SDS-003: Knowledge Graph Service

sds: id: SDS-003 title: Knowledge Graph Service bounded_context: semantic-core satisfies_prds: [PRD-006, PRD-007, PRD-008] satisfies_adrs: [ADR-004, ADR-006, ADR-040] version: 1.1.0 status: approved owners: [“sea-core-team”] created: 2025-12-01 —

Addresses Requirements

PRD-006: Semantic Context for AI
PRD-007: Dynamic Knowledge Discovery
PRD-008: SHACL Runtime Enforcement and Governance

ADR-004: Semantic Core Formalization
ADR-006: Knowledge Layer Implementation
ADR-040: SHACL Runtime Enforcement Policy

MVP Status

✅ MVP

Component Description

The Knowledge Graph Service provides an inferential projection of the Semantic Core, storing and managing enterprise knowledge as a graph of interconnected entities and relationships. It adopts a SPARQL-first approach, prioritizing explicit query patterns over implicit reasoning. While it supports RDF/OWL for semantic representation, heavyweight reasoning is optional and secondary to materialized projections.

Technical Details

Interfaces

Direction	Description	Format
Input	Semantic data	RDF triples (Turtle/JSON-LD)
Input	Queries	SPARQL (Primary), Cypher (Secondary)
Input	Constraints	SHACL definitions
Output	Graph query results	JSON/RDF
Output	Inferred relationships	JSON
Output	SHACL validation reports	JSON

Protocols

Bolt - Oxigraph native protocol
GraphQL API - Flexible querying
REST API (JSON) - Standard access

Data Model

Refer to SDS-001: Data Model Schemas for:

Entity schema (represented as nodes)
Resource schema (represented as nodes)
Flow schema (represented as relationships)
Instance schema (represented as nodes)
Policy schema (represented as nodes with rule links)

Dependencies

Dependency	Type	Version	Justification
Oxigraph	Rust Binary / Python	0.4.x	Production-grade RDF triple store with SPARQL 1.1 engine
pyoxigraph	Python Library	0.4.x	Python bindings for Oxigraph
RDFLib	Python Library	7.1.x	Fallback RDF store for development/testing
Comunica	Node.js Library	3.x	Execute SPARQL queries in Node.js for TypeScript adapters
pySHACL	Python Library	0.29.x	Validate knowledge graph integrity against SHACL shapes
OWL-RL	Python Library	7.1.x	Enable logical inference over OWL ontologies

SHACL Enforcement Configuration

Runtime validation behavior is controlled by a single configuration source of truth and injected into runtime adapters:

Setting	Type	Default	Purpose
`SHACL_ENFORCEMENT_ENABLED`	boolean	`true`	Enable or disable enforcement
`SHACL_ENFORCEMENT_CONTEXTS`	CSV	empty	If empty, all contexts are active
`SHACL_MAINTENANCE_MODE`	boolean	`false`	Log violations but do not raise
`SHACL_SHAPES_VERSION`	string	`v1`	Versioned shapes selection

Rules

Runtime validation must not read environment variables on hot paths.
Configuration must be passed through constructors or DI layers.

SHACL Validation Contract

validate_with_shacl(...) returns a structured ValidationResult at all call sites:

Field	Type	Description
`conforms`	boolean	SHACL conformance result
`violations`	array	Normalized violation details
`report_graph`	string	SHACL report as Turtle or JSON-LD
`requires_context`	array	Missing contexts from `sea:requiresContext`
`shape_version`	string	Shapes version used
`maintenance_mode`	boolean	Whether enforcement was muted
`enforcement_applied`	boolean	Whether an error would be raised
`cache_hit`	boolean	Whether validation used cached result

Fail-Closed Policy

If maintenance_mode is true: return conforms=false without raising.
If enforcement is enabled and context is active: raise ShaclValidationError.
Otherwise: return conforms=false and emit a warning.

Shape Loading and Versioning

Load ontologies/sea-shapes.{version}.shacl when present.
Fall back to ontologies/sea-shapes.shacl.
Shared constraints live in ontologies/shared/core.shacl and are imported via owl:imports.

Validation Scope Rules

Default to delta-only validation for performance.
If any active shape declares sea:validationScope "full", validate against the merged full graph.

Cross-Context Dependencies

Shapes can declare sea:requiresContext "<context-name>".
Missing contexts surface as explicit validation errors.

Legacy Data Exemption

Entities may declare sea:legacyData true with sea:migrationDeadline.
Past deadline, enforcement escalates with an explicit error.

