Triple Store Configuration¶

OntoCast stores ontologies and facts through a unified TripleStoreManager interface. Two backends are supported today:

Apache Fuseki (production) — persistent RDF store with SPARQL
In-Memory (pyoxigraph) (default) — zero-config backend for development and tests

When FUSEKI_URI and FUSEKI_AUTH are set, Fuseki is used. Otherwise OntoCast uses the in-memory backend automatically.

Configuration¶

Environment Variables¶

# Fuseki (optional — production)
FUSEKI_URI=http://localhost:3032
FUSEKI_AUTH=admin:password
#FUSEKI_DATASET=ontocast--test--facts
#FUSEKI_ONTOLOGIES_DATASET=ontocast--test--ontologies

# Seed ontologies (optional — bootstrap only, not persistence)
ONTOCAST_ONTOLOGY_DIRECTORY=/path/to/seed/ttl

Persistence is handled by the triple store only. Local TTL export to working_directory is no longer used.

Tenancy and Partitions¶

Both Fuseki and the in-memory backend isolate data by tenant/project:

{tenant}--{project}--facts — extracted facts graphs
{tenant}--{project}--ontologies — catalog / versioned ontologies

When dataset env vars are unset, OntoCast derives names from the default tenant ontocast and project test. Per-request ?tenant= / ?project= retarget the active partition at runtime. See Tenancy.

Detecting the Active Backend¶

from ontocast.config import Config

config = Config()
tool_config = config.get_tool_config()

if tool_config.fuseki.uri and tool_config.fuseki.auth:
    print("Using Fuseki triple store")
else:
    print("Using in-memory triple store")

Apache Fuseki Setup¶

Sample Docker configs: ontocast/docker.

cd docker/fuseki
cp .env.example .env
docker compose --env-file .env fuseki up -d

Configure OntoCast:

FUSEKI_URI=http://localhost:3032
FUSEKI_AUTH=admin:your-password

In-Memory Backend¶

No setup required. Data lives in process memory (pyoxigraph) and is lost on restart.

Use Fuseki for production deployments. The in-memory backend supports the same tenancy partition model as Fuseki.

Seed Ontologies¶

Place .ttl files in ONTOCAST_ONTOLOGY_DIRECTORY. On startup, ToolBox scans that directory and materializes any ontologies not already present in the triple store. This is a one-way bootstrap path — ongoing persistence is through the triple store.

Backend Comparison¶

Feature	Fuseki	In-Memory
Persistence	Yes	No (process lifetime)
SPARQL	Full 1.1	Internal only
Tenancy partitions	Yes	Yes
Setup	Docker + env	Automatic

Flushing Data¶

# Clean active partition
curl -X POST http://localhost:8999/flush

# Clean a specific tenant/project partition
curl -X POST "http://localhost:8999/flush?tenant=acme&project=demo"

Warning: Flush is irreversible.