merit-activa-api 2.1.0

Python client library for Merit Aktiva / 360 Księgowość API — automated invoicing, customers, payments, departments, and 60+ endpoints

merit-activa-api

Python client library for Merit Aktiva / 360 Księgowość API.

Create invoices, manage customers, register payments — all from Python. Perfect for SaaS platforms, e-commerce, and any system that needs automated invoicing through Merit Aktiva accounting software.

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Why this library?

Merit Aktiva (known as 360 Księgowość in Poland) is a popular cloud accounting software in the Baltic region and Poland. This library provides a clean Python interface to its REST API, so you can automate your accounting workflows:

• SaaS billing — automatically create invoices when customers pay via PayU, Stripe, etc.
• Multi-project accounting — track revenue per project/platform using departments
• KSeF compatible — invoices created via API are picked up by Merit's built-in KSeF integration (configured separately in Merit UI)
• Customer management — sync customers from your app to accounting
• Payment tracking — register payments and mark invoices as paid programmatically

Features

• Full API coverage — 60+ endpoints: sales/purchase invoices, customers, vendors, payments, items, GL transactions, fixed assets, reports
• Payment registration — register_payu_payment() marks invoices as paid with payment gateway reference
• One-call invoicing — invoice_and_pay() does everything: customer → invoice → payment → KSeF → email
• Invoice email delivery — send invoice PDFs directly from Merit to customers
• PDF download — get invoice PDFs as base64
• Department support — assign invoices to departments (per project/platform)
• KSeF compatible — invoices work with Merit's built-in KSeF (Poland's e-invoicing), no extra code needed
• Long period queries — auto-segments requests into 90-day chunks (API limit)
• Service items — create products/services via API for consistent invoicing
• Multi-country — Poland (360 Księgowość), Estonia, Finland
• Type hints — full typing for IDE support
• Minimal dependencies — only requests

Installation

pip install merit-activa-api

Or install from source:

git clone https://github.com/zacharm-ewsoft/360ksiegowoscAPI.git
cd 360ksiegowoscAPI
pip install -e .

Quick Start

1. Get API credentials

In 360 Księgowość / Merit Aktiva: Ustawienia → Główne ustawienia → API → Wygeneruj klucze

You'll get an API ID (UUID) and API Key (base64 string).

2. Initialize client

from merit_activa import MeritClient

client = MeritClient(
    api_id="your_api_id",
    api_key="your_api_key",
    # country="pl"  ← default (Poland / 360 Księgowość)
    # country="ee"  ← Estonia
    # country="fi"  ← Finland
)

3. Create a customer

customer = client.create_customer(
    name="Firma ABC Sp. z o.o.",
    reg_no="1234567890",           # NIP
    email="[e-mail]",
    address="ul. Przykładowa 1",
    city="Warszawa",
    postal_code="00-001",
    payment_deadline=14,
)
print(customer)  # {"Id": "abc-123-...", "Name": "Firma ABC Sp. z o.o."}

4. Create an invoice

result = client.create_simple_invoice(
    customer_name="Firma ABC Sp. z o.o.",
    customer_nip="1234567890",
    description="SaaS subscription - April 2026",
    net_amount=799.00,
    vat_rate=23,
    department_code="MYPROJECT",
)
print(result)  # {"InvoiceId": "...", "InvoiceNo": "FV/2026/001"}

5. Register payment (e.g. after PayU/Stripe webhook)

client.register_payu_payment(
    invoice_id=result["InvoiceId"],
    amount=982.77,  # gross amount (799 + 23% VAT)
    payu_order_id="WZHF5FFDRJ140731GUEST000P01",
)
# Invoice is now marked as paid in Merit

6. Send invoice by email

client.send_invoice_by_email(result["InvoiceId"])
# Merit sends PDF to customer's email automatically

