maesn

What maesn does

Maesn GmbH is a private, venture-backed software company founded in 2023 in Dusseldorf, Germany, that operates a unified REST API platform providing single-integration access to more than 30 European ERP and accounting systems including DATEV, Lexware, Sage, sevdesk, Microsoft Dynamics 365 Business Central, Xero, and QuickBooks. The platform applies a proprietary Common Data Model that normalizes data formats across systems, abstracts authentication (API keys, OAuth, database credentials, and 2FA), and delivers synthetic webhooks for systems that lack native support. Maesn is ISO 27001 certified, GDPR compliant, and built on Microsoft Azure infrastructure hosted in Frankfurt and Amsterdam, processing data in-memory without persistent storage. The company also offers an MCP Server enabling AI systems such as Claude to query the same underlying ERP and accounting data.

The company targets software teams building products that need ERP and accounting integrations, with a horizontal segmentation approach spanning CRM platforms, fintechs, AP/AR automation tools, lenders and neobanks, tax and AI finance tools, and field-service SaaS. Named customers include HubSpot, Tipalti, Paywise, Clockin, Smarta Steuern, Rally, Finto, Hero Software, and Syntinels. Revenue is generated through subscription-based pricing with usage components plus enterprise contracts, distributed via an API-first self-serve motion supplemented by sales-led enterprise engagements and partner-led distribution through official partnerships with DATEV, Lexware, Microsoft, sevdesk, Sage, and Exact.

Maesn is led by CEO and co-founder Dr. Themo Voswinckel, CRO and co-founder Marius Pohle, and CTO and co-founder Lennart Svensson, and operates with more than 15 team members across six European nationalities. The company has raised €2.3 million in seed funding (November 2025) and secured an additional round in April 2026, both led by get.de with participation from Tiny Supercomputer Investment Company and NRW.BANK. Maesn's stated ambition is to become Europe's leading integration platform for financial and business software.

Name

maesn

Legal name

Maesn GmbH

Website

https://maesn.com

Company type

Private

Founded year

2023

Operating status

Operating

Headcount range

1–10 employees

Short description

Maesn GmbH is a Dusseldorf-based unified API platform providing single-integration access to 30-plus European ERP and accounting systems. It serves software teams building products that need compliant, normalized accounting data, with ISO 27001 and GDPR certification.

Ownership category

akta.pro rank

Product category

Unified API Platform

NAICS

Software Publishers (5132), Computing Infrastructure Providers, Data Processing, Web Hosting, and Related Services (5182)

SIC

Services-Computer Integrated Systems Design (7373), Services-Computer Programming, Data Processing, Etc. (7370)

akta.pro primary industry

Managed Databases (Relational/NoSQL/In-Memory DBaaS) (HDABAAAE)

Keywords

• Unified API platform
• ERP integration services
• Accounting API
• SaaS integration platform
• Developer API tools

Headquarters

HQ city

Cologne

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Personnel, Infrastructure, Marketing or Sales, Operations

Revenue model

1. API Subscription/Usage: Subscription-based pricing with usage components. Pricing designed to match customer growth with tiers for different usage levels. Access granted through API keys with billing based on contracted limits.
2. Enterprise Contracts: Enterprise agreements with dedicated support, custom SLAs, and contract-based pricing for larger organizations requiring extensive integrations.

Pricing tiers

Go-to-market motion3 records

Distribution channels4 records

Marketing channels8 records

Core offering

Maesn provides a unified REST API platform that gives software teams single-integration access to 30+ ERP and accounting systems (DATEV, Lexware, sevdesk, Sage, Microsoft Business Central, Xero, QuickBooks, Odoo, Exact Online, Pennylane, and others). The platform normalizes data formats across systems, unifies authentication methods (API keys, OAuth, database credentials, 2FA), delivers webhooks including synthetic webhooks for systems without native support, and provides real-time monitoring and logging. Built and hosted in Germany with ISO 27001 and GDPR compliance, the no-storage architecture processes data in real time without persisting customer data.

Product overview

Maesn is a unified API platform for ERP and accounting integrations in Europe. The core product is the Maesn Unified API Platform, which provides single-integration access to 30+ ERP and accounting systems including DATEV, Lexware, Sage, QuickBooks, Microsoft Business Central, Xero, sevdesk, and others. The platform includes developer tools (SDKs in Python, JavaScript, PHP, Ruby, Go, Java; TypeScript SDK; Postman collections), sandbox environments, and specialized features like the Common Data Model (ISO-standardized data normalization), Unified Authentication (all auth methods abstracted), Unified Webhooks (including synthetic webhooks for systems without native support), Authenticated Passthrough (for custom fields and raw data access), and an MCP Server for ERP & Accounting enabling AI systems to connect to accounting data. The platform is built and hosted in Germany with ISO 27001 and GDPR compliance.

