PRO REST API

REST API in the polski-pro/v1 namespace for managing invoices, settings and legal documents. Requires authentication and manage_woocommerce capability.

Requirements

Polski PRO requires: Polski (free) v1.3.0+, WordPress 6.4+, WooCommerce 8.0+, PHP 8.1+

Authentication

The API requires two authorization elements:

1. WordPress nonce - the X-WP-Nonce header with a value generated by wp_create_nonce('wp_rest')
2. Capability - the logged-in user must have the manage_woocommerce capability

Authentication example (JavaScript)

const response = await fetch('/wp-json/polski-pro/v1/invoices', {
    headers: {
        'X-WP-Nonce': wpApiSettings.nonce,
        'Content-Type': 'application/json',
    },
});

Authentication example (PHP / cURL)

$nonce = wp_create_nonce('wp_rest');

$response = wp_remote_get(
    rest_url('polski-pro/v1/invoices'),
    [
        'headers' => [
            'X-WP-Nonce' => $nonce,
        ],
    ]
);

Unauthenticated requests or requests from users without the required capability receive a 401 Unauthorized or 403 Forbidden response.

Invoice endpoints

Retrieve invoice list

GET /wp-json/polski-pro/v1/invoices

Query parameters:

Parameter	Type	Default	Description
page	int	1	Page number
per_page	int	20	Results per page (max 100)
status	string	any	Status filter: draft, issued, sent, paid, cancelled
date_from	string	null	Date from (Y-m-d)
date_to	string	null	Date to (Y-m-d)
order_id	int	null	Filter by WooCommerce order ID
search	string	null	Search by invoice number or contractor name

Response (200 OK):

{
    "invoices": [
        {
            "id": 1,
            "number": "FV/2026/04/001",
            "order_id": 567,
            "status": "issued",
            "type": "vat",
            "buyer": {
                "name": "Firma Testowa Sp. z o.o.",
                "nip": "1234567890",
                "address": "ul. Testowa 1, 00-001 Warszawa"
            },
            "net_total": "1000.00",
            "tax_total": "230.00",
            "gross_total": "1230.00",
            "currency": "PLN",
            "issued_at": "2026-04-01T10:30:00+02:00",
            "due_date": "2026-04-15",
            "external_id": "FV-12345",
            "provider": "fakturownia"
        }
    ],
    "total": 42,
    "pages": 3
}

Create invoice from order

POST /wp-json/polski-pro/v1/invoices

Body parameters (JSON):

Parameter	Type	Required	Description
order_id	int	Yes	WooCommerce order ID
type	string	No	Type: vat (default), proforma, receipt
issue_date	string	No	Issue date (Y-m-d), defaults to today
due_date	string	No	Payment due date (Y-m-d)
notes	string	No	Invoice notes
send_to_provider	bool	No	Send to accounting system (default true)

Request:

{
    "order_id": 567,
    "type": "vat",
    "due_date": "2026-04-15",
    "notes": "Termin płatności 14 dni",
    "send_to_provider": true
}

Response (201 Created):

{
    "id": 43,
    "number": "FV/2026/04/002",
    "order_id": 567,
    "status": "issued",
    "type": "vat",
    "buyer": {
        "name": "Firma Testowa Sp. z o.o.",
        "nip": "1234567890",
        "address": "ul. Testowa 1, 00-001 Warszawa"
    },
    "net_total": "500.00",
    "tax_total": "115.00",
    "gross_total": "615.00",
    "currency": "PLN",
    "issued_at": "2026-04-05T14:00:00+02:00",
    "due_date": "2026-04-15",
    "external_id": null,
    "provider_status": "pending"
}

Retrieve invoice details

GET /wp-json/polski-pro/v1/invoices/{id}

Returns complete invoice data including line items.

