diff --git a/packages/ai/src/auth-storage.ts b/packages/ai/src/auth-storage.ts
index 20b777eea..ae04587ca 100644
--- a/packages/ai/src/auth-storage.ts
+++ b/packages/ai/src/auth-storage.ts
@@ -336,6 +336,7 @@ export interface AuthCredentialStore {
 	tryAcquireCredentialRefreshLease?(credentialId: number, owner: string, expiresAtMs: number): boolean;
 	getCredentialRefreshLeaseExpiresAt?(credentialId: number): number | undefined;
 	releaseCredentialRefreshLease?(credentialId: number, owner: string): void;
+	renewCredentialRefreshLease?(credentialId: number, owner: string, expiresAtMs: number): boolean;
 	/**
 	 * Append usage-limit snapshots for trend history. Optional: stores without
 	 * durable storage (e.g. the broker remote store) omit it and recording is
@@ -599,6 +600,7 @@ const DEFAULT_OAUTH_REFRESH_TIMEOUT_MS = 10_000;
 const OAUTH_REFRESH_SKEW_MS = 60_000;
 const OAUTH_REFRESH_LEASE_TTL_MS = 15_000;
 const OAUTH_REFRESH_LEASE_POLL_MS = 50;
+const OAUTH_REFRESH_LEASE_RENEW_MS = 5_000;
 /**
  * Cap on the buffered credential_disabled backlog held while no handler is attached.
  * In practice the backlog is 0–N where N ≈ active providers (≤ ~20). The cap exists so
@@ -1873,7 +1875,8 @@ export class AuthStorage {
 		const hasDurableLease =
 			!!this.#store.tryAcquireCredentialRefreshLease &&
 			!!this.#store.getCredentialRefreshLeaseExpiresAt &&
-			!!this.#store.releaseCredentialRefreshLease;
+			!!this.#store.releaseCredentialRefreshLease &&
+			!!this.#store.renewCredentialRefreshLease;
 		const owner = crypto.randomUUID();
 		let leasedCredentialId: number | undefined;
 
@@ -1943,42 +1946,76 @@ export class AuthStorage {
 			const serialized = serializeCredential(provider, current);
 			if (!serialized) return { credential: current, refreshed: false, removed: false };
 
+			let stopLeaseRenewal = false;
+			let leaseRenewalError: unknown;
+			const leaseRenewalStopped = Promise.withResolvers<void>();
+			const leaseRenewal =
+				leasedCredentialId !== undefined
+					? (async () => {
+							while (!stopLeaseRenewal) {
+								await Promise.race([Bun.sleep(OAUTH_REFRESH_LEASE_RENEW_MS), leaseRenewalStopped.promise]);
+								if (stopLeaseRenewal) return;
+								const renewed = this.#store.renewCredentialRefreshLease?.(
+									leasedCredentialId,
+									owner,
+									Date.now() + OAUTH_REFRESH_LEASE_TTL_MS,
+								);
+								if (!renewed) {
+									throw new AIError.ConfigurationError("OAuth refresh ownership was lost before persistence");
+								}
+							}
+						})().catch(error => {
+							leaseRenewalError = error;
+						})
+					: undefined;
+
 			let refreshed: OAuthCredentials;
 			try {
-				refreshed = await options.refresh(current);
-			} catch (error) {
-				if (options.isDefinitiveFailure?.(error)) {
-					const disabledCause = options.disabledCause?.(error) ?? `oauth refresh failed: ${String(error)}`;
-					const disabled = this.#store.tryDisableAuthCredentialIfMatches(row.id, serialized.data, disabledCause);
-					if (disabled) {
-						this.#setStoredCredentials(
-							provider,
-							rows
-								.filter(entry => entry.id !== row.id)
-								.map(entry => ({ id: entry.id, credential: entry.credential })),
+				try {
+					refreshed = await options.refresh(current);
+				} catch (error) {
+					if (options.isDefinitiveFailure?.(error)) {
+						const disabledCause = options.disabledCause?.(error) ?? `oauth refresh failed: ${String(error)}`;
+						const disabled = this.#store.tryDisableAuthCredentialIfMatches(
+							row.id,
+							serialized.data,
+							disabledCause,
 						);
-						this.#resetProviderAssignments(provider);
-						this.#emitCredentialDisabled({ provider, disabledCause });
-						return { credential: undefined, refreshed: false, removed: true };
+						if (disabled) {
+							this.#setStoredCredentials(
+								provider,
+								rows
+									.filter(entry => entry.id !== row.id)
+									.map(entry => ({ id: entry.id, credential: entry.credential })),
+							);
+							this.#resetProviderAssignments(provider);
+							this.#emitCredentialDisabled({ provider, disabledCause });
+							return { credential: undefined, refreshed: false, removed: true };
+						}
+						await this.reload();
+						const latest = this.get(provider);
+						return {
+							credential: latest?.type === "oauth" ? options.credentialFromRow(latest) : undefined,
