Reference

Exact syntax and behaviour: SPARQL functions, configuration keys, and error codes.

Reference pages describe how the machinery behaves — no teaching, no opinion. Every entry of a kind uses the same field order, so entries are quick to scan and compare. To learn a task, start with the Guides instead.

Sections

• SPARQL functions and operators — every function, operator, and property-path operator HornDB evaluates, with signatures and examples.
• Configuration — every setting that controls server and runtime behaviour, across all four layers: the config.toml file (with config.d/*.toml drop-ins), environment variables, serve command-line flags, and build-time feature flags. Covers the named-graph and reasoning-view settings as well as the server’s own.
• Errors and diagnostics — the HTTP status codes and error categories the SPARQL endpoint returns today, and what is stable to rely on.