Port Reference

This service integrates with the following hexagonal ports:

Port	Location	Purpose
`TripleStorePort`	libs/skeleton/graph/ports/src/lib/triple-store.port.ts	RDF triple storage and SPARQL query interface

The TripleStorePort provides:

storeTriples(input: StoreTripleInput): Promise<void> — Store RDF triples
query(sparql: string): Promise<SparqlSelectResult> — Execute SPARQL SELECT
deletePolicy(policyId: string): Promise<void> — Delete triples by policy
getTriplesForPolicy(policyId: string): Promise<RDFTriple[]> — Retrieve triples
exists(policyId: string): Promise<boolean> — Check existence

Debt Ontology (SEA-DEBT)

Prefix: sea-debt: <http://sea-forge.com/schema/debt#>

Class/Property	Type	Description
`sea-debt:SemanticDebtItem`	Class	Represents a recorded instance of semantic debt (e.g., translation loss).
`sea-debt:Evidence`	Class	Proof or context explaining why the debt occurred.
`sea-debt:Decision`	Class	The architectural decision or waiver allowing this debt.
`sea-debt:MitigationPlan`	Class	Planned steps to resolve the debt.
`sea-debt:hasEvidence`	Property	Links DebtItem to Evidence.
`sea-debt:governedBy`	Property	Links DebtItem to a Decision.
`sea-debt:hasMitigation`	Property	Links DebtItem to a MitigationPlan.
`sea-debt:regardingConcept`	Property	Links DebtItem/Evidence to a specific Semantic Concept (URI).
`sea-debt:status`	Property	Status of the debt (e.g., “Accepted”, “Expired”, “Critical”).
`sea-debt:expiryDate`	Property	Date when the accepted debt expires.

Incident Ontology (SEA-INC)

Prefix: sea-inc: <http://sea-forge.com/schema/incident#>

Groups multiple SemanticDebtItem instances under a common root cause. See SDS-016: Semantic Incidents for the complete specification.

Class/Property	Type	Description
`sea-inc:SemanticIncident`	Class	Groups related debt items under common root cause
`sea-inc:RootCause`	Class	The underlying cause of the incident
`sea-inc:hasDebtItem`	Property	Links Incident to constituent DebtItems
`sea-inc:hasRootCause`	Property	Links Incident to RootCause
`sea-inc:affectedContext`	Property	Links Incident to affected BoundedContext
`sea-inc:owner`	Property	Links Incident to responsible Principal
`sea-inc:status`	Property	Current lifecycle state (`open`, `triaging`, `contained`, `resolving`, `resolved`, `postmortem`, `closed`)
`sea-inc:severity`	Property	Aggregate severity
`sea-inc:supersedes`	Property	Links DebtItem to superseded DebtItem

Incident Query: Active Incidents by Severity

PREFIX sea-inc: <http://sea-forge.com/schema/incident#>

SELECT ?incident ?title ?severity (COUNT(?debt) AS ?debtCount)
WHERE {
  ?incident a sea-inc:SemanticIncident ;
            sea-inc:title ?title ;
            sea-inc:severity ?severity ;
            sea-inc:status ?status ;
            sea-inc:hasDebtItem ?debt .
  FILTER (?status IN ("open", "triaging", "contained", "resolving"))
}
GROUP BY ?incident ?title ?severity
ORDER BY DESC(?severity) DESC(?debtCount)

Projection Mappings (Events -> Triples)

These rules define how SemanticDebtCreated events are projected into the graph.

Source: SemanticDebtCreated Event Target: RDF Triples

Debt Item Creation:

<sea:debt:{eventId}> a sea-debt:SemanticDebtItem ;
    rdfs:label "{payload.title}" ;
    sea-debt:status "{payload.status}" ;
    dct:created "{timestamp}" .

Linking Concept:

<sea:debt:{eventId}> sea-debt:regardingConcept <sea:concept:{payload.conceptId}> .

Attaching Evidence:

<sea:evidence:{evidenceId}> a sea-debt:Evidence ;
    rdfs:comment "{payload.evidenceDescription}" .
<sea:debt:{eventId}> sea-debt:hasEvidence <sea:evidence:{evidenceId}> .

Query Cookbook

1. Blockers by Context

Find debt items that are “Blocking” within a specific context (e.g., PaymentProcessing).

