diff --git a/changelog.d/fixes/7157-agent-bridge-dns-405.md b/changelog.d/fixes/7157-agent-bridge-dns-405.md
new file mode 100644
index 0000000000..98a887ce2a
--- /dev/null
+++ b/changelog.d/fixes/7157-agent-bridge-dns-405.md
@@ -0,0 +1 @@
+- fix(dashboard): Agent Bridge DNS toggle now sends POST (was PUT), fixing HTTP 405 on Start/Stop DNS (#7157)
diff --git a/src/app/(dashboard)/dashboard/tools/agent-bridge/AgentBridgePageClient.tsx b/src/app/(dashboard)/dashboard/tools/agent-bridge/AgentBridgePageClient.tsx
index e1a583ea69..99f520478a 100644
--- a/src/app/(dashboard)/dashboard/tools/agent-bridge/AgentBridgePageClient.tsx
+++ b/src/app/(dashboard)/dashboard/tools/agent-bridge/AgentBridgePageClient.tsx
@@ -147,7 +147,7 @@ export default function AgentBridgePageClient({
       setActionError(null);
       try {
         const res = await fetch(`/api/tools/agent-bridge/agents/${agentId}/dns`, {
-          method: "PUT",
+          method: "POST",
           headers: { "Content-Type": "application/json" },
           body: JSON.stringify({ enabled }),
         });
diff --git a/tests/unit/agent-bridge-dns-toggle-method-7157.test.ts b/tests/unit/agent-bridge-dns-toggle-method-7157.test.ts
new file mode 100644
index 0000000000..53a7c4311a
--- /dev/null
+++ b/tests/unit/agent-bridge-dns-toggle-method-7157.test.ts
@@ -0,0 +1,24 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import path from "node:path";
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const clientPath = path.resolve(
+  __dirname,
+  "../../src/app/(dashboard)/dashboard/tools/agent-bridge/AgentBridgePageClient.tsx"
+);
+const source = readFileSync(clientPath, "utf8");
+
+test("#7157: dns toggle fetch call uses method POST (route.ts only exports POST)", () => {
+  const dnsCallMatch = source.match(
+    /\/api\/tools\/agent-bridge\/agents\/\$\{agentId\}\/dns`,\s*\{\s*method:\s*"([A-Z]+)"/
+  );
+  assert.ok(dnsCallMatch, "expected to find the dns fetch call in AgentBridgePageClient.tsx");
+  assert.equal(
+    dnsCallMatch?.[1],
+    "POST",
+    "dns fetch call must use method: 'POST' to match the route.ts export (issue #7157)"
+  );
+});