diff --git a/src/lib/state-store-registrations.ts b/src/lib/state-store-registrations.ts
index 13a22bfce0..849f145848 100644
--- a/src/lib/state-store-registrations.ts
+++ b/src/lib/state-store-registrations.ts
@@ -21,7 +21,7 @@ import {
 } from "../combos/failover";
 import { reconcileComboWarningMemos } from "../combos/request";
 import { reconcileComboRotationState } from "../combos/resolve";
-import { reconcileComboRecall } from "../server/responses/combo-session-recall";
+import { reconcileComboRecall, sweepExpiredComboRecall } from "../server/responses/combo-session-recall";
 import { listLiveComboTargetKeys } from "../combos/types";
 import {
   listLiveConfigOwnershipRoots,
@@ -112,7 +112,11 @@ export const STATE_STORE_REGISTRATIONS = [
   { name: "model-cache-history", reconcileGeneration: reconcileModelCacheGeneration },
   { name: "pool-rotation", reconcileGeneration: reconcilePoolRotationState },
   { name: "combo-rotation", reconcileGeneration: reconcileComboRotationState },
-  { name: "combo-session-recall", reconcileGeneration: reconcileComboRecall },
+  {
+    name: "combo-session-recall",
+    sweepExpired: sweepExpiredComboRecall,
+    reconcileGeneration: reconcileComboRecall,
+  },
   { name: "guardian-backoff", reconcileGeneration: reconcileGuardianBackoff },
   { name: "codex-reauth", reconcileGeneration: reconcileCodexReauthState },
   { name: "oauth-reauth", reconcileGeneration: reconcileOAuthReauthState },
diff --git a/src/server/responses/combo-session-recall.ts b/src/server/responses/combo-session-recall.ts
index 84dfd8d466..aafece9e04 100644
--- a/src/server/responses/combo-session-recall.ts
+++ b/src/server/responses/combo-session-recall.ts
@@ -7,12 +7,16 @@ interface ComboRecallEntry {
   comboId: string;
   target: Pick<OcxComboTarget, "provider" | "model">;
   responseModel: string;
+  responseModelBytes: number;
   at: number;
 }
 
 const RECALL_CAPACITY = 256;
 const RECALL_TTL_MS = 30 * 60 * 1000;
+const RECALL_MODEL_MAX_BYTES = 1024;
+const RECALL_MODEL_TOTAL_BYTES = 64 * 1024;
 const recall = new Map<string, ComboRecallEntry>();
+let retainedModelBytes = 0;
 let lastReconciledGeneration = 0;
 let liveOwners: Pick<GenerationContext, "comboIds" | "comboTargets" | "providerNames"> | undefined;
 
@@ -22,6 +26,22 @@ function ownsEntry(context: Pick<GenerationContext, "comboIds" | "comboTargets"
     && context.comboTargets.has(`${entry.comboId}::${targetKey(entry.target)}`);
 }
 
+function deleteEntry(lane: string): boolean {
+  const entry = recall.get(lane);
+  if (!entry) return false;
+  retainedModelBytes -= entry.responseModelBytes;
+  recall.delete(lane);
+  return true;
+}
+
+function boundedModelBytes(model: string): number | undefined {
+  // UTF-8 is never shorter than the JS string's code-unit length. Reject oversized
+  // upstream values before encoding so validation itself cannot make another large copy.
+  if (model.length > RECALL_MODEL_MAX_BYTES) return undefined;
+  const bytes = new TextEncoder().encode(model).byteLength;
+  return bytes <= RECALL_MODEL_MAX_BYTES ? bytes : undefined;
+}
+
 export function rememberComboForLane(
   lane: string | undefined,
   comboId: string,
@@ -30,16 +50,25 @@ export function rememberComboForLane(
   writerGeneration: number,
 ): void {
   if (!lane || !comboId || !responseModel.trim()) return;
+  const modelBytes = boundedModelBytes(responseModel);
+  if (modelBytes === undefined) return;
   // Reject even a same-named recreated owner: its previous in-flight turn is obsolete.
   if (writerGeneration < Math.max(lastReconciledGeneration, captureConfigGeneration())) return;
-  const entry = { comboId, target: { provider: target.provider, model: target.model }, responseModel, at: Date.now() };
+  const entry = {
+    comboId,
+    target: { provider: target.provider, model: target.model },
+    responseModel,
+    responseModelBytes: modelBytes,
+    at: Date.now(),
+  };
   if (liveOwners && !ownsEntry(liveOwners, entry)) return;
-  recall.delete(lane);
+  deleteEntry(lane);
   recall.set(lane, entry);
-  while (recall.size > RECALL_CAPACITY) {
+  retainedModelBytes += modelBytes;
+  while (recall.size > RECALL_CAPACITY || retainedModelBytes > RECALL_MODEL_TOTAL_BYTES) {
     const oldest = recall.keys().next().value;
     if (oldest === undefined) break;
-    recall.delete(oldest);
+    deleteEntry(oldest);
   }
 }
 
