linkml
Linked Open Data Modeling Language
Decision gist · record as of 2026-08-14
Yes, if you need to author schemas once and generate multiple formats (JSON Schema, RDF, ShEx) from a single source. The active maintenance, permissive license, low install friction, and support for current Python versions make it a solid choice. No known vulnerabilities. Best suited for teams working with linked data, semantic web standards, or multi-format schema requirements.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.10 or later.
- Low install friction with a pure-Python wheel.
- Active maintenance with a release within the last 86 days.
License · maintenance · safety
Apache-2.0 (permissive) — Apache-2.0 permissive license allows commercial and private use with minimal restrictions.
last release 2026-05-20 (86 days)
0 known vulnerabilities (OSV.dev, 2026-08-14) · 446,587 downloads/mo, #6,611 on PyPI
Alternatives
Verify before relying
pip install linkml
from linkml.loaders import yaml_loader
from linkml.generators.jsonschemagen import JsonSchemaGenerator
schema = yaml_loader.load('my_schema.yaml')
generator = JsonSchemaGenerator(schema)
json_schema = generator.serialize()- Specific documentation on schema validation and error handling during conversion.
- Performance characteristics when working with large or deeply nested schemas.
- Community adoption metrics beyond download counts (e.g., active issue resolution, contributor base).
What it is and what it does
LinkML is a linked data modeling language designed to let you define data schemas once in YAML and generate multiple schema representations—JSON Schema, RDF, ShEx, and others—from that single source. It follows object-oriented and ontological principles, making it useful for domains like healthcare and bioinformatics where semantic interoperability matters. The package includes command-line tools and a Python API for schema generation, validation, and conversion.
You author schemas in YAML, then use LinkML's generators to produce the formats your downstream systems need. It depends on a substantial set of libraries—including jsonschema, rdflib, pydantic, and sqlalchemy—to handle schema validation, RDF processing, and data serialization. The project is actively maintained and supports modern Python versions.
Use it for
- Define a biomedical data model once in YAML and generate JSON Schema for API validation and RDF for semantic web publishing.
- Convert an existing ontology or schema into multiple formats for use across different tools and platforms.
- Build a domain-specific schema language for internal data governance, then auto-generate documentation and validation code.
- Create linked data models that integrate with existing RDF and OWL ecosystems.
- Generate TypeScript or Python classes from a YAML schema definition for type-safe data handling.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to author schemas once and generate multiple formats (JSON Schema, RDF, ShEx) from a single source.
The active maintenance, permissive license, low install friction, and support for current Python versions make it a solid choice. No known vulnerabilities. Best suited for teams working with linked data, semantic web standards, or multi-format schema requirements.
Install
linkml on PyPI
Before you install
Low install friction with a pure-Python wheel. Active maintenance with a release within the last 86 days. Supports current Python versions (3.10–3.13).
Requires Python 3.10 or later.
License in practice
Apache-2.0 permissive license allows commercial and private use with minimal restrictions.
Quickstart
pip install linkml
from linkml.loaders import yaml_loader
from linkml.generators.jsonschemagen import JsonSchemaGenerator
schema = yaml_loader.load('my_schema.yaml')
generator = JsonSchemaGenerator(schema)
json_schema = generator.serialize()Verify before relying
- Specific documentation on schema validation and error handling during conversion.
- Performance characteristics when working with large or deeply nested schemas.
- Community adoption metrics beyond download counts (e.g., active issue resolution, contributor base).
Package facts
| License | Apache-2.0 permissive |
| Python support | Supports the current Python release >=3.10 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 25 packagesantlr4-python3-runtimeclickgraphvizhbreaderisodatejinja2jsonasobj2jsonschemalinkml-runtimeopenpyxlparseprefixcommonsprefixmapspydanticpyjsgpyshexpyshexcpython-dateutilpyyamlrdflibrequestssphinx-clicksqlalchemytyping-extensionswatchdog |
| Maintenance | Actively maintained 86 days since the last release |
| First released | |
| Downloads | 446,587 / month, #6,611 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableEnvironment :: ConsoleIntended Audience :: DevelopersIntended Audience :: Healthcare IndustryIntended Audience :: Science/ResearchProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Topic :: Software Development :: Libraries :: Python Modules |
Evidence: linkml-1.11.1-py3-none-any.whl
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See also linkml-runtime · schema-salad · sssom · pronto · PyShEx · owlrl · ShExJSG · followthemoney · rdflib · rdflib-jsonld