diff --git a/backend-tests/ToxiproxyAgentProvisioningIntegrationTests.cs b/backend-tests/ToxiproxyAgentProvisioningIntegrationTests.cs
index f9001d0..326ab83 100644
--- a/backend-tests/ToxiproxyAgentProvisioningIntegrationTests.cs
+++ b/backend-tests/ToxiproxyAgentProvisioningIntegrationTests.cs
@@ -37,6 +37,7 @@ public sealed class ToxiproxyAgentProvisioningIntegrationTests
         await using var toxiproxy = new ToxiproxyBuilder(
                 "ghcr.io/shopify/toxiproxy:2.12.0")
             .WithNetwork(network)
+            .WithNetworkAliases("toxiproxy")
             .Build();
 
         await network.CreateAsync();
@@ -100,22 +101,6 @@ public sealed class ToxiproxyAgentProvisioningIntegrationTests
                 "toxiproxy-approval"));
         Assert.True(approved.Ok);
 
-        gateway.BeforeCreateAsync = async cancellationToken =>
-        {
-            using var toxicResponse = await toxiproxyAdmin.PostAsJsonAsync(
-                "/proxies/openclaw/toxics",
-                new
-                {
-                    name = "delay-create-response",
-                    type = "latency",
-                    stream = "downstream",
-                    toxicity = 1.0,
-                    attributes = new { latency = 1500, jitter = 0 }
-                },
-                cancellationToken);
-            toxicResponse.EnsureSuccessStatusCode();
-        };
-
         Assert.True(await service.ProcessNextAsync());
         Assert.False(await service.ProcessNextAsync());
 
@@ -159,6 +144,7 @@ public sealed class ToxiproxyAgentProvisioningIntegrationTests
         import re
         import threading
         import time
+        import urllib.request
 
         agents = {}
         lock = threading.Lock()
@@ -205,8 +191,24 @@ public sealed class ToxiproxyAgentProvisioningIntegrationTests
                 with lock:
                     agents[agent_id] = created
 
-                # The mutation is committed before the response. Toxiproxy
-                # blocks downstream bytes, recreating an uncertain dispatch.
+                # Install the downstream fault only after the mutation is
+                # committed. This distinguishes an uncertain response from a
+                # request that never crossed the dispatch boundary.
+                toxic = json.dumps({
+                    "name": "delay-create-response",
+                    "type": "latency",
+                    "stream": "downstream",
+                    "toxicity": 1.0,
+                    "attributes": {"latency": 1500, "jitter": 0}
+                }).encode("utf-8")
+                request = urllib.request.Request(
+                    "http://toxiproxy:8474/proxies/openclaw/toxics",
+                    data=toxic,
+                    headers={"Content-Type": "application/json"},
+                    method="POST")
+                with urllib.request.urlopen(request, timeout=2):
+                    pass
+
                 time.sleep(0.1)
                 self.send_json(200, {
                     "ok": True,
@@ -229,7 +231,6 @@ internal sealed class ToxiproxyHttpGatewayConnector(Uri endpoint)
     private int createCalls;
 
     public int CreateCalls => Volatile.Read(ref createCalls);
-    public Func<CancellationToken, Task>? BeforeCreateAsync { get; set; }
     public GatewayConnectionState ConnectionState => GatewayConnectionState.Connected;
     public string? GatewayVersion => "2026.7.1";
     public string? RequiredVersion => "2026.7.1";
@@ -289,8 +290,6 @@ internal sealed class ToxiproxyHttpGatewayConnector(Uri endpoint)
                     break;
                 case "agents.create":
                     Interlocked.Increment(ref createCalls);
-                    if (BeforeCreateAsync is not null)
-                        await BeforeCreateAsync(timeoutSource.Token);
                     response = await client.PostAsJsonAsync(
                         "/agents/create",
                         JsonSerializer.SerializeToNode(parameters),