sqlib | A library for SPARQL queries

What sqlib does with a saved query

All of these work on the same stored queries, in a library you host yourself.

Parameters are declared in the query

A VALUES clause with one all-UNDEF row declares a parameter, and LIMIT 0001 declares a named number. sqlib parses the query once and writes each argument into its slot as one escaped RDF term, so an argument cannot change the query’s structure.

VALUES ?city { UNDEF }
VALUES (?from ?to) { (UNDEF UNDEF) }
LIMIT 0001

Pinned versions

Every save creates an immutable version. A run can pin a version for a reproducible result, or follow the latest.

Publish as tools

A published library exposes each query as an MCP tool and an HTTP route, with one plain argument per parameter.

Query groups

Chain queries on a canvas. One step's results become the next step's arguments.

Notebooks

Write explanation between runnable queries, and name each result for use further down.

SPARQL RL rules

Author inference rules in SRL and run them against any graph.

Tests and benchmarks

Attach tests to a query or rule set. Compare runs across backends and versions.

Why not just…?

sqlib compared to the common ways teams keep SPARQL today.

Approach	Versioned	Safe parameters	Callable by agents
sqlib	every save	bound after parsing	MCP and HTTP
.rq files in a repository	with git	string templates	no
Queries inside application code	with the app	string concatenation	no
Saved queries in a triplestore UI	overwritten	no	no

From query to tool in three steps

Local setup is three commands. A container image is available for deployment.

1

Start the server

One process serves the API and the MCP endpoint, with an Oxigraph store on disk.

pnpm install
pnpm build
just run-local-memory

2

Save a parameterised query

Write SPARQL in the editor. sqlib finds its parameters and saves version 1.

SELECT ?name WHERE {
  VALUES ?city { UNDEF }
  ?p ex:city ?city ; ex:name ?name .
}

3

Call it from anywhere

Publish the library. Each query becomes a route and an MCP tool.

GET /tools/people/find-people
    ?city=Perth&city=Hobart

Documentation

Guides, reference material and design background.

Start here

Concepts

Library, Query, QueryGroup, DataGraph, ArgumentSet, RuleSet: the words every other page uses.

Read concepts

Versioned SPARQL queries, callable from any app or agent.