> ## Documentation Index
> Fetch the complete documentation index at: https://www.truefoundry.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add Tracing to Python Code

> Instrument your Python code with Traceloop SDK using task decorators to capture nested function call traces.

This guide demonstrates how to use TrueFoundry OtelCollector along with the Traceloop SDK to instrument Python code.
In this example, we'll show how to instrument a simple Python application with nested function calls using Traceloop's task decorators.

<Steps>
  <Step title="Create Tracing Project, API Key and copy tracing code">
    Follow the instructions in [Getting Started](/docs/tracing/tracing-getting-started) to create a tracing project, generate API key and copy the
    tracing code.
  </Step>

  <Step title="Install Dependencies">
    First, you need to install the following

    ```shell lines theme={"dark"}
    pip install traceloop-sdk dotenv
    ```
  </Step>

  <Step title="Add Tracing code to Python application">
    For Python applications, we need to add the `Traceloop.init()` call to the application and use the `@task` decorator to trace functions.

    ```python Python Code {4-6,10-18} lines theme={"dark"}
    from dotenv import load_dotenv
    import os

    # importing traceloop sdk and decorators
    from traceloop.sdk import Traceloop
    from traceloop.sdk.decorators import task

    load_dotenv()

    # Add the traceloop init code to your application
    TFY_API_KEY = os.environ.get("TFY_API_KEY")
    Traceloop.init(
        api_endpoint="<enter_your_api_endpoint>",
        headers = {
            "Authorization": f"Bearer {TFY_API_KEY}",
            "TFY-Tracing-Project": "<enter_your_tracing_project_fqn>",
        },
    )

    # Child function — will create its own span
    @task(name="greet_user_task")
    def greet_user(name):
        print(f"Hello, {name}!")

    # Parent function — also creates a span and calls the child
    @task(name="main_task")
    def main():
        user_name = "Sateesh"
        greet_user(user_name)
        print("Main task finished.")

    # Run the main function
    main()
    ```
  </Step>

  <Step title="Run your application and view logged trace">
    <Frame caption="">
      <img src="https://mintcdn.com/truefoundry/2MMcllD7kMlpnaWX/images/tracing_python.png?fit=max&auto=format&n=2MMcllD7kMlpnaWX&q=85&s=a075104d550b815c4e8d7c7bfb1a82ae" width="3024" height="1716" data-path="images/tracing_python.png" />
    </Frame>
  </Step>
</Steps>