diff --git a/.github/workflows/register-keyper-releases.yml b/.github/workflows/register-keyper-releases.yml
index f27c907..b82ca3a 100644
--- a/.github/workflows/register-keyper-releases.yml
+++ b/.github/workflows/register-keyper-releases.yml
@@ -5,6 +5,7 @@ on:
     paths:
       - appcast.xml
       - scripts/sync_keyper_releases.py
+      - scripts/register_keyper_beta.py
       - .github/workflows/register-keyper-releases.yml
   push:
     branches:
@@ -12,6 +13,9 @@ on:
     paths:
       - appcast.xml
   workflow_dispatch:
+  release:
+    types:
+      - published
 
 permissions:
   contents: read
@@ -22,6 +26,7 @@ concurrency:
 
 jobs:
   validate-and-register:
+    if: github.event_name != 'release'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
@@ -35,3 +40,14 @@ jobs:
           KEYPER_RELEASE_TOKEN: ${{ secrets.KEYPER_RELEASE_TOKEN }}
           KEYPER_RELEASE_ENDPOINT: ${{ vars.KEYPER_RELEASE_ENDPOINT }}
         run: python3 scripts/sync_keyper_releases.py --appcast appcast.xml
+
+  register-v4-beta:
+    if: github.event_name == 'release' && github.event.release.prerelease && github.event.release.tag_name == 'beta'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
+      - name: Register published beta with Keyper
+        env:
+          KEYPER_RELEASE_TOKEN: ${{ secrets.KEYPER_RELEASE_TOKEN }}
+          KEYPER_RELEASE_ENDPOINT: ${{ vars.KEYPER_RELEASE_ENDPOINT }}
+        run: python3 scripts/register_keyper_beta.py
diff --git a/README.md b/README.md
index d8ea4e4..8809e6b 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,13 @@
 ExtraDock Updates
+
+# ExtraDock V4 beta registration
+
+The V4 `beta` GitHub pre-release is distributed without an appcast entry.
+Publishing it triggers `register-keyper-releases.yml`, which registers the
+release title's version (for example `B4.4.0` → `4.4.0`) with Keyper as a
+prerelease. This lets installed beta builds pass license version checks while
+the stable update target remains the latest stable appcast version. The mutable
+`beta` download URL is deliberately omitted from Keyper's release history.
+
+The release must contain `extraDock.dmg`, and the workflow requires the existing
+`KEYPER_RELEASE_TOKEN` secret for the V4 stable track.
diff --git a/scripts/register_keyper_beta.py b/scripts/register_keyper_beta.py
new file mode 100644
index 0000000..4b477c4
--- /dev/null
+++ b/scripts/register_keyper_beta.py
@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""Register the published, mutable ExtraDock V4 beta with Keyper."""
+
+from __future__ import annotations
+
+import json
+import os
+from pathlib import Path
+import re
+import sys
+import urllib.error
+import urllib.request
+from datetime import datetime
+
+
+DEFAULT_ENDPOINT = "https://keyper.appitstudio.com/api/releases"
+VERSION_RE = re.compile(r"B(4\.\d+\.\d+)$")
+
+
+def beta_payload(event: dict) -> dict[str, object]:
+    release = event["release"]
+    if event["repository"]["full_name"] != "AppitStudio/extra-dock-updates":
+        raise ValueError("Unexpected release repository")
+    if release["tag_name"] != "beta" or release["prerelease"] is not True:
+        raise ValueError("Expected the published ExtraDock V4 beta release")
+    match = VERSION_RE.fullmatch(release["name"])
+    if match is None:
+        raise ValueError("Beta release title must be B followed by a V4 version")
+    if not any(asset.get("name") == "extraDock.dmg" for asset in release["assets"]):
+        raise ValueError("Published beta release has no extraDock.dmg asset")
+    published_at = release["published_at"]
+    if not isinstance(published_at, str) or datetime.fromisoformat(
+        published_at.replace("Z", "+00:00")
+    ).tzinfo is None:
+        raise ValueError("Published beta release has no timestamp with timezone")
+
+    # The beta tag is replaced on every upload. Keep its mutable download URL
+    # out of the immutable Keyper history while allowing version checks.
+    return {
+        "version": match.group(1),
+        "released_at": published_at,
+        "is_prerelease": True,
+    }
+
+
+def register(endpoint: str, token: str, payload: dict[str, object]) -> int:
+    request = urllib.request.Request(
+        endpoint,
+        data=json.dumps(payload).encode("utf-8"),
+        method="POST",
+        headers={
+            "Accept": "application/json",
+            "Authorization": f"Bearer {token}",
+            "Content-Type": "application/json",
+            "User-Agent": "appit-updates-release-sync/1",
+        },
+    )
+    try:
+        with urllib.request.urlopen(request, timeout=30) as response:
+            return response.status
+    except urllib.error.HTTPError as error:
+        body = error.read().decode("utf-8", errors="replace")[:500]
+        raise RuntimeError(f"Keyper rejected beta with HTTP {error.code}: {body}") from error
+
+
+def main() -> int:
+    try:
+        event = json.loads(Path(os.environ["GITHUB_EVENT_PATH"]).read_text())
+        payload = beta_payload(event)
+        token = os.environ.get("KEYPER_RELEASE_TOKEN", "").strip()
+        if not token:
+            raise ValueError("KEYPER_RELEASE_TOKEN is required")
+        endpoint = os.environ.get("KEYPER_RELEASE_ENDPOINT", "").strip() or DEFAULT_ENDPOINT
+        if not endpoint.startswith("https://"):
+            raise ValueError("KEYPER_RELEASE_ENDPOINT must use HTTPS")
+        status = register(endpoint, token, payload)
+        print(f"Registered ExtraDock V4 beta {payload['version']} (HTTP {status})")
+    except (KeyError, OSError, ValueError, RuntimeError) as error:
+        print(f"error: {error}", file=sys.stderr)
+        return 1
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/scripts/test_register_keyper_beta.py b/scripts/test_register_keyper_beta.py
new file mode 100644
index 0000000..6167489
--- /dev/null
+++ b/scripts/test_register_keyper_beta.py
@@ -0,0 +1,46 @@
+import unittest
+
+from register_keyper_beta import beta_payload
+
+
+def event():
+    return {
+        "repository": {"full_name": "AppitStudio/extra-dock-updates"},
+        "release": {
+            "tag_name": "beta",
+            "prerelease": True,
+            "name": "B4.4.0",
+            "published_at": "2026-09-27T10:41:08Z",
+            "assets": [{"name": "extraDock.dmg"}],
+        },
+    }
+
+
+class BetaRegistrationTest(unittest.TestCase):
+    def test_published_beta_registers_without_mutable_download_url(self):
+        self.assertEqual(
+            beta_payload(event()),
+            {
+                "version": "4.4.0",
+                "released_at": "2026-09-27T10:41:08Z",
+                "is_prerelease": True,
+            },
+        )
+
+    def test_rejects_wrong_release_or_missing_asset(self):
+        for change in (
+            {"prerelease": False},
+            {"tag_name": "prod"},
+            {"name": "B4.4.0;echo unsafe"},
+            {"name": "B5.0.0"},
+            {"assets": []},
+        ):
+            with self.subTest(change=change):
+                payload = event()
+                payload["release"].update(change)
+                with self.assertRaises(ValueError):
+                    beta_payload(payload)
+
+
+if __name__ == "__main__":
+    unittest.main()