diff --git a/CHANGELOG.md b/CHANGELOG.md
index cf4ed70..5e1ed0f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,16 @@ former name, "Daybook".)
 
 _Nothing yet._
 
+## [0.4.1] — 2026-09-05
+
+### Changed
+- Live feed updates now also keep the **source sidebar** current: as new posts
+  arrive, per-source and total unread counts bump, and a source posting for the
+  first time is added to the list (alphabetically) — all derived client-side
+  from the polled rows, no extra request. Sources added live stay
+  keyboard-navigable. Caveat: while filtered to a single source, *other* new
+  sources still only appear on reload (the poll is scoped to the selected view).
+
 ## [0.4.0] — 2026-09-04
 
 ### Added
@@ -155,7 +165,8 @@ First tagged release.
 - Dockerised (Gunicorn + whitenoise), SQLite, `git`-based deploy with a
   runbook (`deploy/cloud_agent_deploy.md`) and health check.
 
-[Unreleased]: https://git.cygnus.systems/peter/daybook/compare/v0.4.0...HEAD
+[Unreleased]: https://git.cygnus.systems/peter/daybook/compare/v0.4.1...HEAD
+[0.4.1]: https://git.cygnus.systems/peter/daybook/compare/v0.4.0...v0.4.1
 [0.4.0]: https://git.cygnus.systems/peter/daybook/compare/v0.3.2...v0.4.0
 [0.3.2]: https://git.cygnus.systems/peter/daybook/compare/v0.3.1...v0.3.2
 [0.3.1]: https://git.cygnus.systems/peter/daybook/compare/v0.3.0...v0.3.1
diff --git a/daybook_project/__init__.py b/daybook_project/__init__.py
index bc935aa..53f5709 100644
--- a/daybook_project/__init__.py
+++ b/daybook_project/__init__.py
@@ -1,4 +1,4 @@
 # Single source of truth for the app version. Bump this, commit, then tag the
 # commit `vX.Y.Z` and deploy. Surfaced on Settings -> About and in
 # GET /api/capabilities ("version").
-__version__ = "0.4.0"
+__version__ = "0.4.1"
diff --git a/templates/artifacts/feed.html b/templates/artifacts/feed.html
index a240ebc..78764fe 100644
--- a/templates/artifacts/feed.html
+++ b/templates/artifacts/feed.html
@@ -195,7 +195,8 @@
       const artifactList = document.querySelector("[data-artifact-list]");
       // Rows grow as older pages load, so always read them live rather than caching an array.
       const allRows = () => Array.from(document.querySelectorAll(".artifact-row"));
-      const sourceLinks = Array.from(document.querySelectorAll(".source-link"));
+      // Live-queried so sources added by live updates are keyboard-navigable too.
+      const sourceLinks = () => Array.from(document.querySelectorAll(".source-link"));
       const csrfToken = document.querySelector("[name=csrfmiddlewaretoken]")?.value || "";
 
       const escapeHtml = (value) => value.replace(/[&<>"]/g, (character) => ({
@@ -383,6 +384,66 @@
         });
       };
 
+      const findSourceLink = (name) =>
+        sourceLinks().find((link) => link.querySelector(".source-name")?.textContent.trim() === name);
+
+      const bumpSourceBadge = (link, delta) => {
+        let badge = link.querySelector(".source-count");
+        if (!badge) {
+          badge = document.createElement("span");
+          badge.className = "source-count";
+          badge.textContent = "0";
+          link.appendChild(badge);
+        }
+        badge.textContent = String((Number(badge.textContent) || 0) + delta);
+      };
+
+      const addSourceLink = (name, count) => {
+        const params = new URLSearchParams();
+        params.set("source", name);
+        if (feed.dataset.selectedLabel) params.set("label", feed.dataset.selectedLabel);
+        if (feed.dataset.selectedKind) params.set("kind", feed.dataset.selectedKind);
+        if (feed.dataset.titleQuery) params.set("q", feed.dataset.titleQuery);
+        params.set("view", feed.dataset.selectedView || "rendered");
+        params.set("preview", "none");
+
+        const link = document.createElement("a");
+        link.className = "source-link";
+        link.href = `?${params.toString()}`;
+        link.innerHTML =
+          `<span class="source-name">${escapeHtml(name)}</span>` +
+          `<span class="source-count">${count}</span>`;
+
+        // Insert alphabetically among the per-source links (after "All sources").
+        const list = document.querySelector(".source-list");
+        const others = sourceLinks().filter(
+          (l) => l.querySelector(".source-name")?.textContent.trim() !== "All sources",
+        );
+        const after = others.find(
+          (l) => (l.querySelector(".source-name")?.textContent.trim() || "") > name,
+        );
+        list.insertBefore(link, after || null);
+      };
+
+      // From the newly-arrived rows: bump each source's unread count (adding a
+      // sidebar entry for a source seen for the first time) plus the total.
+      const registerNewSources = (rows) => {
+        const counts = {};
+        rows.forEach((row) => {
+          const source = row.dataset.source;
+          if (source) counts[source] = (counts[source] || 0) + 1;
+        });
+        let total = 0;
+        Object.entries(counts).forEach(([source, n]) => {
+          total += n;
+          const existing = findSourceLink(source);
+          if (existing) bumpSourceBadge(existing, n);
+          else addSourceLink(source, n);
+        });
+        const allLink = findSourceLink("All sources");
+        if (allLink && total) bumpSourceBadge(allLink, total);
+      };
+
       const renderPreview = (row, pushState = true) => {
         navigationMode = "artifacts";
         markRead(row);
@@ -438,12 +499,13 @@
       };
 
       const moveSource = (direction) => {
-        if (!sourceLinks.length) return;
+        const links = sourceLinks();
+        if (!links.length) return;
         navigationMode = "sources";
         const current = document.querySelector(".source-link.selected");
-        const currentIndex = current ? sourceLinks.indexOf(current) : 0;
-        const nextIndex = Math.max(0, Math.min(sourceLinks.length - 1, currentIndex + direction));
-        const nextSource = sourceLinks[nextIndex];
+        const currentIndex = current ? links.indexOf(current) : 0;
+        const nextIndex = Math.max(0, Math.min(links.length - 1, currentIndex + direction));
+        const nextSource = links[nextIndex];
         if (nextSource && nextSource !== current) window.location.href = nextSource.href;
       };
 
@@ -623,6 +685,7 @@
             node = node.nextElementSibling;
           }
           markArrived(inserted);
+          registerNewSources(inserted);   // update sidebar: counts + any new source
           liveSince = data.newest;
           const dayCount = group.querySelector(".day-separator-count");
           if (dayCount) dayCount.textContent = String((parseInt(dayCount.textContent, 10) || 0) + data.count);