Pond knowledge graph view (#112)

/p/:pondSlug/graph (static segment ranked above :pageSlug, same
documented reserved-slug gap as trash/settings) renders the pond's
readable wikilink graph from GET /ponds/:id/links: pages as nodes
colored by their first label (legend included, DEFAULT_LABEL_COLOR for
unlabeled), resolved links as edges, phantom targets as dashed nodes —
clicking one offers to create the page, which resolves its links.

Rendering is a self-contained SVG force graph: only d3-force is
bundled (no d3 DOM/zoom modules, zero external requests); the layout
runs synchronously to rest, zoom/pan/node-drag are plain pointer math.
SVG over canvas deliberately — every node carries a data-testid the
e2e packs can click. Ponds beyond 500 pages get a capped-view notice.

Sidebar footer links every member to the graph (trash stays
owner-only). New i18n namespace graph (de+en).

Verified live: nodes/edges/legend render, node click opens the page,
phantom click creates it and the node turns solid.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web/package.json

@@ -25,6 +25,7 @@
     "@tiptap/extension-collaboration-caret": "^3.27.1",
     "@tiptap/pm": "^3.27.1",
     "@tiptap/react": "^3.27.1",
+    "d3-force": "^3.0.0",
     "i18next": "^26.3.4",
     "i18next-browser-languagedetector": "^8.2.1",
     "lucide-react": "^1.24.0",
@@ -42,6 +43,7 @@
   },
   "devDependencies": {
     "@playwright/test": "^1.61.1",
+    "@types/d3-force": "^3.0.10",
     "@types/react": "^19.0.0",
     "@types/react-dom": "^19.0.0",
     "@vitejs/plugin-react": "^4.3.0",

apps/web/src/App.tsx

@@ -2,6 +2,7 @@ import { useEffect, useState } from 'react';
 import { Navigate, Route, Routes } from 'react-router-dom';
 
 import { RequireAnonymous, RequireAuth, RequireSiteAdmin } from './auth/guards';
+import { PondGraphPage } from './graph/PondGraphPage';
 import { MAINTENANCE_EVENT } from './lib/api';
 import { MaintenancePage } from './pages/MaintenancePage';
 import { AppLayout } from './layout/AppLayout';
@@ -90,6 +91,8 @@ export function App(): React.JSX.Element {
           <Route path="p/:pondSlug/trash" element={<TrashPage />} />
           {/* Static "settings" wins over :pageSlug, like "trash" above. */}
           <Route path="p/:pondSlug/settings" element={<PondSettingsPage />} />
+          {/* Static "graph" wins over :pageSlug, like "trash" above (#112). */}
+          <Route path="p/:pondSlug/graph" element={<PondGraphPage />} />
           <Route path="p/:pondSlug/:pageSlug" element={<PageEditorPage />} />
         </Route>
         <Route element={<RequireSiteAdmin />}>

