RDF Store User Guide¶

How to configure Flexible GraphRAG to write extracted knowledge graphs to RDF triple stores, and how to explore the data in each store's dashboard.

Configuration¶

Ingestion Mode¶

Set in .env — controls where extracted KG data is written:

# property_graph   — Neo4j / Ladybug / other LPG stores (default)
# rdf_only         — RDF stores only (skips property graph)
# both             — property graph AND RDF stores simultaneously
INGESTION_STORAGE_MODE=both

RDF 1.2 Annotation Syntax¶

Relation properties (e.g. employment_role, proficiency_level) are stored as RDF 1.2 annotations by default:

# RDF_ANNOTATION_SYNTAX controls how relation properties are encoded:
RDF_ANNOTATION_SYNTAX=rdf_1.2      # {| prop value |}  — RDF 1.2 Turtle standard (default)
                                  # Fuseki 5 (Jena 5), GraphDB 10+, Oxigraph 0.4+
RDF_ANNOTATION_SYNTAX=rdf_star   # << s p o >> prop value  — legacy RDF-star lines
                                  # same store support, older syntax
RDF_ANNOTATION_SYNTAX=flat       # onto:rel__prop value    — plain SPARQL 1.1 triples
                                  # works with any triple store, no annotation semantics

RDF 1.2 {| |} annotation example:

:alice_johnson  onto:works_for  :techcorp
    {| onto:since  "2020"^^xsd:string ;
       onto:role   "Engineer"^^xsd:string |} .

Base Namespace¶

RDF_BASE_NAMESPACE=https://integratedsemantics.org/flexible-graphrag/kg/

Named graph URI = base namespace with trailing slash stripped: https://integratedsemantics.org/flexible-graphrag/kg

Apache Fuseki¶

Dashboard: http://localhost:3030
Login: admin / admin (set via ADMIN_PASSWORD in docker/includes/jena-fuseki.yaml)

.env settings¶

FUSEKI_ENABLED=true
FUSEKI_BASE_URL=http://localhost:3030
FUSEKI_DATASET=flexible-graphrag
FUSEKI_USERNAME=admin
FUSEKI_PASSWORD=admin

Dashboard usage¶

1. Open http://localhost:3030 and log in
2. Click flexible-graphrag dataset → query tab
3. The dataset is auto-created on first ingest via the Fuseki admin API

View all entities and relations (readable):

PREFIX base: <https://integratedsemantics.org/flexible-graphrag/kg/>
PREFIX onto: <https://integratedsemantics.org/flexible-graphrag/ontology#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

SELECT ?subjectLabel ?relName ?objectLabel WHERE {
  GRAPH <https://integratedsemantics.org/flexible-graphrag/kg> {
    ?s ?rel ?o .
    ?s rdfs:label ?subjectLabel .
    ?o rdfs:label ?objectLabel .
    BIND(STRAFTER(STR(?rel), STR(onto:)) AS ?relName)
    FILTER(?relName != "")
  }
}
ORDER BY ?subjectLabel ?relName

View RDF 1.2 relation annotations (SPARQL 1.2 rdf:reifies):

PREFIX rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX onto: <https://integratedsemantics.org/flexible-graphrag/ontology#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

SELECT ?subjectLabel ?relName ?objectLabel ?prop ?val WHERE {
  GRAPH <https://integratedsemantics.org/flexible-graphrag/kg> {
    ?s ?rel ?o .
    ?s rdfs:label ?subjectLabel .
    ?o rdfs:label ?objectLabel .
    ?reifier rdf:reifies <<( ?s ?rel ?o )>> ;
             ?annprop ?val .
    BIND(STRAFTER(STR(?rel),     STR(onto:)) AS ?relName)
    BIND(STRAFTER(STR(?annprop), STR(onto:)) AS ?prop)
    FILTER(?prop NOT IN ("source","file_name","file_path","file_type",
                         "modified_at","conversion_method","ref_doc_id"))
    FILTER(?relName != "" && ?prop != "")
  }
}
ORDER BY ?subjectLabel ?relName ?prop

Note: If using legacy RDF_ANNOTATION_SYNTAX=rdf_star, query annotations with:

  << ?s ?rel ?o >> ?annprop ?val .

Drop and reload graph (SPARQL Update tab):

DROP GRAPH <https://integratedsemantics.org/flexible-graphrag/kg>

Download data: Dataset page → download → choose Turtle or TriG.
The raw Turtle file (with annotations) is also available at:

GET http://localhost:3030/flexible-graphrag/data?graph=https://integratedsemantics.org/flexible-graphrag/kg
Accept: text/turtle

Ontotext GraphDB¶

Dashboard: http://localhost:7200
Default login: admin / root (free edition — create a repository first)

.env settings¶

GRAPHDB_ENABLED=true
GRAPHDB_BASE_URL=http://localhost:7200
GRAPHDB_REPOSITORY=flexible-graphrag
GRAPHDB_USERNAME=admin
GRAPHDB_PASSWORD=root

Setup¶

The repository is auto-created on first ingest with RDF 1.2 annotation support enabled. No manual setup required.

If you prefer to create it manually (or need custom settings):

1. Open http://localhost:7200
2. Setup → Repositories → Create new repository
3. Type: GraphDB Repository
4. Repository ID: flexible-graphrag
5. Enable RDF-star: ✅ (required for RDF 1.2 {| |} annotations and rdf:reifies)
6. Click Create

Dashboard usage¶

GraphDB Workbench has the richest visual exploration of the three stores:

• Explore → Visual graph — click any entity to see its connections as a graph diagram
• Explore → Graphs overview — lists all named graphs with triple counts
• SPARQL tab — full SPARQL 1.1/1.2 editor with syntax highlighting and results table/download
• Import tab — upload Turtle/TriG files directly

Use the same SPARQL queries as Fuseki above. GraphDB also supports:

Visual graph exploration:
Explore → Visual graph → search for Alfresco Software → click to expand neighbours

Class hierarchy:
Explore → Class hierarchy → shows all onto: types extracted (company, employee, project, etc.)

