diff --git a/changelog.d/fixes/11556-client-abort-guard-mjs-import.md b/changelog.d/fixes/11556-client-abort-guard-mjs-import.md
new file mode 100644
index 0000000000..941b699e5d
--- /dev/null
+++ b/changelog.d/fixes/11556-client-abort-guard-mjs-import.md
@@ -0,0 +1 @@
+- **sse:** fix LiveWS/embed-WS servers crashing at startup under the Node/tsx runtime — `liveServer.ts`, `embedWsProxy.ts` and `apiBridgeServer.ts` imported `@/shared/utils/httpClientAbortGuard` without the `.mjs` extension, so the client-abort crash guard added by [#11556](https://github.com/diegosouzapw/OmniRoute/pull/11556) was unreachable and every dependent test failed with `ERR_MODULE_NOT_FOUND` ([#11556](https://github.com/diegosouzapw/OmniRoute/pull/11556)).
diff --git a/src/lib/apiBridgeServer.ts b/src/lib/apiBridgeServer.ts
index 6f2f2e6cdc..8ce477c34a 100644
--- a/src/lib/apiBridgeServer.ts
+++ b/src/lib/apiBridgeServer.ts
@@ -6,7 +6,7 @@ import { getApiBridgeTimeoutConfig } from "@/shared/utils/runtimeTimeouts";
 import {
   attachRequestStreamGuards,
   installProcessCrashGuard,
-} from "@/shared/utils/httpClientAbortGuard";
+} from "@/shared/utils/httpClientAbortGuard.mjs";
 
 const API_BRIDGE_TIMEOUTS = getApiBridgeTimeoutConfig(process.env, (message) => {
   console.warn(`[API Bridge] ${message}`);
diff --git a/src/lib/services/embedWsProxy.ts b/src/lib/services/embedWsProxy.ts
index 89bdb3d1a5..9caea7f1a3 100644
--- a/src/lib/services/embedWsProxy.ts
+++ b/src/lib/services/embedWsProxy.ts
@@ -30,7 +30,7 @@ import { getOrCreateApiKey } from "./apiKey";
 import {
   attachRequestStreamGuards,
   installProcessCrashGuard,
-} from "@/shared/utils/httpClientAbortGuard";
+} from "@/shared/utils/httpClientAbortGuard.mjs";
 
 const DEFAULT_HOST = "127.0.0.1";
 const DEFAULT_PORT = 20131;
diff --git a/src/server/ws/liveServer.ts b/src/server/ws/liveServer.ts
index 254e403fb7..a6cd0f5e5d 100644
--- a/src/server/ws/liveServer.ts
+++ b/src/server/ws/liveServer.ts
@@ -36,7 +36,7 @@ import { isAutomatedTestProcess, isBuildProcess } from "@/shared/utils/testProce
 import {
   attachRequestStreamGuards,
   installProcessCrashGuard,
-} from "@/shared/utils/httpClientAbortGuard";
+} from "@/shared/utils/httpClientAbortGuard.mjs";
 
 import {
   buildAllowedOrigins,