@@ -57,7 +86,7 @@ export function recallComboForLane(
     || !Object.hasOwn(config.providers, entry.target.provider)
     || !provider || provider.disabled === true
     || !combo?.targets.some(target => targetKey(target) === targetKey(entry.target))) {
-    recall.delete(lane);
+    deleteEntry(lane);
     return undefined;
   }
   return entry.responseModel === model ? entry.comboId : undefined;
@@ -74,16 +103,27 @@ export function reconcileComboRecall(context: GenerationContext): number {
   let removed = 0;
   for (const [lane, entry] of recall) {
     if (!ownsEntry(context, entry) || Date.now() - entry.at >= RECALL_TTL_MS) {
-      recall.delete(lane);
+      deleteEntry(lane);
       removed += 1;
     }
   }
   return removed;
 }
 
+export function sweepExpiredComboRecall(now: number): number {
+  let removed = 0;
+  for (const [lane, entry] of recall) {
+    if (now - entry.at < RECALL_TTL_MS) continue;
+    deleteEntry(lane);
+    removed += 1;
+  }
+  return removed;
+}
+
 /** Test-only reset, alongside the combo rotation/cooldown resets. */
 export function clearComboRecallForTests(): void {
   recall.clear();
+  retainedModelBytes = 0;
   lastReconciledGeneration = 0;
   liveOwners = undefined;
 }
diff --git a/tests/oauth/state-store-sweeper.test.ts b/tests/oauth/state-store-sweeper.test.ts
index b162e2214b..0420cc8951 100644
--- a/tests/oauth/state-store-sweeper.test.ts
+++ b/tests/oauth/state-store-sweeper.test.ts
@@ -188,6 +188,39 @@ describe("state-store sweeper", () => {
     expect(reconcileLiveStateStores()).toEqual({ storesVisited: 1, rowsRemoved: 2 });
   });
 
+  test("registered combo recall sweep removes dormant expired lanes", () => {
+    registerStateStore(STATE_STORE_REGISTRATIONS.find(row => row.name === "combo-session-recall")!);
+    const config: OcxConfig = {
+      port: 0, defaultProvider: "a",
+      providers: { a: { adapter: "openai-chat", baseUrl: "https://a.example/v1" } },
+      combos: { first: { targets: [{ provider: "a", model: "m1" }] } },
+    };
+    rememberComboForLane("lane", "first", { provider: "a", model: "m1" }, "visible", captureConfigGeneration());
+
+    expect(sweepExpired(Date.now() + 30 * 60 * 1_000)).toEqual({ storesVisited: 1, rowsRemoved: 1 });
+    expect(recallComboForLane(config, "lane", "visible")).toBeUndefined();
+  });
+
+  test("combo recall bounds individual and aggregate upstream model bytes", () => {
+    const config: OcxConfig = {
+      port: 0, defaultProvider: "a",
+      providers: { a: { adapter: "openai-chat", baseUrl: "https://a.example/v1" } },
+      combos: { first: { targets: [{ provider: "a", model: "m1" }] } },
+    };
+    const target = { provider: "a", model: "m1" };
+    rememberComboForLane("oversized-ascii", "first", target, "x".repeat(1025), captureConfigGeneration());
+    rememberComboForLane("oversized-utf8", "first", target, "é".repeat(513), captureConfigGeneration());
+    expect(recallComboForLane(config, "oversized-ascii", "x".repeat(1025))).toBeUndefined();
+    expect(recallComboForLane(config, "oversized-utf8", "é".repeat(513))).toBeUndefined();
+
+    for (let index = 0; index < 65; index += 1) {
+      rememberComboForLane(`lane-${index}`, "first", target, `${index}`.padEnd(1024, "x"), captureConfigGeneration());
+    }
+    expect(recallComboForLane(config, "lane-0", "0".padEnd(1024, "x"))).toBeUndefined();
+    expect(recallComboForLane(config, "lane-1", "1".padEnd(1024, "x"))).toBe("first");
+    expect(recallComboForLane(config, "lane-64", "64".padEnd(1024, "x"))).toBe("first");
+  });
+
   test("combo recall watermark rejects writers after a partially failed generation", () => {
     registerStateStore(STATE_STORE_REGISTRATIONS.find(row => row.name === "combo-session-recall")!);
     const warning = spyOn(console, "warn").mockImplementation(() => {});