PREFIX sea-debt: <http://sea-forge.com/schema/debt#>
PREFIX sea: <http://sea-forge.com/schema/core#>

SELECT ?debt ?label ?concept
WHERE {
  ?debt a sea-debt:SemanticDebtItem ;
        sea-debt:status "Blocking" ;
        rdfs:label ?label ;
        sea-debt:regardingConcept ?concept .
  ?concept sea:inContext <http://sea-forge.com/context/PaymentProcessing> .
}

2. Debt Affecting a Concept + Depth-2 Dependencies

Trace debt on a concept and its upstream dependencies (2 levels deep).

SELECT DISTINCT ?debt ?affectedConcept ?upstreamConcept
WHERE {
   # Debt directly on the concept
   {
     ?debt sea-debt:regardingConcept <http://sea-forge.com/concept/TargetConcept> .
     BIND(<http://sea-forge.com/concept/TargetConcept> AS ?affectedConcept)
   }
   UNION
   # Debt on direct dependency (Level 1)
   {
     <http://sea-forge.com/concept/TargetConcept> sea:dependsOn ?l1 .
     ?debt sea-debt:regardingConcept ?l1 .
     BIND(?l1 AS ?affectedConcept)
   }
   UNION
   # Debt on dependency of dependency (Level 2)
   {
     <http://sea-forge.com/concept/TargetConcept> sea:dependsOn ?l1 .
     ?l1 sea:dependsOn ?l2 .
     ?debt sea-debt:regardingConcept ?l2 .
     BIND(?l2 AS ?affectedConcept)
   }
}

3. Policy Hotspots

Concepts with the highest count of associated debt items.

SELECT ?policy (COUNT(?debt) AS ?debtCount)
WHERE {
  ?debt a sea-debt:SemanticDebtItem ;
        sea-debt:regardingConcept ?policy .
  ?policy a sea:Policy .
}
GROUP BY ?policy
ORDER BY DESC(?debtCount)
LIMIT 10

4. Expired Accepted Debt

Accepted debt that has passed its expiry date.

SELECT ?debt ?decision ?expiry
WHERE {
  ?debt sea-debt:status "Accepted" ;
        sea-debt:governedBy ?decision .
  ?decision sea-debt:expiryDate ?expiry .
  FILTER (?expiry < NOW())
}

5. Break-glass Accepted Debt

Debt accepted under “Break-glass” emergency conditions.

SELECT ?debt ?reason
WHERE {
  ?debt sea-debt:governedBy ?decision .
  ?decision sea-debt:type "BreakGlass" ;
            rdfs:comment ?reason .
}

6. Projection Hotspots

Attributes where translation loss frequency is high.

SELECT ?concept (COUNT(?debt) as ?lossCount)
WHERE {
    ?debt a sea-debt:SemanticDebtItem ;
          sea-debt:type "TranslationLoss" ;
          sea-debt:regardingConcept ?concept .
}
GROUP BY ?concept
ORDER BY DESC(?lossCount)

Snapshot & Versioning Model

Design Principles

Isomorphism: KGS state must be derivable from semantic inputs + applied change sets
Immutability: Snapshot IDs are immutable; identical inputs yield identical snapshots
Idempotency: Applying the same change set twice is safe (dedup by change-set ID/hash)
Determinism: Same change set input → same snapshot hash/id

Snapshot Schema

A Snapshot represents an immutable, versioned state of the Knowledge Graph at a specific point in time.

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "KnowledgeGraphSnapshot",
  "description": "Immutable, versioned state of the Knowledge Graph",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^ifl:snap:[a-f0-9]{64}$",
      "description": "Content-addressable snapshot identifier (SHA-256 hash)"
    },
    "version": {
      "type": "string",
      "description": "Semantic version (e.g., '1.0.0')"
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "UTC timestamp when snapshot was created"
    },
    "parentSnapshotId": {
      "type": "string",
      "pattern": "^ifl:snap:[a-f0-9]{64}$",
      "description": "Parent snapshot ID (null for initial snapshot)"
    },
    "appliedChangeSets": {
      "type": "array",
      "items": {
        "type": "string",
        "pattern": "^ifl:cs:[a-f0-9]{64}$"
      },
      "description": "Ordered list of change set IDs applied to reach this snapshot"
    },
    "tripleCount": {
      "type": "integer",
      "minimum": 0,
      "description": "Total number of RDF triples in this snapshot"
    },
    "contentHash": {
      "type": "string",
      "pattern": "^[a-f0-9]{64}$",
      "description": "SHA-256 hash of canonical triple serialization (Turtle sorted)"
    },
    "metadata": {
      "type": "object",
      "properties": {
        "createdBy": {
          "type": "string",
          "description": "Principal or system that created the snapshot"
        },
        "description": {
          "type": "string",
          "description": "Human-readable description of this snapshot"
        },
        "tags": {
          "type": "array",
          "items": {"type": "string"},
          "description": "Semantic tags (e.g., 'production', 'staging')"
        }
      },
      "additionalProperties": true
    }
  },
  "required": ["id", "version", "timestamp", "contentHash", "appliedChangeSets"]
}

