diff --git a/app/static/index.html b/app/static/index.html
index db4fb01..0226c13 100644
--- a/app/static/index.html
+++ b/app/static/index.html
@@ -1905,9 +1905,7 @@ async function initMap() {
         L.control.zoom({ position: 'topright' }).addTo(map);
         map.attributionControl.setPrefix('');
         let activeHls = null;
-        map.on('popupopen', (e) => {
-            if (activeHls) { try { activeHls.destroy(); } catch (_) {} activeHls = null; }
-            const root = e.popup.getElement();
+        const startHlsFrom = (root) => {
             const v = root && root.querySelector('video[data-hls]');
             if (!v) return;
             const fallback = () => {
@@ -1935,6 +1933,25 @@ async function initMap() {
             };
             if (window.Hls) startHls();
             else loadHls().then(startHls).catch(fallback);
+        };
+        map.on('popupopen', (e) => {
+            if (activeHls) { try { activeHls.destroy(); } catch (_) {} activeHls = null; }
+            const root = e.popup.getElement();
+            const box = root && root.querySelector('.cam-pop[data-cam-id]');
+            if (box && box.dataset.loaded !== '1') {
+                fetch(`${API}/api/cameras/${box.dataset.camId}`)
+                    .then(r => { if (!r.ok) throw new Error('camera detail'); return r.json(); })
+                    .then(c => {
+                        box.outerHTML = camPopupHtml(c);
+                        startHlsFrom(e.popup.getElement());
+                    })
+                    .catch(() => {
+                        const ph = box.querySelector('.thumb.placeholder');
+                        if (ph) ph.textContent = 'preview unavailable';
+                    });
+                return;
+            }
+            startHlsFrom(root);
         });
         map.on('popupclose', () => {
             if (activeHls) { try { activeHls.destroy(); } catch (_) {} activeHls = null; }
@@ -2305,6 +2322,20 @@ function camThumb(c) {
     );
     return `<img class="thumb" src="${first}" alt="camera preview" loading="lazy" onerror="${onerr}">`;
 }
+function camPopupHtml(c) {
+    return `<div class="cam-pop" data-cam-id="${esc(c.id)}" data-loaded="1">` +
+        `<b>${esc(c.location_name || 'Open camera')}</b>` +
+        `${c.id ? camThumb(c) : '<div class="thumb placeholder">no snapshot</div>'}` +
+        `<table>` +
+        `<tr><td class="k">Vendor</td><td>${esc(c.vendor || '?')} ${esc(c.device_type || '')}</td></tr>` +
+        `<tr><td class="k">Source</td><td>${esc(c.discovery_source || '?')}</td></tr>` +
+        `<tr><td class="k">First seen</td><td>${esc((c.first_seen||'').slice(0,16).replace('T',' '))}</td></tr>` +
+        `<tr><td class="k">Last seen</td><td>${esc((c.last_seen||'').slice(0,16).replace('T',' '))}</td></tr>` +
+        `<tr><td class="k">Coords</td><td>${(c.lat!=null&&c.lon!=null) ? c.lat.toFixed(3)+', '+c.lon.toFixed(3) : 'unknown'}</td></tr>` +
+        `</table>` +
+        camSourceLink(c) +
+        `</div>`;
+}
 async function loadCams() {
     if (!map) return;
     if (tooZoomedOut()) {
@@ -2340,18 +2371,9 @@ async function loadCams() {
                 iconSize: [12, 12], iconAnchor: [6, 6],
             });
             camsGroup.addLayer(L.marker([c.lat, c.lon], { icon })
-                .bindPopup(() => `<div class="cam-pop">` +
+                .bindPopup(() => `<div class="cam-pop" data-cam-id="${esc(c.id)}">` +
                     `<b>${esc(c.location_name || 'Open camera')}</b>` +
-                    `${c.id ? camThumb(c) : '<div class="thumb placeholder">no snapshot</div>'}` +
-                    `<table>` +
-                    `<tr><td class="k">Vendor</td><td>${esc(c.vendor || '?')} ${esc(c.device_type || '')}</td></tr>` +
-                    `<tr><td class="k">Source</td><td>${esc(c.discovery_source || '?')}</td></tr>` +
-                    `<tr><td class="k">First seen</td><td>${esc((c.first_seen||'').slice(0,16).replace('T',' '))}</td></tr>` +
-                    `<tr><td class="k">Last seen</td><td>${esc((c.last_seen||'').slice(0,16).replace('T',' '))}</td></tr>` +
-                    `<tr><td class="k">Coords</td><td>${(c.lat!=null&&c.lon!=null) ? c.lat.toFixed(3)+', '+c.lon.toFixed(3) : 'unknown'}</td></tr>` +
-                    `</table>` +
-                    camSourceLink(c) +
-                    `</div>`));
+                    `<div class="thumb placeholder">loading feed…</div></div>`));
         });
         camsGroup.addTo(map);
         camsGroup.eachLayer(l => l.setOpacity && l.setOpacity(camsOpacity));
diff --git a/tests/test_camera_popup_contract.py b/tests/test_camera_popup_contract.py
new file mode 100644
index 0000000..42f1bce
--- /dev/null
+++ b/tests/test_camera_popup_contract.py
@@ -0,0 +1,15 @@
+"""Camera list is slim (no URLs). Popup must fetch GET /api/cameras/{id}."""
+
+from pathlib import Path
+
+HTML = Path(__file__).resolve().parents[1] / "app/static/index.html"
+
+
+def test_popupopen_fetches_camera_detail_row():
+    html = HTML.read_text()
+    start = html.index("map.on('popupopen'")
+    end = html.index("map.on('popupclose'")
+    block = html[start:end]
+    assert "fetch(" in block
+    assert "/api/cameras/" in block
+    assert "camPopupHtml(" in block