max output
65.536K
I/O modalities
Released
2026-09

02

API endpoints

One MixRoute gateway, OpenAI-compatible

  • Gemini /v1beta/models/{model}:generateContent POST
  • OpenAI-compatible /v1/chat/completions POST

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Pricing

Flat rate, unit: /1M Tokens

Input

$0.7500 /1M Tokens

Completion

$3.7500 /1M Tokens

Cache read

$0.0750 /1M Tokens

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Selection summary

Quickly judge whether it fits your workload

What is this model good for?

Flash-speed intelligence for long-horizon engineering

Built for autonomous agents, complex enterprise workflows, and extended software engineering tasks. Delivers the most capable Flash-class performance while keeping the speed and cost efficiency of the Flash tier.

What should you check before using it?

1M context, 65K output, multimodal by default

1,048,576-token context window with 65,536-token max output. Accepts text, image, video, audio, and PDF natively. Supports caching, thinking, structured outputs, function calling, code execution, and search grounding. Knowledge cutoff: 2026-03.

Why use it through MixRoute?

Drop-in via Google Gen AI SDK or OpenAI-compatible endpoint

Use the Google Gen AI SDK or call through MixRoute's OpenAI-compatible endpoint. Supports batch API, flex inference, and priority inference for production workloads.

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Capabilities & compatibility

Unconfirmed capabilities stay "Unknown," no guesses

Available:

Tool calling

Gemini 3.8 Flash supports function and tool calls.

EX Send a tools definition; the response returns tool_calls to execute and feed results back.
Available:

Structured output

Gemini 3.8 Flash can produce JSON-formatted output on demand.

EX response_format: { type: "json_schema" } forces valid JSON output.
Available:

Streaming

Gemini 3.8 Flash supports streamed responses.

EX stream: true streams tokens incrementally, so chat UIs render as they arrive.
Available:

Prompt caching

Gemini 3.8 Flash supports prompt caching under supported routing conditions.

EX Keep the system prompt and tool definitions at the start of the request; repeated prefixes are automatically billed at the cache-read rate.
Available:

Vision input

Gemini 3.8 Flash can process image inputs alongside text.

EX Pass a base64-encoded image in a image_url content part alongside text messages.
Available:

OpenAI SDK

Call Gemini 3.8 Flash through MixRoute's OpenAI-compatible endpoint.

EX Change base_url to https://api.mixroute.ai/v1; everything else follows the OpenAI style.

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Token cost estimator

Live estimate from this page's pricing, not an actual bill

Share of the same prefix read repeatedly, up to 100%

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FAQ

Gemini 3.8 Flash is Google’s most intelligent Flash model with significant gains from 3.7 Flash across software engineering, agentic tasks, and multi-step reasoning.

One endpoint, a testable decision

Test this model and alternate routes with the same request format

Start from a real workload, then let quality, total cost, and failure conditions decide whether to send production traffic.

Create an API key View integration docs