diff --git a/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts b/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
index dec55480af30..2df65ed268f0 100644
--- a/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
+++ b/apps/server/src/orchestration-v2/Adapters/GrokAdapterV2.test.ts
@@ -118,6 +118,43 @@ describe("GrokAdapterV2 capabilities", () => {
       flavor.promptFailure?.(new Error("Rate limit mentioned in an ordinary error")).class,
       "provider_error",
     );
+    assert.deepEqual(
+      flavor.promptFailure?.(
+        new EffectAcpErrors.AcpTransportError({
+          operation: "call-rpc",
+          method: "session/prompt",
+          detail: "private provider diagnostic",
+          cause: new Error("api_key=synthetic-private-key"),
+        }),
+      ),
+      {
+        class: "transport_error",
+        message: "Grok connection failed. Retry the turn.",
+        code: null,
+        retryable: null,
+      },
+    );
+    assert.deepEqual(flavor.promptFailure?.(new EffectAcpErrors.AcpInputStreamEndedError({})), {
+      class: "transport_error",
+      message: "Grok connection failed. Retry the turn.",
+      code: null,
+      retryable: null,
+    });
+    assert.deepEqual(
+      flavor.promptFailure?.(
+        new EffectAcpErrors.AcpProcessExitedError({
+          code: 1,
+          stderr: "private provider diagnostic",
+        }),
+      ),
+      {
+        class: "transport_error",
+        message:
+          "The provider process exited with code 1. Check the server logs for the provider's output, then retry the turn.",
+        code: null,
+        retryable: null,
+      },
+    );
   });
 
   it("terminalizes only foreground tools under the actual Grok flavor", () => {
diff --git a/packages/provider-grok/src/server/adapter.ts b/packages/provider-grok/src/server/adapter.ts
index 9ed1368f1698..48973b2ecc3b 100644
--- a/packages/provider-grok/src/server/adapter.ts
+++ b/packages/provider-grok/src/server/adapter.ts
@@ -86,6 +86,13 @@ const GROK_DRIVER_KIND = GROK_PROVIDER;
 export const GROK_DEFAULT_INSTANCE_ID = defaultInstanceIdForDriver(GROK_DRIVER_KIND);
 const DEFAULT_GROK_SETTINGS = Schema.decodeSync(GrokSettings)({});
 const isAcpRequestError = Schema.is(EffectAcpErrors.AcpRequestError);
+const isAcpConnectionError = Schema.is(
+  Schema.Union([
+    EffectAcpErrors.AcpTransportError,
+    EffectAcpErrors.AcpInputStreamEndedError,
+    EffectAcpErrors.AcpProcessExitedError,
+  ]),
+);
 
 const GrokProviderCapabilitiesV2 = {
   ...AcpProviderCapabilitiesV2,
@@ -314,7 +321,14 @@ export function makeGrokAcpAdapterFlavor(
               code: String(cause.code),
               class: cause.code === xAiRateLimitedErrorCode ? "usage_limit" : "provider_error",
             }
-          : { class: "provider_error" }),
+          : isAcpConnectionError(cause)
+            ? {
+                class: "transport_error",
+                ...(cause._tag === "AcpProcessExitedError"
+                  ? {}
+                  : { message: "Grok connection failed. Retry the turn." }),
+              }
+            : { class: "provider_error" }),
       }),
     registerExtensions: registerGrokAcpExtensions,
     extractSubagentUpdate: extractXAiAcpSubagentUpdate,