Read-only query guard

Data SPARQL Workbench

Execute read-only SPARQL queries against published materials dataset graphs. The guard enforces a LIMIT and blocks update operations before any query reaches the public endpoint.

Data overview Browse datasets Public endpoint

Read Mutation policy

LIMIT Required guard

1,000 Max rows

Unavailable Query execution

Text to SPARQL

Describe the public dataset information you want. MatPortal drafts a read-only SELECT query, then the guard validates it before any run.

SPARQL query editor

Public SPARQL execution is temporarily unavailable. Query validation remains read-only and available below.

SPARQL toolsSparnatural visual builder + sparql-llm assistant

Sparnatural visual query builder

Optional visual SPARQL construction for users who do not want to write raw clauses. Provide a SHACL/Sparnatural config for the current endpoint; generated SELECT drafts are inserted into the existing guarded editor.

Sparnatural docs

Guard passed. The query is read-only and limit-capped.

Normalized query

SELECT ?s ?p ?o WHERE {
 ?s ?p ?o
}
LIMIT 100

Query from tools and notebooks

The MatPortal UI keeps people oriented. Scripts can use the public data endpoint directly for RDF catalogue data, public entity dumps, and guarded query validation.

Catalogue JSON-LD Machine-readable DCAT catalogue for search portals and notebooks. Open JSON-LD

Catalogue Turtle RDF catalogue with DCAT dataset entries. Open Turtle

Public RDF resource dump Turtle dump of indexed public entities for offline graph analysis. Open dump