diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 44c8578..4155f17 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -12,6 +12,8 @@ jobs:
   release:
     name: Build & publish release
     runs-on: macos-15
+    outputs:
+      version: ${{ steps.version.outputs.version }}
     env:
       DEVELOPER_DIR: /Applications/Xcode.app/Contents/Developer
     steps:
@@ -68,3 +70,37 @@ jobs:
             dist/NotchBar.dmg \
             --title "NotchBar $GITHUB_REF_NAME" \
             --generate-notes
+
+  bump-cask:
+    name: Bump the Homebrew cask
+    needs: release
+    runs-on: ubuntu-latest
+    # Only needs to read this repo; every write goes to the tap through TAP_TOKEN.
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Require the tap token
+        env:
+          TAP_TOKEN: ${{ secrets.TAP_TOKEN }}
+        run: |
+          [ -n "$TAP_TOKEN" ] || {
+            echo "::error::TAP_TOKEN is unset. The cask bump needs a fine-grained PAT with contents, pull-requests and issues write access on Periicles/homebrew-tap."
+            exit 1
+          }
+
+      # The tap lives in its own repository, so GITHUB_TOKEN cannot write to it.
+      - name: Check out the tap
+        uses: actions/checkout@v5
+        with:
+          repository: Periicles/homebrew-tap
+          token: ${{ secrets.TAP_TOKEN }}
+          path: tap
+
+      # A PAT-authored PR triggers the tap's brew test-bot; a GITHUB_TOKEN one
+      # would not, and auto-merge would then have no check to wait for.
+      - name: Open the cask bump pull request
+        env:
+          GH_TOKEN: ${{ secrets.TAP_TOKEN }}
+        run: scripts/bump-cask.sh "${{ needs.release.outputs.version }}" tap
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6fcf85..cad6bc4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,16 @@ All notable changes to NotchBar are documented here.
 The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and
 NotchBar adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Changed
+
+- **Publishing a release now bumps the Homebrew cask on its own.** A `bump-cask`
+  job hashes the released `.dmg`, opens a pull request on `Periicles/homebrew-tap`
+  and turns on auto-merge, so it lands as soon as the tap's `brew test-bot` is
+  green. `brew upgrade --cask notchbar` no longer waits on a manual bump.
+- README documents how to update an existing install, per install route.
+
 ## [0.3.0] - 2026-08-15
 
 ### Added
diff --git a/README.md b/README.md
index 7db229a..9ed18e3 100644
--- a/README.md
+++ b/README.md
@@ -101,6 +101,18 @@ Nothing is piped into a shell — every step is visible above. `curl` does not s
 
 On first launch, grant Calendar access when prompted, then hover over the notch and click the settings icon to choose which calendars to track.
 
+## Updating
+
+NotchBar has no network access and does not check for new versions on its own — take the route matching how you installed it:
+
+| Installed with | Update with |
+|---|---|
+| Homebrew | `brew upgrade --cask notchbar` |
+| The one-command install | Quit NotchBar, then re-run the exact same command — it overwrites the copy in `/Applications` |
+| The `.dmg` | Quit NotchBar, download the latest `.dmg` and drag the app over the old one |
+
+The cask is bumped automatically whenever a release is published, so Homebrew is the route that asks the least of you. Your settings and calendar selection survive an update — they live in the app's container, not in the bundle — but macOS may ask for Calendar access again after the app bundle is replaced.
+
 ## Uninstall
 
 1. If you turned on **Launch at login**, hover the notch → open settings → toggle it **off** first (this removes the login item cleanly). You can also remove it later under **System Settings → General → Login Items**.
@@ -190,6 +202,14 @@ git push origin v0.3.0
 
 The version comes from the tag (`vX.Y.Z` → `X.Y.Z`) and is injected into the app at build time — no need to edit `Info.plist`. The `CFBundleShortVersionString` checked into `Supporting/Info.plist` is only a placeholder for local `swift run` builds; every packaged build overwrites it. Releases are published as stable, which is what keeps `/releases/latest/download/NotchBar.dmg` resolving — that URL skips pre-releases.
 
+Publishing a release also bumps the [Homebrew cask](https://github.com/Periicles/homebrew-tap). The `bump-cask` job computes the sha256 of the released `.dmg`, opens a pull request on the tap and turns on auto-merge, so the bump lands as soon as the tap's `brew test-bot` is green and `brew upgrade --cask notchbar` serves the new version with no manual step. It needs one repository secret:
+
+| Secret | For |
+|---|---|
+| `TAP_TOKEN` | fine-grained PAT with **contents**, **pull requests** and **issues** write access on `Periicles/homebrew-tap` |
+
+To rehearse the rewrite without pushing anything: `scripts/bump-cask.sh 0.3.0 "$(brew --repository periicles/tap)" --dry-run`.
+
 **Notarization is not planned** — it needs a paid Apple Developer ID, and the command-line install routes already avoid the Gatekeeper prompt. Kept here in case that ever changes: add these repository secrets and follow the commented hooks in `release.yml` / `scripts/package.sh`.
 