ChangeSet Schema

A ChangeSet represents a set of graph operations (add/delete triples) that can be applied to a snapshot.

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "KnowledgeGraphChangeSet",
  "description": "Set of graph operations to transition between snapshots",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^ifl:cs:[a-f0-9]{64}$",
      "description": "Content-addressable change set identifier (SHA-256 hash)"
    },
    "timestamp": {
      "type": "string",
      "format": "date-time",
      "description": "UTC timestamp when change set was created"
    },
    "sourceSnapshotId": {
      "type": "string",
      "pattern": "^ifl:snap:[a-f0-9]{64}$",
      "description": "Snapshot this change set is based on"
    },
    "operations": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "type": {
            "type": "string",
            "enum": ["add", "delete"],
            "description": "Operation type"
          },
          "triple": {
            "type": "object",
            "properties": {
              "subject": {"type": "string", "format": "uri"},
              "predicate": {"type": "string", "format": "uri"},
              "object": {
                "oneOf": [
                  {"type": "string", "format": "uri"},
                  {
                    "type": "object",
                    "properties": {
                      "value": {"type": "string"},
                      "datatype": {"type": "string", "format": "uri"},
                      "language": {"type": "string"}
                    },
                    "required": ["value"]
                  }
                ]
              }
            },
            "required": ["subject", "predicate", "object"]
          }
        },
        "required": ["type", "triple"]
      },
      "description": "Ordered list of add/delete operations"
    },
    "metadata": {
      "type": "object",
      "properties": {
        "createdBy": {"type": "string"},
        "description": {"type": "string"},
        "source": {
          "type": "string",
          "description": "Origin of change (e.g., 'SemanticDebtCreated event')"
        }
      },
      "additionalProperties": true
    }
  },
  "required": ["id", "timestamp", "sourceSnapshotId", "operations"]
}

Snapshot Query Result Schema

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "SnapshotQueryResult",
  "description": "Result of executing a query against a snapshot",
  "type": "object",
  "properties": {
    "snapshotId": {
      "type": "string",
      "pattern": "^ifl:snap:[a-f0-9]{64}$"
    },
    "query": {
      "type": "object",
      "properties": {
        "language": {
          "type": "string",
          "enum": ["sparql", "cypher"]
        },
        "text": {"type": "string"}
      },
      "required": ["language", "text"]
    },
    "results": {
      "type": "array",
      "items": {"type": "object"},
      "description": "Query result bindings"
    },
    "executionTimeMs": {
      "type": "integer",
      "minimum": 0,
      "description": "Query execution time in milliseconds"
    },
    "resultHash": {
      "type": "string",
      "pattern": "^[a-f0-9]{64}$",
      "description": "SHA-256 hash of canonical result serialization (for stability verification)"
    }
  },
  "required": ["snapshotId", "query", "results", "executionTimeMs", "resultHash"]
}

API Specification

Endpoints

Endpoint	Method	Description
`/graph/query`	POST	Execute Cypher/SPARQL query
`/graph/shacl/validate`	POST	Run SHACL validation
`/graph/snapshots`	GET	List available snapshots
`/graph/snapshots`	POST	Create a new snapshot from current state
`/graph/snapshots/{id}`	GET	Retrieve snapshot metadata
`/graph/snapshots/{id}/query`	POST	Execute query against specific snapshot
`/graph/changesets`	GET	List available change sets
`/graph/changesets`	POST	Create a new change set
`/graph/changesets/{id}`	GET	Retrieve change set details
`/graph/changesets/{id}/apply`	POST	Apply change set to create new snapshot

Snapshot API Request/Response Examples

Create Snapshot

POST /graph/snapshots
{
  "version": "1.0.0",
  "description": "Initial production snapshot",
  "tags": ["production", "release-1.0"],
  "createdBy": "system"
}

