Devkg Sparql

DevKG SPARQL Query Skill

Query the developer knowledge graph at http://localhost:3030/devkg/sparql via SPARQL. This graph contains extracted knowledge triples, entities, Wikidata links, and session metadata from Claude Code, DeepSeek, Grok, and Warp sessions.

Execution Pattern

Always use this one-liner pattern (POST, URL-encoded query, JSON output):

curl -s -X POST 'http://localhost:3030/devkg/sparql' \
  -H 'Accept: application/sparql-results+json' \
  --data-urlencode 'query=YOUR_SPARQL_HERE' \
  | jq -r '.results.bindings[] | [.var1.value, .var2.value] | @tsv'

Adjust the jq expression to match your SELECT variables. Use @tsv for compact tabular output.

For multi-line queries (recommended for readability), use double quotes around the --data-urlencode value and escape inner quotes:

curl -s -X POST 'http://localhost:3030/devkg/sparql' \
  -H 'Accept: application/sparql-results+json' \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  --data-urlencode "query=PREFIX devkg: <http://devkg.local/ontology#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT DISTINCT ?label WHERE {
  ?e a devkg:Entity ; rdfs:label ?label .
  FILTER(LANG(?label) = \"\")
} LIMIT 10" \
  | jq -r '.results.bindings[] | .label.value'

This avoids shell escaping issues with !=, "", and other SPARQL operators inside single-quoted strings.

Fallback Rule

If Fuseki is unreachable (curl fails or times out) or returns 0 results, fall back to grep-based session search:

grep -rli "keyword" ~/.claude/projects/**/

Then read matching JSONL files with Python. Only use this as a last resort — SPARQL is faster and can answer relationship questions that grep cannot.

Result Formatting

Present SPARQL results as markdown tables. Never dump raw JSON to the user.

Prefixes (copy into every query)

PREFIX rdf:     <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs:    <http://www.w3.org/2000/01/rdf-schema#>
PREFIX owl:     <http://www.w3.org/2002/07/owl#>
PREFIX prov:    <http://www.w3.org/ns/prov#>
PREFIX sioc:    <http://rdfs.org/sioc/ns#>
PREFIX skos:    <http://www.w3.org/2004/02/skos/core#>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX devkg:   <http://devkg.local/ontology#>
PREFIX data:    <http://devkg.local/data/>
PREFIX wd:      <http://www.wikidata.org/entity/>

Ontology Cheat Sheet

Classes

Structural Predicates (Session/Message graph)

Key Datatype Properties

Knowledge Predicates (24 total)

These connect devkg:Entity to devkg:Entity via direct edges AND are stored as devkg:triplePredicateLabel strings on reified devkg:KnowledgeTriple nodes:

uses, dependsOn, enables, isPartOf, hasPart, implements, extends, alternativeTo, solves, produces, configures, composesWith, provides, requires, isTypeOf, builtWith, deployedOn, storesIn, queriedWith, integratesWith, broader, narrower, relatedTo, servesAs

Query Templates

1. Entity Lookup — "What do we know about X?"

Returns all relationships (outbound + inbound) for an entity, with source file and content snippet for provenance. Use CONTAINS for fuzzy matching.

SELECT DISTINCT ?direction ?predicate ?otherLabel ?sourceFile ?platform
       (SUBSTR(?content, 1, 150) AS ?snippet) WHERE {
  {
    ?triple a devkg:KnowledgeTriple ;
            devkg:tripleSubject ?s ;
            devkg:triplePredicateLabel ?predicate ;
            devkg:tripleObject ?o ;
            devkg:extractedFrom ?msg ;
            devkg:extractedInSession ?session .
    ?s rdfs:label ?sLabel .
    ?o rdfs:label ?otherLabel .
    FILTER(CONTAINS(LCASE(STR(?sLabel)), "ENTITY_LOWER"))
    BIND("outbound" AS ?direction)
  } UNION {
    ?triple a devkg:KnowledgeTriple ;
            devkg:tripleSubject ?o ;
            devkg:triplePredicateLabel ?predicate ;
            devkg:tripleObject ?obj ;
            devkg:extractedFrom ?msg ;
            devkg:extractedInSession ?session .
    ?obj rdfs:label ?oLabel .
    ?o rdfs:label ?otherLabel .
    FILTER(CONTAINS(LCASE(STR(?oLabel)), "ENTITY_LOWER"))
    BIND("inbound" AS ?direction)
  }
  OPTIONAL { ?session devkg:hasSourceFile ?sourceFile }
  OPTIONAL { ?session devkg:hasSourcePlatform ?platform }
  OPTIONAL { ?msg sioc:content ?content }
}
ORDER BY ?direction ?predicate

Replace ENTITY_LOWER with the lowercase entity name (e.g., neo4j, opentelemetry).

