neo4j-nvl-skill
Neo4j Visualization Library (NVL) — framework-agnostic graph rendering for the browser. Covers @neo4j-nvl/base (NVL class, nodes/relationships, Canvas vs WebGL renderer), @neo4j-nvl/interaction-handlers (ZoomInteraction, PanInteraction, DragNodeInteraction, ClickInteraction, HoverInteraction, BoxSel
By neo4j-contrib · 437 installs
npx skills add neo4j-contrib/neo4j-skills --skill neo4j-nvl-skill
Source repository · Upstream listing
When to Use
Rendering a Neo4j graph in a browser (vanilla JS, React, Vite) with custom interactions, rendering, or data shapes
Visualizing driver.executeQuery results as an interactive graph
Wiring zoom, pan, drag, click, hover, lasso, or box select interactions
Embedding NVL inside an existing app and synchronizing graph state
When NOT to Use
Pre styled embedded graph view with default behavior, no custom interactions → GraphVisualization from @neo4j ndl/react (Neo4j Needle / NDL design system) — wraps NVL with default Neo4j styling. See [Use NVL or the Needle Component?]( use nvl or the needle component) below.
Python / Jupyter notebook graph visualization → neo4j/python graph visualization (the Python port of NVL)
Writing/optimizing Cypher → neo4j cypher skill
Driver setup / executeQuery / sessions → neo4j driver javascript skill
Server side data fetching with no rendering → neo4j driver javascript skill
GDS algorithm execution → neo4j gds skill or neo4j aura graph analytics skill
GraphQL API → neo4j graphql skill
Use NVL or the Needle Component?
Need Use
Embed a graph view with default Neo4j styling, no custom interactions or rendering GraphVisualization from @neo4j ndl/react (Neo4j Needle / NDL design system) — wraps NVL and accepts records shaped { id, labels, properties: { key: { stringified, type } } } ( NeoNode )
Custom interactions, custom rendering, non standard data shapes, or framework agnostic embedding This skill — use NVL directly
If the answer is the first row, install and use the Needle component instead of NVL — do not duplicate styling work.
Install
Peer requirements: React 19 for @neo4j nvl/react . The published peerDependency range still permits React 18, but mixing major versions is not recommended — target 19. @neo4j nvl/layout workers is a transitive dependency — never install directly. neo4j driver is a peer of @neo4j nvl/base only when using nvlResultTransformer .
Starter templates: https://github.com/neo4j devtools/nvl boilerplates — official per framework scaffolds; prefer these over hand rolled setups.
License: NVL ships under the Neo4j Visualization Library License — for use with Neo4j products only. Cannot be used against other graph backends.
Pick the Right Paradigm
Need Use
React app, default interactions <InteractiveNvlWrapper from @neo4j nvl/react
React app, custom interaction wiring <BasicNvlWrapper + own handlers via ref
Vanilla JS, standard interactions NVL + @neo4j nvl/interaction handlers
Vanilla JS, fully custom event logic NVL + container.addEventListener + nvl.getHits()
Static PNG/SVG image export <StaticPictureWrapper or nvl.saveToFile() / nvl.saveToSvg()
Pick the Right Renderer
Renderer Max nodes Detail Use case
'canvas' (default) ~1,000 Full captions, icons, arrows, pixel perfect hit testing Detail investigation, small graphs
'webgl' 100,000+ Reduced label fidelity (bound by GPU max texture size) Large scale pattern exploration
Container Setup
The container must have an explicit width AND height . Missing height → container collapses to 0 → graph invisible. Most reported NVL bug.
Vanilla — Base Library
With options + callbacks:
NVL constructor signature: new NVL(frame, nvlNodes?, nvlRels?, options?, callbacks?) . All but frame are optional and default to empty.
Vanilla — Interaction Handlers
Compose handlers onto an existing NVL instance. Each handler registers callbacks via .updateCallback(name, fn) and must be torn down with .destroy() .
Disable an event without removing the handler: click.removeCallback('onCanvasClick') . Passing true instead of a function enables the event with a no op (useful for default selection behavior).
React — InteractiveNvlWrapper
Pre wires every interaction handler. Toggle events with mouseEventCallbacks (function = on + callback; true = on, no op; false /omit = off).
ref resolves to the underlying NVL instance — call any method on it: nvlRef.current?.fit([]) , nvlRef.current?.setRenderer('webgl') , nvlRef.current?.saveToFile() .
React — BasicNvlWrapper + Ref
No interactions wired. The ref exposes every NVL method via IncludeMethods<NVL — use when building custom interaction logic in React.
