Fluree System Vocabulary Reference

All Fluree system vocabulary lives under a single canonical namespace:

https://ns.flur.ee/db#

Users declare a prefix in their JSON-LD @context to use compact forms:

{ "@context": { "f": "https://ns.flur.ee/db#" } }

Any prefix works (f:, db:, fluree:, etc.) as long as it expands to the canonical IRI. Internally, Fluree always compares on fully expanded IRIs.

The @vector and @fulltext shorthands are exceptions: they are JSON-LD convenience aliases that resolve to f:embeddingVector and f:fullText respectively without requiring a prefix declaration.

Source of truth: All constants are defined in the fluree-vocab crate. This document is the user-facing reference.

---

Commit metadata predicates

These predicates appear on commit subjects in the txn-meta graph. Each commit produces 7-10 flakes describing the commit.

Predicate	Full IRI	Datatype	Description
f:address	https://ns.flur.ee/db#address	xsd:string	Commit ContentId (CID string)
f:alias	https://ns.flur.ee/db#alias	xsd:string	Ledger ID (e.g. mydb:main)
f:v	https://ns.flur.ee/db#v	xsd:int	Commit format version
f:time	https://ns.flur.ee/db#time	xsd:long	Commit timestamp (epoch milliseconds)
f:t	https://ns.flur.ee/db#t	xsd:int	Transaction number (watermark)
f:size	https://ns.flur.ee/db#size	xsd:long	Cumulative data size in bytes
f:flakes	https://ns.flur.ee/db#flakes	xsd:long	Cumulative flake count
f:previous	https://ns.flur.ee/db#previous	@id (ref)	Reference to previous commit (optional)
f:identity	https://ns.flur.ee/db#identity	xsd:string	Authenticated identity acting on the transaction (system-controlled — verified DID for signed requests, otherwise opts.identity / CommitOpts.identity).
f:author	https://ns.flur.ee/db#author	xsd:string	Author claim — user-supplied via f:author in the transaction body (optional). Distinct from f:identity.
f:txn	https://ns.flur.ee/db#txn	xsd:string	Transaction ContentId (CID string, optional)
f:message	https://ns.flur.ee/db#message	xsd:string	Commit message — user-supplied via f:message in the transaction body (optional).
f:asserts	https://ns.flur.ee/db#asserts	xsd:long	Assertion count in this commit
f:retracts	https://ns.flur.ee/db#retracts	xsd:long	Retraction count in this commit

Querying commit metadata

Commit metadata lives in the #txn-meta named graph within each ledger. To query it:

{
  "@context": { "f": "https://ns.flur.ee/db#" },
  "select": ["?t", "?time", "?author"],
  "where": {
    "@graph": "mydb:main#txn-meta",
    "f:t": "?t",
    "f:time": "?time",
    "f:author": "?author"
  }
}

Commit subject identifiers

Commit subjects use the scheme fluree:commit:<content-id> (e.g. fluree:commit:bafybeig...). This is a subject identifier scheme, not part of the db# predicate vocabulary.

---

Datalog rules

Predicate	Full IRI	Description
f:rule	https://ns.flur.ee/db#rule	Datalog rule definition predicate

---

Vector datatype

Term	IRI	Description
f:embeddingVector	https://ns.flur.ee/db#embeddingVector	f32-precision embedding vector datatype
@vector	(shorthand)	JSON-LD alias that resolves to f:embeddingVector

Example usage in a transaction:

{
  "@context": { "f": "https://ns.flur.ee/db#", "ex": "http://example.org/" },
  "insert": {
    "@id": "ex:doc1",
    "ex:embedding": { "@value": [0.1, 0.2, 0.3], "@type": "f:embeddingVector" }
  }
}

Or with the @vector shorthand:

{
  "insert": {
    "@id": "ex:doc1",
    "ex:embedding": { "@value": [0.1, 0.2, 0.3], "@type": "@vector" }
  }
}

---

Fulltext datatype

Term	IRI	Description
f:fullText	https://ns.flur.ee/db#fullText	Inline full-text search datatype
@fulltext	(shorthand)	JSON-LD alias that resolves to f:fullText

Example usage in a transaction:

{
  "@context": { "f": "https://ns.flur.ee/db#", "ex": "http://example.org/" },
  "insert": {
    "@id": "ex:article-1",
    "ex:content": { "@value": "Rust is a systems programming language", "@type": "f:fullText" }
  }
}

Or with the @fulltext shorthand:

{
  "insert": {
    "@id": "ex:article-1",
    "ex:content": { "@value": "Rust is a systems programming language", "@type": "@fulltext" }
  }
}

Values annotated with @fulltext are analyzed (tokenized, stemmed) and indexed into per-predicate fulltext arenas during background index builds. Query with the fulltext() function in bind expressions for BM25 relevance scoring.

