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

# Get started with Centsless in 5 minutes

> Process your first cash transaction with Centsless using curl. Covers ZIP-based jurisdiction resolution, EBT exemption, and compliance receipt generation.

This guide walks you through processing your first jurisdiction-aware cash transaction using curl. By the end, you will have resolved a jurisdiction by ZIP code, applied rounding automatically, confirmed EBT exemption behavior, and generated a compliance receipt — covering the core flow your POS integration will use in production.

## Prerequisites

* An API key for the sandbox environment (contact Centsless to obtain sandbox credentials)
* A tool for making HTTP requests (curl, Postman, or your preferred language)

<Steps>
  <Step title="Check that the API is live">
    Confirm the API is reachable before making authenticated requests:

    ```bash theme={null}
    curl https://api.centsless.org/api/v1/health
    ```

    You should receive a `200 OK` response with system status. This endpoint requires no API key.
  </Step>

  <Step title="Process an Arizona cash transaction">
    Send a cash transaction with an Arizona ZIP code. The engine resolves the jurisdiction and applies Swedish rounding automatically per AZ HB 2938.

    ```bash theme={null}
    curl -X POST https://api.centsless.org/api/v1/transaction \
      -H "Content-Type: application/json" \
      -H "x-api-key: YOUR_API_KEY" \
      -d '{
        "merchant_id": "YOUR-MERCHANT-ID",
        "subtotal_cents": 523,
        "tax_total_cents": 200,
        "payment_method": "cash",
        "zip_code": "85001"
      }'
    ```

    The response includes the rounded cash total, the rounding delta, the jurisdiction that was resolved, and a compliance status:

    ```json theme={null}
    {
      "success": true,
      "transaction": {
        "id": "TXN-2026-04-14-A82C2EAA",
        "calculation": {
          "subtotal_cents": 523,
          "tax_total_cents": 200,
          "ledger_total_cents": 723,
          "cash_total_cents": 725,
          "rounding_delta_cents": 2,
          "payment_method": "cash",
          "cash_rounding_mode": "swedish_rounding",
          "jurisdiction": "US-AZ",
          "rounding_applied": true
        },
        "compliance": {
          "compliance_status": "PASS"
        },
        "fraud_score": 0,
        "risk_level": "NONE"
      }
    }
    ```

    The customer pays \*\*$7.25** instead of $7.23. The 2-cent `rounding_delta_cents` is applied per Arizona HB 2938 (mandatory Swedish rounding). Save the `id` field — you will need it in step 5.

    <Note>
      `ledger_total_cents` is the pre-rounded total (subtotal + tax). `cash_total_cents` is what the customer actually pays. Sales tax is always calculated on the pre-rounded amount.
    </Note>
  </Step>

  <Step title="Try a different state">
    Swap the ZIP code for a state code to see a different rounding methodology. Send the same amounts to Indiana:

    ```bash theme={null}
    curl -X POST https://api.centsless.org/api/v1/transaction \
      -H "Content-Type: application/json" \
      -H "x-api-key: YOUR_API_KEY" \
      -d '{
        "merchant_id": "YOUR-MERCHANT-ID",
        "subtotal_cents": 523,
        "tax_total_cents": 200,
        "payment_method": "cash",
        "state": "IN"
      }'
    ```

    Same input amounts, but Indiana SB 243 gives the operator a choice of rounding method (three-tier, permissive). The jurisdiction field in the response will reflect `US-IN` and the resolved rounding mode will differ from Arizona. This is the core value of jurisdiction-awareness — your POS code stays the same while the correct rule is applied per location.
  </Step>

  <Step title="Verify EBT exemption">
    EBT/SNAP transactions are never rounded, regardless of jurisdiction. Confirm this by submitting the same transaction with `payment_method: "ebt"`:

    ```bash theme={null}
    curl -X POST https://api.centsless.org/api/v1/transaction \
      -H "Content-Type: application/json" \
      -H "x-api-key: YOUR_API_KEY" \
      -d '{
        "merchant_id": "YOUR-MERCHANT-ID",
        "subtotal_cents": 523,
        "tax_total_cents": 200,
        "payment_method": "ebt",
        "state": "AZ"
      }'
    ```

    The response will show `rounding_delta_cents: 0` and include an `ebt_compliance_flag` confirming 7 CFR 278.2 compliance. No rounding is applied even though Arizona mandates it for cash transactions.
  </Step>

  <Step title="Generate a compliance receipt">
    Use the transaction ID from step 2 to generate a receipt. The receipt includes the rounding disclosure language required by state law:

    ```bash theme={null}
    curl https://api.centsless.org/api/v1/transaction/TXN-ID-HERE/receipt \
      -H "x-api-key: YOUR_API_KEY"
    ```

    Replace `TXN-ID-HERE` with the `id` value from the step 2 response (e.g., `TXN-2026-04-14-A82C2EAA`). The default format is `merchant`, which is the customer-facing receipt with rounding disclosure. You can request `audit` or `pos` formats using the `?format=` query parameter.
  </Step>
</Steps>

## Next steps

* [Jurisdiction Resolution](/concepts/jurisdiction-resolution) — understand the full resolution cascade and how ZIP, state, county, and city rules interact
* [Rounding Methods](/concepts/rounding-methods) — details on Swedish rounding, symmetrical rounding, three-tier operator choice, and the other methodologies
* [API Reference](/api-reference/overview) — complete endpoint documentation for all transaction, receipt, audit, and export operations