diff --git a/.gitea/workflows/build-deb.yml b/.gitea/workflows/build-deb.yml
index 1254890..c7b155e 100644
--- a/.gitea/workflows/build-deb.yml
+++ b/.gitea/workflows/build-deb.yml
@@ -149,10 +149,32 @@ jobs:
             "$api/releases/$id/assets?name=$name" >/dev/null
           echo "release $TAG: $GITEA_URL/$REPO/releases/tag/$TAG"
 
+  deploy:
+    name: Deploy to CT 126
+    runs-on: ubuntu-latest
+    needs: [build]
+    if: startsWith(github.ref, 'refs/tags/v')
+    steps:
+      # CT 126's webhook listener runs /usr/lib/devdesk/devdesk-deploy, which
+      # waits for this version in the apt registry and upgrades the package.
+      - name: Trigger devdesk-deploy webhook
+        env:
+          WEBHOOK_SECRET: ${{ secrets.WEBHOOK_SECRET }}
+          GIT_REF: ${{ github.ref }}
+        run: |
+          PAYLOAD="{\"ref\":\"${GIT_REF}\"}"
+          SIG=$(echo -n "$PAYLOAD" | openssl dgst -sha256 -hmac "$WEBHOOK_SECRET" | awk '{print $2}')
+          curl -sf --connect-timeout 10 \
+            -X POST \
+            -H "Content-Type: application/json" \
+            -H "X-Gitea-Signature: ${SIG}" \
+            -d "$PAYLOAD" \
+            "http://10.10.10.58:9000/hooks/devdesk-deploy"
+
   notify-failure:
     name: Notify on failure
     runs-on: ubuntu-latest
-    needs: [build]
+    needs: [build, deploy]
     if: failure() && github.event_name == 'push'
     steps:
       - name: Send Matrix alert
diff --git a/Makefile b/Makefile
index 63ae6a9..804cd46 100644
--- a/Makefile
+++ b/Makefile
@@ -39,7 +39,8 @@ install: all
 	install -m 0755 bin/devdesk $(DESTDIR)$(PREFIX)/bin/devdesk
 	install -m 0644 libexec/devdesk-lib.sh $(DESTDIR)$(LIBDIR)/devdesk-lib.sh
 	install -m 0755 libexec/devdesk-picker libexec/devdesk-claude-run libexec/devdesk-session-hook \
-		libexec/devdesk-tmux-ready libexec/devdesk-serve libexec/devdesk-statusline $(DESTDIR)$(LIBDIR)/
+		libexec/devdesk-tmux-ready libexec/devdesk-serve libexec/devdesk-statusline \
+		libexec/devdesk-deploy $(DESTDIR)$(LIBDIR)/
 	install -m 0755 build/ttyd $(DESTDIR)$(LIBDIR)/bin/ttyd
 	install -m 0644 dist/index.html share/tmux.conf share/claude-settings.json $(DESTDIR)$(SHAREDIR)/
 	install -m 0644 etc/env $(DESTDIR)$(SYSCONFDIR)/devdesk/env
diff --git a/README.md b/README.md
index 7b2ec1d..ce8c4b0 100644
--- a/README.md
+++ b/README.md
@@ -71,8 +71,8 @@ apt install ../devdesk_*_amd64.deb
 
 CI (`.gitea/workflows/build-deb.yml`):
 - Every push lints, tests, builds and smoke-tests the package and uploads it as an artifact.
-- A `v*` tag also publishes to `https://code.lotusguild.org/api/packages/LotusGuild/debian` and creates a release.
+- A `v*` tag also publishes to `https://code.lotusguild.org/api/packages/LotusGuild/debian`, creates a release, and auto-deploys to CT 126. A signed webhook runs `devdesk-deploy`, which upgrades the package; see [docs/DEPLOY.md](docs/DEPLOY.md).
 
 ## Roadmap
-- **v1.1:** `devdesk-api` sidecar for the Repo/CI panel, Matrix notifications when you're away, and auto-deploy.
+- **Next:** Matrix notifications when you're away (needs the Ci-Alert hookshot URL).
 - **v2:** Ops Alerts (Grafana) with "Ask Claude" prompts, and file drop.
diff --git a/debian/changelog b/debian/changelog
index a7a9235..a84cad3 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+devdesk (0.3.1) bookworm; urgency=medium
+
+  * Auto-deploy: tagged releases trigger CT 126's webhook listener (house HMAC
+    pattern), which runs /usr/lib/devdesk/devdesk-deploy to upgrade the
+    package from the apt registry. Running sessions are untouched.
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Wed, 07 Oct 2026 13:20:58 -0400
+
 devdesk (0.3.0) bookworm; urgency=medium
 
   * Repo / CI panel is live: branch, ahead/behind, uncommitted changes, the
diff --git a/docs/DEPLOY.md b/docs/DEPLOY.md
index 3af2d22..5493cb4 100644
--- a/docs/DEPLOY.md
+++ b/docs/DEPLOY.md
@@ -36,7 +36,30 @@ Then run `authelia validate-config --config /etc/authelia/configuration.yml && s
 - **Cloudflare:** add a CNAME `dev` → apex, DNS-only (grey cloud).
 - **Pi-hole:** add `"10.10.10.27 dev.lotusguild.org"` to `dns.hosts` in `pve-infra/containers/163-pihole/etc/pihole/pihole.toml`. A push auto-deploys it, and LAN clients then reach NPM directly instead of hairpinning.
 
