merit-api

Python SDK for the Merit Aktiva API.

Installation

pip install merit-api

Usage

from merit_api import MeritAPI

client = MeritAPI(api_id="YOUR_API_ID", api_key="YOUR_API_KEY")

customers = client.customers.get_list()
invoices = client.sales.get_invoices(
    PeriodStart="2024-01-01",
    PeriodEnd="2024-01-31",
)

Features

• deterministic request-body serialization for signing
• configurable timeout and retry handling — retries apply only to idempotent requests; mutating writes (create invoice, create payment, …) are never retried automatically, because Merit does not deduplicate a POST that timed out after the server already committed it, so a replay would create a duplicate. This holds even when an Idempotency-Key is supplied, since Merit does not honor the header.
• request and response logging hooks with secret redaction
• optional idempotency header generation. Note: Merit's API does not deduplicate on this header, so it is not a duplicate-prevention guarantee — it only prepares for servers that honor it. Real protection comes from the duplicate guards below.
• duplicate-write guards for purchase invoices and payments: by default purchases.send_invoice refuses a second invoice with the same vendor + BillNo, and financial.create_payment refuses a second payment referencing the same BillNo and amount. Pass allow_duplicate=True to override.
• API-level business error parsing from HTTP 200 responses

Testing and method coverage report

Run tests:

pytest -q

Regenerate the method-level read/write coverage report:

python scripts_report_method_test_coverage.py

The report is written to reports/method_test_coverage.md and CI checks that this file stays up to date.