apps/web/src/graph/ForceGraph.tsx

@@ -0,0 +1,227 @@
+import {
+  forceCenter,
+  forceCollide,
+  forceLink,
+  forceManyBody,
+  forceSimulation,
+  type SimulationLinkDatum,
+  type SimulationNodeDatum,
+} from 'd3-force';
+import { useMemo, useRef, useState } from 'react';
+
+/**
+ * Self-contained SVG force graph (issue #112). Only `d3-force` is bundled —
+ * no d3 DOM/zoom modules, no external requests: layout runs synchronously
+ * (deterministic phyllotaxis seed), zoom/pan/drag are plain pointer math.
+ * SVG over canvas deliberately: nodes carry data-testids, so the e2e packs
+ * can click them. Shared by the pond graph view and the local panel (#113).
+ */
+
+export interface ForceGraphNode {
+  /** Stable id — page id or a `phantom:<slug>` key. */
+  id: string;
+  label: string;
+  color: string;
+  /** Phantom targets render dashed and muted. */
+  dashed?: boolean;
+  /** The current page in the local graph gets a highlight ring. */
+  highlight?: boolean;
+  /** Hooks the e2e packs click on. */
+  testId: string;
+}
+
+export interface ForceGraphEdge {
+  from: string;
+  to: string;
+}
+
+interface LayoutNode extends SimulationNodeDatum {
+  id: string;
+}
+
+const TICKS = 250;
+const MIN_ZOOM = 0.2;
+const MAX_ZOOM = 5;
+
+/** Runs the force layout to rest and returns node positions keyed by id. */
+function layout(
+  nodeIds: string[],
+  edges: ForceGraphEdge[],
+  width: number,
+  height: number,
+): Map<string, { x: number; y: number }> {
+  const nodes: LayoutNode[] = nodeIds.map((id) => ({ id }));
+  const links: SimulationLinkDatum<LayoutNode>[] = edges.map((edge) => ({
+    source: edge.from,
+    target: edge.to,
+  }));
+  const simulation = forceSimulation(nodes)
+    .force('charge', forceManyBody().strength(-160))
+    .force(
+      'link',
+      forceLink<LayoutNode, SimulationLinkDatum<LayoutNode>>(links)
+        .id((node) => node.id)
+        .distance(70),
+    )
+    .force('center', forceCenter(0, 0))
+    .force('collide', forceCollide(22))
+    .stop();
+  simulation.tick(TICKS);
+  // Keep the resting layout inside the viewBox for typical pond sizes.
+  const scale = Math.min(
+    1,
+    ...nodes.map((n) =>
+      Math.min(Math.abs((width / 2 - 30) / (n.x || 1)), Math.abs((height / 2 - 30) / (n.y || 1))),
+    ),
+  );
+  return new Map(nodes.map((n) => [n.id, { x: (n.x ?? 0) * scale, y: (n.y ?? 0) * scale }]));
+}
+
+export function ForceGraph({
+  nodes,
+  edges,
+  width = 800,
+  height = 560,
+  onNodeClick,
+}: {
+  nodes: ForceGraphNode[];
+  edges: ForceGraphEdge[];
+  width?: number;
+  height?: number;
+  onNodeClick?: (id: string) => void;
+}): React.JSX.Element {
+  // Callers memoize nodes/edges (they come from query-derived useMemos), so
+  // the layout runs only when the graph's structure actually changes.
+  const basePositions = useMemo(
+    () =>
+      layout(
+        nodes.map((n) => n.id),
+        edges,
+        width,
+        height,
+      ),
+    [nodes, edges, width, height],
+  );
+  /** Manual node drags overlay the computed layout. */
+  const [moved, setMoved] = useState<Map<string, { x: number; y: number }>>(new Map());
+  const [view, setView] = useState({ k: 1, tx: 0, ty: 0 });
+  const drag = useRef<
+    | { kind: 'pan'; startX: number; startY: number; tx: number; ty: number }
+    | { kind: 'node'; id: string; startX: number; startY: number; x: number; y: number }
+    | null
+  >(null);
+  const dragged = useRef(false);
+
+  const positionOf = (id: string): { x: number; y: number } =>
+    moved.get(id) ?? basePositions.get(id) ?? { x: 0, y: 0 };
