diff --git a/README.md b/README.md
index 45bd46a..82ea6db 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 MCP server for [Family Wall](https://www.familywall.com) -- read and manage your family's circles, lists, and tasks directly from Claude.
 
-## Features (v0.4.4)
+## Features (v0.4.5)
 
 ### Read
 
diff --git a/SPEC.md b/SPEC.md
index a87cf7b..c7ea6b8 100644
--- a/SPEC.md
+++ b/SPEC.md
@@ -266,7 +266,7 @@ mit `{"a00": {"un": {"un": {"message": "missing value in: id"}}}}` auf Top-Level
 → wird vom fw_client fälschlich als Erfolg interpretiert. Daher ist der korrekte Parameter-Name
 kritisch.
 
-### `wallmood` – Wall-Post liken / unliken
+### `wallmood` – Wall-Post liken
 POST https://api.familywall.com/api/wallmood
 Content-Type: application/x-www-form-urlencoded
 
@@ -278,9 +278,26 @@ Content-Type: application/x-www-form-urlencoded
 | `moodType` | ja | `"STAR"` (einziger bekannter Wert — entspricht dem Like-Button in der App) |
 
 **Verhalten (verifiziert):**
-- Toggle-Mechanismus: gleicher Call zum Liken und Unliken
-- Erster Aufruf → Like setzen, zweiter Aufruf → Like entfernen
-- `moodType: "LIKE"` wurde als `"STAR"` serverseitig gespeichert → korrekter Wert ist `"STAR"`
+- `wallmood` mit `moodType: "STAR"` ist eine **idempotente SET-Operation** — kein Toggle!
+- Mehrfaches Aufrufen mit denselben Parametern hinterlässt denselben Zustand
+- `moodType: "LIKE"` wurde serverseitig als `"STAR"` gespeichert → korrekter Wert ist `"STAR"`
+- Nur für Post-Typ `STATUS` wirksam; `FAMILY_CREATED` und vermutlich System-Posts ignorieren den Call
+
+**Unlike – nicht implementierbar (Stand: April 2026):**
+
+Ausgiebig getestete Ansätze, die alle fehlschlugen:
+
+| Ansatz | Ergebnis |
+|---|---|
+| `moodType: "NONE"` / `"REMOVE"` / `"DELETE"` / `""` | moodMap unverändert |
+| `moodType` ganz weglassen | moodMap unverändert |
+| `moodStarShortcut: "false"` als Parameter | moodMap unverändert |
+| Alternative Endpoints: `wallmooddelete`, `wallmoodremove`, `wallmoodelete`, `wallunmood`, `wallcommentdelete`, `wallmoodstar`, `wallstar`, `wallreact`, `wallreactdelete` | alle: `"The call X is not registered"` (502) |
+| `metadelete` auf Mood-Comment-ID | löscht den Comment, aber `moodStarShortcut` bleibt gesetzt |
+
+Die Web-App nutzt einen Service Worker, der Requests abfängt — der echte Unlike-Payload
+ist dadurch nicht per Browser-DevTools inspizierbar. Unlike bleibt bis zur weiteren
+Analyse nicht unterstützt.
 