Wiring a Neo4j Driver Result
@neo4j nvl/base exports a ResultTransformer for the JS driver that deduplicates nodes/relationships across any record shape.
For driver lifecycle, session management, Integer handling, and TypeScript types → neo4j driver javascript skill .
Updating the Graph
Method Behavior
addAndUpdateElementsInGraph(nodes, rels) Insert new; update existing by id (only specified fields)
updateElementsInGraph(nodes, rels) Update existing only; ignores unknown ids
addElementsToGraph(nodes, rels) Insert only; throws on existing id
removeNodesWithIds(ids) Remove nodes; adjacent relationships auto removed
removeRelationshipsWithIds(ids) Remove relationships
setNodePositions(nodes, updateLayout?) Override positions; optionally re run layout
restart(options?, retainPositions?) Restart with new options; positions optional
Diff updates use PartialNode / PartialRelationship — only id is required:
Hit Testing (Manual)
Use when NOT using the interaction handlers package. getHits() resolves which node/relationship is under a pointer event.
HitTargetNode / HitTargetRelationship carry data , pointerCoordinates , distance , insideNode (nodes only). See [references/api surface.md](references/api surface.md).
Common Mistakes
Mistake Fix
Container with no height → invisible graph Set explicit width and height on the container
Pass driver.executeQuery result directly Use nvlResultTransformer and consume { nodes, relationships }
WebGL for small label rich graphs Use 'canvas' ; labels are fully supported
Canvas for 10k+ nodes Switch to 'webgl' via renderer option or setRenderer
New NVL per React render Use <InteractiveNvlWrapper / <BasicNvlWrapper or wrap in useEffect + destroy()
Forgetting nvl.destroy() on teardown Call destroy() on unmount; React wrappers handle this automatically
Vanilla handlers not torn down Call .destroy() on every interaction before nvl.destroy()
Worker construction blocked (strict CSP / sandboxed runtime / older bundler) nvlOptions: { disableWebWorkers: true } (NVL has a non worker fallback)
Telemetry enabled in regulated env nvlOptions: { disableTelemetry: true }
Layout never settles Pin anchor nodes with pinNode(id) ; tune layoutTimeLimit
selectOnClick fires double Toggle once at mount; don't flip interactionOptions per render
Hit test misses near node edge Pass { hitNodeMarginWidth: N } to getHits
Captions missing on WebGL GPU max texture size exceeded; fall back to Canvas or shrink captions
References
Load on demand:
[references/api surface.md](references/api surface.md) — complete NVL method table; Node , Relationship , NvlOptions , LayoutOptions , ExternalCallbacks , HitTargets , NvlMouseEvent , StyledCaption , Point ; every interaction handler class + its options + its callback signatures; React <InteractiveNvlWrapper / <BasicNvlWrapper / <StaticPictureWrapper props; MouseEventCallbacks and KeyboardEventCallbacks shapes; named exports inventory; nvlResultTransformer signature
[references/troubleshooting.md](references/troubleshooting.md) — zero height container, build tool agnostic disableWebWorkers fallback, Canvas/WebGL trade offs + WebGL2 note, WebGL texture size cap, onWebGLContextLost recovery, telemetry opt out, memory leaks, stuck layouts, double selection, hit margin tuning, license restriction
Canonical web documentation (use WebFetch when references above are insufficient):
https://neo4j.com/docs/nvl/current/ — user guide (installation, base library, interaction handlers, React wrappers)
https://neo4j.com/docs/api/nvl/current/ — TypeDoc API reference
https://neo4j.com/docs/api/nvl/current/examples.html — runnable examples
https://github.com/neo4j devtools/nvl boilerplates — official starter templates per supported framework
https://github.com/neo4j/python graph visualization — Python port of NVL (use this skill only for the JavaScript/browser path)
Checklist
[ ] Container has explicit width AND height CSS
[ ] Correct paradigm chosen from the decision table (vanilla / handlers / React)
[ ] Renderer matches expected node count (Canvas ≲1k / WebGL 100k+)
[ ] Driver executeQuery results piped through nvlResultTransformer
[ ] database specified on every executeQuery call (delegate to neo4j driver javascript skill )
[ ] All interaction handlers .destroy() ed before nvl.destroy() on teardown
[ ] nvl.destroy() called on React unmount (manual instances only — wrappers handle it)
[ ] disableTelemetry: true set when in regulated / offline environments
[ ] disableWebWorkers: true set when bundler / CSP blocks worker construction
[ ] Graph updates use addAndUpdateElementsInGraph / updateElementsInGraph — not restart
[ ] License compatible: target is a Neo4j product