Integrate all ERP & Accounting with one Unified API.

A Unified API abstracts multiple third-party interfaces, technologies, data formats and models into one normalized data model, so you only integrate once instead of building and maintaining many integrations.

Maesn is built for Software teams who want to build and offer relaible integrations without spending months on custom integration work.

Building integrations in-house means dealing with each system's individual complexity from scratch:
token lifecycle management, three-layer authentication stacks, SOAP APIs, XML files, RPC, CSV uploads, cluster-specific routing per customer instance, asynchronous request models, pagination without page counts, app-level webhooks, webhooks with payloads in the URL, systems that ping and systems that require polling, Dutch-only documentation, long qualification processes, paid sandboxes, registration-walled API docs, annual breaking version changes, missing error handling, multi-call object assembly and more.Every system is different.
Every system requires its own implementation, its own maintenance and its own edge case handling. Maesn abstracts every one of these complexities behind a single unified REST API with our common data model, so your team ships a new accounting or ERP integration in days and never maintains it again.

Maesn connects to ERP, accounting, invoicing and financial systems such as DATEV, Sage, Exact Online, Microsoft Dynamics 365 Business Central and dozens more - see all integrations.

The time required to integrate with Maesn depends on the complexity of your use case. Since Maesn provides a single, well-documented REST API with sandbox environments, integrations typically take anywhere from a few days to a few weeks. Once completed, you support numerous systems, including complex ones, instead of just a single, easy-to-integrate platform.

Yes. You control which integrations are enabled, how data is used, and how they are exposed in your product.

Maesn is built with enterprise-grade security standards as GDPR and ISO 27001 certifications. Maesn doesn't save any data and is designed for sensitive processes. See our security page and trust center.

Maesn manages API updates and breaking changes under the hood, so your integration remains stable without extra work on your side.

Yes. Maesn scales from early-stage SaaS products to enterprise use cases as your customer base and integration needs grow.

Maesn pricing is designed to match your growth, not slow it down. Whether you are just getting started or scaling across hundreds of customers, Maesn works with you to find a pricing structure that supports your product team, enables customer success and accellerates growth for your business. See the pricing page for details.

You can start with a sandbox and demo environment. Let's setup everything in a short meeting. Talk to our experts.

Yes. Maesn offers comprehensive API documentation, a postman collection, SDKs and extensive developer resources.

Yes. You can migrate from in-house integrations by switching from your existing APIs to the Maesn API. We can support you throughout the process to ensure the transition is as seamless as possible for both you and your customers.

Maesn can replace existing integration providers while preserving functionality and improving standardization, reliability, and long-term maintainability.

Maesn monitors third-party systems and handles outages gracefully through retries, status transparency, and error handling, so your application can react predictably. In case of unexpected outages, you will be proactively informed.

Maesn is built and hosted in Germany, with all infrastructure running within Europe. Maesn is GDPR compliant and ISO 27001 certified, does not store end-customer data and treats security and compliance as a first principle. For software teams operating in regulated European markets, Maesn is built to meet the standards your customers expect.