diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e63f8ea..1243803 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,6 +18,8 @@ jobs:
           node-version: 22
       - name: Build UI
         run: cd ui && npm ci && npm run build
+      - name: UI unit tests
+        run: cd ui && npm test
       - name: cargo test
         run: cargo test --workspace --release
   fmt:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 04afe6a..8f53349 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## Unreleased
+
+- Web UI maps human librarium URLs (`/projects/…/doc.md`) to the entries
+  browser instead of sending unknown paths to the library root.
+
 ## 0.1.7 - 2026-05-11
 
 Authentication, concurrency, and operator tooling release.
diff --git a/tests/test_webui_selenium.py b/tests/test_webui_selenium.py
index ef0d591..d4060a0 100644
--- a/tests/test_webui_selenium.py
+++ b/tests/test_webui_selenium.py
@@ -373,6 +373,43 @@ def test_spa_deep_link_not_404(selenium_driver, tabularium_base_url):
     assert "404" not in selenium_driver.title.lower()
 
 
+def test_spa_librarium_abs_path_opens_document(selenium_driver, tabularium_base_url):
+    slug = uuid.uuid4().hex[:8]
+    name = f"pretty_{slug}"
+    mkdir(tabularium_base_url, name)
+    base = tabularium_base_url.rstrip("/")
+    marker = f"pretty-open-{slug}"
+    requests.post(
+        f"{base}/api/doc/{name}",
+        json={"name": "tracker.md", "content": f"# {marker}\n"},
+        timeout=15,
+    ).raise_for_status()
+    selenium_driver.get(f"{base}/{name}/tracker.md")
+    _wait_app_ready(selenium_driver)
+    _wait(selenium_driver).until(lambda d: "open=" in d.current_url)
+    assert f"/entries/{name}" in selenium_driver.current_url
+    _wait(selenium_driver).until(
+        EC.text_to_be_present_in_element(
+            (By.CSS_SELECTOR, "[data-testid='preview-pane']"),
+            marker,
+        ),
+    )
+
+
+def test_spa_librarium_abs_path_opens_directory(
+    selenium_driver, tabularium_base_url, seed_dir: str,
+):
+    selenium_driver.get(f"{tabularium_base_url.rstrip('/')}/{seed_dir}")
+    _wait_app_ready(selenium_driver)
+    _wait(selenium_driver).until(
+        EC.text_to_be_present_in_element(
+            (By.CSS_SELECTOR, "[data-testid='entries-path']"),
+            f"/{seed_dir}",
+        ),
+    )
+    assert "open=" not in selenium_driver.current_url
+
+
 # --- Group E — infrastructure ---
 
 
diff --git a/ui/eslint.config.js b/ui/eslint.config.js
index 5e6b472..094f19b 100644
--- a/ui/eslint.config.js
+++ b/ui/eslint.config.js
@@ -20,4 +20,10 @@ export default defineConfig([
       globals: globals.browser,
     },
   },
+  {
+    files: ['**/*.test.ts'],
+    languageOptions: {
+      globals: globals.node,
+    },
+  },
 ])
diff --git a/ui/package.json b/ui/package.json
index 1643f8e..574a323 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -6,6 +6,7 @@
   "scripts": {
     "dev": "vite",
     "build": "tsc -b && vite build",
+    "test": "node --experimental-strip-types --test src/features/entries/entriesPath.test.ts",
     "lint": "eslint .",
     "preview": "vite preview"
   },
diff --git a/ui/src/App.tsx b/ui/src/App.tsx
index 09f3c84..126d5ef 100644
--- a/ui/src/App.tsx
+++ b/ui/src/App.tsx
@@ -1,11 +1,28 @@
 import { lazy, Suspense } from "react";
-import { BrowserRouter, Navigate, Route, Routes } from "react-router-dom";
+import {
+  BrowserRouter,
+  Navigate,
+  Route,
+  Routes,
+  useLocation,
+} from "react-router-dom";
 import { AppShell } from "./app/AppShell";
 import { AuthShell } from "./app/AuthShell";
+import { entriesUrlFromLibrariumPathname } from "./features/entries/entriesPath";
 import { EntriesView } from "./features/entries/EntriesView";
 
 const StatsView = lazy(() => import("./features/stats/StatsView"));
 
