From c9144789fd8bc3d629b68cbc7a00a18a57179dab Mon Sep 17 00:00:00 2001
From: clawsweeper <274271284+clawsweeper[bot]@users.noreply.github.com>
Date: Mon, 8 Jun 2026 01:58:22 +0000
Subject: [PATCH] fix(agents): do not refresh lastUsedAt on MCP lease release

---
 src/agents/agent-bundle-mcp-runtime.test.ts | 11 +++++++----
 src/agents/agent-bundle-mcp-runtime.ts      |  2 +-
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/agents/agent-bundle-mcp-runtime.test.ts b/src/agents/agent-bundle-mcp-runtime.test.ts
index b9d89c10b19..b035a36f8f4 100644
--- a/src/agents/agent-bundle-mcp-runtime.test.ts
+++ b/src/agents/agent-bundle-mcp-runtime.test.ts
@@ -7,12 +7,12 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 import { createBundleMcpJsonSchemaValidator } from "./agent-bundle-mcp-runtime.js";
 import { cleanupBundleMcpHarness } from "./agent-bundle-mcp-test-harness.js";
 import {
-  testing,
   createSessionMcpRuntime,
   getOrCreateSessionMcpRuntime,
   materializeBundleMcpToolsForRun,
   retireSessionMcpRuntime,
   retireSessionMcpRuntimeForSessionKey,
+  testing,
 } from "./agent-bundle-mcp-tools.js";
 import type { SessionMcpRuntime } from "./agent-bundle-mcp-types.js";
 import { writeExecutable } from "./bundle-mcp-shared.test-harness.js";
@@ -1672,12 +1672,12 @@ process.on("SIGINT", shutdown);`,
     });
     const releaseLease = runtime.acquireLease?.();
 
-    // TTL elapses while the lease is still held — sweep skips active runtimes
+    // TTL elapses while the lease is still held, so sweep skips active runtimes.
     now += 60;
     await expect(manager.sweepIdleRuntimes()).resolves.toBe(0);
 
-    // Release the lease — must not reset lastUsedAt, so the runtime is
-    // evictable on the very next sweep without waiting another full TTL
+    // Release must not reset lastUsedAt; the runtime is evictable on the very
+    // next sweep without waiting another full TTL.
     releaseLease?.();
     await expect(manager.sweepIdleRuntimes()).resolves.toBe(1);
 
@@ -1722,6 +1722,9 @@ process.on("SIGINT", shutdown);`,
       cfg: { mcp: { servers: {} } },
     });
     const lastUsedBefore = runtime.lastUsedAt;
+    if (!runtime.acquireLease) {
+      throw new Error("Expected production session MCP runtime to expose acquireLease");
+    }
     const release = runtime.acquireLease();
     release();
     expect(runtime.lastUsedAt).toBe(lastUsedBefore);
diff --git a/src/agents/agent-bundle-mcp-runtime.ts b/src/agents/agent-bundle-mcp-runtime.ts
index 5e6c15b87fc..771552a4fa2 100644
--- a/src/agents/agent-bundle-mcp-runtime.ts
+++ b/src/agents/agent-bundle-mcp-runtime.ts
@@ -765,7 +765,7 @@ export function createSessionMcpRuntime(params: {
         }
         released = true;
         activeLeases = Math.max(0, activeLeases - 1);
-        // release ≠ use: refreshing lastUsedAt here defeats the idle-sweep TTL.
+        // Release is not use: refreshing lastUsedAt here defeats the idle-sweep TTL.
       };
     },
     getCatalog,