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

# Getting started · 🇦🇹 Austria

> Onboard an Austrian merchant, fiscalize a register under RKSV, and complete a sale with an SCU-signed receipt.

This guide walks the `v1` integration contract for Austria. You create an `aut` API key, onboard a merchant with an Austrian `fiscal_identity`, register a location and terminal, fiscalize the register under RKSV, open a register session, start an operation, and complete it with the typed payment contract.

<Info>
  Examples use `https://sandbox.api.openfiskal.com/v1`. Replace with `https://api.openfiskal.com/v1` when you go live.
</Info>

<Warning>
  Register fiscalization on the public API today is only supported for **DE / KassenSichV**. Calling `POST /registers/{id}/fiscalize` on an Austrian location currently returns `422 validation_error`. Austrian RKSV fiscalization is rolling out — contact [support@openfiskal.com](mailto:support@openfiskal.com) for current AT enablement status before scheduling go-live. The merchant, location, and register data shapes shown here are stable and safe to integrate against now; the fiscalize step and the RKSV `fiscal_information` payload are the parts that activate when AT is enabled for your tenant.
</Warning>

## Prerequisites

* An OpenFiskal tenant
* A tenant-scoped, country-scoped API key (`of_test_aut_…` or `of_live_aut_…`)
* `curl` or an HTTP client
* A backend service / database to store your API key, entity IDs and ETags

## Authentication model

Use the standard bearer header on every request. The key encodes the environment and country — `of_test_aut_…` for the Austrian sandbox, `of_live_aut_…` for Austrian production. An `aut` key rejects payloads for any other country.

```bash theme={null}
-H "Authorization: Bearer of_live_aut_abc123..."
```

Every merchant-scoped request must also include:

```bash theme={null}
-H "X-OpenFiskal-Merchant: merchant_01HXYZ"
```

This header value is the merchant ID returned by `POST /merchants`, not your API key.

## Create resources

Create these resources in order. The register cannot fiscalize until the merchant has an `AUT` `fiscal_identity`.

<Steps>
  <Step title="Create your API key">
    Generate an `aut` key at [console.openfiskal.com](https://console.openfiskal.com). Store it in your secrets manager. Format: `of_{env}_aut_{random}`, e.g. `of_test_aut_abcdefgh12345678`.
  </Step>

  <Step title="Create a merchant">
    `country_code` and every `address.country_code` must be `AUT` (ISO 3166-1 alpha-3). The Austrian `fiscal_identity` requires `legal_entity_id_type` (one of `VAT_ID`, `TAX_ID`, `GLN`). Provide the corresponding identifier — `vat_id` (UID, e.g. `ATU12345678`), `tax_number` (Steuernummer), or `gln` (13-digit Global Location Number).

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/merchants \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "Content-Type: application/json" \
      -d '{
        "legal_name": "Alpenblick Handels GmbH",
        "country_code": "AUT",
        "address": {
          "line1": "Mariahilfer Straße 24",
          "city": "Wien",
          "postal_code": "1070",
          "country_code": "AUT"
        },
        "fiscal_identities": [
          {
            "country_code": "AUT",
            "legal_entity_id_type": "VAT_ID",
            "vat_id": "ATU12345678"
          }
        ]
      }'
    ```

    The returned `id` becomes the `X-OpenFiskal-Merchant` header on every merchant-scoped request that follows.
  </Step>

  <Step title="Create a location">
    A location is a physical point of sale. `timezone` is a **required** IANA zone string.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/locations \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
      -H "Content-Type: application/json" \
      -d '{
        "name": "Wien Neubau",
        "address": {
          "line1": "Mariahilfer Straße 24",
          "city": "Wien",
          "postal_code": "1070",
          "country_code": "AUT"
        },
        "timezone": "Europe/Vienna"
      }'
    ```
  </Step>

  <Step title="Create a register">
    A register is the logical checkout (Registrierkasse) that creates operations.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/registers \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
      -H "Content-Type: application/json" \
      -d '{
        "location_id": "loc_01HXYZ",
        "name": "Kassa 1",
        "external_id": "pos-register-1"
      }'
    ```
  </Step>

  <Step title="Fiscalize the register (rolling out)">
    Once enabled for AT, `POST /registers/{id}/fiscalize` provisions the RKSV components — the SCU and Registrierkasse — using the merchant's `AUT` `fiscal_identity` and the location's country. The response is `202 Accepted`; poll `GET /registers/{id}` until `fiscalization_status` is `"fiscalized"` (the timestamp is `fiscalization.fiscalized_at`). Until AT is enabled for your tenant this call returns `422 validation_error`.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/registers/reg_01HXYZ/fiscalize \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ"
    ```
  </Step>

  <Step title="Verify your saved IDs">
    Persist the returned merchant, location, and register IDs. You will use them for every later operation request.
  </Step>
</Steps>

## Perform a fiscalized sale

Once your register is fiscalized, you can create and complete sale operations. The request body is identical to other countries; the response's `fiscal_information` carries the RKSV-specific shape.

