Predicate

Reasoning memory for AI agents — a self-improving knowledge graph that grows with use.

Predicate gives an AI agent a structured graph it can query, reason over, and grow with use. Facts are stored as RDF triples with per-triple provenance and confidence. An OWL 2 RL reasoner materializes entailments deterministically and produces an explanation path for every derived claim. The schema is versioned like code and evolves under a propose → validate → use-gated promotion loop. Everything runs locally — no daemon, no Docker by default — and nothing leaves the machine.

What that buys an agent that a flat memory doesn’t:

• Auditable answers. kg_explain returns the chain of triples and rules that produced a claim, each step cited back to its source and confidence.
• Contradictions surface instead of averaging out. When two sources disagree about a fact the schema marks as functional or disjoint, the reasoner flags the conflict rather than silently picking one.
• The graph remembers, and the schema earns its keep. Facts persist across sessions. New schema only becomes durable after three real queries reference it within a week — unused proposals expire on their own.

See docs/predicate-prd.md for the full product brief.

Quick start

Prerequisite: Node 20+. Nothing else — no Docker, no database to run.

npm install -g predicate-skill
predicate up        # creates the local store + the 8 named graphs
predicate doctor    # all checks green

That’s it. Your knowledge graph lives at ~/.predicate/store/ (in-process Oxigraph, file-backed). Ask the agent a question and it uses the kg_* MCP tools automatically.

Use it in your agent

/plugin marketplace add NordicAgents/predicate
/plugin install predicate@predicate

predicate up
predicate doctor

npm install -g predicate-skill
predicate up
cp "$(npm root -g)/predicate-skill/hooks/cursor/mcp.json.template" ~/.cursor/mcp.json

npm install -g predicate-skill
predicate up

npm install -g predicate-skill
predicate up

npm install -g predicate-skill
predicate up

npm install -g predicate-skill
predicate up

mcpServers:
  - name: predicate
    command: predicate-skill

npm install -g predicate-skill
predicate up
# server command:
#   node "$(npm root -g)/predicate-skill/server.bundle.mjs"

Storage backends

Predicate ships two interchangeable storage backends behind one adapter:

• Oxigraph (default). In-process, file-backed at ~/.predicate/store/ (one N-Quads file per named graph). No Docker, no daemon, sub-second start. You get this unless you opt out.
• Fuseki (opt-in). Apache Jena Fuseki / TDB2 in Docker. Set PREDICATE_BACKEND=fuseki. Requires Docker. Useful for very large graphs or sharing one store across processes.

Already on Fuseki and want to switch? Migrate in place:

predicate migrate --from fuseki --to oxigraph
unset PREDICATE_BACKEND     # drop it from your shell rc too
predicate down              # stop the Fuseki container; your data is now in Oxigraph

How it works

• Storage. 8 named graphs separate slow-changing schema (kg:tbox) from fast-flowing facts (kg:abox), materialized entailments (kg:inferred), per-triple metadata (kg:provenance), goals (kg:goals), usage logs (kg:usage), staging (kg:tbox-staging), and version history (kg:meta).
• Reasoning. A curated OWL 2 RL rule set runs as SPARQL CONSTRUCT rules to a fixpoint, plus SHACL shapes for closed-world validation. Logical entailment is the engine’s job; the model formulates queries and interprets results.
• Provenance. Every triple is annotated with source, time, confidence, and extraction method using RDF-star. Low-confidence triples stay visible to queries but are excluded from the inference closure so they cannot poison entailment.
• Schema lifecycle. The agent proposes deltas to kg:tbox-staging, never to kg:tbox directly. A proposal is promoted only after the reasoner accepts it and it has been used by N successful queries inside a TTL; unused proposals expire quietly.
• Goal-conditioned growth. Concepts enter the graph because a goal needed them, not because a document mentioned them. The promotion gate makes inferred goals safe by construction.

Bootstrap modes

On first predicate up, choose how to seed the schema:

• Community ontology — install a bundled vocabulary (top, codebase, foaf, schema-org-lite, fhir-core).
• Bring your own — upload a Turtle file as the initial TBox.
• Empty — start with no schema; the agent grows vocabulary through the propose → validate → 3-uses-in-7-days promotion gate.

Run non-interactively with predicate init --mode community --ontology codebase (or --mode empty). Schema-learning is toggleable at runtime via the predicate config get|set CLI command.

MCP tools

CLI

predicate up                # open the store (Oxigraph default) + bootstrap the 8 graphs
predicate init              # seed kg:tbox (community / upload / empty)
predicate down              # close the store (or stop the Fuseki container)
predicate doctor            # backend-aware health checks
predicate stats             # current kg_stats output
predicate migrate --from fuseki --to oxigraph   # move an existing Fuseki store to Oxigraph
predicate maintain          # reaper + generalizer + promotion sweeper
predicate recall <query>    # substring search over session history (files + commands)
predicate dashboard         # localhost web view of session history + reasoning output
predicate config get|set    # runtime config (schema-learning toggle, init keys)
predicate extract --replay <path>   # rebuild extracted abox slice from transcripts

predicate --version
predicate --help

Dashboard

predicate dashboard

Serves a read-only localhost view at http://127.0.0.1:4040 — recent sessions, hotspots (files modified in ≥3 sessions), flaky commands (failed in ≥2 sessions), active files, and a stats snapshot. Auto-refreshes every 30s. --port N to override; --no-open to skip the browser.

Derived classes

The reasoner materializes a few derive-only classes into kg:inferred so action data becomes queryable:

Packages

Development

git clone https://github.com/NordicAgents/predicate
cd predicate
pnpm install
pnpm build            # builds all packages + the plugin bundle
pnpm test             # runs against the default Oxigraph backend, no Docker needed
                      # for the Fuseki leg: PREDICATE_BACKEND=fuseki + a running Fuseki

License

Elastic License 2.0 (ELv2) — source-available. See LICENSE.