Minimax, Synesis and Luceed integration: APIs compared
Do Minimax, Synesis and Luceed have an API, where are the docs and what can you connect: invoices, partners, items, stock. Plus: is Synesis an ERP?
If someone retypes every invoice from your web shop or CRM into your accounting software, that is hours of work every month and a steady source of errors. The first question is always the same: does your software have an API, and what can you connect through it? For three common Croatian programs - Minimax, Synesis and Luceed - the answers differ a lot.
Quick answer
- Minimax has a publicly documented REST API (OAuth2) for customers, items, issued and received invoices, orders, stock and journal entries.
- Luceed has a REST API with JSON and public PDF documentation (324 pages) for items, prices, stock, partners, sales orders and invoices.
- Synesis has no API published on the vendor’s site. It connects through file exchange (CSV, Excel) or a custom solution.
- e-invoicing (eRačun) is supported inside all three apps, but that is not the same as an API for your web shop.
- Where an API exists, a typical integration sends orders and invoices from the web shop into the software, and stock and prices back to the shop.
Comparison: API, data and documentation
We checked these facts on the vendors’ sites on 16 October 2026.
| Software | API? | Typically synced | Public docs? |
|---|---|---|---|
| Minimax | Yes, REST, OAuth2 | customers, items, issued and received invoices, orders, stock and stock entries, journals | Yes, moj.minimax.hr/HR/api |
| Luceed | Yes, REST, JSON, basic auth | items, prices and promotions, stock levels, partners, sales orders, retail and wholesale invoices, received invoices | Yes, PDF on docs.tomsoft.hr |
| Synesis | Not published | report export to Excel, CSV for websites, exchange between two Synesis installs | No API docs |
Minimax: connecting to the API
The Minimax API is a RESTful service, and the technical documentation with a Swagger UI is at moj.minimax.hr/HR/api. To connect you need two things: a developer ClientID and ClientSecret, issued by Minimax support, and a username and password you define yourself in your Minimax account settings (developer guide, in Croatian). Authentication is OAuth2 with grant_type=password.
Mind the limits Minimax states itself: 1,000 API calls per day and 20,000 per month per organisation, and the API is designed for up to 1,000 issued invoices and up to 1,000 orders per month. That is enough for a smaller web shop; higher volumes need a different plan.
Luceed integration
Luceed (by Tomsoft) has a RESTful web service that exchanges data as JSON, with basic authentication (Luceed API). You don’t get credentials from Tomsoft but from the company that runs Luceed, and it decides which methods you can use.
The documentation (version 2.206) covers reading items, prices with promotions, stock per warehouse and partners, creating partners and sales orders, status changes, saving retail invoices and creating received invoices. It also supports fetching only changed records, which matters when syncing a large catalogue. That is why Luceed is most often connected to a web shop - see how to connect a web shop to ERP.
Synesis: API, ERP or accounting software?
Synesis is modular Windows business software by Pupilla (pupilla.hr). It has modules for financial and inventory accounting, VAT, payroll, retail and POS, and documents post automatically into one database. Functionally it covers part of what an ERP does for a small company, but the vendor presents it as business software rather than an ERP, and it is desktop software, not cloud.
We found no public API on the vendor’s site. What exists: export of every report to Excel, a CSV file for websites (for example for price display) and data exchange between two Synesis installations. Connecting it to a web shop or CRM therefore usually means scheduled file exchange or a middleware layer agreed with the vendor. If you need real-time sync, the alternative is software with an API (Minimax, Luceed) or an ERP such as Pantheon - more in our ERP integrations comparison.
e-invoicing is not the same as an API
Synesis connects through its built-in ePortal to information intermediaries (moj e-Račun, FINA B2B and B2G, ePoslovanje, Redok) and books received e-invoices automatically (Synesis eRačun). Minimax issues e-invoices from its outgoing invoices module (guide).
That covers the legal obligation, but not the retyping: someone still has to enter the invoice. For the obligations that apply to your company, read our article on e-invoicing and fiscalization in Croatia.
Example: 30 invoices a day from a web shop into Minimax
Assumptions: 30 outgoing invoices a day, 21 working days a month, 3 minutes per invoice for manual entry (find or create the customer, enter line items, check and issue).
- 30 × 3 min = 90 minutes a day
- 90 min × 21 days = 1,890 minutes, or about 31.5 hours a month
- 630 invoices a month is within Minimax’s 1,000 limit; if one invoice takes about 4 API calls (customer, items, invoice, issue), that is 120 calls a day out of the 1,000 allowed
An integration turns those 31.5 hours into checking exceptions, and retyping errors disappear. What such a project looks like step by step is in API integrations: how they work.
Need Minimax, Luceed or Synesis connected to your web shop or CRM? That is our integrations service.
Frequently Asked Questions
Is Synesis an ERP? The vendor describes it as modular business software, not an ERP. It covers accounting, inventory, payroll and retail in one database, so for a small company it can work much like an ERP, but it has no public API.
Where is the Minimax API documentation? At moj.minimax.hr/HR/api, with a Swagger UI. The general developer guide and the steps to get credentials are on help.minimax.hr.
Does Luceed have an API? Yes, a REST web service with JSON. The documentation is public as a PDF on docs.tomsoft.hr, and access is granted by the company that runs Luceed.
Can Synesis be connected to a web shop? Yes, but without a public API it is usually scheduled CSV or Excel file exchange, not real-time sync.
Related Articles
- How to connect a web shop to ERP: orders, stock, prices
- ERP integrations: SAP, Dynamics & Pantheon
- API integrations: how they work
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