Gemini Native (Image)

curl --request POST \
  --url https://api.mixroute.ai/v1/models/{model}:generateContent

const options = {method: 'POST'};

fetch('https://api.mixroute.ai/v1/models/{model}:generateContent', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mixroute.ai/v1/models/{model}:generateContent",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.mixroute.ai/v1/models/{model}:generateContent"

	req, _ := http.NewRequest("POST", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://api.mixroute.ai/v1/models/{model}:generateContent")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)

response = http.request(request)
puts response.read_body

Gemini Native (Image)

curl --request POST \
  --url https://api.mixroute.ai/v1/models/{model}:generateContent

const options = {method: 'POST'};

fetch('https://api.mixroute.ai/v1/models/{model}:generateContent', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mixroute.ai/v1/models/{model}:generateContent",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://api.mixroute.ai/v1/models/{model}:generateContent"

	req, _ := http.NewRequest("POST", url, nil)

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

require 'uri'
require 'net/http'

url = URI("https://api.mixroute.ai/v1/models/{model}:generateContent")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)

response = http.request(request)
puts response.read_body

Generate and edit images with Gemini using native Content parts and generationConfig settings. POST https://api.mixroute.ai/v1/models/{model}:generateContent

Models

Model ID	Capabilities and Limits
`gemini-nano-banana-2.1`	Nano Banana 2.1; 1K/2K/4K output; MINIMAL/MEDIUM/HIGH thinking, default MEDIUM.
`gemini-3.1-flash-image`	Nano Banana 2; 512, 1K, 2K, 4K output; MINIMAL/HIGH thinking.
`gemini-3.1-flash-image-preview`	Nano Banana 2; 512, 1K, 2K, 4K output; MINIMAL/HIGH thinking.
`gemini-3-pro-image`	Nano Banana Pro; 1K, 2K, 4K output and image/text reasoning.
`gemini-3-pro-image-preview`	Nano Banana Pro; 1K, 2K, 4K output and image/text reasoning.
`gemini-3.1-flash-lite-image`	Nano Banana 2 Lite; 1K output only; no Google Search grounding.
`gemini-2.5-flash-image`	Original Nano Banana; approximately 1K output. Omit imageSize.

Request Parameters

Field	Type	Required	Description
`model (URL path)`	string	Yes	Model ID in the endpoint path, not an extra JSON body field.
`contents`	object[]	Yes	Conversation turns containing text and optional image inputs.
`contents[].role`	string	No	`user` or `model`. Use the model role when preserving previous model output in a conversation.
`contents[].parts`	object[]	Yes	Content parts. Text instructions and image parts can be combined for editing.
`contents[].parts[].text`	string	Conditional	Text prompt or edit instruction.
`contents[].parts[].inlineData`	object	Conditional	Inline image bytes: mimeType plus raw Base64 data. Do not include a data-URI prefix in data.
`contents[].parts[].inlineData.mimeType`	string	Conditional	Image MIME type, such as image/png, image/jpeg, or image/webp.
`contents[].parts[].inlineData.data`	string	Conditional	Base64-encoded image bytes.
`contents[].parts[].fileData`	object	No	Native file reference with fileUri and mimeType. The file must be accessible to the route’s upstream account.
`contents[].parts[].thoughtSignature`	string	No	Opaque signature returned by the model. Preserve it exactly when returning previous model content in a later turn; never invent or modify it.
`systemInstruction`	object	No	Native Content object for system instructions, typically using parts[].text.
`generationConfig`	object	No	Native generation settings.
`generationConfig.responseModalities`	string[]	No	Include IMAGE to request image output, optionally with TEXT. Example: [“TEXT”, “IMAGE”].
`generationConfig.imageConfig.aspectRatio`	string	No	Output aspect ratio. If omitted, the model selects a ratio based on the input; a square is not guaranteed. See the supported ratios below.
`generationConfig.imageConfig.imageSize`	string	No	Default 1K. Nano Banana 2.1 and Pro: 1K/2K/4K. Nano Banana 2 (3.1 Flash Image): 512/1K/2K/4K. Lite: 1K only. Omit for 2.5 Flash Image.
`generationConfig.thinkingConfig.thinkingLevel`	string	No	Nano Banana 2.1: MINIMAL, MEDIUM (default), HIGH. 3.1 Flash Image and Lite: MINIMAL (default) or HIGH. Do not apply one model’s levels to another.
`generationConfig.thinkingConfig.includeThoughts`	boolean	No	Whether to include supported thought summaries/parts in the response. Final-image handling should skip parts marked thought=true.
`generationConfig.maxOutputTokens`	integer	No	Output budget shared by text and image output. A very small budget can prevent a complete image response; respect the model limit.
`tools`	object[]	No	Native tools. Nano Banana 2.1, 3.1 Flash Image, and Pro support Google Search grounding where enabled by the route. Lite and 2.5 Flash Image do not support this workflow.
`safetySettings`	object[]	No	Native safety settings with category and threshold, subject to model and account policy. Do not repeat the same category.

Model Constraints

Nano Banana 2.1 uses the same native Content/Part request envelope. Configure image output under generationConfig.imageConfig, without metadata or asset wrappers. Its supported output tiers are 1K, 2K, and 4K, not 512. Omit unsupported temperature, topP, topK, seed, and logprobs fields. See Nano Banana 2.1 for the model-specific limits. 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, 21:9 Nano Banana 2.1 and Gemini 3.1 Flash Image additionally support 1:4, 4:1, 1:8, and 8:1. Only use sizes/aspect ratios supported by the selected model. Gemini 3 image models support up to 14 reference images with model-specific subject limits; Lite is optimized for lightweight workflows. The image API is not controlled by an OpenAI n or size field.

Examples

Use your MixRoute key in the MIXROUTE_API_KEY environment variable. Requests use Authorization: Bearer .... Replace source-image placeholders with accessible images or local files before editing.

curl --request POST "https://api.mixroute.ai/v1/models/gemini-nano-banana-2.1:generateContent" \
  --header "Authorization: Bearer $MIXROUTE_API_KEY" \
  --header "Content-Type: application/json" \
  --data '{
  "contents": [
    {
      "role": "user",
      "parts": [
        {
          "text": "A clean product photograph of a red ceramic mug on a white background."
        }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": [
      "TEXT",
      "IMAGE"
    ],
    "imageConfig": {
      "aspectRatio": "1:1",
      "imageSize": "1K"
    }
  }
}'

Python

import json
import os
import requests

payload = json.loads(r'''
{
  "contents": [
    {
      "role": "user",
      "parts": [
        {
          "text": "A clean product photograph of a red ceramic mug on a white background."
        }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": [
      "TEXT",
      "IMAGE"
    ],
    "imageConfig": {
      "aspectRatio": "1:1",
      "imageSize": "1K"
    }
  }
}
''')
response = requests.post(
    "https://api.mixroute.ai/v1/models/gemini-nano-banana-2.1:generateContent",
    headers={"Authorization": "Bearer " + os.environ["MIXROUTE_API_KEY"]},
    json=payload,
    timeout=180,
)
response.raise_for_status()
result = response.json()
import base64
from pathlib import Path

image_index = 0
for candidate in result.get("candidates", []):
    for part in candidate.get("content", {}).get("parts", []):
        if part.get("thought"):
            continue
        inline = part.get("inlineData")
        if inline and inline.get("data"):
            extension = {"image/png": "png", "image/jpeg": "jpg", "image/webp": "webp"}.get(inline.get("mimeType"), "bin")
            Path(f"image_{image_index}.{extension}").write_bytes(base64.b64decode(inline["data"]))
            image_index += 1
        elif "text" in part:
            print(part["text"])

Image Editing and Conversation

For editing, add an inlineData image part to the user turn alongside the text instruction. For a subsequent edit, append the complete prior candidate.content object to contents and then add the next user turn; this retains native image data and thought signatures. Do not replace the model history with text alone.

{
  "contents": [
    {
      "role": "user",
      "parts": [
        {
          "text": "Make the mug blue while preserving its shape, lighting, and background."
        },
        {
          "inlineData": {
            "mimeType": "image/png",
            "data": "BASE64_IMAGE_DATA"
          }
        }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": [
      "TEXT",
      "IMAGE"
    ],
    "imageConfig": {
      "aspectRatio": "1:1",
      "imageSize": "1K"
    }
  }
}

Response

Read text and image parts from candidates[].content.parts[]. Images normally use inlineData with mimeType and Base64 data; preserve thoughtSignature when reusing model turns. Check promptFeedback and finishReason when an image is absent. usageMetadata contains token usage, not image-generation settings. Gemini image streaming

Popular Models

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Gemini Native (Image)

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Request Parameters

Model Constraints

Examples

Python

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Response

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Response