diff --git a/extensions/webui/api_call_after/.gitkeep b/extensions/webui/fetch_api_call_after/.gitkeep
similarity index 100%
rename from extensions/webui/api_call_after/.gitkeep
rename to extensions/webui/fetch_api_call_after/.gitkeep
diff --git a/extensions/webui/api_call_before/.gitkeep b/extensions/webui/fetch_api_call_before/.gitkeep
similarity index 100%
rename from extensions/webui/api_call_before/.gitkeep
rename to extensions/webui/fetch_api_call_before/.gitkeep
diff --git a/extensions/webui/json_api_call_after/.gitkeep b/extensions/webui/json_api_call_after/.gitkeep
new file mode 100644
index 000000000..e69de29bb
diff --git a/extensions/webui/json_api_call_after/cache_reset.js b/extensions/webui/json_api_call_after/cache_reset.js
new file mode 100644
index 000000000..b09e96bbc
--- /dev/null
+++ b/extensions/webui/json_api_call_after/cache_reset.js
@@ -0,0 +1,14 @@
+import { clear } from "/js/cache.js";
+
+export default async function resetCache(ctx) {
+  try {
+    // clear frontend cache areas when backend caches are cleared via API
+    if (ctx.endpoint == "cache_reset") {
+      for (const area of ctx.data.areas) {
+        clear(area);
+      }
+    }
+  } catch (e) {
+    console.error(e);
+  }
+}
diff --git a/extensions/webui/json_api_call_before/.gitkeep b/extensions/webui/json_api_call_before/.gitkeep
new file mode 100644
index 000000000..e69de29bb
diff --git a/helpers/plugins.py b/helpers/plugins.py
index 8b1a53371..d29e6457d 100644
--- a/helpers/plugins.py
+++ b/helpers/plugins.py
@@ -71,7 +71,7 @@ class PluginListItem(BaseModel):
     toggle_state: ToggleState = "disabled"
 
 
-def invalidate_plugin_cache():
+def clear_plugin_cache():
     cache.clear("*(plugins)*")
 
 
@@ -189,6 +189,7 @@ def delete_plugin(plugin_name: str):
     if not files.is_in_dir(plugin_dir, custom_plugins_dir):
         raise ValueError("Only custom plugins can be deleted")
     files.delete_dir(plugin_dir)
+    clear_plugin_cache()
 
 
 def get_plugin_paths(*subpaths: str) -> List[str]:
@@ -347,6 +348,7 @@ def toggle_plugin(
         files.write_file(enabled_file, "")
     else:
         files.write_file(disabled_file, "")
+    clear_plugin_cache()
 
 
 def get_plugin_config(
@@ -401,6 +403,7 @@ def save_plugin_config(
     )
     if file_path:
         files.write_file(file_path, json.dumps(settings))
+        clear_plugin_cache()
 
 
 def find_plugin_asset(
diff --git a/jsconfig.json b/jsconfig.json
index 17f9b2537..102bdfe5a 100644
--- a/jsconfig.json
+++ b/jsconfig.json
@@ -13,5 +13,5 @@
         "/usr/plugins/*": ["usr/plugins/*"]
       }
     },
-    "include": ["webui/**/*.js", "plugins/**/*.js", "usr/plugins/**/*.js"]
+    "include": ["webui/**/*.js", "extensions/**/*.js", "plugins/**/*.js", "usr/plugins/**/*.js"]
   }
\ No newline at end of file
diff --git a/plugins/plugin_installer/helpers/install.py b/plugins/plugin_installer/helpers/install.py
index ed92fb063..db8542060 100644
--- a/plugins/plugin_installer/helpers/install.py
+++ b/plugins/plugin_installer/helpers/install.py
@@ -12,7 +12,7 @@ from helpers import files
 from helpers.plugins import (
     META_FILE_NAME,
     PluginMetadata,
-    invalidate_plugin_cache,
+    clear_plugin_cache,
 )
 from helpers import yaml as yaml_helper
 
@@ -29,7 +29,7 @@ def _sanitize_plugin_name(name: str) -> str:
     Converts dots and dashes to underscores for Python import compatibility.
     Raises ValueError if the name is unsafe for filesystem use."""
     name = name.strip().strip(".")
-    name = re.sub(r"[-.]", "_", name)
+    name = re.sub(r"[^a-zA-Z0-9]+", "_", name)
     if not name or not _SAFE_NAME_RE.match(name):
         raise ValueError(
             f"Invalid plugin name: '{name}'. "
@@ -107,7 +107,7 @@ def install_from_zip(zip_path: str) -> dict:
         dest = os.path.join(_get_user_plugins_dir(), plugin_name)
         os.makedirs(os.path.dirname(dest), exist_ok=True)
         shutil.move(plugin_root, dest)
-        invalidate_plugin_cache()
+        clear_plugin_cache()
 
         return {
             "success": True,
@@ -147,6 +147,7 @@ def install_from_git(url: str, token: Optional[str] = None) -> dict:
     except Exception as e:
         # Cleanup partial clone
         shutil.rmtree(dest, ignore_errors=True)
+        clear_plugin_cache()
         raise ValueError(f"Git clone failed: {e}") from e
 
     try:
@@ -154,9 +155,10 @@ def install_from_git(url: str, token: Optional[str] = None) -> dict:
     except ValueError:
         # No plugin.yaml — remove cloned repo
         shutil.rmtree(dest, ignore_errors=True)
+        clear_plugin_cache()
         raise
 
