semlayer

The Semlayer validation client — validate your RDF instance data (ABox) against a pinned ontology (owner/repo@version), its SHACL shapes, and its full dependency closure, pulled from the Semlayer registry. Runs in your environment — your data never leaves your network.

Status: functional (v0.1.0). Self-contained + contextual validation, registry bundle fetch, token auth, and semlayer login (device flow) all work end-to-end. Designed in Semlayer's CLIENT.md. Not yet published to PyPI.

Why

Semlayer hosts the TBox (versioned ontologies + author SHACL shapes). This client is the quality gate: check that new instance data conforms to a pinned schema before it hits your production triple store or an LLM/RAG pipeline. CI-native, engine = pySHACL (full SHACL Core + SPARQL + Advanced Features).

Install (once published)

pip install semlayerio            # CLI + SDK — installs the `semlayer` command
pip install "semlayerio[aws]"     # + AWS SigV4 signing for Amazon Neptune

(The PyPI distribution is named semlayerio — semlayer was already taken by an unrelated project — but the installed command is still semlayer.)

Usage

# self-contained: validate a payload as a closed graph
semlayer validate --schema acme/health-model@v1.2.0 --data ./incoming.ttl

# contextual: resolve references against a target store (GraphDB/Fuseki/…)
semlayer validate --schema acme/health-model@v1.2.0 --data ./incoming.ttl \
  --target-endpoint https://graphdb.internal/repositories/prod --target-auth basic \
  --context-depth 2 --inference none --format json

# contextual against Amazon Neptune (IAM auth → SigV4)
semlayer validate --schema acme/health-model@v1.2.0 --data ./incoming.ttl \
  --target-endpoint https://…neptune.amazonaws.com:8182/sparql \
  --target-auth sigv4 --aws-region eu-west-1

# authenticate for local dev (OAuth device flow)
semlayer login

Auth: all programmatic pulls need a Semlayer token — --token, SEMLAYER_API_TOKEN, or semlayer login (device flow). Exit codes: 0 conforms · 1 non-conforming · 2 error.

Layout

Develop

python -m venv .venv && . .venv/bin/activate
pip install -e ".[dev,aws]"
pytest && ruff check . && mypy src

License: MIT.