-## 5. Optional hardening
+## 5. Auto-deploy on release
+A `v*` tag makes CI publish the package, then send a signed webhook (the house HMAC pattern) to CT 126's existing `webhook` listener on :9000. The listener runs `/usr/lib/devdesk/devdesk-deploy <ref>`, which waits for that version in the apt registry and upgrades only `devdesk` with `--force-confold`. Running Claude sessions are untouched. The log is `/var/log/devdesk-deploy.log`.
+
+**Setup, done once:**
+1. Generate a secret.
+2. Add this hook to `/etc/webhook/hooks.json`, next to `126-config-deploy`. The file is local and untracked because it holds secrets.
+   ```json
+   {
+     "id": "devdesk-deploy",
+     "execute-command": "/usr/lib/devdesk/devdesk-deploy",
+     "command-working-directory": "/",
+     "pass-arguments-to-command": [{"source": "payload", "name": "ref"}],
+     "trigger-rule": {"and": [
+       {"match": {"type": "payload-hash-sha256", "secret": "<WEBHOOK_SECRET>",
+                  "parameter": {"source": "header", "name": "X-Gitea-Signature"}}},
+       {"match": {"type": "regex", "regex": "^refs/tags/v[0-9]+\\.[0-9]+\\.[0-9]+$",
+                  "parameter": {"source": "payload", "name": "ref"}}}
+     ]}
+   }
+   ```
+3. Run `systemctl restart webhook`.
+4. Store the same secret as the devdesk repo's Actions secret `WEBHOOK_SECRET`.
+
+## 6. Optional hardening
 Enable the Proxmox firewall on CT 126 (`firewall=1` on net0) and allow tcp/7681 only from 10.10.10.27. The same rule suits code-server on :8680.
 
 ## Operations
diff --git a/libexec/devdesk-deploy b/libexec/devdesk-deploy
new file mode 100755
index 0000000..da4aca2
--- /dev/null
+++ b/libexec/devdesk-deploy
@@ -0,0 +1,54 @@
+#!/bin/bash
+# Upgrade DevDesk from the LotusGuild apt registry. Run by the host's webhook
+# listener (hook "devdesk-deploy") when CI publishes a v* tag; the tag's ref is
+# passed as $1. Safe for running sessions: package upgrades restart only
+# devdesk.service (ttyd), never devdesk-tmux.service where Claude lives.
+set -euo pipefail
+
+LOG=${DEVDESK_DEPLOY_LOG:-/var/log/devdesk-deploy.log}
+SOURCES=${DEVDESK_APT_SOURCES:-sources.list.d/lotusguild.list}
+
+log() {
+    printf '%s %s\n' "$(date '+%F %T')" "$*" >>"$LOG"
+}
+
+exec 9>/run/devdesk-deploy.lock
+flock -w 900 9 || {
+    log "another deploy is still running; giving up"
+    exit 1
+}
+
+want=${1:-}
+want=${want#refs/tags/}
+want=${want#v}
+before=$(dpkg-query -W -f='${Version}' devdesk 2>/dev/null || echo none)
+log "=== deploy: installed $before, release ${want:-latest}"
+
+refresh() {
+    apt-get update -q -o Dir::Etc::sourcelist="$SOURCES" -o Dir::Etc::sourceparts=- \
+        -o APT::Get::List-Cleanup=0 >>"$LOG" 2>&1
+}
+
+# The registry can lag the release by a few seconds: wait for the tagged version.
+candidate=""
+for _ in $(seq 1 18); do
+    refresh || true
+    candidate=$(apt-cache policy devdesk | awk '/Candidate:/ {print $2}')
+    if [ -z "$want" ] || [ "$candidate" = "$want" ]; then
+        break
+    fi
+    sleep 10
+done
+
+if [ -n "$want" ] && [ "$candidate" != "$want" ]; then
+    log "registry still offers $candidate, not $want; giving up"
+    exit 1
+fi
+if [ "$candidate" = "$before" ]; then
+    log "already at $before; nothing to do"
+    exit 0
+fi
+
+DEBIAN_FRONTEND=noninteractive apt-get install -y -q --only-upgrade \
+    -o Dpkg::Options::=--force-confold devdesk </dev/null >>"$LOG" 2>&1
+log "devdesk $before -> $(dpkg-query -W -f='${Version}' devdesk)"