+							refreshed: false,
+							removed: false,
+						};
 					}
-					await this.reload();
-					const latest = this.get(provider);
-					return {
-						credential: latest?.type === "oauth" ? options.credentialFromRow(latest) : undefined,
-						refreshed: false,
-						removed: false,
-					};
+					options.onRefreshFailure?.(error);
+					const keepCredential =
+						typeof options.keepCredentialOnRefreshFailure === "function"
+							? options.keepCredentialOnRefreshFailure(error)
+							: options.keepCredentialOnRefreshFailure === true;
+					if (keepCredential) {
+						return { credential: current, refreshed: false, removed: false };
+					}
+					throw error;
 				}
-				options.onRefreshFailure?.(error);
-				const keepCredential =
-					typeof options.keepCredentialOnRefreshFailure === "function"
-						? options.keepCredentialOnRefreshFailure(error)
-						: options.keepCredentialOnRefreshFailure === true;
-				if (keepCredential) {
-					return { credential: current, refreshed: false, removed: false };
-				}
-				throw error;
+			} finally {
+				stopLeaseRenewal = true;
+				leaseRenewalStopped.resolve();
+				await leaseRenewal;
 			}
+			if (leaseRenewalError) throw leaseRenewalError;
 
 			const merged: T = options.mergeRefreshedCredential
 				? options.mergeRefreshedCredential(current, refreshed)
@@ -5413,6 +5450,7 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 	#deleteExpiredCredentialBlocksStmt: Statement;
 	#acquireCredentialRefreshLeaseStmt: Statement;
 	#getCredentialRefreshLeaseStmt: Statement;
+	#renewCredentialRefreshLeaseStmt: Statement;
 	#releaseCredentialRefreshLeaseStmt: Statement;
 	#credentialBlockReconcileAfter: Map<string, number> = new Map();
 	#insertUsageHistoryStmt: Statement;
@@ -5492,6 +5530,9 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 		this.#getCredentialRefreshLeaseStmt = this.#db.prepare(
 			"SELECT expires_at_ms FROM auth_credential_refresh_leases WHERE credential_id = ?",
 		);
+		this.#renewCredentialRefreshLeaseStmt = this.#db.prepare(
+			`UPDATE auth_credential_refresh_leases SET expires_at_ms = ?, updated_at = ${SQLITE_NOW_EPOCH} WHERE credential_id = ? AND owner = ?`,
+		);
 		this.#releaseCredentialRefreshLeaseStmt = this.#db.prepare(
 			"DELETE FROM auth_credential_refresh_leases WHERE credential_id = ? AND owner = ?",
 		);
@@ -6058,32 +6099,28 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 	}
 
 	tryUpdateAuthCredentialIfMatches(id: number, expectedData: string, credential: AuthCredential): boolean {
+		const providerStmt = this.#db.prepare("SELECT provider FROM auth_credentials WHERE id = ?");
+		let providerRow: { provider?: string } | undefined;
 		try {
-			const providerStmt = this.#db.prepare("SELECT provider FROM auth_credentials WHERE id = ?");
-			let providerRow: { provider?: string } | undefined;
-			try {
-				providerRow = providerStmt.get(id) as { provider?: string } | undefined;
-			} finally {
-				providerStmt.finalize();
-			}
-			const provider = providerRow?.provider ?? "";
-			const serialized = serializeCredential(provider, credential);
-			if (!serialized) return false;
-			const result = this.#updateIfMatchesStmt.run(
-				serialized.credentialType,
-				serialized.data,
-				serialized.identityKey,
-				id,
-				expectedData,
-			) as { changes: number };
-			if (result.changes !== 1) return false;
-			if (provider) {
-				this.#purgeSupersededDisabledRows(provider, this.listAuthCredentials(provider));
-			}
-			return true;
-		} catch {
-			return false;
+			providerRow = providerStmt.get(id) as { provider?: string } | undefined;
+		} finally {
+			providerStmt.finalize();
 		}
+		const provider = providerRow?.provider ?? "";
+		const serialized = serializeCredential(provider, credential);
+		if (!serialized) return false;
+		const result = this.#updateIfMatchesStmt.run(
+			serialized.credentialType,
+			serialized.data,
+			serialized.identityKey,
+			id,
+			expectedData,
+		) as { changes: number };
+		if (result.changes !== 1) return false;
+		if (provider) {
+			this.#purgeSupersededDisabledRows(provider, this.listAuthCredentials(provider));
+		}
+		return true;
 	}
 
 	deleteAuthCredential(id: number, disabledCause: string): void {
@@ -6101,16 +6138,11 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 	 * row between our pre-check and the disable.
