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gemini-3.5-flash

Googlegeminiopenai

gemini-3.5-flash is a Google chat and completion model you can call through flatkey.ai's OpenAI-compatible API. On flatkey it runs at $1 per 1M input tokens — about 33% below the $1.5 official list price, and $6 per 1M output tokens. One API key covers GPT, Claude, Gemini, DeepSeek, Seedance and 500+ other models, so you can switch models without changing SDKs or juggling separate accounts. Billing is prepaid with live usage analytics and a single invoice, which keeps spend predictable as you scale.

Get your API keySave ~33% vs official pricing
30-day success rate
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Throughput
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First-token latency
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Requests (30 days)
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Stacked discount
up to 50% offModels are priced at 60–90% of the official list. Top up $200 and get $100 free — both discounts stack, as low as 50% of the official price. →

Pricing

Input
List price $1.5
$1/ 1M tokens
Output
List price $9
$6/ 1M tokens
Cache read
List price $0.15
$0.1/ 1M tokens

Specifications

Provider
Google
Modality
Text / chat
Access
OpenAI-compatible API
Endpoints
gemini, openai

How to use the gemini-3.5-flash API

  1. 1
    Create a flatkey.ai account and API key
    Sign up for free, then generate an API key in the console. New accounts get bonus credit on their first top-up.
  2. 2
    Point your OpenAI client at flatkey
    Set base_url to https://router.flatkey.ai/v1 and use your flatkey key as the API key. No other code changes are needed — the API is OpenAI-compatible.
  3. 3
    Call gemini-3.5-flash
    Send a request with model set to "gemini-3.5-flash" using the OpenAI SDK or curl. Copy a ready-to-run example below.
API example
curl "https://router.flatkey.ai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $FLATKEY_API_KEY" \
  -d '{"model":"gemini-3.5-flash","messages":[{"role":"user","content":"Say hello in one sentence."}]}'

Availability (last 30 days)

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Frequently asked questions

How much does the gemini-3.5-flash API cost?

On flatkey.ai, gemini-3.5-flash costs $1 per 1M input tokens and $6 per 1M output tokens, roughly 33% below the official list price. Top up $200 and get $100 free to stretch the budget further.

Is gemini-3.5-flash OpenAI-compatible?

Yes. Keep your existing OpenAI SDK, switch base_url to https://router.flatkey.ai/v1, and use your flatkey key. The model id stays "gemini-3.5-flash".

Is gemini-3.5-flash free to use?

Usage is pay-as-you-go, but priced well below the official list (about 33% cheaper), and new accounts receive bonus credit on their first top-up, so you can start testing at low cost.

How do I get an API key for gemini-3.5-flash?

Sign up on flatkey.ai, create an API key in the console, and add prepaid balance. You can start calling gemini-3.5-flash in minutes.

What other models can I use with the same key?

One flatkey key gives you GPT, Claude, Gemini, DeepSeek, Seedance and 500+ other models through a single OpenAI-compatible endpoint and one invoice.

How reliable is gemini-3.5-flash on flatkey?

We publish the live 30-day success rate, throughput and latency for gemini-3.5-flash directly on this page, updated from real traffic.

More Google models

gemini-3.1-flash-lite-preview$0.166667gemini-flash-latest$0.2nano-banana-pro-preview$1.3333gemini-2.5-pro$0.75gemini-3-pro-image-preview$1.3333gemini-3.1-pro-preview-customtools$1.3333

Start building with gemini-3.5-flash

One OpenAI-compatible key, prepaid billing, and bonus credit on your first top-up. Sign up in under a minute.

Get your API key