Create /get_pln_exchange_rate

Create a new process named /get_pln_exchange_rate.

The process should have one start variable:

• $currency — string, for example USD, EUR, or GBP.

Normalize the value by trimming whitespace and converting it to uppercase.

Create a $result variable with two optional root fields.

When the currency is found:

{
  "found": {
    "code": "USD",
    "mid": 3.7667
  }
}

When it is not found:

{
  "notFound": true
}

NBP API

Use the NBP API:

GET https://api.nbp.pl/api/exchangerates/tables/{table}/?format=json

Use only tables A and B, as both provide exchange rates using the mid field.

Example of a truncated response from table A:

[
  {
    "table": "A",
    "no": "179/A/NBP/2026",
    "effectiveDate": "2026-09-15",
    "rates": [
      {
        "currency": "dolar amerykański",
        "code": "USD",
        "mid": 3.7667
      },
      {
        "currency": "euro",
        "code": "EUR",
        "mid": 4.3445
      }
    ]
  }
]

Search the rates array and match the requested currency against the code field.

The lookup should work as follows:

1. Fetch table A and search for $currency.
2. If found, set $result.found with the code and mid value.
3. Otherwise, fetch table B and search again.
4. If the currency is not found in either table, set:

{
  "notFound": true
}

Use a Script step with the built-in Node.js fetch. Read $currency and write the result to $result.

If an NBP request fails or returns an invalid response, fail the script with a meaningful error instead of returning notFound.

Start form

Add a start form that collects $currency before the process begins.

Keep it minimal:

• one text input for the currency code;
• one button to start the process;
• a short label or heading;
• validation that the value is not empty.

Use minimal HTML and CSS. The form should be responsive and work well on mobile and desktop.

Finish step

At the end, use a Finish step and return $result.

Add a form directly to the Finish step that displays the result.

Set an example value for $result in the form definition so the form can be previewed with realistic data:

{
  "found": {
    "code": "USD",
    "mid": 3.7667
  }
}

Keep the HTML and CSS minimal and simple.

When the currency is found, show the currency code and exchange rate clearly, for example:

USD
1 USD = 3.7667 PLN

When it is not found, display:

Currency not found

The Start and Finish forms should use the same simple visual style, with consistent typography, spacing, input/button styling, and responsive behavior across mobile and desktop screens.