 	 */
 	tryDisableAuthCredentialIfMatches(id: number, expectedData: string, disabledCause: string): boolean {
-		try {
-			const result = this.#deleteIfMatchesStmt.run(normalizeDisabledCause(disabledCause), id, expectedData) as {
-				changes: number;
-			};
-			return result.changes === 1;
-		} catch {
-			return false;
-		}
+		const result = this.#deleteIfMatchesStmt.run(normalizeDisabledCause(disabledCause), id, expectedData) as {
+			changes: number;
+		};
+		return result.changes === 1;
 	}
-
 	deleteAuthCredentialsForProvider(provider: string, disabledCause: string): void {
 		try {
 			this.#deleteByProviderStmt.run(normalizeDisabledCause(disabledCause), provider);
@@ -6233,6 +6265,13 @@ export class SqliteAuthCredentialStore implements AuthCredentialStore {
 		return row.expires_at_ms;
 	}
 
+	renewCredentialRefreshLease(credentialId: number, owner: string, expiresAtMs: number): boolean {
+		const result = this.#renewCredentialRefreshLeaseStmt.run(expiresAtMs, credentialId, owner) as {
+			changes: number;
+		};
+		return result.changes === 1;
+	}
+
 	releaseCredentialRefreshLease(credentialId: number, owner: string): void {
 		try {
 			this.#releaseCredentialRefreshLeaseStmt.run(credentialId, owner);
diff --git a/packages/ai/test/auth-storage-oauth-refresh-race.test.ts b/packages/ai/test/auth-storage-oauth-refresh-race.test.ts
index 6b9323958..b5179e450 100644
--- a/packages/ai/test/auth-storage-oauth-refresh-race.test.ts
+++ b/packages/ai/test/auth-storage-oauth-refresh-race.test.ts
@@ -432,4 +432,82 @@ describe("AuthStorage OAuth refresh race", () => {
 		expect(cRow?.credential.type).toBe("oauth");
 		if (cRow?.credential.type === "oauth") expect(cRow.credential.refresh).toBe("c-ref");
 	});
+
+	test("propagates CAS update storage errors instead of treating them as peer refresh wins", async () => {
+		if (!authStorage || !store) throw new Error("test setup failed");
+
+		await authStorage.set("unit-oauth-cas-update-error", [
+			{
+				type: "oauth",
+				access: "access-old",
+				refresh: "refresh-old",
+				expires: Date.now() - 60_000,
+			},
+		]);
+
+		const failure = new Error("sqlite update failed");
+		vi.spyOn(store, "tryUpdateAuthCredentialIfMatches").mockImplementation(() => {
+			throw failure;
+		});
+
+		await expect(
+			authStorage.refreshStoredOAuthCredential("unit-oauth-cas-update-error", {
+				credentialFromRow: row => row,
+				forceRefresh: true,
+				refresh: async credential => ({
+					...credential,
+					access: "access-fresh",
+					refresh: "refresh-fresh",
+					expires: Date.now() + 60 * 60_000,
+				}),
+			}),
+		).rejects.toThrow("sqlite update failed");
+
+		const stored = store.listAuthCredentials("unit-oauth-cas-update-error");
+		expect(stored).toHaveLength(1);
+		expect(stored[0]?.credential).toMatchObject({
+			type: "oauth",
+			access: "access-old",
+			refresh: "refresh-old",
+		});
+	});
+
+	test("propagates CAS disable storage errors instead of treating them as peer rotations", async () => {
+		if (!authStorage || !store) throw new Error("test setup failed");
+
+		await authStorage.set("unit-oauth-cas-disable-error", [
+			{
+				type: "oauth",
+				access: "access-old",
+				refresh: "refresh-old",
+				expires: Date.now() - 60_000,
+			},
+		]);
+
+		const failure = new Error("sqlite disable failed");