 | Secret | For |
diff --git a/scripts/bump-cask.sh b/scripts/bump-cask.sh
new file mode 100755
index 0000000..aaadc11
--- /dev/null
+++ b/scripts/bump-cask.sh
@@ -0,0 +1,106 @@
+#!/usr/bin/env bash
+# Bumps the notchbar cask in the Homebrew tap to a published release, as an
+# auto-merging pull request.
+#
+# Usage: bump-cask.sh VERSION TAP_DIR [--dry-run]
+#   VERSION   the released version, without the leading v (e.g. 0.4.0)
+#   TAP_DIR   a checkout of Periicles/homebrew-tap
+#   --dry-run rewrite the cask and print the diff, then stop before any push
+#
+# The sha256 is computed from the .dmg attached to the GitHub release, not from
+# a local build: it has to match the exact bytes Homebrew will download.
+#
+# Pushing needs a token with contents, pull-requests and issues write access on
+# the tap (CI passes TAP_TOKEN); `gh` reads it from GH_TOKEN.
+set -euo pipefail
+
+TAP_REPO="Periicles/homebrew-tap"
+CASK_PATH="Casks/notchbar.rb"
+DMG_URL_BASE="https://github.com/Periicles/Notchapp/releases/download"
+
+VERSION="${1:-}"
+TAP_DIR="${2:-}"
+DRY_RUN=""
+[ "${3:-}" = "--dry-run" ] && DRY_RUN=1
+
+if [ -z "$VERSION" ] || [ -z "$TAP_DIR" ]; then
+  sed -n '2,12p' "$0" >&2
+  exit 2
+fi
+if ! [[ "$VERSION" =~ ^[0-9]+(\.[0-9]+)+$ ]]; then
+  echo "error: '$VERSION' is not a version like 0.4.0" >&2
+  exit 2
+fi
+
+CASK="$TAP_DIR/$CASK_PATH"
+test -f "$CASK" || { echo "error: $CASK not found — is $TAP_DIR a tap checkout?" >&2; exit 2; }
+
+sha256_of() {
+  if command -v shasum >/dev/null 2>&1; then
+    shasum -a 256 "$1" | awk '{print $1}'
+  else
+    sha256sum "$1" | awk '{print $1}'
+  fi
+}
+
+DMG_URL="$DMG_URL_BASE/v$VERSION/NotchBar.dmg"
+DMG="$(mktemp -t notchbar-dmg)"
+trap 'rm -f "$DMG"' EXIT
+
+echo "==> Downloading $DMG_URL"
+curl -fsSL -o "$DMG" "$DMG_URL"
+SHA="$(sha256_of "$DMG")"
+echo "==> sha256 $SHA"
+
+CURRENT_VERSION="$(sed -n 's/^  version "\(.*\)"$/\1/p' "$CASK")"
+CURRENT_SHA="$(sed -n 's/^  sha256 "\(.*\)"$/\1/p' "$CASK")"
+if [ "$CURRENT_VERSION" = "$VERSION" ] && [ "$CURRENT_SHA" = "$SHA" ]; then
+  echo "==> Cask is already on $VERSION with a matching sha256 — nothing to do"
+  exit 0
+fi
+
+echo "==> Rewriting the cask: $CURRENT_VERSION -> $VERSION"
+sed -i.bak \
+  -e "s|^  version \".*\"$|  version \"$VERSION\"|" \
+  -e "s|^  sha256 \".*\"$|  sha256 \"$SHA\"|" \
+  "$CASK"
+rm -f "$CASK.bak"
+
+# A silent no-op sed here would open an empty PR that auto-merges into nothing.
+grep -q "^  version \"$VERSION\"$" "$CASK" || { echo "error: version line not rewritten" >&2; exit 1; }
+grep -q "^  sha256 \"$SHA\"$" "$CASK" || { echo "error: sha256 line not rewritten" >&2; exit 1; }
+
+git -C "$TAP_DIR" --no-pager diff -- "$CASK_PATH"
+
+if [ -n "$DRY_RUN" ]; then
+  echo "==> Dry run: stopping before commit"
+  exit 0
+fi
+
+BRANCH="chore/notchbar-$VERSION"
+echo "==> Pushing $BRANCH to $TAP_REPO"
+git -C "$TAP_DIR" config user.name "github-actions[bot]"
+git -C "$TAP_DIR" config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+git -C "$TAP_DIR" checkout -B "$BRANCH"
+git -C "$TAP_DIR" add "$CASK_PATH"
+git -C "$TAP_DIR" commit -m "chore(cask): notchbar $VERSION"
+# Force-push so re-running a failed release job reuses the same branch and PR.
+git -C "$TAP_DIR" push --force origin "HEAD:refs/heads/$BRANCH"
+
+PR_URL="$(gh pr list --repo "$TAP_REPO" --head "$BRANCH" --state open --json url --jq '.[0].url // empty')"
+if [ -n "$PR_URL" ]; then
+  echo "==> Reusing the open PR $PR_URL"
+else
+  echo "==> Opening the pull request"
+  PR_URL="$(gh pr create --repo "$TAP_REPO" --base main --head "$BRANCH" --assignee @me \
+    --title "chore(cask): notchbar $VERSION" \
+    --body "NotchBar $VERSION is published, so the cask has to follow — until it does, \`brew upgrade --cask notchbar\` is a no-op and Homebrew users stay on $CURRENT_VERSION.
+
+Version and sha256 come from the .dmg attached to the [v$VERSION release]($DMG_URL_BASE/v$VERSION/NotchBar.dmg), computed on the exact bytes Homebrew downloads.
+
+Verification: \`brew test-bot --only-tap-syntax\` on this PR, then \`brew upgrade --cask notchbar\`.")"
+fi
+
+echo "==> Enabling auto-merge on $PR_URL"
+gh pr merge --repo "$TAP_REPO" --auto --squash --delete-branch "$PR_URL"
+echo "==> Done: $PR_URL"