+
+  function onWheel(event: React.WheelEvent<SVGSVGElement>): void {
+    const factor = Math.exp(-event.deltaY * 0.002);
+    setView((prev) => {
+      const k = Math.min(MAX_ZOOM, Math.max(MIN_ZOOM, prev.k * factor));
+      return { ...prev, k };
+    });
+  }
+
+  function onPointerDown(event: React.PointerEvent<SVGSVGElement>): void {
+    event.currentTarget.setPointerCapture(event.pointerId);
+    dragged.current = false;
+    const nodeId = (event.target as Element)
+      .closest('[data-node-id]')
+      ?.getAttribute('data-node-id');
+    if (nodeId) {
+      const pos = positionOf(nodeId);
+      drag.current = {
+        kind: 'node',
+        id: nodeId,
+        startX: event.clientX,
+        startY: event.clientY,
+        ...pos,
+      };
+    } else {
+      drag.current = {
+        kind: 'pan',
+        startX: event.clientX,
+        startY: event.clientY,
+        tx: view.tx,
+        ty: view.ty,
+      };
+    }
+  }
+
+  function onPointerMove(event: React.PointerEvent<SVGSVGElement>): void {
+    const current = drag.current;
+    if (!current) return;
+    const dx = event.clientX - current.startX;
+    const dy = event.clientY - current.startY;
+    if (Math.abs(dx) + Math.abs(dy) > 3) dragged.current = true;
+    if (current.kind === 'pan') {
+      setView((prev) => ({ ...prev, tx: current.tx + dx, ty: current.ty + dy }));
+    } else {
+      const next = { x: current.x + dx / view.k, y: current.y + dy / view.k };
+      setMoved((prev) => new Map(prev).set(current.id, next));
+    }
+  }
+
+  function onPointerUp(event: React.PointerEvent<SVGSVGElement>): void {
+    const current = drag.current;
+    drag.current = null;
+    // A click (no real drag) on a node opens it.
+    if (current?.kind === 'node' && !dragged.current) onNodeClick?.(current.id);
+    event.currentTarget.releasePointerCapture(event.pointerId);
+  }
+
+  return (
+    <svg
+      className="force-graph"
+      viewBox={`${-width / 2} ${-height / 2} ${width} ${height}`}
+      role="img"
+      onWheel={onWheel}
+      onPointerDown={onPointerDown}
+      onPointerMove={onPointerMove}
+      onPointerUp={onPointerUp}
+    >
+      <g transform={`translate(${view.tx} ${view.ty}) scale(${view.k})`}>
+        {edges.map((edge) => {
+          const from = positionOf(edge.from);
+          const to = positionOf(edge.to);
+          return (
+            <line
+              key={`${edge.from}→${edge.to}`}
+              className="force-graph__edge"
+              x1={from.x}
+              y1={from.y}
+              x2={to.x}
+              y2={to.y}
+            />
+          );
+        })}
+        {nodes.map((node) => {
+          const pos = positionOf(node.id);
+          return (
+            <g
+              key={node.id}
+              className={
+                node.dashed ? 'force-graph__node force-graph__node--phantom' : 'force-graph__node'
+              }
+              transform={`translate(${pos.x} ${pos.y})`}
+              data-node-id={node.id}
+              data-testid={node.testId}
+            >
+              {node.highlight && <circle className="force-graph__ring" r={13} />}
+              <circle
+                className="force-graph__dot"
+                r={8}
+                fill={node.dashed ? 'transparent' : node.color}
+                stroke={node.color}
+              />
+              <text className="force-graph__label" y={22} textAnchor="middle">
+                {node.label}
+              </text>
+            </g>
+          );
+        })}
+      </g>
+    </svg>
+  );
+}