+		vi.spyOn(store, "tryDisableAuthCredentialIfMatches").mockImplementation(() => {
+			throw failure;
+		});
+
+		await expect(
+			authStorage.refreshStoredOAuthCredential("unit-oauth-cas-disable-error", {
+				credentialFromRow: row => row,
+				forceRefresh: true,
+				refresh: async () => {
+					throw new Error('HTTP 400 invalid_grant {"error":"invalid_grant"}');
+				},
+				isDefinitiveFailure: error => error instanceof Error && error.message.includes("invalid_grant"),
+				disabledCause: error => `oauth refresh failed: ${error instanceof Error ? error.message : String(error)}`,
+			}),
+		).rejects.toThrow("sqlite disable failed");
+
+		expect(events).toHaveLength(0);
+		const stored = store.listAuthCredentials("unit-oauth-cas-disable-error");
+		expect(stored).toHaveLength(1);
+		expect(stored[0]?.credential).toMatchObject({
+			type: "oauth",
+			access: "access-old",
+			refresh: "refresh-old",
+		});
+	});
 });
diff --git a/packages/coding-agent/test/mcp-manager-oauth-refresh.test.ts b/packages/coding-agent/test/mcp-manager-oauth-refresh.test.ts
index 7c5f1521e..8ad061a0f 100644
--- a/packages/coding-agent/test/mcp-manager-oauth-refresh.test.ts
+++ b/packages/coding-agent/test/mcp-manager-oauth-refresh.test.ts
@@ -10,7 +10,7 @@
  * Bearer injection, so the next request surfaces a clean auth error instead.
  */
 import { Database } from "bun:sqlite";
-import { afterEach, beforeEach, describe, expect, test, vi } from "bun:test";
+import { afterEach, beforeEach, describe, expect, setSystemTime, test, vi } from "bun:test";
 import * as fs from "node:fs/promises";
 import * as os from "node:os";
 import * as path from "node:path";
@@ -37,6 +37,54 @@ function getAuthorizationHeader(config: MCPServerConfig): string | undefined {
 	return config.headers?.Authorization;
 }
 
+type ControlledSleep = {
+	ms: number;
+	resolved: boolean;
+	resolve: () => void;
+};
+
+function installControlledBunSleep(): ControlledSleep[] {
+	const calls: ControlledSleep[] = [];
+	vi.spyOn(Bun, "sleep").mockImplementation((ms: number | Date) => {
+		const { promise, resolve } = Promise.withResolvers<void>();
+		let call: ControlledSleep;
+		const delayMs = typeof ms === "number" ? ms : Math.max(0, ms.getTime() - Date.now());
+		call = {
+			ms: delayMs,
+			resolved: false,
+			resolve: () => {
+				if (call.resolved) return;
+				call.resolved = true;
+				resolve();
+			},
+		};
+		calls.push(call);
+		return promise;
+	});
+	return calls;
+}
+
+async function drainMicrotasks(count = 10): Promise<void> {
+	for (let attempt = 0; attempt < count; attempt++) {
+		await Promise.resolve();
+	}
+}
+
+async function waitForControlledSleep(calls: ControlledSleep[], ms: number): Promise<ControlledSleep> {
+	for (let attempt = 0; attempt < 20; attempt++) {
+		const call = calls.find(candidate => !candidate.resolved && candidate.ms === ms);
+		if (call) return call;
+		await Promise.resolve();
+	}
+	throw new Error(`Timed out waiting for Bun.sleep(${ms})`);
+}
+
+function resolvePendingControlledSleeps(calls: ControlledSleep[]): void {
+	for (const call of calls) {
+		if (!call.resolved) call.resolve();
+	}
+}
+
 async function withSharedSQLiteAuth<T>(
 	fn: (context: {
 		authA: AuthStorage;
@@ -176,6 +224,98 @@ describe("MCPManager OAuth refresh failure", () => {
 });
 
 describe("MCPManager shared SQLite OAuth refresh", () => {
+	afterEach(() => {