The sourceFile column gives the full path to the original JSONL/JSON file — use Read to access it if deeper context is needed.

2. Entity-to-Entity — "How does X relate to Y?"

SELECT DISTINCT ?predicate ?sourceSnippet WHERE {
  ?triple a devkg:KnowledgeTriple ;
          devkg:tripleSubject ?s ;
          devkg:triplePredicateLabel ?predicate ;
          devkg:tripleObject ?o ;
          devkg:extractedFrom ?msg .
  ?s rdfs:label ?sLabel .
  ?o rdfs:label ?oLabel .
  OPTIONAL { ?msg sioc:content ?c . BIND(SUBSTR(?c, 1, 150) AS ?sourceSnippet) }
  FILTER(
    CONTAINS(LCASE(STR(?sLabel)), "ENTITY_X") &&
    CONTAINS(LCASE(STR(?oLabel)), "ENTITY_Y")
  )
}

3. Predicate Search — "What uses/enables/solves X?"

SELECT DISTINCT ?subjectLabel ?objectLabel WHERE {
  ?triple a devkg:KnowledgeTriple ;
          devkg:tripleSubject ?s ;
          devkg:triplePredicateLabel "PREDICATE" ;
          devkg:tripleObject ?o .
  ?s rdfs:label ?subjectLabel .
  ?o rdfs:label ?objectLabel .
  FILTER(CONTAINS(LCASE(STR(?subjectLabel)), "ENTITY_LOWER")
      || CONTAINS(LCASE(STR(?objectLabel)), "ENTITY_LOWER"))
}

Replace PREDICATE with one of the 24 predicates (e.g., uses, integratesWith).

4. Session Listing — "What sessions exist?"

SELECT ?session ?platform ?created ?title WHERE {
  ?session a devkg:Session .
  OPTIONAL { ?session devkg:hasSourcePlatform ?platform }
  OPTIONAL { ?session dcterms:created ?created }
  OPTIONAL { ?session dcterms:title ?title }
}
ORDER BY ?created

5. Topic Search — "What sessions discussed X?"

SELECT DISTINCT ?session ?platform ?created ?sourceFile WHERE {
  ?triple a devkg:KnowledgeTriple ;
          devkg:extractedInSession ?session .
  { ?triple devkg:tripleSubject ?e . ?e rdfs:label ?label . }
  UNION
  { ?triple devkg:tripleObject ?e . ?e rdfs:label ?label . }
  FILTER(CONTAINS(LCASE(STR(?label)), "TOPIC_LOWER"))
  OPTIONAL { ?session devkg:hasSourcePlatform ?platform }
  OPTIONAL { ?session dcterms:created ?created }
  OPTIONAL { ?session devkg:hasSourceFile ?sourceFile }
}
ORDER BY ?created

The sourceFile gives the path to the original session file for deeper reading.

6. Cross-Platform Overlap — "What entities appear across platforms?"

SELECT ?label (GROUP_CONCAT(DISTINCT ?platform; separator=", ") AS ?platforms)
       (COUNT(DISTINCT ?platform) AS ?platformCount) WHERE {
  ?triple a devkg:KnowledgeTriple ;
          devkg:tripleSubject ?e ;
          devkg:extractedInSession ?session .
  ?session devkg:hasSourcePlatform ?platform .
  ?e rdfs:label ?label .
}
GROUP BY ?label
HAVING(COUNT(DISTINCT ?platform) > 1)
ORDER BY DESC(?platformCount)

7. Wikidata Enrichment — "What is X?"

SELECT ?label ?wikidataURI ?description WHERE {
  ?entity a devkg:Entity ;
          rdfs:label ?label ;
          owl:sameAs ?wikidataURI .
  FILTER(STRSTARTS(STR(?wikidataURI), "http://www.wikidata.org"))
  FILTER(CONTAINS(LCASE(STR(?label)), "ENTITY_LOWER"))
  OPTIONAL { ?entity dcterms:description ?description }
}

8. Full-Text Content Search — "Find messages mentioning keyword X"

SELECT ?session ?created (SUBSTR(?content, 1, 200) AS ?snippet) WHERE {
  ?msg a devkg:UserMessage ;
       sioc:content ?content ;
       devkg:usedInSession ?session .
  OPTIONAL { ?msg dcterms:created ?created }
  FILTER(CONTAINS(LCASE(?content), "KEYWORD_LOWER"))
}
ORDER BY ?created
LIMIT 20

9. 2-Hop Neighborhood — "What connects to X and what connects to those?"

