Sdcreader MCP server

sdcreader

<!-- mcp-name: io.github.SemanticDataCharter/sdcreader -->

Read a published Semantic Data Charter model's package for projection into other standards.

A projection describes a model's governed data records in another standard's terms: CDIF, DCAT-US 3.0, DCAT-AP 3.0.1, HealthDCAT-AP, and whatever comes next. What every projection describes is the same evidence, the model's package, and reads it into the same shape. sdcreader is that evidence and that shape, once, with nothing about any projection in it. The four projection writers (sdccdif, sdcdcat3us, sdcdcat3ap, sdchealthdcat_ap) carried it as identical copies until this package.

pip install sdcreader            # the reader, with HTTP for fetching from the public catalog (since 4.1.0 no extra is needed)

from sdcreader import fetch_package, load_package, read_model

pkg = load_package("samples/nhanes-participant")          # a package on disk
pkg = fetch_package("xy8upneajsb8vdcmnve01g6g", save_to="pkg/")   # or from SDCStudio's public catalog, no account
model = read_model(pkg)

pkg.schema_url_pinned        # https://sdcstudio.axius-sdc.com/dmlib/dm-xy8u...xsd?sha256=0df4...   the exact bytes the records are validated against
model.title, model.leaves    # 'NHANES Participant', 153 leaves in document order, each with its path of clusters
model.codes[ct_id]           # the enumerated values of a component with the IRI, definition and code the schema annotates them with
model.dc("publisher")        # what the modeler wrote, None where SDCStudio's default sits

What a package is

SDCStudio generates a package for every published model and serves it publicly for models in public projects:

A package directory holds those four files. The reader refuses a directory without the JSON-LD and the schema, a JSON-LD whose identifier is not the directory's model, and a schema whose bytes are not the published current version: a projection cites the schema by URL and SHA-256, so the bytes have to be the ones that URL serves.

Two gaps in the package are on SDCStudio's issue tracker: the JSON-LD metadata drops fields the schema header carries (#748), and the header omits dc:source (#749). The reader takes the model's Dublin Core from the header, which is complete.

What the reader gives

Shortened. The full README is on GitHub.