linkml-map
LinkML Map is a framework for specifying and executing declarative mappings between data models. At its core is the TransformationSpecification — a YAML-based language for describing how to map one data model to another, independent of serialization format or execution engine.
Features:
- YAML-based lightweight transformation syntax
- Python library for executing mappings on data files
- Tabular data support (TSV/CSV) with streaming for large datasets
- Experimental SQL compilation backend (DuckDB) for set-based transforms
- Derivation of target (implicit) schemas, allowing easy customization of data models (profiling)
- Simple YAML dictionaries for simple mappings
- Automatic unit conversion
- Use of subset of Python to specify complex mappings
- Visualizations of mappings
- Mappings are reversible (provided all expressions used are reversible)
- Multiple output formats (YAML, JSON, JSONL, TSV, CSV)
For full documentation see linkml.io/linkml-map/.
Status:
The transformation data model is not yet fully stable, and may be subject to change. Not all parts of the model are implemented in the reference Python framework.
Quickstart
Install:
pip install linkml-map
# or, in a uv-managed project: uv add linkml-map
When using uv, prefix CLI invocations with uv run (e.g. uv run linkml-map --help).
Run the included example (the example files live in this repo):
git clone https://github.com/linkml/linkml-map.git
cd linkml-map/tests/input/examples/personinfo_basic
linkml-map map-data --unrestricted-eval \
-T transform/personinfo-to-agent.transform.yaml \
-s source/personinfo.yaml \
data/Container-001.yaml
See the Quick Start guide for the expected output and next steps.