7. Full flow — one call does everything

result = client.invoice_and_pay(
    customer_name="Firma ABC Sp. z o.o.",
    customer_nip="1234567890",
    customer_email="[e-mail]",
    description="Professional subscription - May 2026",
    net_amount=799.00,
    department_code="MYPROJECT",
    payu_order_id="WZHF5FFDRJ140731GUEST000P01",
)
# Creates customer (if needed) → creates invoice → registers payment → sends email
# Merit handles KSeF submission separately (configured in Merit UI)
print(result)
# {
#     "customer_id": "...",
#     "invoice_id": "...",
#     "invoice_no": "FV/2026/...",
#     "email_sent": True,
#     "payment_registered": True
# }

Departments (Działy)

Departments let you track revenue per project/platform in a single Merit account:

# List existing departments
departments = client.get_departments()

# Use in invoices — each project gets its own department
client.create_simple_invoice(
    ...,
    department_code="NIS2PILOT",  # or "CLIPFORGE", "SHOPIFY", etc.
)

# Filter invoices by department
invoices = client.get_invoices(
    period_start="20260401",
    period_end="20260430",
    department_code="NIS2PILOT",
)

Note: Departments must be created manually in Merit UI: Menu → Ustawienia → Dodatkowe parametry → Działy

Service Items (Artykuły)

Create reusable service/product items for consistent invoicing:

# Get VAT rate ID (needed for items)
taxes = client.get_taxes()
vat23_id = next(t["Id"] for t in taxes if "23" in t["Code"])

# Create service items
client.create_items([
    {
        "Code": "SVC-PRO-M",
        "Description": "Professional Plan — monthly subscription",
        "Type": 2,          # 2 = service
        "Usage": 1,         # 1 = sales
        "TaxId": vat23_id,
        "UOMName": "szt.",
        "SalesAccCode": "700",
    },
])

# List all items
items = client.get_items()

KSeF Compatibility (Poland)

KSeF (Krajowy System e-Faktur) is Poland's mandatory e-invoicing system, required for all businesses since April 2026.

This library does NOT communicate with KSeF directly. KSeF submission is handled entirely by Merit Aktiva / 360 Księgowość itself (configured in Merit UI under Ustawienia → KSeF).

What this library does support:

• Creating invoices that Merit then submits to KSeF automatically
• Passing a ksef_number field when creating invoices (if you already have one)
• Reading the KSeF number from invoice details after Merit processes it

# Create invoice — Merit submits to KSeF on its own
invoice = client.create_simple_invoice(
    customer_name="Firma ABC",
    customer_nip="1234567890",
    description="Consulting service",
    net_amount=299.00,
)

# Later, after Merit submits to KSeF, the number appears in details:
details = client.get_invoice_details(invoice["InvoiceId"])
ksef_number = details.get("KsefNumber")

Django / Celery Integration

Ideal for SaaS platforms — trigger invoicing from payment webhooks:

# settings.py
MERIT_API_ID = os.environ["MERIT_API_ID"]
MERIT_API_KEY = os.environ["MERIT_API_KEY"]
MERIT_DEPARTMENT = "MYPROJECT"

# apps/billing/services.py
from django.conf import settings
from merit_activa import MeritClient

def get_merit_client():
    return MeritClient(
        api_id=settings.MERIT_API_ID,
        api_key=settings.MERIT_API_KEY,
    )

# apps/billing/tasks.py (Celery)
@shared_task(bind=True, max_retries=3)
def issue_invoice_after_payment(self, subscription_id, payu_order_id):
    """Called from PayU webhook after COMPLETED status."""
    from apps.billing.models import Subscription
    sub = Subscription.objects.get(id=subscription_id)
    client = get_merit_client()

    result = client.invoice_and_pay(
        customer_name=sub.organization.name,
        customer_nip=sub.organization.nip,
        customer_email=sub.invoice_email,
        description=f"{settings.MERIT_DEPARTMENT} {sub.plan} — {sub.billing_cycle}",
        net_amount=sub.price_net,
        department_code=settings.MERIT_DEPARTMENT,
        payu_order_id=payu_order_id,
    )
    sub.merit_invoice_id = result["invoice_id"]
    sub.save()

See examples/django_integration.py for more details.