<Steps>
  <Step title="Open a session">
    Every POS sale, return, or exchange must bind to an open register session. Send a `session_open` operation with the register, currency, and counted opening cash float. Without an open session, `POST /operations` with `source: POS` is rejected.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/operations \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
      -H "Idempotency-Key: ses-2026-04-30-reg_01HXYZ-open" \
      -H "Content-Type: application/json" \
      -d '{
        "type": "session_open",
        "register_id": "reg_01HXYZ",
        "currency": "EUR",
        "opening_balance_amount": "50.00"
      }'
    ```

    Persist the returned `session_id`. See [Sessions](/sessions) for cash adjustments, end-of-shift counting, and closing.
  </Step>

  <Step title="Start an operation">
    `POST /operations` is a single-shot create. All monetary fields are decimal strings, not integers. `pretax_amount + tax_amount + tip_amount` must equal `total_amount`. `line_items` is required with at least one entry.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/operations \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
      -H "Idempotency-Key: op-order-1001-start" \
      -H "Content-Type: application/json" \
      -d '{
        "register_id": "reg_01HXYZ",
        "source": "POS",
        "type": "sale",
        "currency": "EUR",
        "external_id": "order-1001",
        "pretax_amount": "39.72",
        "tax_amount": "2.78",
        "tip_amount": "0.00",
        "total_amount": "42.50",
        "line_items": [
          {
            "title": "Mittagsmenü",
            "sku_identifier": "MENU-LUNCH",
            "quantity": 1,
            "unit_price": "42.50",
            "total_amount": "42.50",
            "taxes": [
              { "name": "USt. 10%", "rate": "0.10", "tax_amount": "2.78" }
            ]
          }
        ]
      }'
    ```

    <Warning>
      Always send `line_items[].taxes[]`.
    </Warning>
  </Step>

  <Step title="Complete the operation">
    Completion includes typed payment legs. Use one entry per tender leg and include processor references where available. Send the latest `ETag` in `If-Match`. The completed operation returns `fiscal_information` with the RKSV regime.

    ```bash theme={null}
    curl -X POST https://sandbox.api.openfiskal.com/v1/operations/op_01HXYZ/complete \
      -H "Authorization: Bearer of_test_aut_abc123..." \
      -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
      -H "Idempotency-Key: op-order-1001-complete" \
      -H 'If-Match: "1"' \
      -H "Content-Type: application/json" \
      -d '{
        "payments": [
          {
            "payment_id": "pay_1001_card",
            "method": "card",
            "amount": "42.50",
            "currency": "EUR",
            "status": "captured",
            "processor": "sumup",
            "card_brand": "visa",
            "processor_reference": "ch_123",
            "processed_at": "2026-02-26T12:05:00Z"
          }
        ]
      }'
    ```

    Response:

    ```http theme={null}
    HTTP/1.1 200 OK
    ETag: "2"
    X-Request-Id: req_01JCOMPLETE
    ```

    ```json theme={null}
    {
      "id": "op_01HXYZ",
      "resource_version": 2,
      "status": "completed",
      "payments": [
        {
          "payment_id": "pay_1001_card",
          "method": "card",
          "amount": "42.50",
          "currency": "EUR",
          "status": "captured",
          "processor": "sumup",
          "processor_reference": "ch_123",
          "card_brand": "visa",
          "processed_at": "2026-02-26T12:05:00Z"
        }
      ],
      "fiscal_information": {
        "regime": "RKSV",
        "document_number": "2026-000123",
        "document_type": "Beleg",
        "transmitted_at": "2026-02-26T12:05:01Z",
        "cashbox_id": "cashbox-01HXYZ",
        "certificate_serial": "1A2B3C4D5E6F",
        "signature": {
          "signed_at": "2026-02-26T12:05:00Z",
          "transaction_counter": 4822,
          "turnover_counter": "12345.67",
          "signature": "base64encodedSignature==",
          "certificate_serial": "1A2B3C4D5E6F"
        },
        "verification": {
          "qr_data": "_R1-AT0_cashbox-01HXYZ_4822_2026-02-26T12:05:00_42.50_0.00_0.00_0.00_0.00_..."
        }
      }
    }
    ```
  </Step>
</Steps>

## Void an open operation

If the sale is abandoned before completion, void the open operation:

```bash theme={null}
curl -X POST https://sandbox.api.openfiskal.com/v1/operations/op_01HXYZ/void \
  -H "Authorization: Bearer of_test_aut_abc123..." \
  -H "X-OpenFiskal-Merchant: merchant_01HXYZ" \
  -H "Idempotency-Key: op-order-1001-void" \
  -H 'If-Match: "1"' \
  -H "Content-Type: application/json" \
  -d '{ "reason": "void_before_completion" }'
```

## Next steps

* [Transaction lifecycle](/pos-operation-ingestion) — operation lifecycle in detail
* [Payment lifecycle](/payment-lifecycle) — split tender, asynchronous settlement