apps/web/src/graph/PondGraphPage.tsx

@@ -0,0 +1,151 @@
+import type { PageView, PondGraphView, PondView } from '@dorfteich/shared';
+import { DEFAULT_LABEL_COLOR } from '@dorfteich/shared';
+import { useQuery, useQueryClient } from '@tanstack/react-query';
+import { useMemo } from 'react';
+import { useTranslation } from 'react-i18next';
+import { useNavigate, useParams } from 'react-router-dom';
+
+import { FormError } from '../components/forms';
+import { usePondLabels } from '../labels/use-pond-labels';
+import { apiGet, apiPost } from '../lib/api';
+import { ForceGraph, type ForceGraphEdge, type ForceGraphNode } from './ForceGraph';
+
+/** Above this the layout cost stops being worth it — show a notice instead
+ * (issue #112; ponds do not realistically reach it). */
+const MAX_GRAPH_NODES = 500;
+
+const PHANTOM_PREFIX = 'phantom:';
+
+/**
+ * The pond's knowledge graph (issue #112): readable pages as nodes, resolved
+ * wikilinks as edges, phantom targets as dashed nodes (click → create the
+ * page, which resolves the links, #47). Nodes are colored by their first
+ * label; the legend lists the colors in use.
+ */
+export function PondGraphPage(): React.JSX.Element {
+  const { t } = useTranslation('graph');
+  const { pondSlug = '' } = useParams<{ pondSlug: string }>();
+  const navigate = useNavigate();
+  const queryClient = useQueryClient();
+
+  const pond = useQuery({
+    queryKey: ['pond', pondSlug],
+    queryFn: () => apiGet<PondView>(`/ponds/${pondSlug}`),
+  });
+  const graph = useQuery({
+    queryKey: ['pond-links', pond.data?.id],
+    queryFn: () => apiGet<PondGraphView>(`/ponds/${pond.data!.id}/links`),
+    enabled: Boolean(pond.data),
+  });
+  const { byId } = usePondLabels(pond.data?.id);
+
+  const slugById = useMemo(
+    () => new Map((graph.data?.nodes ?? []).map((node) => [node.id, node.slug])),
+    [graph.data],
+  );
+
+  const { nodes, edges, legend } = useMemo(() => {
+    const data = graph.data;
+    if (!data) {
+      return { nodes: [] as ForceGraphNode[], edges: [] as ForceGraphEdge[], legend: [] };
+    }
+    const usedLabelIds = new Set<string>();
+    let hasUnlabeled = false;
+    const nodes: ForceGraphNode[] = data.nodes.map((node) => {
+      const label = node.labelIds.map((id) => byId.get(id)).find(Boolean);
+      if (label) usedLabelIds.add(label.id);
+      else hasUnlabeled = true;
+      return {
+        id: node.id,
+        label: node.title,
+        color: label?.color ?? DEFAULT_LABEL_COLOR,
+        testId: `graph-node-${node.slug}`,
+      };
+    });
+    const edges: ForceGraphEdge[] = data.edges.map((edge) => ({
+      from: edge.from,
+      to: edge.to,
+    }));
+    for (const phantom of data.phantoms) {
+      const id = `${PHANTOM_PREFIX}${phantom.targetSlug}`;
+      nodes.push({
+        id,
+        label: phantom.targetSlug,
+        color: DEFAULT_LABEL_COLOR,
+        dashed: true,
+        testId: `graph-phantom-${phantom.targetSlug}`,
+      });
+      for (const referrer of phantom.referencedBy) edges.push({ from: referrer, to: id });
+    }
+    const legend = [...usedLabelIds]
+      .map((id) => byId.get(id)!)
+      .sort((a, b) => a.name.localeCompare(b.name))
+      .map((label) => ({ name: label.name, color: label.color }));
+    if (hasUnlabeled) legend.push({ name: t('unlabeled'), color: DEFAULT_LABEL_COLOR });
+    return { nodes, edges, legend };
+  }, [graph.data, byId, t]);
+
+  async function onNodeClick(id: string): Promise<void> {
+    if (id.startsWith(PHANTOM_PREFIX)) {
+      const slug = id.slice(PHANTOM_PREFIX.length);
+      if (!window.confirm(t('createPhantom', { slug }))) return;
+      // Title = the slug, so the generated slug matches and the links resolve.
+      const page = await apiPost<PageView>(`/ponds/${pond.data!.id}/pages`, { title: slug });
+      await queryClient.invalidateQueries({ queryKey: ['pond-links', pond.data!.id] });
+      await queryClient.invalidateQueries({ queryKey: ['pages', pond.data!.id] });
+      navigate(`/p/${pondSlug}/${page.slug}`);
+      return;
+    }
+    const slug = slugById.get(id);
+    if (slug) navigate(`/p/${pondSlug}/${slug}`);
+  }
+
+  if (pond.error) return <FormError error={pond.error} />;
+  if (graph.error) return <FormError error={graph.error} />;
+  if (!pond.data || !graph.data) return <></>;
+
+  const pageCount = graph.data.nodes.length;
+
+  return (
+    <div className="graph-page">
+      <header className="graph-page__header">
+        <h1>
+          {t('title')} — {pond.data.name}
+        </h1>
+        <p className="graph-page__counts">
+          {t('counts', { pages: pageCount, links: graph.data.edges.length })}
+        </p>
+      </header>
+      {pageCount === 0 ? (
+        <p className="graph-page__hint">{t('empty')}</p>
+      ) : pageCount > MAX_GRAPH_NODES ? (
+        <p className="graph-page__hint">{t('tooLarge', { max: MAX_GRAPH_NODES })}</p>
+      ) : (
+        <>
+          <p className="graph-page__hint">{t('hint')}</p>
+          <div className="graph-page__canvas">
+            <ForceGraph nodes={nodes} edges={edges} onNodeClick={(id) => void onNodeClick(id)} />
+          </div>
+          <footer className="graph-legend" aria-label={t('legend')}>
+            {legend.map((entry) => (
+              <span key={entry.name} className="graph-legend__entry">
+                <span
+                  className="label-chip__swatch"
+                  style={{ backgroundColor: entry.color }}
+                  aria-hidden
+                />
+                {entry.name}
+              </span>
+            ))}
+            {graph.data.phantoms.length > 0 && (
+              <span className="graph-legend__entry graph-legend__entry--phantom">
+                <span className="graph-legend__phantom-swatch" aria-hidden />
+                {t('phantomLegend')}
+              </span>
+            )}
+          </footer>
+        </>
+      )}
+    </div>
+  );
+}

