Code execution

The Gemini API provides a code execution tool that enables the model to generate and run Python code. The model can then learn iteratively from the code execution results until it arrives at a final output. You can use code execution to build applications that benefit from code-based reasoning. For example, you can use code execution to solve equations or process text. You can also use the libraries included in the code execution environment to perform more specialized tasks.

Gemini is only able to execute code in Python. You can still ask Gemini to generate code in another language, but the model can't use the code execution tool to run it.

Enable code execution

To enable code execution, configure the code execution tool on the model. This allows the model to generate and run code.

Python

from google import genai

client = genai.Client()

interaction = client.interactions.create(
    model="gemini-3.7-flash",
    input="What is the sum of the first 50 prime numbers? "
          "Generate and run code for the calculation, and make sure you get all 50.",
    tools=[{"type": "code_execution"}]
)

for step in interaction.steps:
    if step.type == "model_output":
        for content_block in step.content:
            if content_block.type == "text":
                print(content_block.text)
    elif step.type == "code_execution_call":
        print(step.arguments.code)
    elif step.type == "code_execution_result":
        print(step.result)

JavaScript

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

const client = new GoogleGenAI({});

const interaction = await client.interactions.create({
    model: "gemini-3.7-flash",
    input: "What is the sum of the first 50 prime numbers? " +
           "Generate and run code for the calculation, and make sure you get all 50.",
    tools: [{ type: "code_execution" }]
});

for (const step of interaction.steps) {
    if (step.type === "model_output") {
        for (const contentBlock of step.content) {
            if (contentBlock.type === "text") {
                console.log(contentBlock.text);
            }
        }
    } else if (step.type === "code_execution_call") {
        console.log(step.arguments.code);
    } else if (step.type === "code_execution_result") {
        console.log(step.result);
    }
}

REST

curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
-H "x-goog-api-key: $GEMINI_API_KEY" \
-H 'Content-Type: application/json' \
-d '{
    "model": "gemini-3.7-flash",
    "input": "What is the sum of the first 50 prime numbers? Generate and run code for the calculation, and make sure you get all 50.",
    "tools": [{"type": "code_execution"}]
}'

The output might look something like the following, which has been formatted for readability:

Okay, I need to calculate the sum of the first 50 prime numbers. Here's how I'll
approach this:

1.  **Generate Prime Numbers:** I'll use an iterative method to find prime
    numbers. I'll start with 2 and check if each subsequent number is divisible
    by any number between 2 and its square root. If not, it's a prime.
2.  **Store Primes:** I'll store the prime numbers in a list until I have 50 of
    them.
3.  **Calculate the Sum:**  Finally, I'll sum the prime numbers in the list.

Here's the Python code to do this:

def is_prime(n):
  """Efficiently checks if a number is prime."""
  if n <= 1:
    return False
  if n <= 3:
    return True
  if n % 2 == 0 or n % 3 == 0:
    return False
  i = 5
  while i * i <= n:
    if n % i == 0 or n % (i + 2) == 0:
      return False
    i += 6
  return True

primes = []
num = 2
while len(primes) < 50:
  if is_prime(num):
    primes.append(num)
  num += 1

sum_of_primes = sum(primes)
print(f'{primes=}')
print(f'{sum_of_primes=}')

primes=[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67,
71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151,
157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229]
sum_of_primes=5117

The sum of the first 50 prime numbers is 5117.

This output combines several content parts that the model returns when using code execution:

  • text: Inline text generated by the model
  • code_execution_call: Code generated by the model that is meant to be executed
  • code_execution_result: Result of the executable code

Code Execution with images (Gemini 3)

The Gemini 3 Flash model can now write and execute Python code to actively manipulate and inspect images.

Use cases

  • Zoom and inspect: The model implicitly detects when details are too small (e.g., reading a distant gauge) and writes code to crop and re-examine the area at higher resolution.
  • Visual math: The model can run multi-step calculations using code (e.g., summing line items on a receipt).
  • Image annotation: The model can annotate images to answer questions, such as drawing arrows to show relationships.

Enable Code Execution with images

Code Execution with images is officially supported in Gemini 3 Flash. You can activate this behavior by enabling both Code Execution as a tool and Thinking.