Download: SPARQL results → CSV / JSON / TSV buttons in the results toolbar.

Oxigraph¶

Dashboard: http://localhost:7878
No login required.

.env settings — HTTP mode (recommended)¶

OXIGRAPH_ENABLED=true
OXIGRAPH_URL=http://localhost:7878

Uses the Oxigraph Docker container as an HTTP server. No file-locking issues; safe for concurrent requests from the API server.

.env settings — Embedded mode¶

OXIGRAPH_ENABLED=true
OXIGRAPH_STORE_PATH=./data/oxigraph_store

Uses pyoxigraph directly with a local RocksDB file store. Limitations: - Only one process can hold the file lock at a time — if the API server is running, a second ingestion request will fail with IO error: Failed to create lock file: LOCK - Not recommended when the backend API server is already running - Best suited for standalone scripts or single-process use

The adapter auto-recovers from RocksDB corruption (CURRENT file corrupted) by wiping and recreating the store directory.

Docker setup (HTTP mode)¶

# docker/includes/oxigraph.yaml — already configured
command: ["serve", "--bind", "0.0.0.0:7878", "--location", "/data"]

The --bind 0.0.0.0:7878 flag is required — without it the Oxigraph HTTP server binds to 127.0.0.1 inside the container and is unreachable from the host via Docker port forwarding.

Start with:

docker compose --profile oxigraph up -d

Dashboard usage¶

Oxigraph's dashboard is a minimal YASGUI SPARQL editor only — no visual graph or data browser. Results can be downloaded as CSV, JSON, or TSV from the toolbar.

Add these prefixes to every query (YASGUI doesn't persist them):

PREFIX base: <https://integratedsemantics.org/flexible-graphrag/kg/>
PREFIX onto: <https://integratedsemantics.org/flexible-graphrag/ontology#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

All entities and relations:

SELECT ?subjectLabel ?relName ?objectLabel WHERE {
  GRAPH <https://integratedsemantics.org/flexible-graphrag/kg> {
    ?s ?rel ?o .
    ?s rdfs:label ?subjectLabel .
    ?o rdfs:label ?objectLabel .
    BIND(STRAFTER(STR(?rel), STR(onto:)) AS ?relName)
    FILTER(?relName != "")
  }
}
ORDER BY ?subjectLabel ?relName

RDF 1.2 annotations (meaningful only):

SELECT ?subjectLabel ?relName ?objectLabel ?prop ?val WHERE {
  GRAPH <https://integratedsemantics.org/flexible-graphrag/kg> {
    ?s ?rel ?o .
    ?s rdfs:label ?subjectLabel .
    ?o rdfs:label ?objectLabel .
    FILTER(STRSTARTS(STR(?rel), STR(onto:)))
    BIND(STRAFTER(STR(?rel), STR(onto:)) AS ?relName)
    OPTIONAL {
      ?reifier rdf:reifies <<( ?s ?rel ?o )>> ;
               ?annprop ?val .
      BIND(STRAFTER(STR(?annprop), STR(onto:)) AS ?prop)
      FILTER(?prop NOT IN ("source","file_name","file_path","file_type",
                           "modified_at","conversion_method","ref_doc_id"))
    }
  }
}
ORDER BY ?subjectLabel ?relName ?objectLabel ?prop

Raw data download (outside YASGUI):

GET http://localhost:7878/store?graph=https://integratedsemantics.org/flexible-graphrag/kg
Accept: text/turtle

Store Comparison¶

LangChain RDF Retrieval¶

When USE_LANGCHAIN_RDF=true, extracted RDF data is queried at search/Q&A time via LangChain graph QA chains fused into the same QueryFusionRetriever as vector, BM25, and property graph results.

How it works¶

1. A natural language query arrives at /api/search or /api/qa
2. SynonymExpander (if USE_SYNONYM_EXPLODER=true) generates related keywords and adds them to the query bundle — the original query string is preserved unchanged for SPARQL generation
3. TextToGraphQueryRetriever translates the query to SPARQL via LangChain and executes it against the configured RDF store
4. Results are returned as a synthesized answer node, scored and ranked alongside all other retriever results

Per-store chain type¶

Configuration¶

USE_LANGCHAIN_RDF=true
RDF_STORE_TYPE=graphdb        # graphdb | fuseki | oxigraph

# Optional: expand query keywords before SPARQL generation
USE_SYNONYM_EXPLODER=true
SYNONYM_EXPLODER_SCOPE=langchain_rdf_graph   # or: all | none | comma-separated tag list

Additional LangChain PG retrievers (property graphs)¶

When GRAPH_DB=neo4j is set, two additional retrievers can be enabled alongside the RDF retriever:

• GraphEntityVectorRetriever (LANGCHAIN_PG_VECTOR_SEARCH=true) — Neo4j entity embedding similarity search via LangChain
• GraphNeighborhoodRetriever (USE_PG_NEIGHBORHOOD=true) — k-hop graph expansion from seed entity nodes

Implementation Status¶

A summary of what is confirmed working, what is wired but untested end-to-end, and what is not yet implemented.

Fully Working¶

These paths are confirmed working end-to-end.

Implemented — Not Yet Tested End-to-End¶

Code exists and is wired into the app, but these paths have not been verified in testing.

Not Implemented / Stubbed¶

Reference / Example Files¶

These files in examples/rdf/ are standalone rdf usage examples — not re-tested.