+function LibrariumPathRedirect() {
+  const { pathname, hash } = useLocation();
+  return (
+    <Navigate
+      to={`${entriesUrlFromLibrariumPathname(pathname)}${hash}`}
+      replace
+    />
+  );
+}
+
 export default function App() {
   return (
     <BrowserRouter>
@@ -22,7 +39,7 @@ export default function App() {
                 </Suspense>
               }
             />
-            <Route path="*" element={<Navigate to="/entries" replace />} />
+            <Route path="*" element={<LibrariumPathRedirect />} />
           </Route>
         </Route>
       </Routes>
diff --git a/ui/src/features/entries/entriesPath.test.ts b/ui/src/features/entries/entriesPath.test.ts
new file mode 100644
index 0000000..05f43b1
--- /dev/null
+++ b/ui/src/features/entries/entriesPath.test.ts
@@ -0,0 +1,37 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { entriesUrlFromLibrariumPathname } from "./entriesPath.ts";
+
+test("opens a nested markdown path as preview, not entries root", () => {
+  assert.equal(
+    entriesUrlFromLibrariumPathname(
+      "/projects/turret/design/sas-architecture-tracker.md",
+    ),
+    "/entries/projects/turret/design?open=%2Fprojects%2Fturret%2Fdesign%2Fsas-architecture-tracker.md",
+  );
+});
+
+test("opens a root-level document", () => {
+  assert.equal(
+    entriesUrlFromLibrariumPathname("/notes.md"),
+    "/entries?open=%2Fnotes.md",
+  );
+});
+
+test("treats a path without a file suffix as a directory", () => {
+  assert.equal(
+    entriesUrlFromLibrariumPathname("/projects/turret/design"),
+    "/entries/projects/turret/design",
+  );
+});
+
+test("maps empty path to entries root", () => {
+  assert.equal(entriesUrlFromLibrariumPathname("/"), "/entries");
+});
+
+test("opens a hidden file as preview", () => {
+  assert.equal(
+    entriesUrlFromLibrariumPathname("/secrets/.gitignore"),
+    "/entries/secrets?open=%2Fsecrets%2F.gitignore",
+  );
+});
diff --git a/ui/src/features/entries/entriesPath.ts b/ui/src/features/entries/entriesPath.ts
index 6fd3986..79313dd 100644
--- a/ui/src/features/entries/entriesPath.ts
+++ b/ui/src/features/entries/entriesPath.ts
@@ -1,20 +1,14 @@
 /**
  * Browser routes for the entries browser — `/entries` + optional path segments.
  * Optional `?open=` holds absolute document path for preview + refresh (Enginseer / Ferrum).
+ * Human links may omit `/entries` (`/projects/…/doc.md`); those map via
+ * `entriesUrlFromLibrariumPathname`.
  */
 
 const PREFIX = "/entries";
 
-/** Librarium dir path from location (always a directory in the URL). */
-export function dirPathFromEntriesLocation(pathname: string): string {
-  if (pathname === PREFIX || pathname === `${PREFIX}/`) {
-    return "/";
-  }
-  if (!pathname.startsWith(`${PREFIX}/`)) {
-    return "/";
-  }
-  const rest = pathname.slice(PREFIX.length + 1);
-  const segments = rest
+function decodePathSegments(pathname: string): string[] {
+  return pathname
     .split("/")
     .filter(Boolean)
     .map((s) => {
@@ -24,6 +18,31 @@ export function dirPathFromEntriesLocation(pathname: string): string {
         return s;
       }
     });
+}
+
+function absFromPathname(pathname: string): string {
+  const segments = decodePathSegments(pathname);
+  return segments.length === 0 ? "/" : `/${segments.join("/")}`;
+}
+
+/** Last segment looks like a file name (`notes.md`, `.gitignore`), not `.` / `..`. */
+function looksLikeDocumentName(name: string): boolean {
+  if (name === "." || name === "..") {
+    return false;
+  }
+  return name.includes(".");
+}
+
+/** Librarium dir path from location (always a directory in the URL). */
+export function dirPathFromEntriesLocation(pathname: string): string {
+  if (pathname === PREFIX || pathname === `${PREFIX}/`) {
+    return "/";
+  }
+  if (!pathname.startsWith(`${PREFIX}/`)) {
+    return "/";
+  }
+  const rest = pathname.slice(PREFIX.length + 1);
+  const segments = decodePathSegments(rest);
   return `/${segments.join("/")}`;
 }
 
@@ -51,3 +70,21 @@ export function withOpenDocQuery(
   q.set("open", docAbsolutePath);
   return `${path}?${q.toString()}`;
 }
+
+/**
+ * Maps a human librarium URL (`/projects/…/doc.md`) to the entries browser route.
+ * Last path segment containing `.` is treated as a document; otherwise a directory.
+ */
+export function entriesUrlFromLibrariumPathname(pathname: string): string {
+  const abs = absFromPathname(pathname);
+  if (abs === "/") {
+    return PREFIX;
+  }
+  const slash = abs.lastIndexOf("/");
+  const name = abs.slice(slash + 1);
+  if (looksLikeDocumentName(name)) {
+    const dirPath = slash <= 0 ? "/" : abs.slice(0, slash);
+    return withOpenDocQuery(dirPath, abs);
+  }
+  return entriesPathForDir(abs);
+}
diff --git a/ui/tsconfig.app.json b/ui/tsconfig.app.json
index af516fc..160e659 100644
--- a/ui/tsconfig.app.json
+++ b/ui/tsconfig.app.json
@@ -24,5 +24,6 @@
     "noFallthroughCasesInSwitch": true,
     "noUncheckedSideEffectImports": true
   },
-  "include": ["src"]
+  "include": ["src"],
+  "exclude": ["src/**/*.test.ts"]
 }