API Reference

Client Initialization

MeritClient(api_id, api_key, country="pl", base_url=None, timeout=30)

Parameter	Type	Default	Description
api_id	str	required	API identifier (UUID) from Merit settings
api_key	str	required	API secret key (base64 string)
country	str	"pl"	Country: "pl" (Poland), "ee" (Estonia), "fi" (Finland)
base_url	str	None	Override base URL (takes precedence over country)
timeout	int	30	Request timeout in seconds

High-Level Convenience Methods

Method	Description
find_or_create_customer(name, reg_no, ...)	Find customer by NIP, create if not exists
create_simple_invoice(name, nip, desc, amount, ...)	Create a single-line invoice with auto tax lookup
invoice_full_flow(name, nip, email, ...)	Customer → invoice → email in one call
invoice_and_pay(name, nip, email, ..., payu_order_id)	Customer → invoice → payment → email in one call
register_payu_payment(invoice_id, amount, payu_order_id)	Register payment from PayU/Stripe/etc.

Customers

Method	Description
get_customers(name, reg_no, ...)	List customers with filters
create_customer(name, reg_no, email, ...)	Create new customer
update_customer(customer_id, **fields)	Update customer fields
get_customer_groups()	List customer groups
create_customer_group(code, name)	Create customer group

Sales Invoices

Method	Description
get_invoices(start, end, unpaid, department)	List invoices (max 3 months)
get_invoices_period(start, end, ...)	List invoices (auto-segments long periods)
get_invoice_details(invoice_id)	Full invoice details
create_invoice(customer, rows, tax, ...)	Create invoice with full control
delete_invoice(invoice_id)	Delete invoice
create_credit_invoice(data)	Create credit/corrective note
send_invoice_by_email(invoice_id)	Email invoice PDF to customer
get_invoice_pdf(invoice_id)	Download PDF (base64)

Payments

Method	Description
get_payments(start, end)	List payments
get_payment_types()	Available payment types
send_payment(data)	Register sales invoice payment
send_purchase_payment(data)	Register purchase invoice payment
delete_payment(id)	Delete payment
send_bank_statement(data)	Import bank statement
send_prepayment(data)	Register prepayment

Items / Services

Method	Description
get_items()	List all items/services
create_items(items)	Create items (wrap in {Items: [...]} automatically)
update_item(data)	Update item
get_item_groups()	List item groups
create_item_groups(groups)	Create item groups

Purchase Invoices

Method	Description
get_purchase_invoices(start, end)	List purchase invoices
get_purchase_invoice_details(id)	Purchase invoice details
create_purchase_invoice(data)	Create purchase invoice
delete_purchase_invoice(id)	Delete purchase invoice
create_purchase_order(data)	Create purchase order

Sales Offers

Method	Description
get_offers(start, end)	List offers
get_offer_details(id)	Offer details
create_offer(data)	Create offer
update_offer(data)	Update offer
set_offer_status(id, status)	Change offer status
create_invoice_from_offer(id)	Convert offer to invoice

Inventory

Method	Description
get_locations()	List warehouses
get_inventory_movements(start, end)	List movements
send_inventory_movements(data)	Create movements

General Ledger

Method	Description
get_gl_batches(start, end)	List GL transactions
get_gl_batch_details(id)	GL transaction details
create_gl_batch(data)	Create GL transaction

Fixed Assets

Method	Description
get_fixed_assets()	List fixed assets
get_fixed_asset_locations()	Asset locations
get_responsible_employees()	Responsible employees
create_fixed_assets(data)	Create assets

Prices & Discounts

Method	Description
get_prices()	Price list
get_price(item_code)	Item price
send_prices(data)	Create/update prices
get_discounts()	Discount list
send_discounts(data)	Create/update discounts