-    invalidate_plugin_cache()
+    clear_plugin_cache()
 
     return {
         "success": True,
diff --git a/webui/js/api.js b/webui/js/api.js
index 4eb6ee219..ee7e9d964 100644
--- a/webui/js/api.js
+++ b/webui/js/api.js
@@ -1,3 +1,22 @@
+let _extensionsModule = null;
+
+async function _getExtensions() {
+  if (!_extensionsModule) _extensionsModule = await import("./extensions.js");
+  return _extensionsModule;
+}
+
+async function _shouldCallApiExtensions(apiUrl) {
+  const extensions = await _getExtensions();
+  const excluded = extensions.API_EXTENSION_EXCLUDED_ENDPOINTS;
+  return !(excluded instanceof Set && excluded.has(apiUrl));
+}
+
+function _normalizeApiUrl(url) {
+  return url.startsWith("/api/") || url.startsWith("api/")
+    ? `/${url.replace(/^\/+/, "")}`
+    : `/api/${url.replace(/^\/+/, "")}`;
+}
+
 /**
  * Call a JSON-in JSON-out API endpoint
  * Data is automatically serialized
@@ -6,21 +25,54 @@
  * @returns {Promise<any>} The JSON response from the API
  */
 export async function callJsonApi(endpoint, data) {
-  const response = await fetchApi(endpoint, {
+  const apiUrl = _normalizeApiUrl(endpoint);
+
+  /** @type {{ endpoint: string, data: any, response: Response | null, result: any, error: Error | null }} */
+  const ctx = {
+    endpoint,
+    data,
+    response: null,
+    result: null,
+    error: null,
+  };
+
+  if (await _shouldCallApiExtensions(apiUrl)) {
+    const extensions = await _getExtensions();
+    await extensions.callJsExtensions("json_api_call_before", ctx);
+  }
+
+  const response = await fetchApi(ctx.endpoint, {
     method: "POST",
     headers: {
       "Content-Type": "application/json",
     },
     credentials: "same-origin",
-    body: JSON.stringify(data),
+    body: JSON.stringify(ctx.data),
   });
+  ctx.response = response;
 
   if (!response.ok) {
     const error = await response.text();
-    throw new Error(error);
+    ctx.error = new Error(error);
+
+    if (await _shouldCallApiExtensions(apiUrl)) {
+      const extensions = await _getExtensions();
+      await extensions.callJsExtensions("json_api_call_error", ctx);
+    }
+
+    if (ctx.error) throw ctx.error;
+    
+    return ctx.result;
   }
-  const jsonResponse = await response.json();
-  return jsonResponse;
+
+  ctx.result = await response.json();
+
+  if (await _shouldCallApiExtensions(apiUrl)) {
+    const extensions = await _getExtensions();
+    await extensions.callJsExtensions("json_api_call_after", ctx);
+  }
+
+  return ctx.result;
 }
 
 /**
@@ -31,25 +83,6 @@ export async function callJsonApi(endpoint, data) {
  * @returns {Promise<Response>} The fetch response
  */
 export async function fetchApi(url, request) {
-  async function _getExtensions() {
-    try {
-      return await import("./extensions.js");
-    } catch {
-      return null;
-    }
-  }
-
-  /**
-   * @param {string} apiUrl
-   * @returns {Promise<boolean>}
-   */
-  async function _shouldCallApiExtensions(apiUrl) {
-    const extensions = await _getExtensions();
-    if (!extensions) return false;
-    const excluded = extensions.API_EXTENSION_EXCLUDED_ENDPOINTS;
-    return !(excluded instanceof Set && excluded.has(apiUrl));
-  }
-
   async function _wrap(retry) {
     // get the CSRF token
     const token = await getCsrfToken();
@@ -64,7 +97,7 @@ export async function fetchApi(url, request) {
     finalRequest.headers["X-CSRF-Token"] = token;
 
     // perform the fetch with the updated request
-    const apiUrl = url.startsWith('/api/') || url.startsWith('api/') ? `/${url.replace(/^\/+/, '')}` : `/api/${url.replace(/^\/+/, '')}`;
+    const apiUrl = _normalizeApiUrl(url);
 
     /** @type {{ url: string, apiUrl: string, request: any, response: Response | null, retry: boolean }} */
     const ctx = {
@@ -77,19 +110,15 @@ export async function fetchApi(url, request) {
 
     if (await _shouldCallApiExtensions(apiUrl)) {
       const extensions = await _getExtensions();
-      if (extensions) {
-        await extensions.callJsExtensions("api_call_before", ctx);
-      }
+      await extensions.callJsExtensions("fetch_api_call_before", ctx);
     }
 
-    const response = ctx.response || await fetch(ctx.apiUrl, ctx.request);
+    const response = ctx.response || (await fetch(ctx.apiUrl, ctx.request));
     ctx.response = response;
 
     if (await _shouldCallApiExtensions(apiUrl)) {
       const extensions = await _getExtensions();
-      if (extensions) {
-        await extensions.callJsExtensions("api_call_after", ctx);
-      }
+      await extensions.callJsExtensions("fetch_api_call_after", ctx);
     }
 
     const finalResponse = ctx.response;