// Response
{
  "id": "ifl:snap:a3b8c9d2e1f4567890abcdef1234567890abcdef1234567890abcdef12345678",
  "version": "1.0.0",
  "timestamp": "2025-12-30T10:00:00Z",
  "parentSnapshotId": null,
  "appliedChangeSets": [],
  "tripleCount": 1523,
  "contentHash": "a3b8c9d2e1f4567890abcdef1234567890abcdef1234567890abcdef12345678",
  "metadata": {
    "createdBy": "system",
    "description": "Initial production snapshot",
    "tags": ["production", "release-1.0"]
  }
}

List Snapshots

GET /graph/snapshots?tags=production&limit=10

// Response
{
  "snapshots": [
    {
      "id": "ifl:snap:a3b8c9d2...",
      "version": "1.0.0",
      "timestamp": "2025-12-30T10:00:00Z",
      "tripleCount": 1523,
      "tags": ["production", "release-1.0"]
    },
    {
      "id": "ifl:snap:b4c9d8e2...",
      "version": "1.1.0",
      "timestamp": "2025-12-31T14:30:00Z",
      "tripleCount": 1687,
      "tags": ["production", "release-1.1"]
    }
  ],
  "total": 2,
  "limit": 10,
  "offset": 0
}

Query Snapshot

POST /graph/snapshots/ifl:snap:a3b8c9d2.../query
{
  "language": "sparql",
  "query": "PREFIX sea-debt: <http://sea-forge.com/schema/debt#> SELECT ?debt ?status WHERE { ?debt a sea-debt:SemanticDebtItem ; sea-debt:status ?status . } LIMIT 10"
}

// Response
{
  "snapshotId": "ifl:snap:a3b8c9d2...",
  "query": {
    "language": "sparql",
    "text": "PREFIX sea-debt: <http://sea-forge.com/schema/debt#> SELECT ?debt ?status WHERE { ?debt a sea-debt:SemanticDebtItem ; sea-debt:status ?status . } LIMIT 10"
  },
  "results": [
    {
      "debt": "http://sea-forge.com/debt/123",
      "status": "Blocking"
    },
    {
      "debt": "http://sea-forge.com/debt/456",
      "status": "Accepted"
    }
  ],
  "executionTimeMs": 45,
  "resultHash": "f1e2d3c4b5a6978901234567890abcdef1234567890abcdef1234567890abcdef"
}

Create ChangeSet

POST /graph/changesets
{
  "sourceSnapshotId": "ifl:snap:a3b8c9d2...",
  "description": "Add new debt item from SemanticDebtCreated event",
  "createdBy": "event-projector",
  "source": "SemanticDebtCreated:evt-789",
  "operations": [
    {
      "type": "add",
      "triple": {
        "subject": "http://sea-forge.com/debt/789",
        "predicate": "http://www.w3.org/1999/02/22-rdf-syntax-ns#type",
        "object": "http://sea-forge.com/schema/debt#SemanticDebtItem"
      }
    },
    {
      "type": "add",
      "triple": {
        "subject": "http://sea-forge.com/debt/789",
        "predicate": "http://www.w3.org/2000/01/rdf-schema#label",
        "object": {
          "value": "Missing validation for payment amount",
          "datatype": "http://www.w3.org/2001/XMLSchema#string"
        }
      }
    },
    {
      "type": "add",
      "triple": {
        "subject": "http://sea-forge.com/debt/789",
        "predicate": "http://sea-forge.com/schema/debt#status",
        "object": {
          "value": "Blocking",
          "datatype": "http://www.w3.org/2001/XMLSchema#string"
        }
      }
    }
  ]
}

// Response
{
  "id": "ifl:cs:c4d5e6f7g8h9i0j1k2l3m4n5o6p7q8r9s0t1u2v3w4x5y6z7a8b9c0d1e2f3g4h5",
  "timestamp": "2025-12-30T11:15:00Z",
  "sourceSnapshotId": "ifl:snap:a3b8c9d2...",
  "operations": [...],
  "metadata": {
    "createdBy": "event-projector",
    "description": "Add new debt item from SemanticDebtCreated event",
    "source": "SemanticDebtCreated:evt-789"
  }
}

Apply ChangeSet

POST /graph/changesets/ifl:cs:c4d5e6f7.../apply
{
  "version": "1.0.1",
  "description": "Applied debt item creation",
  "tags": ["development"]
}