Python

from google import genai
import requests
import base64
from PIL import Image
import io

image_path = "https://goo.gle/instrument-img"
image_bytes = requests.get(image_path).content

client = genai.Client()

interaction = client.interactions.create(
    model="gemini-3.7-flash",
    input=[
        {"type": "image", "data": base64.b64encode(image_bytes).decode('utf-8'), "mime_type": "image/jpeg"},
        {"type": "text", "text": "Zoom into the expression pedals and tell me how many pedals are there?"}
    ],
    tools=[{"type": "code_execution"}]
)

for step in interaction.steps:
    if step.type == "model_output":
        for content_block in step.content:
            if content_block.type == "text":
                print(content_block.text)
            elif content_block.type == "image":
                img = Image.open(io.BytesIO(base64.b64decode(content_block.data)))
                img.show()  # or: img.save("output_image.jpg")
    elif step.type == "code_execution_call":
        print(step.arguments.code)
    elif step.type == "code_execution_result":
        print(step.result)

JavaScript

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

async function main() {
  const client = new GoogleGenAI({});

  const imageUrl = "https://goo.gle/instrument-img";
  const response = await fetch(imageUrl);
  const imageArrayBuffer = await response.arrayBuffer();
  const base64ImageData = Buffer.from(imageArrayBuffer).toString('base64');

  const interaction = await client.interactions.create({
    model: "gemini-3.7-flash",
    input: [
      {
        type: "image",
        data: base64ImageData,
        mime_type: "image/jpeg"
      },
      { type: "text", text: "Zoom into the expression pedals and tell me how many pedals are there?" }
    ],
    tools: [{ type: "code_execution" }]
  });

  for (const step of interaction.steps) {
    if (step.type === "model_output") {
      for (const contentBlock of step.content) {
        if (contentBlock.type === "text") {
          console.log("Text:", contentBlock.text);
        }
      }
    } else if (step.type === "code_execution_call") {
      console.log(`\nGenerated Code:\n`, step.arguments.code);
    } else if (step.type === "code_execution_result") {
      console.log(`\nExecution Output:\n`, step.result);
    }
  }
}

main();

REST

IMG_URL="https://goo.gle/instrument-img"
MODEL="gemini-3.7-flash"

MIME_TYPE=$(curl -sIL "$IMG_URL" | grep -i '^content-type:' | awk -F ': ' '{print $2}' | sed 's/\r$//' | head -n 1)
if [[ -z "$MIME_TYPE" || ! "$MIME_TYPE" == image/* ]]; then
  MIME_TYPE="image/jpeg"
fi

if [[ "$(uname)" == "Darwin" ]]; then
  IMAGE_B64=$(curl -sL "$IMG_URL" | base64 -b 0)
elif [[ "$(base64 --version 2>&1)" = *"FreeBSD"* ]]; then
  IMAGE_B64=$(curl -sL "$IMG_URL" | base64)
else
  IMAGE_B64=$(curl -sL "$IMG_URL" | base64 -w0)
fi

# Use jq to create the JSON payload to avoid "Argument list too long" error with large base64 strings
echo -n "$IMAGE_B64" > image_b64.txt
jq -n \
  --rawfile b64 image_b64.txt \
  --arg mime "$MIME_TYPE" \
  '{
    model: "gemini-3.7-flash",
    input: [
      {type: "image", data: $b64, mime_type: $mime},
      {type: "text", text: "Zoom into the expression pedals and tell me how many pedals are there?"}
    ],
    tools: [{type: "code_execution"}]
  }' > payload.json

curl -X POST "https://generativelanguage.googleapis.com/v1beta/interactions" \
    -H "x-goog-api-key: $GEMINI_API_KEY" \
    -H 'Content-Type: application/json' \
    -d @payload.json

Use code execution in multi-turn interactions

You can also use code execution as part of a multi-turn conversation using previous_interaction_id.

Python

from google import genai

client = genai.Client()

interaction1 = client.interactions.create(
    model="gemini-3.7-flash",
    input="I have a math question for you.",
    tools=[{"type": "code_execution"}]
)
print(interaction1.output_text)

interaction2 = client.interactions.create(
    model="gemini-3.7-flash",
    previous_interaction_id=interaction1.id,
    input="What is the sum of the first 50 prime numbers? "
          "Generate and run code for the calculation, and make sure you get all 50.",
    tools=[{"type": "code_execution"}]
)

for step in interaction2.steps:
    if step.type == "model_output":
        for content_block in step.content:
            if content_block.type == "text":
                print(content_block.text)
    elif step.type == "code_execution_call":
        print(step.arguments.code)
    elif step.type == "code_execution_result":
        print(step.result)

JavaScript

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

const client = new GoogleGenAI({});

const interaction1 = await client.interactions.create({
    model: "gemini-3.7-flash",
    input: "I have a math question for you.",
    tools: [{ type: