Google: Nano Banana (Gemini 2.5 Flash Image)

google/gemini-2.5-flash-image

Gemini 2.5 Flash Image, a.k.a. "Nano Banana," is now generally available. It is a state of the art image generation model with contextual understanding. It is capable of image generation, edits, and m...

vision
MODALITIES
INPUT PRICE
$0.30per 1M
OUTPUT PRICE
$2.50per 1M
CONTEXT
32.8K
RELEASED
Oct 8, 2025
ProviderCacheUptimeChat
$0.3$2.5
Cache read$0.03

Capabilities

Input modalities
imagetext
Output modalities
imagetext
Features
max_tokensresponse_formatseedstopstructured_outputstemperaturetop_p
1

Get your API key

Create an API key from the Keys page, then set it as an environment variable:

export ONLIST_API_KEY=sk-...
2

Make your first request

Endpoints

POSThttps://onlist.io/v1/images/generations
Request Headers
Authorization:Bearer $ONLIST_API_KEY
Content-Type:application/json
Model:google/gemini-2.5-flash-image

Code samples

curl https://onlist.io/v1/images/generations \
  -H "Authorization: Bearer $ONLIST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "model": "google/gemini-2.5-flash-image",
       "prompt": "A white siamese cat",
       "n": 1,
       "size": "1024x1024"
     }'

Replace $ONLIST_API_KEY with the API key from your Keys page.

Authentication

All requests must include an Authorization: Bearer <TOKEN> header. Generate keys from the Keys page; keys can be scoped to specific models, groups, IP ranges, and rate limits.

Supported parameters

NameTypeDescription
max_tokensintegerMaximum number of tokens to generate in the completion.
response_formatobjectSpecifies the output format. Use {"type": "json_object"} for JSON mode.
seedintegerIf specified, the system will attempt deterministic sampling for reproducible results.
stopstring | arrayUp to 4 sequences where the API will stop generating tokens.
structured_outputs
temperaturenumberSampling temperature between 0 and 2. Higher values make output more random.
top_pnumberNucleus sampling. The model considers tokens with top_p probability mass.

These are the request parameters this model accepts. Parameter semantics follow the OpenAI Chat Completions specification.