Traverses outbound edges from X, then follows outbound edges from each neighbor. Shows the subgraph reachable in 2 hops.

SELECT DISTINCT ?aLabel ?p1 ?bLabel ?p2 ?cLabel WHERE {
  ?t1 a devkg:KnowledgeTriple ;
       devkg:tripleSubject ?a ;
       devkg:triplePredicateLabel ?p1 ;
       devkg:tripleObject ?b .
  ?a rdfs:label ?aLabel .
  ?b rdfs:label ?bLabel .
  FILTER(LANG(?aLabel) = "" && LANG(?bLabel) = "")
  FILTER(CONTAINS(LCASE(?aLabel), "ENTITY_LOWER"))
  OPTIONAL {
    ?t2 a devkg:KnowledgeTriple ;
         devkg:tripleSubject ?b ;
         devkg:triplePredicateLabel ?p2 ;
         devkg:tripleObject ?c .
    ?c rdfs:label ?cLabel .
    FILTER(LANG(?cLabel) = "")
  }
}
ORDER BY ?bLabel ?cLabel

For bidirectional 2-hop (also follows inbound edges), add a second UNION branch that reverses subject/object in each hop.

10. Hub Detection — "What are the most connected entities?"

Finds entities with the highest total degree (sum of inbound + outbound edges). These are the core concepts in the knowledge graph.

SELECT ?label (COUNT(DISTINCT ?triple) AS ?degree) WHERE {
  {
    ?triple a devkg:KnowledgeTriple ;
            devkg:tripleSubject ?e .
    ?e rdfs:label ?label .
    FILTER(LANG(?label) = "")
  } UNION {
    ?triple a devkg:KnowledgeTriple ;
            devkg:tripleObject ?e .
    ?e rdfs:label ?label .
    FILTER(LANG(?label) = "")
  }
}
GROUP BY ?label
ORDER BY DESC(?degree)
LIMIT 20

11. Cross-Session Entity Overlap — "What sessions share knowledge?"

Finds pairs of sessions that discuss the same entities, with the shared entity list. Reveals hidden connections between sessions.

SELECT ?s1File ?s2File
       (COUNT(DISTINCT ?label) AS ?shared)
       (GROUP_CONCAT(DISTINCT ?label; separator=", ") AS ?sharedEntities)
WHERE {
  ?t1 a devkg:KnowledgeTriple ;
      devkg:tripleSubject ?e1 ;
      devkg:extractedInSession ?sess1 .
  ?t2 a devkg:KnowledgeTriple ;
      devkg:tripleSubject ?e2 ;
      devkg:extractedInSession ?sess2 .
  ?e1 rdfs:label ?label .
  ?e2 rdfs:label ?label .
  FILTER(LANG(?label) = "")
  FILTER(STR(?sess1) < STR(?sess2))
  OPTIONAL { ?sess1 devkg:hasSourceFile ?s1File }
  OPTIONAL { ?sess2 devkg:hasSourceFile ?s2File }
}
GROUP BY ?s1File ?s2File
HAVING(COUNT(DISTINCT ?label) > 2)
ORDER BY DESC(?shared)
LIMIT 10

12. Path Discovery — "How does X connect to Y?" (via intermediate entities)

Finds 2-hop paths between two entities in either direction. If no result, the entities are more than 2 hops apart or unconnected.