Response (200 OK):

{
    "id": 43,
    "number": "FV/2026/04/002",
    "order_id": 567,
    "status": "issued",
    "type": "vat",
    "buyer": {
        "name": "Firma Testowa Sp. z o.o.",
        "nip": "1234567890",
        "address": "ul. Testowa 1, 00-001 Warszawa"
    },
    "seller": {
        "name": "Mój Sklep Sp. z o.o.",
        "nip": "9876543210",
        "address": "ul. Sklepowa 5, 02-222 Warszawa"
    },
    "items": [
        {
            "name": "Produkt testowy",
            "sku": "TEST-001",
            "quantity": 2,
            "unit": "szt.",
            "net_price": "100.00",
            "tax_rate": 23,
            "tax_amount": "46.00",
            "gross_price": "246.00"
        },
        {
            "name": "Dostawa - InPost Paczkomat",
            "sku": null,
            "quantity": 1,
            "unit": "szt.",
            "net_price": "12.20",
            "tax_rate": 23,
            "tax_amount": "2.80",
            "gross_price": "15.00"
        }
    ],
    "net_total": "212.20",
    "tax_total": "48.80",
    "gross_total": "261.00",
    "currency": "PLN",
    "payment_method": "transfer",
    "issued_at": "2026-04-05T14:00:00+02:00",
    "due_date": "2026-04-15",
    "notes": "Termin płatności 14 dni",
    "external_id": "FV-12346",
    "provider": "fakturownia",
    "provider_status": "issued",
    "ksef_number": null
}

Response (404 Not Found):

{
    "code": "invoice_not_found",
    "message": "Faktura o podanym ID nie istnieje.",
    "data": { "status": 404 }
}

Regenerate invoice PDF

POST /wp-json/polski-pro/v1/invoices/{id}/pdf

Regenerates the invoice PDF file and returns the download URL.

Body parameters (optional):

Parameter	Type	Description
template	string	PDF template: default, minimal, detailed
language	string	Language: pl, en, de

Response (200 OK):

{
    "id": 43,
    "pdf_url": "https://example.com/wp-content/uploads/polski-pro/invoices/FV-2026-04-002.pdf",
    "generated_at": "2026-04-05T14:05:00+02:00",
    "file_size": 45678
}

Submit invoice to KSeF

POST /wp-json/polski-pro/v1/invoices/{id}/ksef

Submits the invoice to the National e-Invoice System (KSeF).

Body parameters (optional):

Parameter	Type	Description
test_mode	bool	Submit to the KSeF test environment (default false)

Response (200 OK):

{
    "id": 43,
    "ksef_number": "1234567890-20260405-ABC123DEF456",
    "ksef_status": "accepted",
    "submitted_at": "2026-04-05T14:10:00+02:00",
    "upo_url": "https://example.com/wp-content/uploads/polski-pro/ksef/UPO-43.xml"
}

Response (422 Unprocessable Entity):

{
    "code": "ksef_validation_error",
    "message": "Faktura nie spełnia wymagań schematu KSeF.",
    "data": {
        "status": 422,
        "errors": [
            "Brak numeru NIP nabywcy",
            "Nieprawidłowa stawka VAT dla pozycji 2"
        ]
    }
}

Create correction invoice

POST /wp-json/polski-pro/v1/invoices/{id}/correction

Creates a correction invoice linked to the source invoice.

Body parameters (JSON):

Parameter	Type	Required	Description
reason	string	Yes	Reason for correction
items	array	Yes	Corrected items
items[].original_index	int	Yes	Item index on the source invoice (from 0)
items[].quantity	int	No	New quantity
items[].net_price	string	No	New net price

Request:

{
    "reason": "Zwrot 1 sztuki produktu",
    "items": [
        {
            "original_index": 0,
            "quantity": 1,
            "net_price": "100.00"
        }
    ]
}

Response (201 Created):

{
    "id": 44,
    "number": "FK/2026/04/001",
    "type": "correction",
    "original_invoice_id": 43,
    "original_invoice_number": "FV/2026/04/002",
    "reason": "Zwrot 1 sztuki produktu",
    "items": [
        {
            "name": "Produkt testowy",
            "quantity_before": 2,
            "quantity_after": 1,
            "net_difference": "-100.00",
            "tax_difference": "-23.00",
            "gross_difference": "-123.00"
        }
    ],
    "net_total": "-100.00",
    "tax_total": "-23.00",
    "gross_total": "-123.00",
    "status": "issued",
    "issued_at": "2026-04-05T15:00:00+02:00"
}

Statistics endpoint

Retrieve invoice statistics

GET /wp-json/polski-pro/v1/invoices/stats

Query parameters:

Parameter	Type	Default	Description
days	int	30	Number of days back
group_by	string	day	Grouping: day, week, month

Response (200 OK):

{
    "period": {
        "from": "2026-03-06",
        "to": "2026-04-05"
    },
    "summary": {
        "total_invoices": 156,
        "total_net": "125430.00",
        "total_tax": "28848.90",
        "total_gross": "154278.90",
        "total_corrections": 3,
        "average_invoice_value": "989.22"
    },
    "by_status": {
        "issued": 120,
        "sent": 25,
        "paid": 8,
        "cancelled": 3
    },
    "by_tax_rate": {
        "23": { "count": 140, "net": "110000.00", "tax": "25300.00" },
        "8": { "count": 12, "net": "12000.00", "tax": "960.00" },
        "5": { "count": 4, "net": "3430.00", "tax": "171.50" }
    },
    "timeline": [
        { "date": "2026-04-05", "count": 5, "gross": "4890.00" },
        { "date": "2026-04-04", "count": 7, "gross": "6230.00" }
    ]
}

Settings endpoint

Update PRO settings

POST /wp-json/polski-pro/v1/settings

Body parameters (JSON):

Parameter	Type	Description
section	string	Settings section: invoices, catalog, quote, inpost, accounting
settings	object	Object with key-value setting pairs

Request:

{
    "section": "invoices",
    "settings": {
        "auto_issue": true,
        "trigger_status": "processing",
        "default_type": "vat",
        "due_days": 14,
        "number_format": "FV/{year}/{month}/{number}"
    }
}

Response (200 OK):

{
    "section": "invoices",
    "settings": {
        "auto_issue": true,
        "trigger_status": "processing",
        "default_type": "vat",
        "due_days": 14,
        "number_format": "FV/{year}/{month}/{number}"
    },
    "updated_at": "2026-04-05T14:20:00+02:00"
}

Legal document generation endpoint

Generate legal document

POST /wp-json/polski-pro/v1/legal/generate

Generates legal documents (terms of service, privacy policy) based on store data.

Body parameters (JSON):

Parameter	Type	Required	Description
type	string	Yes	Document type: terms, privacy, withdrawal, cookies
company_data	object	Yes	Company data
company_data.name	string	Yes	Company name
company_data.nip	string	Yes	VAT ID (NIP)
company_data.address	string	Yes	Address
company_data.email	string	Yes	Contact email
company_data.phone	string	No	Phone number
format	string	No	Format: html (default), markdown, pdf
language	string	No	Language: pl (default)

Request:

{
    "type": "terms",
    "company_data": {
        "name": "Mój Sklep Sp. z o.o.",
        "nip": "9876543210",
        "address": "ul. Sklepowa 5, 02-222 Warszawa",
        "email": "[email protected]",
        "phone": "+48 123 456 789"
    },
    "format": "html"
}

Response (200 OK):

{
    "type": "terms",
    "content": "<h1>Regulamin sklepu internetowego...</h1>...",
    "format": "html",
    "generated_at": "2026-04-05T14:25:00+02:00",
    "word_count": 3200,
    "sections": [
        "Postanowienia ogólne",
        "Składanie zamówień",
        "Płatności",
        "Dostawa",
        "Prawo odstąpienia od umowy",
        "Reklamacje",
        "Dane osobowe",
        "Postanowienia końcowe"
    ]
}

Error codes

All endpoints return standardized error codes:

HTTP code	Error code	Description
400	invalid_params	Invalid request parameters
401	rest_not_logged_in	User not logged in
403	rest_forbidden	Missing manage_woocommerce capability
404	invoice_not_found	Invoice does not exist
409	invoice_already_exists	Invoice for this order already exists
422	validation_error	Data validation error
429	rate_limit_exceeded	Request rate limit exceeded (60/min)
500	internal_error	Internal server error

Limits and throttling

The API applies rate limiting: a maximum of 60 requests per minute per user. After exceeding the limit, a 429 response is returned with a Retry-After header.

HTTP/1.1 429 Too Many Requests
Retry-After: 30

Next steps

• Report issues: GitHub Issues
• Related: Accounting integrations

This page is for informational purposes only and does not constitute legal advice. Consult a lawyer before implementation. Polski for WooCommerce is open source software (GPLv2) provided without warranty.