OntoRAG

Ontology-driven retrieval & grounded reasoning
RAG, but with a spine

Stop retrieving paragraphs.
Start retrieving meaning.

OntoRAG is a practical approach to Retrieval-Augmented Generation where the ontology becomes the contract: a governed model of your domain, linked to evidence, and callable by agents through tools.

The goal is simple: answers that are traceable, consistent, and operational — not just plausible.

RDF / OWL SPARQL Knowledge Graph Governance Tool-using agents
What changes vs. classic RAG preview
User: “Can I combine Seraph + Syndicate backgrounds?” Classic RAG: retrieves chunks → summarizes → might miss constraints OntoRAG: 1) Map question to ontology: Background, canCombineWith (if defined) 2) Query instances + rules (SPARQL) 3) Answer with evidence & provenance 4) If missing rule: propose schema addition (governed) Result: grounded answer, plus a clean “what’s missing” report.

Why OntoRAG exists

RAG is great at “find text and paraphrase it”, but it struggles when the domain has structure, constraints, and operational semantics.

  • Schema drift: the model invents fields, types, and relationships.
  • Weak traceability: you get quotes, not structured evidence.
  • Inconsistent reasoning: the same question yields different “truths”.
  • No governance: changes happen implicitly, not through reviewable proposals.

The OntoRAG bet

Treat your ontology as the center of gravity: a shared, explicit model that both humans and agents can rely on.

  • Ontology as API: classes and relations define what the system can say and do.
  • Instances with provenance: every entity can point back to source location.
  • Governed evolution: missing semantics becomes a proposal, not a hallucination.
  • Agents that act: tool calls are generated from the graph itself.

How it works

From documents → ontology → instances → tools
1

Induce & align the schema

An LLM proposes classes, attributes, and relations — then aligns them to what already exists. The output is reviewable and diff-friendly.

2

Extract instances with provenance

Entities and relations are extracted from documents with “where it came from” metadata: page, paragraph, offsets, snippets.

3

Query, plan, and act

Agents translate questions into semantic plans and execute them via SPARQL-backed tools. Writes become proposals unless explicitly confirmed.

MCP: tools generated from the graph

OntoRAG uses MCP to let agents call a semantic API. The twist: the API can be generated from the ontology itself (entity descriptors, relation descriptors, command descriptors).

list_* get_*_by_id get_*_for_* write-proposal commands

This is intentionally minimal: a thin layer between agent intent and a governed knowledge graph.

Good defaults

  • Prefer read-only tools
  • No invented schema terms
  • Evidence-first answers
  • Write = proposal by default

FAQ

Quick clarity before the rabbit hole
Is OntoRAG a product?

Not (yet). Think of it as a reference architecture and an open toolkit that can evolve into product(s). The focus is on reproducible patterns: schema cards, provenance, semantic diffs, and tool-driven agents.

Do I need a big graph database?

No. For small/medium setups, two Turtle files (ontology + instances) can be enough. As volume grows, you can switch to a SPARQL backend (Blazegraph, QLever, etc.) without changing the mental model.

Is this “GraphRAG”?

It’s adjacent. OntoRAG is about making the ontology explicit and governed, and using it to generate reliable tool calls. Graph retrieval is part of it, but the emphasis is on semantic contracts and stewardship.

What’s the biggest risk?

Alignment quality. If extraction drifts or mappings are sloppy, the graph becomes noisy. OntoRAG assumes governance: review loops, confidence thresholds, and “propose, don’t overwrite”.