Run Gemma with the Gemini API

The Gemini API provides hosted access to Gemma as a programming API you can use in application development or prototyping. This API is a convenient alternative to setting up your own local instance of Gemma and web service to handle generative AI tasks.

Supported Models

The Gemini API supports the following Gemma 4 models:

  • gemma-4-31b-it
  • gemma-4-26b-a4b-it

The following example shows how to use Gemma with the Gemini API:

Python

from google import genai

client = genai.Client()

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    contents="Roses are red...",
)

print(response.text)

JavaScript

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI();

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: "Roses are red...",
});
console.log(response.text);

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [{
    "parts":[{"text": "Roses are red..."}]
    }]
   }'

Get API Key

You can access the Gemini API on many platforms, such as mobile, web, and cloud services, and with multiple programming languages. For more information on Gemini API SDK packages, see the Gemini API SDK downloads page. For a general introduction to the Gemini API, see the Gemini API quickstart.

Thinking

Gemma 4 utilizes an internal "thinking process" that optimizes its multi-step reasoning, delivering superior performance in logically demanding domains such as algorithmic coding and advanced mathematical proofs.

While Gemma 4 strictly supports toggling this feature on or off, you enable it in the API by setting the thinking level to "high".

The following example demonstrates how to activate the thinking process:

Python

from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    contents="What is the water formula?",
    config=types.GenerateContentConfig(
        thinking_config=types.ThinkingConfig(thinking_level="high")
    ),
)

print(response.text)

JavaScript

import { GoogleGenAI, ThinkingLevel } from "@google/genai";

const ai = new GoogleGenAI();

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: "What is the water formula?",
  config: {
    thinkingConfig: {
      thinkingLevel: ThinkingLevel.HIGH,
    },
  },
});
console.log(response.text);

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [{
    "parts":[{"text": "What is the water formula?"}]
    }],
    "generationConfig": {
      "thinkingConfig": {
            "thinkingLevel": "high"
      }
    }
   }'

Learn more about Thinking:

Image Understanding

Gemma 4 models can process images, enabling many frontier developer use cases that would have historically required domain specific models.

The following example shows how to use Gemma Image inputs with the Gemini API:

Python

from google import genai

client = genai.Client()

my_file = client.files.upload(file="path/to/sample.jpg")

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    contents=[my_file, "Caption this image."],
)

print(response.text)

JavaScript

import {
  GoogleGenAI,
  createUserContent,
  createPartFromUri,
} from "@google/genai";

const ai = new GoogleGenAI();

const myfile = await ai.files.upload({
  file: "path/to/sample.jpg",
  config: { mimeType: "image/jpeg" },
});