+		setSystemTime();
+		vi.restoreAllMocks();
+	});
+
+	test("renews refresh ownership while the token endpoint is blocked", async () => {
+		await withSharedSQLiteAuth(async ({ authA, authB, storeA }) => {
+			const startMs = Date.parse("2026-07-10T12:00:00.000Z");
+			setSystemTime(new Date(startMs));
+			const sleeps = installControlledBunSleep();
+			const renewSpy = vi.spyOn(storeA, "renewCredentialRefreshLease");
+
+			await authA.set(SHARED_CREDENTIAL_ID, {
+				type: "oauth",
+				access: SHARED_STALE_ACCESS,
+				refresh: SHARED_STALE_REFRESH,
+				expires: startMs - 60_000,
+			});
+			await authB.reload();
+
+			const refreshStarted = Promise.withResolvers<void>();
+			const allowRefreshResponse = Promise.withResolvers<void>();
+			const refreshTokens: string[] = [];
+			let refreshRequests = 0;
+			const tokenServer = Bun.serve({
+				hostname: "127.0.0.1",
+				port: 0,
+				async fetch(req) {
+					if (req.method !== "POST" || new URL(req.url).pathname !== "/token") {
+						return new Response("not found", { status: 404 });
+					}
+					refreshRequests += 1;
+					const body = new URLSearchParams(await req.text());
+					refreshTokens.push(body.get("refresh_token") ?? "");
+					if (refreshRequests === 1) {
+						refreshStarted.resolve();
+						await allowRefreshResponse.promise;
+						return Response.json({
+							access_token: SHARED_FRESH_ACCESS,
+							refresh_token: SHARED_FRESH_REFRESH,
+							expires_in: 3600,
+						});
+					}
+					return Response.json({ error: "invalid_grant" }, { status: 400 });
+				},
+			});
+			try {
+				const managerA = new MCPManager(process.cwd());
+				managerA.setAuthStorage(authA);
+				const managerB = new MCPManager(process.cwd());
+				managerB.setAuthStorage(authB);
+				const config: MCPServerConfig = {
+					type: "http",
+					url: "https://logfire.example.com/mcp",
+					auth: {
+						type: "oauth",
+						credentialId: SHARED_CREDENTIAL_ID,
+						tokenUrl: `http://127.0.0.1:${tokenServer.port}/token`,
+					},
+				};
+
+				const preparedA = managerA.prepareConfig(config);
+				await refreshStarted.promise;
+				const renewalSleep = await waitForControlledSleep(sleeps, 5_000);
+
+				setSystemTime(new Date(startMs + 5_000));
+				renewalSleep.resolve();
+				await drainMicrotasks();
+				expect(renewSpy).toHaveBeenCalledTimes(1);
+
+				setSystemTime(new Date(startMs + 16_000));
+				const preparedB = managerB.prepareConfig(config);
+				const peerLeaseWait = await waitForControlledSleep(sleeps, 250);
+
+				expect(refreshRequests).toBe(1);
+				expect(refreshTokens).toEqual([SHARED_STALE_REFRESH]);
+
+				allowRefreshResponse.resolve();
+				const resolvedA = await preparedA;
+				peerLeaseWait.resolve();
+				const resolvedB = await preparedB;
+
+				expect(getAuthorizationHeader(resolvedA)).toBe(`Bearer ${SHARED_FRESH_ACCESS}`);
+				expect(getAuthorizationHeader(resolvedB)).toBe(`Bearer ${SHARED_FRESH_ACCESS}`);
+				expect(refreshRequests).toBe(1);
+				expect(refreshTokens).toEqual([SHARED_STALE_REFRESH]);
+			} finally {
+				resolvePendingControlledSleeps(sleeps);
+				tokenServer.stop(true);
+			}
+		});
+	});
 	test("shares refresh ownership so peer managers do not replay a rotating refresh token", async () => {
 		await withSharedSQLiteAuth(async ({ authA, authB }) => {
 			await authA.set(SHARED_CREDENTIAL_ID, {