Graph/cypher

Language

cypher

Node Details

Public graph metadata

Updated5/1/2026

PageRank0.0011

Connections

50 linked nodes

WRITTEN_INComponent

neo4j

WRITTEN_INSolution

Preserve properties explicitly. — Plain Cypher: `MATCH (a)-[r:OLD]->(b) MERGE (a)-[r2:NEW]->(b) ON CREATE SET r2 = properties(r) DELETE r`. Tension: Use MERGE (not CREATE) to dedup against any NEW edge already present for the pair; ON CREATE SET avoids clobbering an existing one. Outcome: Both forms are idempotent (a re-run matches no OLD edges).

WRITTEN_INQuestion

GDS pipeline writes 0 ClusterConcept nodes on sparse graph despite communities existing

WRITTEN_INComponent

neo4j

WRITTEN_INSolution

Broaden the MATCH to include all semantic node types — same set community detection uses. Outcome: MATCH (n) WHERE (n:Problem OR n:RootCause OR n:FailurePattern OR n:DesignPattern OR n:Solution).

WRITTEN_INSolution

Added a `sanitizeEdgeType()` function — Applied at both Cypher interpolation points. Tension: This is defense-in-depth — the LLM prompt already specifies valid types, but sanitization catches hallucinations at the boundary before they reach Neo4j.

WRITTEN_INSolution

Coerce the nullable property to a non-null sentinel before the string operation — NOT coalesce(n.extractionSource, '') STARTS WITH $prefix AND (trustedSource OR n.reinforcementCount > 0). Tension: `coalesce(null, '')` is '', `'' STARTS WITH 'quarantined:'` is FALSE, `NOT FALSE` is TRUE. Outcome: the guard behaves as intended for unstamped nodes.

Broaden the MATCH to include all semantic node types — same set community detection uses. Outcome: MATCH (n) WHERE (n:Problem OR n:RootCause OR n:FailurePattern OR n:DesignPattern OR n:Solution).

AFFECTSRootCause

The BURST_BOTH_FILTER in taxonomy.ts excluded all structural edges (OCCURS_IN, WRITTEN_IN, OCCURS_ON) — in an earlier attempt to prevent hub fan-out. Tension: excluding the edges meant APOC path expansion had nothing to traverse from a Context seed. Outcome: a walk from a Problem node that DID include those edges would blow up through the hub.

PERTAIN_TORootCause

`n.createdAt < datetime() - duration('PT48H')`: row vanished here. Tension: Comparing values of different types returns null. Outcome: Mixed-type `<` evaluates to `null`, and `WHERE null` filters the row.

PERTAIN_TOSolution

legacy-imported nodes without `createdAt`. Tension: Relying on implicit null propagation means correctness depends on Cypher's null semantics in two places instead of one. Outcome: Coerce the string in the WHERE clause + explicit null guard so legacy-imported nodes without `createdAt` aren't accidentally mass-deleted on the next run:.

PERTAIN_TOSolution

Added a `sanitizeEdgeType()` function — Applied at both Cypher interpolation points. Tension: This is defense-in-depth — the LLM prompt already specifies valid types, but sanitization catches hallucinations at the boundary before they reach Neo4j.

PERTAIN_TORootCause

O(1536 * 3) floating-point operations per node, for 50+ nodes — Cypher's interpreted reduce(). Tension: all executed in Cypher's unoptimized expression evaluator. Outcome: The similarity computation in Cypher's interpreted reduce() was the bottleneck.

OCCURS_INProblem

phase 2 (~67k edges, no LIMIT) returned zero records to the client and the connection closed mid-response — A Hono endpoint streamed graph data from Neo4j to the browser via NDJSON. Tension: Locally against a Docker Neo4j it worked; against managed AuraDB it failed every time. Outcome: client received the full nodes phase, then 'done' was never emitted and the renderer rendered an empty graph.

OCCURS_INProblem

a soft-written node created via the API was byte-different from one created via the prose path — missing two annotations — two code paths are meant to produce identical writes. Tension: Both paths passed their own unit tests; the divergence was invisible because nothing compared the two outputs.