apps/web/src/i18n/index.ts

@@ -7,6 +7,7 @@ import deErrors from '@dorfteich/shared/i18n/de/errors.json';
 import deExport from '@dorfteich/shared/i18n/de/export.json';
 import deFiles from '@dorfteich/shared/i18n/de/files.json';
 import deFont from '@dorfteich/shared/i18n/de/font.json';
+import deGraph from '@dorfteich/shared/i18n/de/graph.json';
 import deImport from '@dorfteich/shared/i18n/de/import.json';
 import deLabels from '@dorfteich/shared/i18n/de/labels.json';
 import deLegal from '@dorfteich/shared/i18n/de/legal.json';
@@ -32,6 +33,7 @@ import enErrors from '@dorfteich/shared/i18n/en/errors.json';
 import enExport from '@dorfteich/shared/i18n/en/export.json';
 import enFiles from '@dorfteich/shared/i18n/en/files.json';
 import enFont from '@dorfteich/shared/i18n/en/font.json';
+import enGraph from '@dorfteich/shared/i18n/en/graph.json';
 import enImport from '@dorfteich/shared/i18n/en/import.json';
 import enLabels from '@dorfteich/shared/i18n/en/labels.json';
 import enLegal from '@dorfteich/shared/i18n/en/legal.json';
@@ -74,6 +76,7 @@ void i18n
         export: enExport,
         files: enFiles,
         font: enFont,
+        graph: enGraph,
         import: enImport,
         labels: enLabels,
         legal: enLegal,
@@ -101,6 +104,7 @@ void i18n
         export: deExport,
         files: deFiles,
         font: deFont,
+        graph: deGraph,
         import: deImport,
         labels: deLabels,
         legal: deLegal,

apps/web/src/layout/Sidebar.tsx

@@ -357,15 +357,19 @@ function SidebarContent({
         {announcement}
       </p>
 
-      {/* The trash stays a text link, pinned to the sidebar's bottom
+      {/* Graph + trash stay text links, pinned to the sidebar's bottom
-          (M10 follow-up; pond settings moved to the TopBar gear icon). */}
+          (M10 follow-up; pond settings moved to the TopBar gear icon).
-      {isOwner && (
+          The graph is for every member (#112); the trash is owner-only. */}
       <div className="sidebar__footer">
+        <Link to={`/p/${pondSlug}/graph`} className="linklike sidebar__graph-link">
+          {t('graph:link')}
+        </Link>
+        {isOwner && (
           <Link to={`/p/${pondSlug}/trash`} className="linklike sidebar__trash-link">
             {t('editor:trash.link')}
           </Link>
-        </div>
         )}
+      </div>
     </>
   );
 }

