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

# Getting Started

> Get started with the Junction Sense Python SDK for authentication, query construction, and integration with Polars and Pandas DataFrames.

<Note>
  The [`junction-api-sdk` PyPI package](/home/libraries) (Junction API Python SDK) provides typed bindings
  of the Junction API in Python that track our OpenAPI Schema.

  Junction Sense Python SDK is a standalone product offering, separate from the `junction-api-sdk` PyPI package.
</Note>

**Junction Sense Python SDK** bridges Junction's data aggregation and intelligence capabilities with the
rich Python ecosystem for scientific computing and data analysis.

## Authentication

<AccordionGroup>
  <Accordion title="Deployed Services" icon="server" defaultOpen>
    Use the same [Junction API Keys](/api-details/junction-api#authentication) your system uses to interact with the Junction API.

    To set the Junction API Key for the Junction Sense Python SDK, you can:

    * Pass the Junction API Key explicitly to the Junction Sense SDK entity's constructor (e.g., the Query Executor); or
    * Set the Junction API Key as the `VITAL_API_KEY` environment variable.
  </Accordion>

  <Accordion title="Data Scientists and Developers" icon="user" defaultOpen>
    Sign-in locally on your machine with your [Junction Dashboard](https://app.junction.com/) account. You can
    do so through the [Junction Sense SDK Command Line Tool](#sdk-command-line-tool) as detailed below.
  </Accordion>
</AccordionGroup>

## Installation

### Aggregation API

<Steps>
  <Step title="Add a dependency">
    Add the `vitalx-aggregation` package to your project.

    ```bash theme={null}
    poetry add vitalx-aggregation
    ```
  </Step>
</Steps>

### SDK Command Line Tool

<Steps>
  <Step title="Add a dependency">
    Add the `vitalx-cli` package as a dev dependency to your project.

    ```bash theme={null}
    poetry add -G dev vitalx-cli
    ```
  </Step>

  <Step title="Start the device authentication process">
    Create the `~/.vitalx` directory, and grant it execute permission. The SDK requires execute
    permission to maintain a file lock.

    ```bash theme={null}
    mkdir -p ~/.vitalx && chmod +x ~/.vitalx
    ```

    Call the `auth login` CLI subcommand on the `vitalx-cli` package to start the authentication
    process.

    ```bash theme={null}
    poetry run vitalx-cli auth login
    ```
  </Step>

  <Step title="Sign in with your Junction Dashboard account">
    You will be prompted in your default web browser to sign in to the [Junction Dashboard](https://app.junction.com/).
    You will then be asked to confirm the device authorization.

    <Frame>
      <img src="https://mintcdn.com/vital/deJB3IUUpJEYmyW_/img/horizon-ai/python-sdk-cli-signin.png?fit=max&auto=format&n=deJB3IUUpJEYmyW_&q=85&s=e211c70cacfcde01e12c2feeff0d778c" alt="Device Confirmation prompt" width="300" data-path="img/horizon-ai/python-sdk-cli-signin.png" />
    </Frame>
  </Step>

  <Step title="Voilà!">
    You have now signed in. You can now use any Junction Sense SDK entity without a Junction API Key.

    <Note>
      Your permanent session is stored at `~/.vitalx/`.
    </Note>
  </Step>
</Steps>

## Example

[tryvital/vitalx-notebook](https://github.com/tryVital/vitalx-notebook) is a pre-configured Jupyter Notebook project
with dependencies on Aggregation API and SDK Command Line Tool.

The notebook also includes an example to compute *Chronotypes* using the Aggregation API.