OCCURS_INReport

Neo4j silently drops null-valued properties — 'k' IN keys(n) is false after CREATE (n {k: null})

OCCURS_INRootCause

`CREATE (n {a: null}) RETURN keys(n)` returns `[]`. Tension: `keys(n)` never includes a null-valued property → `'k' IN keys(n)` is false. Outcome: Setting a property to null on CREATE/SET is equivalent to NOT setting it (and on an existing node, REMOVES it).

OCCURS_INProblem

The production API returned 404 for the expected admin cleanup route — A demo benchmark needed to wipe only its own graph namespace before each run. Tension: the harness could not authenticate cleanup because the local secret used an older environment variable alias. The fallback was a manual Cypher delete, which made clean runs unreliable.

OCCURS_INReport

Neo4j relationship-type relabel silently drops edge properties unless preserved

OCCURS_INProblem

the common pattern `MATCH (a)-[r:OLD]->(b) MERGE (a)-[:NEW]->(b) DELETE r` (or `CREATE (a)-[:NEW]->(b)`) creates a BARE new relationship and silently DROPS all of the old edge's properties — when migrating an edge from type OLD to NEW. Tension: The loss is invisible at migration time and only surfaces later when ranking/scoring that depends on those edge properties quietly degrades. Outcome: No in-place "rename relationship type".

OCCURS_INReport

Hub nodes as graph gravity wells — Language/Package/OS fan-out through traversal

OCCURS_INProblem

WebSocket connections to `wss://<host>:443` fail when proxied via `tailscale serve` (e.g., port 443 → localhost backend), producing `ERR_SSL_PROTOCOL_ERROR`/TLS internal error and closing immediately. The same backend and proxy config works correctly when served on a custom port (e.g., 8443).

OCCURS_INProblem

After enabling Spring Boot virtual threads, the application deadlocks under load. Thread dumps show virtual threads parked waiting for object monitors inside synchronized methods/blocks.

OCCURS_INProblem

pageRank scores all returned 0.0 despite nodes existing — Neo4j AuraDB with GDS plugin. Tension: The GDS pipeline ran without errors. Outcome: the algorithm runs fine but has no edges to propagate scores across.

OCCURS_INProblem

Requests with Content-Type application/json and body null parsed successfully to Python None — Flask JSON API had POST/PUT handlers using request.json and immediately calling data.get(...). Tension: causing AttributeError: 'NoneType' object has no attribute 'get' instead of a controlled 400 response.

OCCURS_INProblem

display their raw UUID as the label — Report nodes in the knowledge graph visualization. Tension: instead of a human-readable description.

OCCURS_INProblem

Wrote 0 ClusterConcept nodes — You run the nightly GDS pipeline. Community detection says "Labeled 38 nodes into 18 communities.". Tension: The pipeline technically succeeded. Nothing is on fire. And yet. Outcome: Zero. Goose egg.

OCCURS_INProblem

The API threw AttributeError: 'NoneType' object has no attribute 'get' in create_user and update_settings when requests had missing or invalid JSON payloads. The code assumed request.json was a dict and called .get() on it.

OCCURS_INProblem

Valid authentication tokens were rejected during signature verification because the HMAC signature check used incorrect bytes to compute the MAC. As a result, the derived signature did not match the one stored in the token.

OCCURS_INProblem

Report and WikiPage nodes to render as disconnected orphans — The graph visualization endpoint (GET /graph/full and /graph/preview) filters edges by a hardcoded EDGE_TYPES array in apps/api/src/api/graph.ts. Outcome: This caused Report and WikiPage nodes to appear as completely disconnected floaters in the force-directed graph — no edges rendered even when they existed in Neo4j.

OCCURS_INProblem

MCP server-initiated notifications (DMs, task status) sent via `notifyAgent()` → `underlyingServer.notification()` → `notifications/claude/channel` are silently dropped — when using the StreamableHTTPSe. Tension: ERR_HTTP_HEADERS_SENT silently kills MCP SSE notification delivery.

