diff --git a/understand-anything-plugin/packages/core/src/persistence/index.ts b/understand-anything-plugin/packages/core/src/persistence/index.ts
index 56db519..cf1cab6 100644
--- a/understand-anything-plugin/packages/core/src/persistence/index.ts
+++ b/understand-anything-plugin/packages/core/src/persistence/index.ts
@@ -1,5 +1,5 @@
 import { readFileSync, writeFileSync, mkdirSync, existsSync } from "node:fs";
-import { join } from "node:path";
+import { join, isAbsolute, relative, basename } from "node:path";
 import type { KnowledgeGraph, AnalysisMeta, ProjectConfig } from "../types.js";
 import type { FingerprintStore } from "../fingerprint.js";
 import { validateGraph } from "../schema.js";
@@ -18,9 +18,68 @@ function ensureDir(projectRoot: string): string {
   return dir;
 }
 
+/**
+ * Sanitise every node's filePath before writing to disk.
+ *
+ * The analysis agent produces absolute paths like:
+ *   /Users/alice/company/src/auth.ts
+ *
+ * We convert them to paths relative to projectRoot:
+ *   src/auth.ts
+ *
+ * Three cases are handled:
+ *   1. Path is inside projectRoot      → make it relative
+ *   2. Path is absolute but outside    → keep only the filename (last segment)
+ *   3. Path is already relative        → leave it untouched
+ *
+ * This means the developer's home directory, username, and company
+ * directory layout are never written to knowledge-graph.json.
+ */
+function sanitiseFilePaths(
+  graph: KnowledgeGraph,
+  projectRoot: string,
+): KnowledgeGraph {
+  const normalRoot = projectRoot.endsWith("/")
+    ? projectRoot
+    : projectRoot + "/";
+
+  const sanitisedNodes = graph.nodes.map((node) => {
+    if (typeof node.filePath !== "string") return node;
+
+    const fp = node.filePath;
+
+    if (!isAbsolute(fp)) {
+      // Already relative — nothing to do.
+      return node;
+    }
+
+    if (fp.startsWith(normalRoot) || fp.startsWith(projectRoot)) {
+      // Inside the project root — make it relative.
+      return { ...node, filePath: relative(projectRoot, fp) };
+    }
+
+    // Absolute but outside the project root — use only the filename
+    // so we leak as little as possible.
+    return { ...node, filePath: basename(fp) };
+  });
+
+  return { ...graph, nodes: sanitisedNodes };
+}
+
 export function saveGraph(projectRoot: string, graph: KnowledgeGraph): void {
   const dir = ensureDir(projectRoot);
-  writeFileSync(join(dir, GRAPH_FILE), JSON.stringify(graph, null, 2), "utf-8");
+
+  // FIX — sanitise absolute file paths before persisting.
+  // Without this, absolute paths like /Users/alice/company/src/auth.ts
+  // are written verbatim into knowledge-graph.json and later served
+  // by the dashboard server, leaking the developer's directory layout.
+  const sanitised = sanitiseFilePaths(graph, projectRoot);
+
+  writeFileSync(
+    join(dir, GRAPH_FILE),
+    JSON.stringify(sanitised, null, 2),
+    "utf-8",
+  );
 }
 
 export function loadGraph(
diff --git a/understand-anything-plugin/packages/dashboard/src/App.tsx b/understand-anything-plugin/packages/dashboard/src/App.tsx
index 78ded8f..d4867a8 100644
--- a/understand-anything-plugin/packages/dashboard/src/App.tsx
+++ b/understand-anything-plugin/packages/dashboard/src/App.tsx
@@ -19,6 +19,13 @@ import { ThemeProvider } from "./themes/index.ts";
 import { ThemePicker } from "./components/ThemePicker.tsx";
 import type { ThemeConfig } from "./themes/index.ts";
 
