diff --git a/README.md b/README.md
index d6605cf..9cd3961 100644
--- a/README.md
+++ b/README.md
@@ -212,7 +212,7 @@ configure
 
 It covers:
 
-- **Your Federated Computer Core.** Give it your Superpanel's address (e.g. https://superpanel.example.com), your Core email, name and password, and it adds Superpanel to your applications, joins this computer to your Core's Tailscale network, adds your Nextcloud (calendar, contacts and files) and email to GNOME's Online Accounts, and mounts your Nextcloud files at /mnt/example.com ("example.com" in the Files sidebar). For Nextcloud and the files it creates a Nextcloud app password, which you can revoke in Nextcloud under Settings > Security.
+- **Your Federated Computer Core.** Give it your Superpanel's address (e.g. https://superpanel.example.com), your Core email, name and password, and it adds Superpanel to your applications, joins this computer to your Core's Tailscale network, adds your Nextcloud (calendar, contacts and files) and email to GNOME's Online Accounts, and mounts your Nextcloud files at /mnt/example.com ("example.com" in the Files sidebar), and points Element at your Core's Matrix server. For Nextcloud and the files it creates a Nextcloud app password, which you can revoke in Nextcloud under Settings > Security.
 - Signing in to Claude Code, opencode and Hermes Agent and choosing their model providers.
 
 To set up one thing, name it, e.g. `configure hermes`; `configure --list` shows the names.
diff --git a/configure.d/10-core.sh b/configure.d/10-core.sh
index 81f327b..d1b4590 100755
--- a/configure.d/10-core.sh
+++ b/configure.d/10-core.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 
 TITLE="Federated Computer Core"
-DESCRIPTION="Superpanel, Tailscale, Nextcloud, email and files"
+DESCRIPTION="Superpanel, Tailscale, Nextcloud, email, files and Element"
 
 # What you entered last time, so running this again only does what's missing
 CORE_CONF="$HOME/.config/coredesktop/core.conf"
@@ -15,6 +15,8 @@ core_names() {
   WEBDAV="$NEXTCLOUD/remote.php/dav/files/$CORE_USER"
   MOUNT="/mnt/$CORE_DOMAIN"
   SUPERPANEL_DESKTOP="$HOME/.local/share/applications/core-$CORE_DOMAIN-superpanel.desktop"
+  MATRIX="https://matrix.$CORE_DOMAIN"
+  ELEMENT_CONFIG="$HOME/.config/Element/config.json"
 }
 
 superpanel_done() {
@@ -40,10 +42,22 @@ files_done() {
   grep -qs " $MOUNT davfs " /etc/fstab && grep -qs "^$MOUNT " "$HOME/.davfs2/secrets"
 }
 
+element_installed() {
+  command -v element-desktop > /dev/null
+}
+
+# Done when Element isn't installed, as there's nothing to set up
+element_done() {
+  element_installed || return 0
+  jq -e --arg url "$MATRIX" \
+    '.default_server_config["m.homeserver"].base_url | rtrimstr("/") == $url' \
+    "$ELEMENT_CONFIG" &> /dev/null
+}
+
 is_configured() {
   [ -n "$CORE_DOMAIN" ] || return 1
   core_names
-  superpanel_done && tailscale_done && nextcloud_done && email_done && files_done
+  superpanel_done && tailscale_done && nextcloud_done && email_done && files_done && element_done
 }
 
 save_conf() {
@@ -255,6 +269,25 @@ EOF
   echo "Your Nextcloud files are at $MOUNT (\"$CORE_DOMAIN\" in the Files sidebar)."
 }
 
+# Element Desktop reads ~/.config/Element/config.json over its built-in
+# settings. Pointing it at the Core's Matrix server means you only choose
+# "Sign in" (the Core offers single sign-on through Authelia). The Core's Matrix
+# server is named after its address, matrix.<domain>, and says where its API is.
+setup_element() {
+  local base_url config
+  base_url="$(curl -sf --max-time 15 "$MATRIX/.well-known/matrix/client" \
+    | jq -r '.["m.homeserver"].base_url // empty' 2> /dev/null)"
+  base_url="${base_url:-$MATRIX}"
+
+  mkdir -p "$(dirname "$ELEMENT_CONFIG")"
+  config="$(cat "$ELEMENT_CONFIG" 2> /dev/null)"
+  [ -n "$config" ] || config='{}'
+  jq --arg url "${base_url%/}" --arg name "matrix.$CORE_DOMAIN" \
+    '.default_server_config = {"m.homeserver": {base_url: $url, server_name: $name}}' \
+    <<< "$config" > "$ELEMENT_CONFIG.tmp" && mv -f "$ELEMENT_CONFIG.tmp" "$ELEMENT_CONFIG" || return 1
+  echo "Element will use $MATRIX the next time it starts."
+}
+
 # Run a step unless it's done; a failed step doesn't stop the ones after it
 step() {
   local name="$1" title="$2"
@@ -310,6 +343,7 @@ run_configure() {
   step nextcloud "Nextcloud in Online Accounts"
   step email "Email in Online Accounts"
   step files "Nextcloud files at $MOUNT"
+  element_installed && step element "Element with your Core's Matrix server"
   unset PASSWORD APP_PASSWORD
   return $STATUS
 }