KLM — Knowledge Layers Model
An open-source record contract and validation toolkit for knowledge provenance, evidence relationships and assessment traces in language-model outputs.
A language-model answer raises questions beyond its wording: Where did the knowledge enter? Which evidence supports each claim? Can the system show the procedures it executed and the assessments it made?
KLM — Knowledge Layers Model provides an open-source record contract and validation tools for those questions. It describes an output alongside its knowledge units, claims, evidence, procedures and assessment traces.
Three dimensions, six layers
The layers are not six sequential processing steps. One knowledge unit can occupy several dimensions at once.
- Origin — Where did knowledge enter? Parametric knowledge (L0) and injected knowledge (L1).
- Function — What did it do? Declarative knowledge (L2) and behavioural procedures (L3).
- Reflection — How was generation assessed? Metacognitive assessment (L4) and governance (L5).
A policy document, for example, can enter as injected knowledge. Its evidence can be connected to a particular output claim. Loading a review procedure, triggering it and actually executing it are separate recorded states.
More than a source list
A bibliography alone does not establish which source supports which claim. KLM gives knowledge, evidence, claims and procedures identifiable objects and typed relationships. Output spans can be connected to those objects.
Signals declare one of four epistemic statuses: measured, heuristic, synthesized or unavailable. A measurement, an approximation and a model's interpretation are not presented as equivalent evidence. An unavailable signal is represented by null with a reason.
Open-source tools
The repository contains record and epistemic-vector schemas, Python validators, signing tools, a hash-chained record log and disclosure views for different readers. The verification path is designed to use Python's standard library. Examples include both valid records and adversarial records that must be rejected.
The conformance ladder runs from KLM-0 to KLM-5: declaration, traceability, grounding, reflection, attribution and independent verifiability. These levels describe record structure and evidence infrastructure. They do not grade model intelligence or certify that an answer is true. A well-described record can contain a claim explicitly marked unsupported or contradicted.
The project is published under the Apache-2.0 license.
Status and limits
At the inspected revision, the specification is a v0.3 working draft and the attestation record schema is klm-attestation/0.2. Legacy 0.1 records retain their original rules. Specification, record-schema and toolchain versions are distinct.
KLM is a candidate reference standard, not a ratified standard. The project identifies independently built implementations using different mechanisms as an important next test. Cryptographic integrity, trust in a source and factual correctness also remain separate questions.
Read next
Sources and revision
This article is based on the public repository inspected on 9 October 2026. The links below are pinned to that revision; the project may subsequently change.
This connects to
Explores KLM’s principle of preserving unavailable signals explicitly.
Documents the KLM record validator using valid and invalid examples.