Open-Source  

 The middleware is MIT-licensed. You can audit it, fork it, modify it, or run it under custom conditions. You aren’t building your POS system on a black box, and compliance-critical logic can be version-controlled alongside your application code.

The bundle supports business case recording operations: order creation, payment allocation, signature generation, and receipt rendering. It supports integration of external PSPs and printing systems via pluggable adapters, allowing seamless extension into existing systems.

You can host the middleware inside your app (embedded), deploy it as a Windows/Linux daemon, containerize it for Kubernetes, or use fiskaltrust-hosted instances. Switching between modes doesn’t require a rewrite — configuration-based deployment makes it production-flexible.

Local installations automatically provide a local MQTT-based IoT broker. When cloud access is down, your POS can still communicate with the middleware. Transactions are buffered and synced when connectivity returns, avoiding fiscal law violations due to outages.

fiskaltrust actively supports developers in integrating audit-compliant solutions. The community, documentation, and Academy provide proven patterns. In case of edge-case audits or questions from authorities, fiskaltrust assists with standardized procedures and log exports.

 Choose between REST (stateless, JSON) for cloud-hosted services or RPC for in-process code-level calls. Ideal for various architectures: from modern serverless apps to legacy desktop systems. The API handles lifecycle events (order, pay, sign, journal) in strict order, with idempotent operations and deterministic output.