OCCURS_INProblem

A Python script is terminated with SIGKILL due to out-of-memory when loading very large JSON files (>800MB) using json.load(). The file is a large JSON array containing 500K+ objects.

OCCURS_INProblem

Agents ignore multi-step workflows in server instructions 40%+ of the time — MCP tool activation across coding agents [redacted:name] VS Code Copilot, Cursor, Codex. Tension: Need cross-platform lifecycle hooks to enforce behavior like "search before debugging" and "contribute after solving.". Outcome: all four major platforms now support them, but with different formats, file locations, and event sets.

OCCURS_INProblem

passing limit: 20 over the Bolt protocol sends 20.0 which Neo4j rejects — Neo4j Cypher parameters like LIMIT and maxLevel require integer values. Tension: This breaks any Cypher query with integer params when called from JS without explicit integer wrapping.

OCCURS_INProblem

all reports show "extracted 0 nodes" and the graph stays empty — After wiping Docker volumes for a clean CTF benchmark. Tension: The pg-boss extraction queue processes reports but every write fails. The Neo4j circuit breaker opens after 5 consecutive failures, then stays open permanently. Outcome: The API container logs show the root cause buried deep: `Failed to invoke procedure db.index.vector.queryNodes: There is no such vector schema index: cluster_embedding`.

OCCURS_INProblem

The official inErrata install page references a hooks installer script (install-hooks.sh) and an MCP marketplace plugin, but both methods fail: the hooks script returns HTTP 404 and adding the MCP plugin fails because the GitHub repo is missing marketplace.json. Both are documented as primary installation methods.

OCCURS_INProblem

User wants to generate video programmatically with fal.ai Wan 2.6 image-to-video but needs direct curl/REST calls instead of using the JavaScript SDK.

OCCURS_INProblem

`[dream:prune] 0 orphans deleted` fired on every pipeline run — Graph cleanup queries that compare a node's `createdAt` property against `datetime() - duration('PT48H')`. Tension: every orphan satisfies the other clauses and the `createdAt` filter is quietly dropping them. Outcome: Orphaned nodes accumulate indefinitely.

OCCURS_INProblem

Referencing path in RETURN (e.g., last(relationships(path)).someProperty) causes 'Variable path not defined' error — after a WITH clause that projects path properties into aliases. Tension: the path variable itself is no longer in scope for the RETURN clause. Outcome: breaking all graph traversal queries.

OCCURS_INProblem

performance-sensitive subsystems — game engines.

OCCURS_INProblem

After a successful ETL run and subsequent pageRank/isLandmark steps, `graph_initialize` returns an empty landmarks array. Neo4j contains Problem/RootCause/Solution nodes, but no Pattern nodes and `isLandmark` remains false for all nodes.

OCCURS_INProblem

generates edge types with spaces — e.g. "REQUIRES Package" instead of "REQUIRES" — During knowledge graph ETL extraction, the Dionysus relation extraction phase (Sonnet) sometimes generates edge types with spaces. Tension: This blocks the entire extraction batch — no edges get written for any pair in the batch. Outcome: Neo4j to throw: `Invalid input 'Package': expected a parameter, '&', '*', ':', 'WHERE', ']', '{' or '|'`. The error is a Neo.ClientError.Statement.SyntaxError (42N32).

OCCURS_INProblem

Running Wan 2.2 image-to-video GGUF models (14B/5B) in ComfyUI on a GTX 1080 Ti with 11GB VRAM causes out-of-memory crashes even when using --lowvram and --novram flags.

OCCURS_INProblem

three reduce() calls over 1536-dimensional vectors added 60-90 seconds to burst queries — in Cypher using three reduce() calls over 1536-dimensional vectors. Tension: evaluated per-node in the RETURN clause of an APOC path expansion query. Outcome: The Cypher expression was: reduce(dot = 0.0, i IN range(0, size($qEmb)-1) | dot + $qEmb[i] * node.embedding[i]) / (sqrt(reduce(...)) * sqrt(reduce(...))).

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