See Inline Fulltext Search for details.

Fulltext configuration predicates

These predicates live in the ledger's #config named graph and declare which properties to full-text index (no per-value @fulltext annotation needed). See Configured full-text properties for the end-user guide and Setting groups for the full schema reference.

Term	IRI	Description
f:fullTextDefaults	https://ns.flur.ee/db#fullTextDefaults	Setting group on f:LedgerConfig / f:GraphConfig
f:FullTextDefaults	https://ns.flur.ee/db#FullTextDefaults	Class (type) of the setting-group node
f:defaultLanguage	https://ns.flur.ee/db#defaultLanguage	BCP-47 tag used for untagged plain strings on configured properties
f:property	https://ns.flur.ee/db#property	One entry per full-text-indexed property (cardinality 0..n)
f:FullTextProperty	https://ns.flur.ee/db#FullTextProperty	Class of each f:property entry
f:target	https://ns.flur.ee/db#target	IRI of the property being indexed (on f:FullTextProperty)

---

Search query vocabulary

These predicates are used in WHERE clause patterns for BM25 and vector search. Users write compact forms like "f:searchText" (with "f" in their @context) or full IRIs.

BM25 search

Predicate	Full IRI	Required	Description
f:graphSource	https://ns.flur.ee/db#graphSource	Yes	Graph source ID (name:branch, e.g. "my-search:main")
f:searchText	https://ns.flur.ee/db#searchText	Yes	Search query text (string or variable)
f:searchResult	https://ns.flur.ee/db#searchResult	Yes	Result binding (variable or nested object)
f:searchLimit	https://ns.flur.ee/db#searchLimit	No	Maximum results
f:syncBeforeQuery	https://ns.flur.ee/db#syncBeforeQuery	No	Wait for index sync before querying (boolean)
f:timeoutMs	https://ns.flur.ee/db#timeoutMs	No	Query timeout in milliseconds

Vector search

Predicate	Full IRI	Required	Description
f:graphSource	https://ns.flur.ee/db#graphSource	Yes	Graph source ID (name:branch)
f:queryVector	https://ns.flur.ee/db#queryVector	Yes	Query vector (array of numbers or variable)
f:searchResult	https://ns.flur.ee/db#searchResult	Yes	Result binding
f:distanceMetric	https://ns.flur.ee/db#distanceMetric	No	Distance metric: "cosine", "dot", "euclidean" (default: "cosine")
f:searchLimit	https://ns.flur.ee/db#searchLimit	No	Maximum results
f:syncBeforeQuery	https://ns.flur.ee/db#syncBeforeQuery	No	Wait for index sync (boolean)
f:timeoutMs	https://ns.flur.ee/db#timeoutMs	No	Query timeout in milliseconds

Nested result objects

Both BM25 and vector search support nested result bindings:

Predicate	Full IRI	Description
f:resultId	https://ns.flur.ee/db#resultId	Document/subject ID binding
f:resultScore	https://ns.flur.ee/db#resultScore	Search score binding
f:resultLedger	https://ns.flur.ee/db#resultLedger	Source ledger ID (multi-ledger disambiguation)

Example BM25 search with nested result:

{
  "@context": { "f": "https://ns.flur.ee/db#" },
  "select": ["?doc", "?score"],
  "where": {
    "f:graphSource": "my-search:main",
    "f:searchText": "software engineer",
    "f:searchLimit": 10,
    "f:searchResult": {
      "f:resultId": "?doc",
      "f:resultScore": "?score"
    }
  }
}

---

Nameservice record vocabulary

Ledger record fields

These predicates appear on ledger nameservice records (the metadata Fluree stores about each ledger).

Predicate	Full IRI	Description
f:ledger	https://ns.flur.ee/db#ledger	Ledger name/identifier
f:branch	https://ns.flur.ee/db#branch	Branch name (e.g. main)
f:t	https://ns.flur.ee/db#t	Current transaction watermark
f:ledgerCommit	https://ns.flur.ee/db#ledgerCommit	Pointer to latest commit ContentId
f:ledgerIndex	https://ns.flur.ee/db#ledgerIndex	Pointer to latest index root
f:status	https://ns.flur.ee/db#status	Record status (ready, etc.)
f:defaultContextCid	https://ns.flur.ee/db#defaultContextCid	Default JSON-LD context ContentId

Graph source record fields

Predicate	Full IRI	Description
f:name	https://ns.flur.ee/db#name	Graph source base name
f:branch	https://ns.flur.ee/db#branch	Branch
f:status	https://ns.flur.ee/db#status	Status
f:graphSourceConfig	https://ns.flur.ee/db#graphSourceConfig	Configuration JSON
f:graphSourceDependencies	https://ns.flur.ee/db#graphSourceDependencies	Dependent ledger IDs
f:graphSourceIndex	https://ns.flur.ee/db#graphSourceIndex	Index ContentId reference
f:graphSourceIndexT	https://ns.flur.ee/db#graphSourceIndexT	Index watermark (commit t)
f:graphSourceIndexAddress	https://ns.flur.ee/db#graphSourceIndexAddress	Index ContentId (string form)

Record type taxonomy

Nameservice records use @type to classify what kind of graph source a record represents.

Required kind types (exactly one per record):

Type	Full IRI	Description
f:LedgerSource	https://ns.flur.ee/db#LedgerSource	Ledger-backed knowledge graph
f:IndexSource	https://ns.flur.ee/db#IndexSource	Index-backed graph source (BM25/HNSW/GEO)
f:MappedSource	https://ns.flur.ee/db#MappedSource	Mapped database (Iceberg, R2RML)

Optional subtype @type values (further classify the record):

Type	Full IRI	Description
f:Bm25Index	https://ns.flur.ee/db#Bm25Index	BM25 full-text search index
f:HnswIndex	https://ns.flur.ee/db#HnswIndex	HNSW vector similarity search index
f:GeoIndex	https://ns.flur.ee/db#GeoIndex	Geospatial index
f:IcebergMapping	https://ns.flur.ee/db#IcebergMapping	Iceberg-mapped database
f:R2rmlMapping	https://ns.flur.ee/db#R2rmlMapping	R2RML relational mapping

---

Policy vocabulary

These predicates are used to define access control policies.

Predicate	Full IRI	Description
f:policyClass	https://ns.flur.ee/db#policyClass	Marks a class as policy-governed
f:allow	https://ns.flur.ee/db#allow	Allow/deny flag on a policy rule
f:action	https://ns.flur.ee/db#action	Action this rule governs (view or modify)
f:view	https://ns.flur.ee/db#view	View action IRI
f:modify	https://ns.flur.ee/db#modify	Modify action IRI
f:onProperty	https://ns.flur.ee/db#onProperty	Property-level policy targeting
f:onSubject	https://ns.flur.ee/db#onSubject	Subject-level policy targeting
f:onClass	https://ns.flur.ee/db#onClass	Class-level policy targeting
f:query	https://ns.flur.ee/db#query	Policy query (determines applicability)
f:required	https://ns.flur.ee/db#required	Whether the policy is required (boolean)
f:exMessage	https://ns.flur.ee/db#exMessage	Error message when policy denies access

See Policy model and inputs for usage details.

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Config graph vocabulary

These predicates define ledger-level configuration stored in the config graph. See Ledger configuration for full documentation.

Core types

Type	Full IRI	Description
f:LedgerConfig	https://ns.flur.ee/db#LedgerConfig	Ledger-wide configuration resource
f:GraphConfig	https://ns.flur.ee/db#GraphConfig	Per-graph configuration override
f:GraphRef	https://ns.flur.ee/db#GraphRef	Reference to a graph source

Setting group predicates

Predicate	Full IRI	Description
f:policyDefaults	https://ns.flur.ee/db#policyDefaults	Policy enforcement defaults
f:shaclDefaults	https://ns.flur.ee/db#shaclDefaults	SHACL validation defaults
f:reasoningDefaults	https://ns.flur.ee/db#reasoningDefaults	OWL/RDFS reasoning defaults
f:datalogDefaults	https://ns.flur.ee/db#datalogDefaults	Datalog rule defaults
f:transactDefaults	https://ns.flur.ee/db#transactDefaults	Transaction constraint defaults

Policy fields

Predicate	Full IRI	Description
f:defaultAllow	https://ns.flur.ee/db#defaultAllow	Default allow/deny when no policy matches (boolean)
f:policySource	https://ns.flur.ee/db#policySource	Graph containing policy rules (GraphRef)
f:policyClass	https://ns.flur.ee/db#policyClass	Default policy classes to apply

SHACL fields

Predicate	Full IRI	Description
f:shaclEnabled	https://ns.flur.ee/db#shaclEnabled	Enable/disable SHACL validation (boolean)
f:shapesSource	https://ns.flur.ee/db#shapesSource	Graph containing SHACL shapes (GraphRef)
f:validationMode	https://ns.flur.ee/db#validationMode	f:ValidationReject or f:ValidationWarn

Reasoning fields

Predicate	Full IRI	Description
f:reasoningModes	https://ns.flur.ee/db#reasoningModes	Reasoning modes: f:RDFS, f:OWL2QL, f:OWL2RL, f:Datalog
f:schemaSource	https://ns.flur.ee/db#schemaSource	Graph containing schema triples (GraphRef)

Datalog fields

Predicate	Full IRI	Description
f:datalogEnabled	https://ns.flur.ee/db#datalogEnabled	Enable/disable datalog rules (boolean)
f:rulesSource	https://ns.flur.ee/db#rulesSource	Graph containing f:rule definitions (GraphRef)
f:allowQueryTimeRules	https://ns.flur.ee/db#allowQueryTimeRules	Allow ad-hoc query-time rules (boolean)

Transact / uniqueness fields

Predicate	Full IRI	Description
f:uniqueEnabled	https://ns.flur.ee/db#uniqueEnabled	Enable unique constraint enforcement (boolean)
f:constraintsSource	https://ns.flur.ee/db#constraintsSource	Graph(s) containing constraint annotations (GraphRef)
f:enforceUnique	https://ns.flur.ee/db#enforceUnique	Annotation on property IRIs: enforce value uniqueness (boolean)

Override control

Term	Full IRI	Description
f:overrideControl	https://ns.flur.ee/db#overrideControl	Override gating on a setting group
f:OverrideNone	https://ns.flur.ee/db#OverrideNone	No overrides permitted
f:OverrideAll	https://ns.flur.ee/db#OverrideAll	Any request can override (default)
f:IdentityRestricted	https://ns.flur.ee/db#IdentityRestricted	Only verified identities can override
f:controlMode	https://ns.flur.ee/db#controlMode	Control mode (for identity-restricted objects)
f:allowedIdentities	https://ns.flur.ee/db#allowedIdentities	List of DIDs authorized to override

Graph targeting

Predicate	Full IRI	Description
f:graphOverrides	https://ns.flur.ee/db#graphOverrides	List of f:GraphConfig per-graph overrides
f:targetGraph	https://ns.flur.ee/db#targetGraph	Target graph IRI for a f:GraphConfig
f:graphSelector	https://ns.flur.ee/db#graphSelector	Graph selector within a f:GraphRef
f:defaultGraph	https://ns.flur.ee/db#defaultGraph	Sentinel IRI for the default graph
f:txnMetaGraph	https://ns.flur.ee/db#txnMetaGraph	Sentinel IRI for the txn-meta graph

See Ledger configuration for usage details.

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RDF-Star annotation predicates

Fluree supports RDF-Star annotations for transaction metadata. These predicates can appear in annotation triples:

Predicate	Full IRI	Description
f:t	https://ns.flur.ee/db#t	Transaction number on an annotated triple
f:op	https://ns.flur.ee/db#op	Operation type (assert/retract)

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Namespace codes (internal)

Fluree encodes namespace IRIs as integer codes for compact storage. These are internal implementation details but useful for contributors working on the core.

Code	Namespace	IRI
0	(empty)	""
1	JSON-LD	@
2	XSD	http://www.w3.org/2001/XMLSchema#
3	RDF	http://www.w3.org/1999/02/22-rdf-syntax-ns#
4	RDFS	http://www.w3.org/2000/01/rdf-schema#
5	SHACL	http://www.w3.org/ns/shacl#
6	OWL	http://www.w3.org/2002/07/owl#
7	Fluree DB	https://ns.flur.ee/db#
8	DID Key	did:key:
9	Fluree Commit	fluree:commit:
10	Blank Node	_:
11	OGC GeoSPARQL	http://www.opengis.net/ont/geosparql#
100+	User-defined	(allocated at first use)

---

Standard W3C namespaces

Fluree also recognizes these standard W3C namespaces:

Prefix	IRI	Common predicates
rdf:	http://www.w3.org/1999/02/22-rdf-syntax-ns#	rdf:type, rdf:first, rdf:rest
rdfs:	http://www.w3.org/2000/01/rdf-schema#	rdfs:label, rdfs:subClassOf, rdfs:range
xsd:	http://www.w3.org/2001/XMLSchema#	xsd:string, xsd:int, xsd:dateTime
owl:	http://www.w3.org/2002/07/owl#	owl:sameAs, owl:inverseOf
sh:	http://www.w3.org/ns/shacl#	sh:path, sh:datatype, sh:minCount

See IRIs, namespaces, and JSON-LD @context for details on prefix declarations and IRI resolution.