Differentiator

Problem solved

Functional benefit

Products and services

• Maesn Unified API Platform A unified REST API that provides single-integration access to 30+ ERP and accounting systems including DATEV, Lexware, Sage, QuickBooks, Microsoft Business Central, Xero, sevdesk, Odoo, Exact Online, and others. The platform normalizes data formats, unifies authentication (API keys, OAuth, database credentials, 2FA), provides webhooks for all systems (including synthetic webhooks for systems that don't natively support them), and offers real-time monitoring and logging. Built and hosted in Germany with ISO 27001 and GDPR compliance, the no-storage architecture processes data in real time without persisting customer data. Targeted at SaaS companies, fintechs, and enterprise software teams building products that need ERP and accounting integrations for their end customers.
• Maesn SDKs (Python, JavaScript, PHP, Ruby, Go, Java, cURL) Software Development Kits and code samples in multiple programming languages (Python, JavaScript, PHP, Ruby, Go, Java, cURL, plus an official TypeScript SDK) enabling developers to integrate with the Maesn Unified API. Includes quickstarts, documentation, and Postman collections for language-agnostic integration development.
• Maesn Sandboxes Sandbox environments for testing integrations without affecting production data. Available for all supported accounting and ERP systems, enabling developers to validate integration flows prior to live deployment.
• Maesn MCP Server for ERP & Accounting A Model Context Protocol (MCP) server that enables AI systems such as Claude to connect to DATEV, Exact Online, and 30+ ERP and accounting systems through Maesn's unified API. Allows AI applications to access structured financial and accounting data via a standardized protocol.

Quantifiable outcome

• 40% lower churn rate for integrated software
• +2 more outcomes

Named customers9 records

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Integration29 records

Feature7 records

Partnerships

Six partnerships are on record, tiered core and major.

• DATEVcoreTechnology or IntegrationOfficial DATEV Interface Partner providing integrations to DATEV Unternehmen Online and DATEV Rechnungswesen systems. Enables automated invoice processing, booking proposals, journal entries, and accounting data access.
• LexwarecoreTechnology or IntegrationOfficial Lexware Technology Partner helping SaaS companies and developers navigate the partner qualification process, obtain required OAuth scopes, and abstract complex workflows through their unified API platform.
• MicrosoftcoreTechnology or IntegrationOfficial Microsoft Partner with integration support for Microsoft Dynamics 365 Business Central. Infrastructure hosted on Microsoft Azure in Germany data centers.
• sevdeskmajorTechnology or IntegrationOfficial sevdesk technology partner providing seamless integration with sevdesk accounting system through Maesn's unified API.
• SagemajorTechnology or IntegrationOfficial Sage Partner providing integrations to Sage Active and Sage Accounting systems across European markets.
• ExactmajorTechnology or IntegrationOfficial Exact Technology Partner enabling integration with Exact Online ERP and accounting system.

Scale indicators3 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• Workato: Workato is an enterprise iPaaS for workflow automation and system integration across ERP, CRM, finance and IT systems. Comparable enterprise integration category to Maesn but at much larger scale with broader workflow capabilities.
• Tink (Visa): Tink, owned by Visa, provides open-banking and account-data aggregation across Europe. Comparable to Maesn's European financial-data ambition and represents a much larger, established incumbent with similar geographic focus.
• Plaid: Plaid is the dominant financial-data connectivity layer in the US/UK, used by thousands of fintechs for bank account, transaction and balance access. While primarily bank-data focused, Plaid has expanded into accounting and represents a well-capitalized broad incumbent in financial-data connectivity.
• Celigo: Celigo is an iPaaS focused on business-user-friendly integrations for ERP, finance, ecommerce and SaaS systems. Operates in overlapping integration territory with Maesn but serves a broader mid-market and enterprise ERP customer base.

Direct peers

• Apideck: Apideck offers a unified API for SaaS companies to integrate with accounting, HRIS, CRM and other systems via a single integration. Comparable product model to Maesn with overlapping accounting-integration coverage but different geographic focus.
• Codat: Codat is a unified API specifically focused on accounting, banking, commerce and ERP integrations for SMBs and their software providers. Closest direct competitor to Maesn's accounting/ERP wedge, though Codat is London-based and more globally distributed.
• Nylas: Nylas provides unified APIs for productivity, calendar, contacts and email data, following a similar normalized-API-as-a-service model to Maesn. Different vertical (productivity vs accounting) but comparable infrastructure, pricing and developer-first GTM motion.
• Prismatic: Prismatic is an embedded iPaaS aimed at B2B SaaS companies that need to build customer-facing integrations. Comparable to Maesn in serving SaaS product teams, but Prismatic takes a workflow/connector-builder approach vs Maesn's pre-built normalized-API approach.
• Merge: Merge provides a unified API for HR, accounting, CRM, recruiting, ticketing and other business systems. Directly competes with Maesn in the unified-API / ERP-and-accounting category, though Merge's coverage is broader across HR and US-centric systems rather than deep on DACH accounting.

Emerging players

• Finto: Finto is an AI-finance software company that uses Maesn as a customer to integrate DATEV and other accounting systems. Adjacent rather than competitive, but illustrates the category of AI-native finance apps that could either be Maesn's biggest customers or eventually build competing integration layers.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• GitHubgithub.com/maesndev
• YouTubeyoutube.com/@Maesn_One-API
• LinkedInlinkedin.com/company/maesn-integration

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds1 record

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about maesn