SELECT DISTINCT ?p1 ?midLabel ?p2 WHERE {
  {
    ?t1 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?a ;
        devkg:triplePredicateLabel ?p1 ;
        devkg:tripleObject ?mid .
    ?t2 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?mid ;
        devkg:triplePredicateLabel ?p2 ;
        devkg:tripleObject ?b .
  } UNION {
    ?t1 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?mid ;
        devkg:triplePredicateLabel ?p1 ;
        devkg:tripleObject ?a .
    ?t2 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?mid ;
        devkg:triplePredicateLabel ?p2 ;
        devkg:tripleObject ?b .
  } UNION {
    ?t1 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?a ;
        devkg:triplePredicateLabel ?p1 ;
        devkg:tripleObject ?mid .
    ?t2 a devkg:KnowledgeTriple ;
        devkg:tripleSubject ?b ;
        devkg:triplePredicateLabel ?p2 ;
        devkg:tripleObject ?mid .
  }
  ?a rdfs:label ?aLabel .
  ?b rdfs:label ?bLabel .
  ?mid rdfs:label ?midLabel .
  FILTER(LANG(?aLabel) = "" && LANG(?bLabel) = "" && LANG(?midLabel) = "")
  FILTER(CONTAINS(LCASE(?aLabel), "ENTITY_X"))
  FILTER(CONTAINS(LCASE(?bLabel), "ENTITY_Y"))
  FILTER(?a != ?b && ?a != ?mid && ?mid != ?b)
}

Present as: ENTITY_X --p1--> intermediate --p2--> ENTITY_Y

13. Project Knowledge Map — "What does project X know about?"

Lists the most connected entities within a specific project's sessions.

SELECT ?label (COUNT(DISTINCT ?triple) AS ?mentions) WHERE {
  ?session devkg:belongsToProject ?project .
  ?project rdfs:label ?projectLabel .
  FILTER(CONTAINS(LCASE(?projectLabel), "PROJECT_LOWER"))
  ?triple a devkg:KnowledgeTriple ;
          devkg:extractedInSession ?session .
  { ?triple devkg:tripleSubject ?e . ?e rdfs:label ?label . }
  UNION
  { ?triple devkg:tripleObject ?e . ?e rdfs:label ?label . }
  FILTER(LANG(?label) = "")
}
GROUP BY ?label
ORDER BY DESC(?mentions)
LIMIT 30

14. Sibling Entities — "What else uses/requires/enables the same thing as X?"

Finds entities that share a common neighbor with X via the same predicate. Reveals peers and alternatives.

SELECT DISTINCT ?siblingLabel ?predicate ?sharedLabel WHERE {
  ?t1 a devkg:KnowledgeTriple ;
      devkg:tripleSubject ?x ;
      devkg:triplePredicateLabel ?predicate ;
      devkg:tripleObject ?shared .
  ?t2 a devkg:KnowledgeTriple ;
      devkg:tripleSubject ?sibling ;
      devkg:triplePredicateLabel ?predicate ;
      devkg:tripleObject ?shared .
  ?x rdfs:label ?xLabel .
  ?sibling rdfs:label ?siblingLabel .
  ?shared rdfs:label ?sharedLabel .
  FILTER(LANG(?xLabel) = "" && LANG(?siblingLabel) = "" && LANG(?sharedLabel) = "")
  FILTER(CONTAINS(LCASE(?xLabel), "ENTITY_LOWER"))
  FILTER(?x != ?sibling)
}
ORDER BY ?predicate ?sharedLabel

Example: "What else uses the same things as fosfomycin?" → finds nitrofurantoin (both --uses--> empiric antibiotic therapy).

Wikidata Graph Traversal

Many entities in the local graph have owl:sameAs links to Wikidata QIDs. You can cross into Wikidata's public SPARQL endpoint to discover knowledge that doesn't exist locally — drug classes, software ecosystems, related technologies, disambiguation, etc.

Wikidata endpoint: https://query.wikidata.org/sparql

Execution pattern (same as local, but different URL + requires User-Agent header):

curl -s -X POST 'https://query.wikidata.org/sparql' \
  -H 'Accept: application/sparql-results+json' \
  -H 'User-Agent: DevKG/1.0' \
  --data-urlencode "query=YOUR_SPARQL_HERE" \
  | jq -r '...'

Rate limits: Wikidata allows ~60 requests/minute for anonymous users. Add 1-second delay between queries if doing batch lookups.

Workflow: Local → Wikidata → Back to Local

1. Start local: Use Template 1 to find what you know about entity X
2. Get QID: Use Template 7 to retrieve the owl:sameAs Wikidata URI
3. Cross to Wikidata: Use the QID in Wikidata templates below to discover new knowledge
4. Come back: Use what you learned to ask better local queries (e.g., discovered a peer → check if it exists locally)

W1. Entity Properties — "What does Wikidata know about QID?"

Returns all direct properties with human-readable labels. Use this first to understand what's available.

