mcp_fact_graph 0.3.0

Temporal knowledge graph with evidence-based fact management, candidate confirmation, and automatic summarization for the MCP ecosystem.

example/example.dart

// Evidence in, a fact out, a context bundle and a checked answer: the path
// through the four layers with the in-memory runtime.

import 'package:mcp_fact_graph/mcp_fact_graph.dart';

Future<void> main() async {
  // The engine ships mechanisms; the words it judges by, the object types it
  // requires fields of and the domain views it computes are the host's. The
  // multilingual policy and the starter sets are ready-made choices.
  final graph = FactGraphRuntime.inMemory(
    defaultWorkspaceId: 'demo',
    responsePolicy: const ResponsePolicy.multilingual(),
    minimumFields: FactGraphService.starterMinimumFields,
    viewComputers: starterViewComputers,
  );

  // L0: evidence and a fragment read from it.
  final evidence = await graph.evidenceService.ingestEvidence(IngestionInput(
    workspaceId: 'demo',
    sourceType: EvidenceSourceType.text,
    sourceId: 'meeting-notes',
    content: 'Pilot is set for December 12. Legal review is due November 8.',
  ));
  final fragment = await graph.evidenceService.addFragment(
    evidence.evidenceId,
    {'summary': 'Pilot is set for December 12'},
  );

  // L1: a candidate built from the fragment, confirmed into a fact.
  final candidate = await graph.factGraphService.createCandidate(
    workspaceId: 'demo',
    objectType: 'decision',
    fragments: [fragment],
  );
  final confirmation =
      await graph.factGraphService.confirmCandidate(candidate.candidateId);
  print('fact ${confirmation.factId}');

  // Read-only search, ranked by the terms the facts share with the query.
  final found = await graph.factGraphService
      .searchFacts(workspaceId: 'demo', query: 'pilot december');
  print('${found.length} fact(s) match');

  // L2: the context bundle for a question, within a token budget.
  final bundle = await graph.contextService.buildContext(
    workspaceId: 'demo',
    query: 'When is the pilot?',
    tokenBudget: 512,
  );
  print('bundle holds ${bundle.facts.length} fact(s)');

  // L2: an answer checked against the facts before it reaches the user.
  final check = await graph.responseValidationService!.validate(
    workspaceId: 'demo',
    responseText: 'The pilot is set for December 12.',
  );
  print('${check.result.name}: ${check.sanitizedResponse}');
}