Code execution

The Gemini API code execution feature enables the model to generate and run Python code and learn iteratively from the results until it arrives at a final output. You can use this code execution capability to build applications that benefit from code-based reasoning and that produce text output. For example, you could use code execution in an application that solves equations or processes text.

Code execution is available in both AI Studio and the Gemini API. In AI Studio, you can enable code execution under Advanced settings. The Gemini API provides code execution as a tool, similar to function calling. After you add code execution as a tool, the model decides when to use it.

Get started with code execution

This section assumes that you've installed a Gemini SDK and configured an API key, as shown in the quickstart.

Code execution versus function calling

Code execution and function calling are similar features:

  • Code execution lets the model run code in the API backend in a fixed, isolated environment.
  • Function calling lets you run the functions that the model requests, in whatever environment you want.

In general you should prefer to use code execution if it can handle your use case. Code execution is simpler to use (you just enable it) and resolves in a single GenerateContent request (thus incurring a single charge). Function calling takes an additional GenerateContent request to send back the output from each function call (thus incurring multiple charges).

For most cases, you should use function calling if you have your own functions that you want to run locally, and you should use code execution if you'd like the API to write and run Python code for you and return the result.


There's no additional charge for enabling code execution from the Gemini API. You'll be billed at the current rate of input and output tokens.

Here are a few other things to know about billing for code execution:

  • You're only billed once for the input tokens you pass to the model, and you're billed for the final output tokens returned to you by the model.
  • Tokens representing generated code are counted as output tokens.
  • Code execution results are also counted as output tokens.


  • The model can only generate and execute code. It can't return other artifacts like media files.
  • The feature doesn't support file I/O or use cases that involve non-text output (for example, data plots).
  • Code execution can run for a maximum of 30 seconds before timing out.
  • In some cases, enabling code execution can lead to regressions in other areas of model output (for example, writing a story).
  • There is some variation in the ability of the different models to use code execution successfully. Gemini 1.5 Pro is the best performing model, based on our testing.