SELECT ?propLabel ?valLabel WHERE {
  wd:QID ?p ?val .
  ?prop wikibase:directClaim ?p .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
} LIMIT 30

Key properties to look for:

• instance of (P31) — what kind of thing it is
• subclass of (P279) — broader category
• has use (P366) — what it's used for
• programmed in (P277) — implementation language (software)
• uses (P2283) — technologies it depends on
• part of (P361) — larger system it belongs to
• ATC code (P267) — drug classification (medications)
• route of administration (P636) — how a drug is taken

W2. Peer Discovery — "What else is the same kind of thing as X?"

Given a QID, finds its instance of class, then finds all other instances of that class. Discovers alternatives and competitors.

SELECT ?peerLabel ?peerDescription WHERE {
  wd:QID wdt:P31 ?class .
  ?peer wdt:P31 ?class .
  FILTER(?peer != wd:QID)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
} LIMIT 20

Examples:

• Neo4j (Q1628290) → instance of: graph database management system → finds ArangoDB, JanusGraph, Amazon Neptune, Dgraph, etc.
• Fosfomycin (Q183554) → instance of: type of chemical entity → (too broad, use P2868 "subject has role" or ATC code instead)

W3. Disambiguation — "Is this the right entity?"

When an entity label is ambiguous, fetch the Wikidata description to verify. Use this before trusting an owl:sameAs link.

SELECT ?label ?description WHERE {
  wd:QID rdfs:label ?label .
  wd:QID schema:description ?description .
  FILTER(LANG(?label) = "en")
  FILTER(LANG(?description) = "en")
}

W4. Broader Categories — "What category tree does X belong to?"

Traverses subclass of (P279) upward to find the classification hierarchy.

SELECT ?classLabel ?superClassLabel WHERE {
  wd:QID wdt:P31 ?class .
  ?class wdt:P279* ?superClass .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
} LIMIT 20

W5. Relationship Bridge — "How do two entities connect in Wikidata?"

When two local entities have Wikidata links but no direct local connection, check if Wikidata knows a relationship.

SELECT ?propLabel WHERE {
  wd:QID_X ?p wd:QID_Y .
  ?prop wikibase:directClaim ?p .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
}

If no direct link, try 2-hop:

SELECT ?propLabel1 ?midLabel ?propLabel2 WHERE {
  wd:QID_X ?p1 ?mid .
  ?mid ?p2 wd:QID_Y .
  ?prop1 wikibase:directClaim ?p1 .
  ?prop2 wikibase:directClaim ?p2 .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
} LIMIT 10

W6. Batch QID Lookup — "Enrich all linked entities at once"

First get all QIDs from the local graph, then query Wikidata for their classes in one request.

Step 1 (local): Extract QIDs

SELECT ?label (REPLACE(STR(?wikidata), "http://www.wikidata.org/entity/", "") AS ?qid) WHERE {
  ?e a devkg:Entity ; rdfs:label ?label ; owl:sameAs ?wikidata .
  FILTER(LANG(?label) = "")
  FILTER(STRSTARTS(STR(?wikidata), "http://www.wikidata.org"))
}

Step 2 (Wikidata): Get classes for multiple QIDs at once (use VALUES clause):

SELECT ?item ?itemLabel ?classLabel WHERE {
  VALUES ?item { wd:Q1628290 wd:Q183554 wd:Q28865 }
  ?item wdt:P31 ?class .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
}

When to Use Wikidata Traversal

Tips

• Always use DISTINCT — duplicate triples exist from lang-tagged vs untagged literals.
• Always use FILTER(LANG(?label) = "") to avoid duplicate rows from lang-tagged literals.
• Entity labels are lowercase in the graph. Always use LCASE() in FILTER for safety.
• For "What integrates with X?" questions, use Template 1 (bidirectional) — the relationship may be stored in either direction.
• KnowledgeTriple nodes carry provenance: extractedFrom → source message, extractedInSession → session. Always join these when the user needs context about where knowledge came from.
• Combine templates: e.g., Template 1 + Template 7 to get both relationships and Wikidata descriptions.
• Start with Template 10 (hubs) when exploring an unfamiliar graph — it reveals the most connected entities to anchor further queries.
• Use Template 12 (path discovery) before concluding two concepts are unrelated — they may connect through intermediates.
• Use Template 14 (siblings) to discover alternatives and peers — e.g., "what else is an alternative to X?" or "what else requires the same dependencies?"

Source: robertoshimizu/session-graph — distributed by TomeVault.