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: createUserContent([
    createPartFromUri(myfile.uri, myfile.mimeType),
    "Caption this image.",
  ]),
});
console.log(response.text);
 ```

REST

IMAGE_PATH="cats-and-dogs.jpg"
MIME_TYPE=$(file -b --mime-type "${IMAGE_PATH}")
NUM_BYTES=$(wc -c < "${IMAGE_PATH}")
DISPLAY_NAME=IMAGE

tmp_header_file=upload-header.tmp

# Initial resumable request defining metadata.
curl "https://generativelanguage.googleapis.com/upload/v1beta/files" \
  -D upload-header.tmp \
  -H "X-Goog-Upload-Protocol: resumable" \
  -H "X-Goog-Upload-Command: start" \
  -H "X-Goog-Upload-Header-Content-Length: ${NUM_BYTES}" \
  -H "X-Goog-Upload-Header-Content-Type: ${MIME_TYPE}" \
  -H "Content-Type: application/json" \
  -d "{'file': {'display_name': '${DISPLAY_NAME}'}}" 2> /dev/null

upload_url=$(grep -i "x-goog-upload-url: " "${tmp_header_file}" | cut -d" " -f2 | tr -d "\r")
rm "${tmp_header_file}"

# Upload the actual bytes.
curl "${upload_url}" \
  -H "Content-Length: ${NUM_BYTES}" \
  -H "X-Goog-Upload-Offset: 0" \
  -H "X-Goog-Upload-Command: upload, finalize" \
  --data-binary "@${IMAGE_PATH}" 2> /dev/null > file_info.json

file_uri=$(jq -r ".file.uri" file_info.json)
echo file_uri=$file_uri

# Now generate content using that file
curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
    -H 'Content-Type: application/json' \
    -X POST \
    -d '{
      "contents": [{
        "parts":[
          {"file_data":{"mime_type": "'"${MIME_TYPE}"'", "file_uri": "'"${file_uri}"'"}},
          {"text": "Caption this image."}]
        }]
      }' 2> /dev/null > response.json

cat response.json
echo

jq -r ".candidates[].content.parts[].text" response.json

Learn more about Image Understanding:

System Instructions

You can pass a system instruction to set the model's behavior:

Python

from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    config=types.GenerateContentConfig(
        system_instruction="You are a wise Kyoto tea master. Speak calmly and poetically, using nature metaphors. Keep answers under 3 sentences."
    ),
    contents="What is the purpose of the tea ceremony?"
)
print(response.text)

JavaScript

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI();

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: "What is the purpose of the tea ceremony?",
  config: {
    systemInstruction: "You are a wise Kyoto tea master. Speak calmly and poetically, using nature metaphors. Keep answers under 3 sentences."
  }
});
console.log(response.text);

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [{
    "parts":[{"text": "What is the purpose of the tea ceremony?"}]
  }],
  "systemInstruction": {
    "parts": [{"text": "You are a wise Kyoto tea master. Speak calmly and poetically, using nature metaphors. Keep answers under 3 sentences."}]
  }
}'

Multi-turn Conversations

The SDK provides a chat interface that tracks conversation history automatically:

Python

from google import genai

client = genai.Client()
chat = client.chats.create(model="gemma-4-26b-a4b-it")

response = chat.send_message("What are the three most famous castles in Japan?")
print(response.text)

response = chat.send_message("Which one should I visit in spring for cherry blossoms?")
print(response.text)

JavaScript

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI();
const chat = ai.chats.create({ model: "gemma-4-26b-a4b-it" });

let response = await chat.sendMessage({ message: "What are the three most famous castles in Japan?" });
console.log(response.text);

response = await chat.sendMessage({ message: "Which one should I visit in spring for cherry blossoms?" });
console.log(response.text);

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [
    {
      "role": "user",
      "parts": [{ "text": "What are the three most famous castles in Japan?" }]
    },
    {
      "role": "model",
      "parts": [{ "text": "Himeji Castle, Matsumoto Castle, and Kumamoto Castle are often considered the top three." }]
    },
    {
      "role": "user",
      "parts": [{ "text": "Which one should I visit in spring for cherry blossoms?" }]
    }
  ]
}'

Function Calling

Define tools as function declarations. The model decides when to call them:

Python

from google import genai
from google.genai import types

# Define the function declaration
get_weather = {
    "name": "get_weather",
    "description": "Get current weather for a given location.",
    "parameters": {
        "type": "object",
        "properties": {
            "location": {
                "type": "string",
                "description": "City and state, e.g. 'San Francisco, CA'",
            },
        },
        "required": ["location"],
    },
}

client = genai.Client()
tools = types.Tool(function_declarations=[get_weather])
config = types.GenerateContentConfig(tools=[tools])

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    contents="Should I bring an umbrella to Kyoto today?",
    config=config,
)

# The model returns a function call instead of text
if response.function_calls:
    for fc in response.function_calls:
        print(f"Function to call: {fc.name}")
        print(f"ID: {fc.id}")
        print(f"Arguments: {fc.args}")
else:
    print("No function call found in the response.")
    print(response.text)

JavaScript

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI();

const get_weather = {
    name: "get_weather",
    description: "Get current weather for a given location.",
    parameters: {
        type: "object",
        properties: {
            location: {
                type: "string",
                description: "City and state, e.g. 'San Francisco, CA'",
            },
        },
        required: ["location"],
    },
};

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: "Should I bring an umbrella to Kyoto today?",
  config: {
    tools: [{ functionDeclarations: [get_weather] }]
  }
});

if (response.functionCalls) {
    for (const fc of response.functionCalls) {
        console.log(`Function to call: ${fc.name}`);
        console.log(`Arguments: ${JSON.stringify(fc.args)}`);
    }
} else {
    console.log("No function call found in the response.");
    console.log(response.text);
}

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [{
    "parts":[{"text": "Should I bring an umbrella to Kyoto today?"}]
  }],
  "tools": [{
    "functionDeclarations": [{
      "name": "get_weather",
      "description": "Get current weather for a given location.",
      "parameters": {
        "type": "OBJECT",
        "properties": {
          "location": {
            "type": "STRING",
            "description": "City and state, e.g. 'San Francisco, CA'"
          }
        },
        "required": ["location"]
      }
    }]
  }]
}'

Ground Gemma 4 responses in real-time web data with Google Search:

Python

from google import genai
from google.genai import types

client = genai.Client()

response = client.models.generate_content(
    model="gemma-4-26b-a4b-it",
    contents="What are the dates for cherry blossom season in Tokyo this year?",
    config=types.GenerateContentConfig(
        tools=[{"google_search":{}}]
    ),
)

print(response.text)

# Access grounding metadata for citations
for chunk in response.candidates[0].grounding_metadata.grounding_chunks:
    print(f"Source: {chunk.web.title} — {chunk.web.uri}")

JavaScript

import { GoogleGenAI } from "@google/genai";

const ai = new GoogleGenAI();

const response = await ai.models.generateContent({
  model: "gemma-4-26b-a4b-it",
  contents: "What are the dates for cherry blossom season in Tokyo this year?",
  config: {
    tools: [{ googleSearch: {} }]
  }
});

console.log(response.text);

if (response.candidates?.[0]?.groundingMetadata?.groundingChunks) {
    for (const chunk of response.candidates[0].groundingMetadata.groundingChunks) {
        if (chunk.web) {
            console.log(`Source: ${chunk.web.title} — ${chunk.web.uri}`);
        }
    }
}

REST

curl "https://generativelanguage.googleapis.com/v1beta/models/gemma-4-26b-a4b-it:generateContent" \
-H 'Content-Type: application/json' \
-X POST \
-d '{
  "contents": [{
    "parts":[{"text": "What are the dates for cherry blossom season in Tokyo this year?"}]
  }],
  "tools": [{"googleSearch": {}}]
}'