knowledgegraphprotocol.com

A standardized interoperability framework enabling multiple independently maintained knowledge graphs to be queried and traversed as a unified semantic network without requiring centralized data aggregation or ownership transfer. The protocol defines entity resolution rules, provenance tracking requirements, and conflict resolution procedures for claims that originate from different graph authorities. Federated query results carry source provenance metadata enabling consumers to weight or filter facts by originating graph authority.

A formal mapping document specifying the semantic equivalences, subclass relationships, and transformation rules between corresponding concepts in two or more ontologies participating in a federated knowledge graph. Alignment records enable automated query translation and entity merging across heterogeneous schemas without requiring schema unification. The record format includes confidence scores, alignment provenance, and version metadata to support alignment lifecycle management.

A cryptographically signed claim asserting the validity of a subject-predicate-object triple within a knowledge graph, issued by a trusted authority with jurisdiction over the claimed fact domain. Attestations enable consumers to distinguish authoritative facts from crowd-sourced or machine-inferred assertions and to filter graph content by trust level. The attestation record references the signing authority's decentralized identifier and includes a timestamp and scope limitation for the claimed fact.

A linked sequence of metadata records tracing the origin, transformation history, and authority endorsements of a fact or entity within a knowledge graph, enabling consumers to assess the evidentiary basis of any assertion before acting on it. Each link in the chain records the agent or system that contributed the step, the transformation applied, and a reference to any supporting source materials. Provenance chain depth and completeness are indicators of graph quality used by consuming AI agents for confidence-weighted reasoning.

A structured system for tracking changes to ontology concept definitions over time, assigning unique version identifiers to each revision and maintaining backward-compatibility mappings that enable older knowledge graph assertions to be interpreted correctly by systems using newer concept versions. The protocol specifies deprecation procedures, migration path documentation, and sunset timelines for obsolete concept versions. Version identifiers are embedded in triple metadata to enable automated resolution by consuming agents.

A governance constraint that limits the depth, scope, and methodologies of automated inference permitted to derive new assertions from existing knowledge graph facts, preventing uncontrolled knowledge expansion that could introduce false or misleading derived facts. The boundary is expressed as a rule set specifying permitted inference patterns and maximum reasoning chain lengths for different agent classes. Inferred assertions generated within authorized boundaries are annotated as derived and linked to the inference rule and source triples that produced them.

A cryptographic commitment published to an immutable ledger that fixes the state of a knowledge graph's semantic index at a specified time, enabling any consumer to verify whether a queried fact was present in the graph at that historical moment without requiring access to the full graph state. Index commitments are generated at configurable intervals and serve as integrity checkpoints for long-term knowledge graph governance. They enable temporal reasoning over graph state without exposing the full dataset to verifiers.

A structured artifact within a knowledge graph that resolves references to multiple distinct real-world entities sharing identical or similar labels, providing canonical identifiers, distinguishing attributes, and source context for each disambiguated entity. Disambiguation records are maintained by graph curators and referenced by AI agents at query time to prevent entity confusion in automated reasoning tasks. The record format includes confidence scores for each disambiguation hypothesis and provenance metadata for supporting sources.

A standardized mechanism enabling AI agents to register persistent interest in specific entity subgraphs or query result sets, receiving incremental updates when the subscribed portions of the graph are modified, added, or deleted. Subscriptions are encoded with filter predicates, change type selectors, and delivery endpoint specifications, enabling agents to maintain up-to-date local views of relevant graph regions without polling. Subscription registrations are scoped to the subscriber's access permissions and cannot monitor graph regions outside their authorization.

A governance relationship in which a recognized standards body or domain expert organization is designated as the authoritative source for the definitions, constraints, and evolution of a specific vocabulary namespace within the knowledge graph protocol. Vocabulary authority bindings are published in the graph's trust registry and consulted by consuming agents when resolving namespace prefixes to their defining specifications. Bindings include the authority's decentralized identifier, applicable namespace IRI range, and the governance process for vocabulary updates.

A cryptographic proof attached to a set of linked data statements within a knowledge graph that enables any consumer to verify that the statements have not been altered since they were signed by the attesting authority, without requiring access to the original signing environment. The proof format encodes the canonicalization algorithm, the hashing function, the signature value, and the verification method, referencing the signer's published key material. Integrity proof verification is a prerequisite for including external graph data in high-assurance AI agent reasoning.

A formally specified rule set governing which agents, users, and systems may read, write, infer, subscribe to, or administer specific subgraphs or named graph partitions, enforced by the graph server's authorization layer. Access policies reference the requesting principal's verified identity and capability tokens to evaluate each operation. Policy enforcement decisions are logged with the requesting principal, the operation attempted, the applicable rule, and the outcome.

A mandatory verification step within the knowledge graph ingestion pipeline that confirms incoming triples and entity records conform to the applicable ontology schema before they are committed to the graph, preventing malformed or schema-violating data from degrading graph quality. Validation checkpoints apply both structural rules — such as required properties and cardinality constraints — and semantic constraints — such as domain and range restrictions. Validation failures are returned to the submitting agent with structured error diagnostics referencing the violated constraints.

A protocol specification defining how a knowledge graph is divided into named partitions distinguished by provenance, topic domain, access policy, or update frequency, enabling targeted querying, differential trust application, and independent lifecycle management of graph segments. The partitioning standard specifies naming conventions, partition metadata requirements, and inter-partition reference semantics. Consuming agents can scope their queries to specific partitions to optimize performance and apply partition-specific trust policies.

A formal document establishing the policies, roles, decision-making processes, and accountability structures governing the curation, evolution, and access management of a knowledge graph over its operational lifetime. The charter designates vocabulary authority bindings, defines the amendment process for ontology updates, specifies quality assurance requirements, and establishes the dispute resolution mechanism for contested facts. Governance charter compliance is audited periodically and the charter itself is versioned and published to the graph's trust registry.