 **Response-Struktur (verifiziert):**
 ```
@@ -325,4 +342,5 @@ jeweilige Account geliked hat. Leere Map oder fehlender Key = kein Like.
 - ~~`taskmark`: korrekter Parameter-Name~~ → **`taskId`** (nicht `metaId`!) (verifiziert)
 - ~~`metadelete`: korrekter Parameter-Name + Response-Struktur~~ → **`id`**, Response `"true"` (verifiziert)
 - ~~`wallmood`: Parameter-Name `wallId`~~ → **`wall_message_id`** (verifiziert via API-Fehlermeldung)
-- ~~`wallmood`: `moodType`-Werte, Toggle vs. explizit, Response-Struktur~~ → vollständig verifiziert via FW_DEBUG=1 (siehe oben)
\ No newline at end of file
+- ~~`wallmood`: `moodType`-Werte, Toggle vs. explizit, Response-Struktur~~ → verifiziert: idempotentes SET mit `"STAR"`, kein Toggle (siehe oben)
+- `wallmood` Unlike: Mechanismus unbekannt — Service Worker verhindert Browser-Inspektion; alle getesteten Ansätze fehlgeschlagen (siehe oben)
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 7300796..d3a3e24 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "mcp-familywall"
-version = "0.4.4"
+version = "0.4.5"
 description = "MCP server for Family Wall — read your family's lists and tasks via Claude"
 readme = "README.md"
 requires-python = ">=3.12"
diff --git a/src/mcp_familywall/server.py b/src/mcp_familywall/server.py
index f51a70f..333dbfc 100644
--- a/src/mcp_familywall/server.py
+++ b/src/mcp_familywall/server.py
@@ -478,22 +478,36 @@ def delete_task(task_id: str) -> str:
 
 @mcp.tool()
 def like_post(post_id: str, like: bool = True) -> str:
-    """Like or unlike a wall post/activity.
+    """Like a wall post/activity with a STAR mood.
+
+    Note: Unlike (like=False) is not yet supported. The Family Wall API offers
+    no discoverable endpoint or parameter to remove a like. Passing like=False
+    returns an error without making any API call.
 
     Args:
         post_id: Wall post ID from get_activities (e.g. ``wall/23431854_31119189``).
-        like: ``True`` to like the post, ``False`` to unlike.
+        like: Must be ``True``. ``False`` is reserved for future unlike support.
 
     Returns:
         JSON success indicator or an error message.
     """
-    # wallmood toggles the STAR mood on a wall post (same endpoint for like/unlike).
+    # Unlike is not yet supported: extensive FW_DEBUG=1 testing showed that
+    # wallmood with moodType="STAR" is an idempotent SET operation (not a toggle).
+    # Tested and ruled out: moodType variations ("NONE", "REMOVE", "DELETE", ""),
+    # moodStarShortcut parameter, and alternative endpoints (all return 502).
+    # See SPEC.md for full investigation notes.
+    if not like:
+        return json.dumps(
+            {"error": "Unlike is not yet supported. The unlike mechanism is unknown."},
+            ensure_ascii=False,
+            indent=2,
+        )
+
     # Verified via FW_DEBUG=1:
     #   - Parameter 'wall_message_id': post ID as returned by get_activities
-    #   - Parameter 'moodType': "STAR" (Family Wall's internal like type)
-    #   - Response a00.r.r: full wall message object with moodMap showing current state
-    # The endpoint is a toggle — calling it again removes the mood.
-    # 'like=False' relies on this toggle behaviour (call again to undo).
+    #   - Parameter 'moodType': "STAR" (Family Wall's internal like type; "LIKE" is silently
+    #     mapped to "STAR" server-side — use "STAR" directly)
+    #   - Response a00.r.r: full wall message object with moodMap showing resulting state
     params: dict[str, Any] = {
         "wall_message_id": post_id,
         "moodType": "STAR",
@@ -504,7 +518,7 @@ def like_post(post_id: str, like: bool = True) -> str:
     except RuntimeError as exc:
         return f"Error: {exc}"
 
-    # Extract moodMap from response to determine actual resulting state.
+    # Extract moodMap from the response to confirm the like was recorded.
     try:
         wall_obj = data["a00"]["r"]["r"]
         if not isinstance(wall_obj, dict):
@@ -518,8 +532,7 @@ def like_post(post_id: str, like: bool = True) -> str:
             indent=2,
         )
 
-    # Determine whether the post is now liked by checking if any entry in
-    # moodMap contains "STAR" (the server-side representation of a like).
+    # Confirm the STAR is present in moodMap (server-side representation of a like).
     now_liked = any("STAR" in moods for moods in mood_map.values())
 
     return json.dumps(