Sdcgovernance MCP server

sdcgovernance

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

W3C standards-based governance advisory engine for Semantic Data Charter instances.

A Python library that validates governance content in XML data instances against governance components defined in the SDC data model. If the model defines governance (workflow, attestation, party/role, provenance, audit), the instance must carry that content - and this library validates it.

Returns decisions using OASIS XACML semantics: PERMIT, DENY, or INDETERMINATE.

No framework dependency. No middleware. A function call.

How It Works

SDC data models (XSD) can optionally include governance components: Workflow state machines, Attestation authority requirements, Party/Role constraints, Provenance requirements, and Audit definitions. These are part of the data model, not a separate governance layer.

When governance components are defined, every XML data instance must carry the corresponding governance content. This library validates that content against the model:

from sdcgovernance import validate_governance

result = validate_governance("model.xsd", "instance.xml")

print(result.decision)      # PERMIT, DENY, or INDETERMINATE
print(result.has_governance) # True if model defines governance components
print(result.errors)         # list of governance validation errors
print(result.receipt)        # tamper-evident decision receipt

If the model does not define governance components, the result is PERMIT - no governance to enforce.

Two Independent Libraries

sdcvalidator and sdcgovernance are separate, independent libraries. There is no hook, no chaining, no automatic invocation of one from the other.

sdcvalidator (structural validation)
    Does the instance conform to the XSD schema?
    Single-pass. Instance in, pass/fail out.

sdcgovernance (governance advisory)
    Does the model define governance components?
    If yes: does the instance carry valid governance content?
    Conversational. Agents query multiple times during a workflow.

Both libraries read the schema from the instance. Agents call each one independently, at different points in a workflow, in whatever order the operational logic requires. A single workflow may involve multiple calls to both libraries.

What Gets Validated

Governance components are discovered by their position in the DMType root (fixed RM slots: workflow, attestation, party/role, audit, and related), not by CUID2 identity. Once a slot is found, its content is validated by vocabulary binding against the relevant standard (PROV-O, SCXML, VC, DPV). Any component occupying the right slot and bound to the right vocabulary is recognized - whether it comes from the Default project or was custom-built.

Enforcement Decisions (OASIS XACML)

Every decision produces a W3C PROV record and a SHA-256 hash-chained receipt.

Shortened. The full README is on GitHub.