ERPNext

ERPNext implementation, operations and AI automation

ERPNext implementation for German requirements, from e-invoicing to the DATEV export. Then AI agents handle the routine, and the approvals stay with you.

Many ERP systems in mid-sized companies have aged badly. They can't produce e-invoices, have no open interface and tie every change to a single vendor. Meanwhile Germany's e-invoicing mandate keeps getting closer.

ERPNext is a complete open-source ERP with no per-user licence fees. It runs accounting, purchasing and sales, inventory and manufacturing in one system. Interlusion handles ERPNext implementation from the first audit to day-to-day operations: e-invoicing, the DATEV export for your tax advisor, custom extensions and moving your data across.

Then AI agents take over the recurring work: matching bank statements, attaching receipts to entries and preparing invoices. Each agent works with its own rights and fixed limits. Anything that moves money or can't be undone is approved by a person.

Interlusion recommends ERPNext because it runs ERPNext itself. Its own instance lives on Interlusion's Kubernetes platform, with the configuration as code and backups that are restored automatically every week as a test. The company's own books move over next.

Services

ERPNext implementation, e-invoicing and AI agents from one partner

Six building blocks, on their own or together. The result is an ERP you own and agents can operate.

Implementation & Operations: ERPNext with the German extensions for DATEV export, e-invoicing and bank import, set up for one company or several. The configuration lives in code, not only in the database, so it stays intact through updates and a rebuild. ERPNext runs on your infrastructure or on Interlusion's platform, with backups that are regularly restored as a test.
AI Agents in ERPNext: Agents handle the routine: matching bank statements, attaching receipts, preparing invoices and payment reminders. Each agent has its own user with its own rights and a fixed list of tasks. Anything that moves money needs a person's approval.
Custom Extensions: Whatever ERPNext lacks for your business becomes an app of its own: print formats with every mandatory detail, reports, interfaces to other systems. Every extension is versioned, tested and survives updates.
Migration: Master data, open items and fixed assets move over from Lexoffice or other systems. The switch lands on the start of a quarter or a year. The old system stays readable for as long as retention periods run.
E-Invoicing: ERPNext issues outgoing invoices as XRechnung or ZUGFeRD. If the switch comes too late for your deadline, a converter bridges the gap. It turns your old system's invoices into valid e-invoices and checks each one before it is sent.
Local & Private AI: The agents can work with open-weight models that run entirely on your own hardware or in a private cloud. Your accounting data then stays in-house.

Why ERPNext

An open ERP, built to be extended

Everything about ERPNext is open: the code, the data and the interfaces. There is no lock-in to a vendor. Whatever is missing becomes an app of its own, without touching the core.

Interlusion chose ERPNext for itself after comparing it with Odoo, and runs it in-house.

Open source: ERPNext is licensed under the GPL. There are no per-user licence fees.
One system: Accounting, purchasing and sales, inventory and manufacturing, for one company or several.
German requirements: Extensions for the DATEV export, bank import and EN 16931 e-invoicing, mandatory in Germany for larger companies from 2027 and for all from 2028.
Open API: All data and processes are reachable through a REST API. That is where the agents work.

Headless Company

ERPNext as the backend of a Headless Company

A Headless Company is a company whose operations are carried by AI agents. People own it, steer it and answer for it, but they don't operate it. The "head" is the operating layer, not the leadership. Leadership stays with people.

The ERP is the backbone of such a company: customers, invoices, payments and stock all live there. ERPNext exposes all its data and processes through an open REST API, so agents work directly in the system instead of clicking through a user interface.

Interlusion builds itself on this principle. Your ERPNext follows the same rules.

One user per agent: That user's role in ERPNext is the upper limit for everything the agent can do.
Sign-in through your identity provider: Access runs through your central sign-in and can be revoked at any time.
Fixed tasks, no master key: Each agent gets a fixed list of operations, with reading and writing kept apart. There is no open access to arbitrary data.
Approvals by amount and consequence: Anything that moves money or can't be undone is approved by a person.
Checks with different blind spots: Work is checked by fixed rules, a different model or a person. Never by the model that did it.
Every change attributed: ERPNext records who created and changed every document, agents included.

Process

From legacy system to an ERP agents can operate

Five phases, each with clear deliverables. The e-invoicing deadlines often set the order.

Discovery & Audit

Map processes, data and obligations such as e-invoicing and the DATEV handover. Then find where agents take real work off people's desks.

Solution Design

Decide modules, companies and the chart of accounts, agreed with your tax advisor. Set the agents' rights and the limits above which a person approves.

Build & Validate

Configuration as code, tested against real data. An ERP is done when real months and real invoices run through without rework.

Deploy & Enable

Switch over at the start of a quarter or a year, train the team, document operations. If you run it yourself, you don't need Interlusion afterwards.

Optimise & Evolve

Updates, new automations and reports. Whatever proves itself gets the next task.

Engagement Models

From a sprint to day-to-day operations

The same models as for all of Interlusion's AI services.

2–4 weeks

AI Opportunity Sprint

A look at your commercial processes: where your ERP stands, which obligations are coming and where agents take real work off your team. The result is a prioritised roadmap, including whether ERPNext fits you.

Best for: Managing directors, finance leads, IT leads

2–6 months

End-to-End Build

Implementation from audit to production: setup and extensions, data migration, agents and training. One partner, no hand-offs.

Best for: Companies changing their ERP

Monthly

Managed AI Operations

Operations, updates and backups for your ERPNext, on your infrastructure or on Interlusion's platform. Plus ongoing care and development of the agents.

Best for: Companies without in-house ERP support

Frequently asked questions

ERPNext is open source and has no licence fees, per user or otherwise. The costs are for implementation, operations and further development. The AI Opportunity Sprint works out what that comes to for you, based on your processes.

Yes. ERPNext exports the entries in DATEV format. Interlusion agrees the chart of accounts and the handover schedule with your tax advisor before the first entry is booked.

A converter bridges the gap. It turns your existing invoices into valid XRechnung or ZUGFeRD files and checks each one before it is sent. Once you move to ERPNext, it is no longer needed.

Your company, just as with an entry made by an employee. That's why approval limits are liability limits too: anything that moves money or can't be undone is approved by a person. ERPNext records who created and changed every document, agents included.

Where you decide: on your own infrastructure or on Interlusion's platform. The agents can work with open-weight models that run entirely on your side. Your accounting data then never leaves the house.

Kersten Lorenz designs the architecture, directs the agents and reviews every change. Everything lives documented in your repository, so any team can take over.

Ready for an ERP that agents can operate?

Whether it's a new ERP, e-invoicing or the first agents in your accounting: it starts with a conversation. Kersten Lorenz replies within 24 hours.

Let's talk