Dictionaries / Configuration

Method	Description
get_taxes()	Tax rates (VAT) — TaxId needed for invoices and items
get_departments()	Departments list
get_projects()	Projects list
get_cost_centers()	Cost centers
get_accounts()	Chart of accounts
get_banks()	Banks / bank accounts
get_units_of_measure()	Units of measure
get_financial_years()	Financial years
get_dimensions()	Dimensions
add_dimensions(data)	Add dimensions
add_dimension_values(data)	Add dimension values

Reports

Method	Description
get_customer_debts_report()	Receivables / outstanding debts
get_customer_payment_report()	Customer payments
get_profit_loss_statement(start, end)	Profit & Loss
get_balance_sheet(date)	Balance sheet

Vendors (Suppliers)

Method	Description
get_vendors(name, reg_no)	List vendors
create_vendor(name, ...)	Create vendor
update_vendor(id, **fields)	Update vendor
get_vendor_groups()	Vendor groups
create_vendor_group(code, name)	Create vendor group

Recurring Invoices

Method	Description
get_recurring_invoices()	List recurring templates
get_recurring_invoice_details(id)	Template details
create_recurring_invoice(data)	Create recurring template

Error Handling

from merit_activa import (
    MeritClient, MeritApiError, MeritAuthError,
    MeritValidationError, MeritNotFoundError,
)

client = MeritClient(api_id="...", api_key="...")

try:
    invoice = client.create_simple_invoice(...)
except MeritAuthError:
    print("Bad API credentials — check API ID and API Key")
except MeritValidationError as e:
    print(f"Invalid data: {e}")
except MeritNotFoundError:
    print("Resource not found")
except MeritApiError as e:
    print(f"API error {e.status_code}: {e}")

Logging

Enable debug logging to see all API requests and responses:

import logging
logging.basicConfig(level=logging.DEBUG)
# All API calls are logged to the "merit_activa" logger

Merit Aktiva Setup Checklist

Before using this library, configure these in Merit Aktiva UI:

1. Generate API keys: Ustawienia → Główne ustawienia → API
2. Create departments (optional): Ustawienia → Dodatkowe parametry → Działy
3. Add bank account for payments (optional): Ustawienia → Konta bankowe → e.g. "PayU"
4. Configure KSeF (Poland): Ustawienia → KSeF → token/certyfikat

Service items can be created via API using create_items().

Official API Documentation

• Reference Manual: https://api.merit.ee/connecting-robots/reference-manual/
• Merit Aktiva API overview: https://api.merit.ee/merit-aktiva-api/
• Polish base URL: https://program.360ksiegowosc.pl/api
• KSeF info (Poland): https://www.360ksiegowosc.pl/ksef/

Author

Marek Zacharewicz Infortel Sp. z o.o. Email: [e-mail] GitHub: @zacharm-ewsoft

License

GNU General Public License v3.0 — see LICENSE for details.

Contributing

Contributions are welcome! Here's how:

1. Fork the repo
2. Create a feature branch (git checkout -b feature/new-endpoint)
3. Install dev dependencies: pip install -e ".[dev]"
4. Run tests: pytest
5. Submit a pull request

Changelog

2.0.0 (2026-04-03)

• Complete rewrite as pip-installable library
• Full API coverage (60+ endpoints)
• HMAC-SHA256 request signing (verified against live API)
• Payment registration: register_payu_payment(), invoice_and_pay()
• Convenience methods: find_or_create_customer(), create_simple_invoice(), invoice_full_flow()
• Service item creation via create_items() with correct {Items: [...]} format
• Invoice email delivery (send_invoice_by_email()) and PDF download (get_invoice_pdf())
• Department support for multi-project revenue tracking
• KSeF compatible (Merit handles KSeF separately — this library just creates invoices)
• Auto-segmentation for long period queries (90-day API limit)
• Type hints, comprehensive docstrings, and error hierarchy
• 10 unit tests with full mock coverage

1.0.0 (2024-01-10)

• Initial release — tkinter GUI for data retrieval only