fix: migrate legacy thread binding expiry and reduce hot-path disk writes

src/discord/monitor/message-handler.process.ts

@@ -118,7 +118,7 @@ export async function processDiscordMessage(ctx: DiscordMessagePreflightContext)
   }
 
   if (ctx.threadBinding?.threadId) {
-    threadBindings.touchThread({ threadId: ctx.threadBinding.threadId, persist: true });
+    threadBindings.touchThread({ threadId: ctx.threadBinding.threadId, persist: false });
   }
   const ackReaction = resolveAckReaction(cfg, route.agentId, {
     channel: "discord",

src/discord/monitor/reply-delivery.ts

@@ -272,6 +272,6 @@ export async function deliverDiscordReply(params: {
   }
 
   if (binding && deliveredAny) {
-    params.threadBindings?.touchThread({ threadId: binding.threadId, persist: true });
+    params.threadBindings?.touchThread({ threadId: binding.threadId, persist: false });
   }
 }

src/discord/monitor/thread-bindings.lifecycle.test.ts

@@ -746,6 +746,104 @@ describe("thread binding lifecycle", () => {
     expect(manager.getByThreadId("thread-acp-uncertain")).toBeDefined();
   });
 
+  it("migrates legacy expiresAt bindings to idle/max-age semantics", () => {
+    const previousStateDir = process.env.OPENCLAW_STATE_DIR;
+    const stateDir = fs.mkdtempSync(path.join(os.tmpdir(), "openclaw-thread-bindings-"));
+    process.env.OPENCLAW_STATE_DIR = stateDir;
+    try {
+      __testing.resetThreadBindingsForTests();
+      const bindingsPath = __testing.resolveThreadBindingsPath();
+      fs.mkdirSync(path.dirname(bindingsPath), { recursive: true });
+      const boundAt = Date.now() - 10_000;
+      const expiresAt = boundAt + 60_000;
+      fs.writeFileSync(
+        bindingsPath,
+        JSON.stringify(
+          {
+            version: 1,
+            bindings: {
+              "thread-legacy-active": {
+                accountId: "default",
+                channelId: "parent-1",
+                threadId: "thread-legacy-active",
+                targetKind: "subagent",
+                targetSessionKey: "agent:main:subagent:legacy-active",
+                agentId: "main",
+                boundBy: "system",
+                boundAt,
+                expiresAt,
+              },
+              "thread-legacy-disabled": {
+                accountId: "default",
+                channelId: "parent-1",
+                threadId: "thread-legacy-disabled",
+                targetKind: "subagent",
+                targetSessionKey: "agent:main:subagent:legacy-disabled",
+                agentId: "main",
+                boundBy: "system",
+                boundAt,
+                expiresAt: 0,
+              },
+            },
+          },
+          null,
+          2,
+        ),
+        "utf-8",
+      );
+
+      const manager = createThreadBindingManager({
+        accountId: "default",
+        persist: false,
+        enableSweeper: false,
+        idleTimeoutMs: 24 * 60 * 60 * 1000,
+        maxAgeMs: 0,
+      });
+
+      const active = manager.getByThreadId("thread-legacy-active");
+      expect(active).toBeDefined();
+      expect(active?.idleTimeoutMs).toBe(0);
+      expect(active?.maxAgeMs).toBe(expiresAt - boundAt);
+      expect(
+        resolveThreadBindingMaxAgeExpiresAt({
+          record: active!,
+          defaultMaxAgeMs: manager.getMaxAgeMs(),
+        }),
+      ).toBe(expiresAt);
+      expect(
+        resolveThreadBindingInactivityExpiresAt({
+          record: active!,
+          defaultIdleTimeoutMs: manager.getIdleTimeoutMs(),
+        }),
+      ).toBeUndefined();
+
+      const disabled = manager.getByThreadId("thread-legacy-disabled");
+      expect(disabled).toBeDefined();
+      expect(disabled?.idleTimeoutMs).toBe(0);
+      expect(disabled?.maxAgeMs).toBe(0);
+      expect(
+        resolveThreadBindingMaxAgeExpiresAt({
+          record: disabled!,
+          defaultMaxAgeMs: manager.getMaxAgeMs(),
+        }),
+      ).toBeUndefined();
+      expect(
+        resolveThreadBindingInactivityExpiresAt({
+          record: disabled!,
+          defaultIdleTimeoutMs: manager.getIdleTimeoutMs(),
+        }),
+      ).toBeUndefined();
+    } finally {
+      __testing.resetThreadBindingsForTests();
+      if (previousStateDir === undefined) {
+        delete process.env.OPENCLAW_STATE_DIR;
+      } else {
+        process.env.OPENCLAW_STATE_DIR = previousStateDir;
+      }
+      fs.rmSync(stateDir, { recursive: true, force: true });
+    }
+  });
+
   it("persists unbinds even when no manager is active", () => {
     const previousStateDir = process.env.OPENCLAW_STATE_DIR;
     const stateDir = fs.mkdtempSync(path.join(os.tmpdir(), "openclaw-thread-bindings-"));

src/discord/monitor/thread-bindings.state.ts

@@ -177,6 +177,30 @@ function normalizePersistedBinding(threadIdKey: string, raw: unknown): ThreadBin
     typeof value.maxAgeMs === "number" && Number.isFinite(value.maxAgeMs)
       ? Math.max(0, Math.floor(value.maxAgeMs))
       : undefined;
+  const legacyExpiresAt =
+    typeof (value as { expiresAt?: unknown }).expiresAt === "number" &&
+    Number.isFinite((value as { expiresAt?: unknown }).expiresAt)
+      ? Math.max(0, Math.floor((value as { expiresAt?: number }).expiresAt ?? 0))
+      : undefined;
+
+  let migratedIdleTimeoutMs = idleTimeoutMs;
+  let migratedMaxAgeMs = maxAgeMs;
+  if (
+    migratedIdleTimeoutMs === undefined &&
+    migratedMaxAgeMs === undefined &&
+    legacyExpiresAt != null
+  ) {
+    if (legacyExpiresAt <= 0) {
+      migratedIdleTimeoutMs = 0;
+      migratedMaxAgeMs = 0;
+    } else {
+      const baseBoundAt = boundAt > 0 ? boundAt : lastActivityAt;
+      // Legacy expiresAt represented an absolute timestamp; map it to max-age and disable idle timeout.
+      migratedIdleTimeoutMs = 0;
+      migratedMaxAgeMs = Math.max(1, legacyExpiresAt - Math.max(0, baseBoundAt));
+    }
+  }
+
   return {
     accountId,
     channelId,
@@ -190,8 +214,8 @@ function normalizePersistedBinding(threadIdKey: string, raw: unknown): ThreadBin
     boundBy,
     boundAt,
     lastActivityAt,
-    idleTimeoutMs,
-    maxAgeMs,
+    idleTimeoutMs: migratedIdleTimeoutMs,
+    maxAgeMs: migratedMaxAgeMs,
   };
 }