+// Extract the access token from the URL so protected endpoints can be fetched.
+const ACCESS_TOKEN = new URLSearchParams(window.location.search).get("token");
+
+function tokenUrl(path: string): string {
+  return ACCESS_TOKEN ? `${path}?token=${ACCESS_TOKEN}` : path;
+}
+
 function App() {
   const graph = useDashboardStore((s) => s.graph);
   const setGraph = useDashboardStore((s) => s.setGraph);
@@ -34,7 +41,7 @@ function App() {
   const [metaTheme, setMetaTheme] = useState<ThemeConfig | null>(null);
 
   useEffect(() => {
-    fetch("/meta.json")
+    fetch(tokenUrl("/meta.json"))
       .then((r) => (r.ok ? r.json() : null))
       .then((meta) => {
         if (meta?.theme) setMetaTheme(meta.theme);
@@ -133,7 +140,7 @@ function App() {
   useKeyboardShortcuts(shortcuts);
 
   useEffect(() => {
-    fetch("/knowledge-graph.json")
+    fetch(tokenUrl("/knowledge-graph.json"))
       .then((res) => res.json())
       .then((data: unknown) => {
         const result = validateGraph(data);
@@ -162,7 +169,7 @@ function App() {
   }, [setGraph]);
 
   useEffect(() => {
-    fetch("/diff-overlay.json")
+    fetch(tokenUrl("/diff-overlay.json"))
       .then((res) => {
         if (!res.ok) return null;
         return res.json();
diff --git a/understand-anything-plugin/packages/dashboard/vite.config.ts b/understand-anything-plugin/packages/dashboard/vite.config.ts
index aa60f93..cd43a83 100644
--- a/understand-anything-plugin/packages/dashboard/vite.config.ts
+++ b/understand-anything-plugin/packages/dashboard/vite.config.ts
@@ -3,8 +3,21 @@ import react from "@vitejs/plugin-react";
 import tailwindcss from "@tailwindcss/vite";
 import path from "path";
 import fs from "fs";
+import crypto from "crypto";
+
+// Generate a one-time token when the server process starts.
+// This token is printed to the terminal and must be in the URL
+// to fetch knowledge-graph.json or diff-overlay.json.
+const ACCESS_TOKEN = crypto.randomBytes(16).toString("hex");
 