// Response
{
  "newSnapshotId": "ifl:snap:b4c9d8e2...",
  "version": "1.0.1",
  "timestamp": "2025-12-30T11:15:30Z",
  "parentSnapshotId": "ifl:snap:a3b8c9d2...",
  "appliedChangeSets": ["ifl:cs:c4d5e6f7..."],
  "tripleCount": 1526,
  "contentHash": "b4c9d8e2f1a3567890abcdef1234567890abcdef1234567890abcdef12345678",
  "metadata": {
    "description": "Applied debt item creation",
    "tags": ["development"]
  }
}

Request/Response

Graph Query

POST /graph/query
{
  "language": "cypher",
  "query": "MATCH (c:Customer)-[:PLACED]->(o:Order) RETURN c, o LIMIT 10"
}

// Response
{
  "results": [
    {"c": {...}, "o": {...}},
    ...
  ]
}

SHACL Validation

POST /graph/shacl/validate
{
  "targetGraph": "production",
  "context": "semantic-core",
  "shapesVersion": "v1",
  "validationScope": "delta",
  "dataGraph": "@prefix sea: <http://sea-forge.com/schema/core#> . ..."
}

// Response
{
  "conforms": false,
  "shapeVersion": "v1",
  "maintenanceMode": false,
  "enforcementApplied": true,
  "violations": [
    {
      "shape": "http://sea-forge.com/shapes/EmailFormatShape",
      "focusNode": "customer:123",
      "path": "sea:email",
      "message": "Invalid email format",
      "severity": "Violation",
      "requiresContext": []
    }
  ],
  "requiresContext": [],
  "reportGraph": "@prefix sh: <http://www.w3.org/ns/shacl#> . ..."
}

Error Codes

Code	Description
`400 Bad Request`	Invalid query/SHACL syntax
`404 Not Found`	Snapshot or change set not found
`409 Conflict`	Change set cannot be applied (conflict)
`422 Unprocessable Entity`	Invalid change set operations
`500 Internal Server Error`	Graph database error
`503 Service Unavailable`	Snapshot creation in progress (retry later)

Installation Commands

# Python dependencies (add to pyproject.toml)
pip install pyoxigraph rdflib pyshacl owlrl

# Node.js dependencies (add to package.json)
pnpm add @comunica/query-sparql

Port/Adapter Architecture

interface KnowledgeGraphPort {
  querySparql(snapshotId: string, query: string): Promise<SparqlResult>;
  validateShacl(snapshotId: string, shapeUri: string, dataGraph: string): Promise<ValidationReport>;
  inferOwl(snapshotId: string, ontologyUri: string): Promise<InferenceResult>;
  createSnapshot(metadata: SnapshotMetadata): Promise<Snapshot>;
  applyChangeSet(changeSetId: string, targetMetadata: SnapshotMetadata): Promise<Snapshot>;
  getSnapshot(snapshotId: string): Promise<Snapshot>;
  listSnapshots(filters: SnapshotFilters): Promise<Snapshot[]>;
}

Error Handling

Clear error messages for query syntax issues or SHACL violations
Structured ValidationResult with actionable SHACL diagnostics
Enforcement failures raise ShaclValidationError only when enabled and active
Robust handling of graph traversal errors
Timeout handling for long-running queries
Connection pool management

Performance Considerations

Optimized graph traversal and query execution
Indexing strategies for frequently accessed properties
Query result caching for common patterns
Validation caching uses canonical N-Triples sorted lines for stable hashes
Batch processing for bulk updates

Security Considerations

Fine-grained access control for graph data
Secure authentication for API access
Data classification enforcement (PII, Confidential)
Query injection prevention

Testing Strategy

Unit Tests: Graph data modeling and query construction
Integration Tests: Graph traversal and SHACL validation scenarios
Validation Tests: Enforcement gating, maintenance mode, versioned shapes, and cross-context dependencies
Performance Tests: Query latency and throughput under load
Load Tests: Concurrent query handling
Determinism Tests: Verify identical inputs produce identical snapshot IDs
- Same change set applied twice → same snapshot hash
- Same SPARQL query on same snapshot → same result hash
Snapshot Integrity Tests: Verify snapshot immutability and lineage
- Parent snapshot ID chain is valid
- Applied change sets produce expected triple count
- Content hash matches canonical serialization
Idempotency Tests: Verify applying same change set multiple times is safe
- Change set deduplication by ID
- No duplicate triples created

References

SDS-031: Authority and Ownership Boundaries