Vertex AI

Vertex AI: Gemini 3.5 Flash (Vertex)

stable

Gemini 3.5 Flash (Vertex) is available through Everstack's OpenAI-compatible gateway with routing, fallback, retries, and observability.

gemini-3.5-flashgemini-flashreleased May 19, 2026
ProviderQuick start
Context
1.0M
tokens
Max output
65.5K
tokens
Input
$1.50
per 1M
Output
$9.00
per 1M

Activity

Daily period usage
Aggregated managed Everstack traffic. Buckets below 5 tenants or 100 requests are withheld.

Providers

ProviderContextInput /MOutput /M
Google
Google
1.0M$1.50$9.00
OpenRouter
OpenRouter
1.0M$1.50$9.00
Vertex AI
Vertex AI
1.0M$1.50$9.00

Pricing

ItemPriceUnit
Input$1.50per 1M tokens
Output$9.00per 1M tokens
Cache read$0.15per 1M tokens

Performance

Reliability

Compare

Compare usage and performance
Place this model beside up to three other catalog models.

Capabilities

Capabilities
Modalities
Input
Output
Details
Model ID
gemini-3.5-flash
Family
gemini-flash
Status
stable
Knowledge
Jan 1, 2025
Released
May 19, 2026
Gateway Config
API
v1
Auth
GOOGLE_APPLICATION_CREDENTIALS
Discovery
static
Provider type
static

Quick Start

index.ts
import Everstack from "@everstack/node";const client = new Everstack({  apiKey: process.env.EVERSTACK_API_KEY!,  baseUrl: "https://{instance}.{region}.everstack.ai",});const completion = await client.chat.completions.create({  model: "@vertex-ai/gemini-3.5-flash",  messages: [{ role: "user", content: "Explain vector cache routing." }],});console.log(completion.choices[0]?.message?.content);

Endpoint

Base URL
https://{location}-aiplatform.googleapis.com/v1/projects/{project}/locations/{location}
Chat completions
https://{location}-aiplatform.googleapis.com/v1/projects/{project}/locations/{location}/chat/completions
Model
gemini-3.5-flash
Auth env
GOOGLE_APPLICATION_CREDENTIALS

Gemini 3.5 Flash (Vertex) FAQ

How much does the Gemini 3.5 Flash (Vertex) API cost?

Through Vertex AI, Gemini 3.5 Flash (Vertex) costs $1.50 per 1M input tokens and $9.00 per 1M output tokens.

What is the context window of Gemini 3.5 Flash (Vertex)?

Gemini 3.5 Flash (Vertex) accepts up to 1.0M tokens of context and returns up to 65.5K output tokens on Vertex AI.

Which providers offer Gemini 3.5 Flash (Vertex)?

Gemini 3.5 Flash (Vertex) is available from Google, OpenRouter and Vertex AI. Everstack can route between them with automatic fallback when one is unavailable.

What can Gemini 3.5 Flash (Vertex) do?

Gemini 3.5 Flash (Vertex) supports chat, function calling, image input and reasoning. It accepts text, image, video, audio and PDF input.

How do I call Gemini 3.5 Flash (Vertex) through Everstack?

Point any OpenAI-compatible SDK at your Everstack gateway and set the model to @vertex-ai/gemini-3.5-flash. Everstack adds retries, provider fallback, caching, per-tenant budgets and OpenTelemetry traces for every request.