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

# Link a W&B run to trace function calls

> Associate Weave traces with W&B runs for experiment tracking

## View a W\&B run in the Traces table

With W\&B Weave, you can trace function calls in your code and link them directly to the [W\&B runs](https://docs.wandb.ai/models/runs/) in which they were executed.
When you trace a function with `@weave.op()` and call it inside a `wandb.init()` context, Weave automatically associates the trace with the W\&B run.
Links to any associated runs are shown in the Traces table.

<Tabs>
  <Tab title="Python">
    The following Python code shows how traced Ops are linked to W\&B
    runs when executed inside a `wandb.init()` context. These traces appear in the
    Weave UI and are associated with the corresponding run.

    To view a W\&B run as a Weave trace:

    1. In the terminal, install dependencies.

    ```bash lines theme={null}
    pip install wandb weave
    ```

    2. Log in to W\&B.

    ```bash lines theme={null}
    wandb login
    ```

    3. In the following script, replace `your-team-name/your-project-name` with your actual W\&B entity/project:

    ```python lines theme={null}
    import wandb
    import weave

    def example_wandb(projname):
        # Split projname into entity and project
        entity, project = projname.split("/", 1)

        # Initialize Weave context for tracing
        weave.init(projname)

        # Define a traceable Op
        @weave.op()
        def say(message: str) -> str:
            return f"I said: {message}"

        # First W&B run
        with wandb.init(
            entity=entity,
            project=project,
            notes="Experiment 1",
            tags=["baseline", "paper1"],
        ) as run:
            say("Hello, world!")
            say("How are you!")
            run.log({"messages": 2})

        # Second W&B run
        with wandb.init(
            entity=entity,
            project=project,
            notes="Experiment 2",
            tags=["baseline", "paper1"],
        ) as run:
            say("Hello, world from experiment 2!")
            say("How are you!")
            run.log({"messages": 2})

    if __name__ == "__main__":
        # Replace this with your actual W&B username/project
        example_wandb("your-team-name/your-project-name")
    ```

    4. Run the script.

    ```bash lines theme={null}
    python weave_trace_with_wandb.py
    ```

    5. Navigate to [https://wandb.ai](https://wandb.ai) and select your project.
    6. In the **Weave project sidebar**, click **Traces**.  Links to any associated runs are displayed in the Traces table.
  </Tab>

  <Tab title="TypeScript">
    ```plaintext theme={null}
    This feature is not available for the TypeScript SDK yet.
    ```
  </Tab>
</Tabs>