Lemma is a an open source language for business rules, that helps teams govern their systems and workflows.
Only the pliable outlast the storm
Most organisations fail to innovate not for a lack of ideas, but because their operational rules are locked inside systems and business processes. When the modus operandi overrides leadership, the enterprise loses its capacity to adapt.
Frontier organisations use Lemma to break free from operational constraints. By governing with rules instead of procedures, they constantly adapt and drive innovation across products, services, and autonomous workflows.
With the explosion of AI-generated code, applications and workflows, organisations are handing operational control to autonomous systems. Those systems decide prices, eligibility and actions at machine speed, often in forms no one can read or challenge.
AI writes the systems
Generated applications and workflows appear faster than anyone can govern them.
Agents act without a readable mandate
Decisions land in opaque code and prompts, not in rules leadership can own.
Control is the scarce resource
Opportunity only holds if systems and agents run on provable rules.
Lemma was created as an open standard so governance is interoperable and portable: not bound to one system, vendor or runtime. Organisations need rules that can move with them across environments and partners.
That demands a language designed for people first. Clear readability, not imperative code, and not a format shaped first and foremost for computers.
Interoperable
The same rules across systems, vendors and partners
Portable
Not trapped in one product, runtime or environment
Readable by people
Written for stakeholders first, not as computer-first code
In any workflow, process or situation, the organisation must be able to say why a decision was taken: which rules applied, and why. Lemma always answers that question.
The explanation is not a log guess. It is the rules that ran, and it is provably correct.
Which rules applied
The mandate that produced the outcome, not a reconstructed guess from logs.
Why they applied
The path through the rules, readable for auditors, operators and leadership.
Provably correct
The explanation is the evaluation itself, across every workflow and situation.
Operational rules change: law, policy, products and markets never stand still. A governance language that freezes the past fails the present.
Lemma is built so change is normal: rules can be revised, timed and replaced while the organisation keeps control of what applies when.
Revise
Change the rules when the business changes, without rewriting every system.
Time
Publish what applies next while keeping what applied before.
Replace
Keep control of which version runs, and when.
Lenders write affordability and interest rules in Lemma so a mortgage offer is calculated the same way whether it comes from a branch, a website or a call centre. Tax authorities and benefits agencies write the criteria for allowances and assessments. Municipalities write zoning conditions to check permit applications against.
Health insurers write reimbursement conditions. Logistics companies write customs and tariff rules that differ per country and per product.
Lemma is published under the Apache 2.0 licence. Anyone can use it, including in commercial products, and rules written in Lemma are not tied to any supplier.
LemmaBase.com is the platform where teams write, review and publish those rules, but is not required to use Lemma.
Apache 2.0
Free use, modification and distribution. Commercial use is permitted, including in proprietary products. Rules stay yours; they are not locked to a vendor format.