NanoBanana OpenAI chat format

curl --request POST \
  --url https://api.getinfinityblue.com/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "nanobanana_pro",
  "stream": false,
  "messages": [
    {
      "role": "user",
      "content": "Draw a cat sitting on a rooftop under moonlight"
    }
  ],
  "extra_body": {
    "google": {
      "image_config": {
        "aspect_ratio": "16:9",
        "image_size": "2K"
      }
    }
  }
}
'

{
  "id": "chatcmpl-20251211160744809365000fdOhL0KY",
  "model": "nanobanana_pro",
  "object": "chat.completion",
  "created": 1765440499,
  "choices": [
    {
      "index": 123,
      "message": {
        "role": "assistant",
        "content": "![image](data:image/jpeg;base64,/9j/4AAQ...)"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 123,
    "completion_tokens": 123,
    "total_tokens": 123
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

POST

chat

completions

curl --request POST \
  --url https://api.getinfinityblue.com/v1/chat/completions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "nanobanana_pro",
  "stream": false,
  "messages": [
    {
      "role": "user",
      "content": "Draw a cat sitting on a rooftop under moonlight"
    }
  ],
  "extra_body": {
    "google": {
      "image_config": {
        "aspect_ratio": "16:9",
        "image_size": "2K"
      }
    }
  }
}
'

{
  "id": "chatcmpl-20251211160744809365000fdOhL0KY",
  "model": "nanobanana_pro",
  "object": "chat.completion",
  "created": 1765440499,
  "choices": [
    {
      "index": 123,
      "message": {
        "role": "assistant",
        "content": "![image](data:image/jpeg;base64,/9j/4AAQ...)"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 123,
    "completion_tokens": 123,
    "total_tokens": 123
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

{
  "error": {
    "message": "Invalid size. Supported sizes are 1024x1024, 1536x1024, 1024x1536.",
    "type": "invalid_request_error",
    "param": "size",
    "code": "invalid_size"
  }
}

Models you can use

Model ID	Notes
`nanobanana`	Standard version
`nanobanana_pro`	High-quality version
`nanobanana_2`	2nd generation — budget tier only, this format exclusively

Image configuration

Pass Google extension parameters through the extra_body field:

{
  "extra_body": {
    "google": {
      "image_config": {
        "aspect_ratio": "16:9",
        "image_size": "2K"
      }
    }
  }
}

Response format

The image is embedded in choices[0].message.content as Markdown:

![image](data:image/jpeg;base64,/9j/4AAQ...)

Relationship to the chat endpoint

The path /v1/chat/completions is shared with the chat completions endpoint. This page specifically describes the image-generation behavior and the unique extra_body parameters when model is a NanoBanana ID.

Authorizations

Authorization

string

header

required

Bearer token authentication, format: Authorization: Bearer sk-xxxxxx. Get your API key in the console.

Body

application/json

NanoBanana OpenAI chat-format image generation request body.

model

string

required

NanoBanana model ID. Options: nanobanana, nanobanana_pro, nanobanana_2. The budget-tier nanobanana_2 only supports this format and cannot be used with the Gemini native endpoint.

Examples:

"nanobanana_pro"

"nanobanana_2"

messages

object[]

required

Conversation messages containing the image generation prompt.

Show child attributes

stream

boolean

default:false

Whether to stream the response. Set to false for image generation.

extra_body

object

Extension parameters. Pass image configuration (aspect ratio and resolution) via google.image_config.

Show child attributes

Response

Image generated successfully

NanoBanana OpenAI chat-format response body. The image is embedded in the message content as a Markdown inline image.

string

Unique identifier for this request.

Example:

"chatcmpl-20251211160744809365000fdOhL0KY"

model

string

The model that processed the request.

Example:

"nanobanana_pro"

object

string

Object type.

Example:

"chat.completion"

created

integer

Unix timestamp (seconds) of creation.

Example:

1765440499

choices

object[]

List of generated results.

Show child attributes

usage

object

Token usage statistics.

Show child attributes

Get Started

Models

Chat

Images

Videos

Guides

NanoBanana OpenAI chat format

Models you can use

Image configuration

Response format

Relationship to the chat endpoint

Authorizations

Body

Response

​Models you can use

​Image configuration

​Response format

​Relationship to the chat endpoint

Authorizations

Body

Response

Models you can use

Image configuration

Response format

Relationship to the chat endpoint