 export default defineConfig({
+  // FIX 1 — bind only to localhost, not 0.0.0.0
+  // This blocks access from any other device on the same LAN / WiFi.
+  server: {
+    host: "127.0.0.1",
+    port: 5173,
+  },
+
   resolve: {
     alias: {
       "@understand-anything/core/schema": path.resolve(__dirname, "../core/dist/schema.js"),
@@ -12,53 +25,119 @@ export default defineConfig({
       "@understand-anything/core/types": path.resolve(__dirname, "../core/dist/types.js"),
     },
   },
+
   plugins: [
     react(),
     tailwindcss(),
     {
       name: "serve-knowledge-graph",
       configureServer(server) {
+        // Print the access URL once so the developer can open it.
+        server.httpServer?.once("listening", () => {
+          console.log(
+            `\n  🔑  Dashboard URL: http://127.0.0.1:5173?token=${ACCESS_TOKEN}\n`
+          );
+        });
+
         server.middlewares.use((req, res, next) => {
-          if (req.url === "/knowledge-graph.json") {
-            // GRAPH_DIR env var points to the project being analyzed
-            // Falls back to monorepo root, then public/ (demo)
-            const graphDir = process.env.GRAPH_DIR;
-            const candidates = [
-              ...(graphDir
-                ? [path.resolve(graphDir, ".understand-anything/knowledge-graph.json")]
-                : []),
-              path.resolve(process.cwd(), ".understand-anything/knowledge-graph.json"),
-              path.resolve(process.cwd(), "../../../.understand-anything/knowledge-graph.json"),
-            ];
-            for (const candidate of candidates) {
-              if (fs.existsSync(candidate)) {
-                res.setHeader("Content-Type", "application/json");
-                fs.createReadStream(candidate).pipe(res);
-                return;
-              }
-            }
-          }
-          if (req.url === "/diff-overlay.json") {
-            const graphDir = process.env.GRAPH_DIR;
-            const candidates = [
-              ...(graphDir
-                ? [path.resolve(graphDir, ".understand-anything/diff-overlay.json")]
-                : []),
-              path.resolve(process.cwd(), ".understand-anything/diff-overlay.json"),
-              path.resolve(process.cwd(), "../../../.understand-anything/diff-overlay.json"),
-            ];
-            for (const candidate of candidates) {
-              if (fs.existsSync(candidate)) {
-                res.setHeader("Content-Type", "application/json");
-                fs.createReadStream(candidate).pipe(res);
-                return;
-              }
-            }
-            res.statusCode = 404;
-            res.end();
+          const url = new URL(req.url ?? "/", "http://127.0.0.1:5173");
+          const pathname = url.pathname;
+          const isProtectedEndpoint =
+            pathname === "/knowledge-graph.json" ||
+            pathname === "/diff-overlay.json" ||
+            pathname === "/meta.json";
+
+          if (!isProtectedEndpoint) {
+            next();
             return;
           }
-          next();
+
+          // FIX 3 — require the one-time token on all data endpoints.
+          // Requests without a matching ?token= get a 403.
+          if (url.searchParams.get("token") !== ACCESS_TOKEN) {
+            res.statusCode = 403;
+            res.setHeader("Content-Type", "application/json");
+            res.end(JSON.stringify({ error: "Forbidden: missing or invalid token" }));
+            return;
+          }
+
+          const fileName =
+            pathname === "/diff-overlay.json"
+              ? "diff-overlay.json"
+              : pathname === "/meta.json"
+              ? "meta.json"
+              : "knowledge-graph.json";
+
+          const graphDir = process.env.GRAPH_DIR;
+          const candidates = [
+            ...(graphDir
+              ? [path.resolve(graphDir, `.understand-anything/${fileName}`)]
+              : []),
+            path.resolve(process.cwd(), `.understand-anything/${fileName}`),
+            path.resolve(
+              process.cwd(),
+              `../../../.understand-anything/${fileName}`
+            ),
+          ];
+
+          for (const candidate of candidates) {
+            if (!fs.existsSync(candidate)) continue;
+
+            // FIX 2 — sanitise absolute file paths before sending the JSON.
+            // Nodes can contain filePath values like /Users/alice/company/src/auth.ts.
+            // We convert those to relative paths (src/auth.ts) so the developer's
+            // home directory and company directory layout are not leaked.
+            try {
+              const raw = JSON.parse(fs.readFileSync(candidate, "utf-8")) as {
+                nodes?: Array<Record<string, unknown>>;
+                [key: string]: unknown;
+              };
+
+              // Derive the project root from the candidate path so we can
+              // make file paths relative to it.
+              const projectRoot = path.dirname(
+                candidate.replace(
+                  `${path.sep}.understand-anything${path.sep}${fileName}`,
+                  ""
+                )
+              );
+
+              if (Array.isArray(raw.nodes)) {
+                raw.nodes = raw.nodes.map((node) => {
+                  if (typeof node.filePath !== "string") return node;
+                  const abs = node.filePath;
+                  // Only relativise paths that actually sit inside projectRoot.
+                  // Leave external or already-relative paths untouched.
+                  const rel = abs.startsWith(projectRoot)
+                    ? abs.slice(projectRoot.length).replace(/^[\\/]/, "")
+                    : path.isAbsolute(abs)
+                    ? path.basename(abs) // absolute but outside root — use filename only
+                    : abs;              // already relative — keep as-is
+                  return { ...node, filePath: rel };
+                });
+              }
+
+              res.setHeader("Content-Type", "application/json");
+              res.end(JSON.stringify(raw));
+            } catch (err) {
+              // If we cannot parse or sanitise the file, refuse to serve it
+              // rather than accidentally leaking raw content.
+              console.error("[understand-anything] Failed to sanitise graph file:", err);
+              res.statusCode = 500;
+              res.setHeader("Content-Type", "application/json");
+              res.end(JSON.stringify({ error: "Failed to read graph file" }));
+            }
+            return;
+          }
+
+          // No matching file found on disk.
+          res.statusCode = 404;
+          if (pathname === "/knowledge-graph.json") {
+            res.setHeader("Content-Type", "application/json");
+            res.end(JSON.stringify({ error: "No knowledge graph found. Run /understand first." }));
+          } else {
+            res.end();
+          }
         });
       },
     },
diff --git a/understand-anything-plugin/skills/understand-dashboard/SKILL.md b/understand-anything-plugin/skills/understand-dashboard/SKILL.md
index e0614d7..4c20dbb 100644
--- a/understand-anything-plugin/skills/understand-dashboard/SKILL.md
+++ b/understand-anything-plugin/skills/understand-dashboard/SKILL.md
@@ -56,7 +56,7 @@ Start the Understand Anything dashboard to visualize the knowledge graph for the
 
 5. Start the Vite dev server pointing at the project's knowledge graph:
    ```bash
-   cd <dashboard-dir> && GRAPH_DIR=<project-dir> npx vite --open
+   cd <dashboard-dir> && GRAPH_DIR=<project-dir> npx vite --host 127.0.0.1 --open
    ```
    Run this in the background so the user can continue working.