Our mission
We exist so that when a law, tax rule, care protocol, or commercial term is applied in digital systems, the people accountable for that decision can read it, explain it, and prove it.
About LemmaBase
Our law, tax codes, care protocols, and commercial terms are governed through software. LemmaBase ensures these rules stay legible, verifiable, and under the control of the institutions and businesses accountable for them. We build Lemma, an open language for writing rules, and LemmaBase.com, the platform where teams manage and deploy them.
Why it matters
Rules are handed to engineers or AI agents, get lost in translation and end up scattered across applications, databases, services and integrations in a form only those systems can read. Move a VAT rate to 22% and the question stops being legal: it becomes how many applications need changing and how to coordinate that.
Our clients
Public institutions, insurers, lenders, banks, healthcare providers, and IT service agencies that build for them. Governments and businesses are accountable for what they promise and cannot point at an AI agent when the promise fails.
Our communities
Lemma is a free and open source language, licensed under Apache 2.0. The format in which we write our rules, legislation and business policies belongs in the public domain and LemmaBase is proud to support that.
What we do
Lemma
The open-source language for writing rules in a form all people can read and machines can evaluate with certainty, proof and explainability.
LemmaBase.com
LemmaBase.com is the platform where teams write, review, version, and publish Lemma rules for use in production.
Who we are
What we believe
Rules that carry commercial, legal, or democratic weight do not belong inside probabilistic systems, application code, or vendor-specific formats. They belong in a form that can be read, reviewed, and explained by those who are responsible for them.
Founding team
Joost Cordes
Chief Commercial Officer
Joost has spent twenty years commercialising and customising digital products, much of it in telecom. He has seen how hard it is to keep what a customer was promised aligned with what systems actually do.
"As a business, you are responsible for your promises and accountable for your actions. You cannot give a customer a guarantee and then, if it fails, point to an AI agent. You have to own the rules you apply, and be able to show them."
Ben Rogmans
Chief Executive Officer & creator of Lemma
As an entrepreneur and CTO in ecommerce, telecom, and healthcare, Ben has experienced firsthand how policy is drowning in operational software. When rules are encoded in complex IT systems, they become hard to change, even harder to track over time, and often impossible to explain under compliance pressure. He created Lemma so that business rules live outside operational systems, in an open language people and machines can trust.
Contact us
If your organisation applies rules through software, we want to hear how you change them and how you explain them afterwards.