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

# Quick start

> The fastest way to get started with the Symmetry Tax Logic (STL) API — test with Postman, run a sample client, or dive into the full tutorial.

## Before you begin

### Download the developer integration kit

The [Developer Integration Kit](/ste/ai-interfaces/tax-logic-api/developer-integration-kit) is the fastest way to get started.

It includes:

* Complete API documentation
* Sample requests and responses
* A Postman collection
* An AI integration accelerator (located in the `skills/` folder) that works with Cursor and other AI-assisted IDEs

[Download the Developer Integration Kit](/ste/ai-interfaces/tax-logic-api/developer-integration-kit) and open it in your IDE. After providing your API key, the included copilot can guide you through:

* Authentication
* Request construction
* Payload validation
* Response interpretation

Using the provided samples and tools, you can stand up and test a working integration in minutes. As a reminder, you can integrate in three quick steps:

<Steps>
  <Step title="Retain the payroll context">
    Your application retains the STE payroll calculation log or JSON request (the payroll context).
  </Step>

  <Step title="Send the data to the STL API">
    You send that data to the STL API.
  </Step>

  <Step title="Display the explanation">
    The API returns a structured explanation and you display it in your UI.
  </Step>
</Steps>

## Option 1: Test with Postman (recommended first step)

The fastest way to see STL in action is with the provided Postman collection.

<Steps>
  <Step title="Import the Postman collection and environment file">
    [**Download the collection and environment (.zip)**](/ste/assets/files/symmetry-tax-logic-api-postman.zip), then extract it to get both files:

    * `symmetry-tax-logic-api.postman_collection.json` — sample requests to all endpoints, including `/explain`.
    * `symmetry-tax-logic-api.postman_environment.json` — variables used in requests. Enter your unique API key provided by Symmetry.
  </Step>

  <Step title="Configure your Postman environment">
    Configure your Postman environment using the following variables:

    | Variable   | What to enter                    | Example                                          |
    | ---------- | -------------------------------- | ------------------------------------------------ |
    | `auth_url` | Symmetry authentication base URL | `https://api.symmetry.com`                       |
    | `base_url` | STL API base URL                 | `https://api.symmetry.com/stl`                   |
    | `api_key`  | Your Symmetry API key            | *(provided by the Symmetry Client Success team)* |

    Leave the other variables as-is — they are auto-populated by the collection scripts:

    * `bearer_token` — set automatically after authentication
    * `conversation_id` — set automatically after an explain call
    * `api_version` — defaults to `v1`
  </Step>

  <Step title="Run the Full Workflow">
    * In the Tax Logic AI API workspace, click on the **"3. Full Workflow (Run All)"** folder
    * Click the **Run** button (▶) at the top of the folder — this opens the **Collection Runner**
    * Click **"Run Tax Logic API"** to start

    The runner executes two steps in sequence:

    * **Step 1: Authenticate** — calls `GET {{auth_url}}/authentication/login` with your API key and stores the Bearer token
    * **Step 2: Explain Tax** — calls `POST {{base_url}}/v1/explain` with sample PayCalc data (FICA, Medicare, FIT)
  </Step>

  <Step title="Check the Test Results tab">
    Both steps should show green checkmarks.
  </Step>

  <Step title="Review the explanations">
    Click on **Step 2** to see the AI-generated tax explanations in the response body.
  </Step>
</Steps>

## Option 2: Run a sample client

Pick your language and follow the README in the corresponding folder within the [Developer Integration Kit](/ste/ai-interfaces/tax-logic-api/developer-integration-kit).

| Language       | Client Code                        | README                         |
| -------------- | ---------------------------------- | ------------------------------ |
| **Python**     | `samples/python/stl_client.py`     | `samples/python/README.md`     |
| **JavaScript** | `samples/javascript/stl-client.js` | `samples/javascript/README.md` |
| **Java**       | `samples/java/StlApiClient.java`   | `samples/java/README.md`       |
| **C#**         | `samples/csharp/StlApiClient.cs`   | `samples/csharp/README.md`     |

## Option 3: Dive into the full tutorial

Read the [**Full Workflow**](/ste/ai-interfaces/tax-logic-api/full-workflow) for a step-by-step walkthrough from authentication through UI display.

## Explore with Swagger

Our Swagger documentation lets you explore and test the STL API endpoints interactively: [**Swagger**](https://api.symmetry.com/tla/docs).

<Steps>
  <Step title="Authorize access">
    To test STL API endpoints using our Swagger documentation, authenticate with your API key:

    * Click **Authorize**
    * Enter your API key in the **value** field and click **Authorize**
  </Step>

  <Step title="Test an endpoint">
    * Navigate to any endpoint (for example, `/explain`)
    * Click **Try it out**
    * Click **Execute**

    Swagger will display the API's response, including the status code, response body, and headers.
  </Step>
</Steps>