apps/web/src/styles/base.css

@@ -1728,6 +1728,104 @@ button {
 .sidebar__footer {
   margin-top: auto;
   padding-top: var(--space-4);
+  display: flex;
+  gap: var(--space-3);
+}
+
+.sidebar__graph-link {
+  font-size: 0.85rem;
+  white-space: nowrap;
+}
+
+/* Knowledge graph (issue #112) + local graph panel (#113). */
+.graph-page__header {
+  display: flex;
+  align-items: baseline;
+  gap: var(--space-3);
+  flex-wrap: wrap;
+}
+
+.graph-page__counts {
+  margin: 0;
+  color: var(--color-text-muted);
+  font-size: 0.9rem;
+}
+
+.graph-page__hint {
+  color: var(--color-text-muted);
+  font-size: 0.9rem;
+}
+
+.graph-page__canvas {
+  border: 1px solid var(--color-border);
+  border-radius: var(--radius);
+  background: var(--color-surface);
+  overflow: hidden;
+}
+
+.force-graph {
+  display: block;
+  width: 100%;
+  height: auto;
+  touch-action: none;
+  cursor: grab;
+}
+
+.force-graph__edge {
+  stroke: var(--color-border);
+  stroke-width: 1.2;
+}
+
+.force-graph__node {
+  cursor: pointer;
+}
+
+.force-graph__dot {
+  stroke-width: 2;
+}
+
+.force-graph__node--phantom .force-graph__dot {
+  stroke-dasharray: 3 3;
+}
+
+.force-graph__node--phantom .force-graph__label {
+  fill: var(--color-text-muted);
+  font-style: italic;
+}
+
+.force-graph__ring {
+  fill: none;
+  stroke: var(--color-accent);
+  stroke-width: 2;
+}
+
+.force-graph__label {
+  font-size: 11px;
+  fill: var(--color-text);
+  pointer-events: none;
+  user-select: none;
+}
+
+.graph-legend {
+  display: flex;
+  flex-wrap: wrap;
+  gap: var(--space-3);
+  margin-top: var(--space-3);
+  font-size: 0.85rem;
+  color: var(--color-text-muted);
+}
+
+.graph-legend__entry {
+  display: inline-flex;
+  align-items: center;
+  gap: var(--space-1);
+}
+
+.graph-legend__phantom-swatch {
+  width: 0.8rem;
+  height: 0.8rem;
+  border-radius: 50%;
+  border: 2px dashed var(--color-text-muted);
 }
 
 /* Pond settings page + label manager. */

packages/shared/i18n/de/graph.json

@@ -0,0 +1,15 @@
+{
+  "title": "Wissensgraph",
+  "link": "Graph",
+  "hint": "Klick öffnet die Seite, Ziehen ordnet Knoten an, Scrollen zoomt.",
+  "counts": "{{pages}} Seiten · {{links}} Verknüpfungen",
+  "empty": "Noch keine Seiten — der Graph erscheint, sobald Seiten aufeinander verweisen.",
+  "tooLarge": "Dieser Teich hat mehr als {{max}} Seiten — die Graph-Ansicht ist begrenzt.",
+  "legend": "Labels",
+  "unlabeled": "Ohne Label",
+  "phantomLegend": "Fehlende Seite (Wikilink-Ziel)",
+  "createPhantom": "Seite „{{slug}}“ anlegen? Die darauf zeigenden Wikilinks werden aufgelöst.",
+  "localTitle": "Lokaler Graph",
+  "localDepth1": "Direkte Nachbarn",
+  "localDepth2": "Zwei Ebenen"
+}

packages/shared/i18n/en/graph.json

@@ -0,0 +1,15 @@
+{
+  "title": "Knowledge graph",
+  "link": "Graph",
+  "hint": "Click a page to open it, drag nodes to rearrange, scroll to zoom.",
+  "counts": "{{pages}} pages · {{links}} links",
+  "empty": "No pages yet — the graph appears once pages link to each other.",
+  "tooLarge": "This pond has more than {{max}} pages — the graph view is capped.",
+  "legend": "Labels",
+  "unlabeled": "No label",
+  "phantomLegend": "Missing page (wikilink target)",
+  "createPhantom": "Create the page “{{slug}}”? The wikilinks pointing at it will resolve.",
+  "localTitle": "Local graph",
+  "localDepth1": "Direct neighbors",
+  "localDepth2": "Two hops"
+}

pnpm-lock.yaml

@@ -287,6 +287,9 @@ importers:
       '@tiptap/react':
         specifier: ^3.27.1
         version: 3.27.1(@floating-ui/dom@1.7.6)(@tiptap/core@3.27.1(@tiptap/pm@3.27.1))(@tiptap/pm@3.27.1)(@types/react-dom@19.2.3(@types/react@19.2.17))(@types/react@19.2.17)(react-dom@19.2.7(react@19.2.7))(react@19.2.7)
+      d3-force:
+        specifier: ^3.0.0
+        version: 3.0.0
       i18next:
         specifier: ^26.3.4
         version: 26.3.4(typescript@5.9.3)
@@ -333,6 +336,9 @@ importers:
       '@playwright/test':
         specifier: ^1.61.1
         version: 1.61.1
+      '@types/d3-force':
+        specifier: ^3.0.10
+        version: 3.0.10
       '@types/react':
         specifier: ^19.0.0
         version: 19.2.17