diff --git a/docs/api-patterns.md b/docs/api-patterns.md
index 26c88fc72..83dff8403 100644
--- a/docs/api-patterns.md
+++ b/docs/api-patterns.md
@@ -43,6 +43,8 @@ The `base44Client` automatically handles token refresh:
 2. If expired, refreshes token and saves new tokens
 3. On 401 response, attempts refresh and retries once
 
+Refresh tokens rotate on use, so `refreshAndSaveTokens()` holds a lock file (`~/.base44/auth/auth.json.lock`) across processes. A process that waited for the lock and finds a new refresh token in `auth.json` uses it instead of refreshing again. Auth is deleted only when the server rejects the refresh token (400/401), not on network or server errors.
+
 ## Environment-Supplied Credentials
 
 ### Workspace API keys
@@ -72,7 +74,7 @@ validates), pairs it with `BASE44_REFRESH_TOKEN`, and writes a standard
 
 This overwrites an existing login when env vars are present, and no-ops when
 they can't form a complete record. The seeded file looks like a normal login, so
-a 401 refresh applies to it too; if refresh fails it deletes the file, which
+a 401 refresh applies to it too; if the refresh token is rejected it deletes the file, which
 self-heals on the next command (re-seeded from the still-present env vars). See
 `seedAuthFromEnv()` in `core/auth/config.js`.
 
diff --git a/packages/cli/src/core/auth/config.ts b/packages/cli/src/core/auth/config.ts
index d24bfc489..e524e80cf 100644
--- a/packages/cli/src/core/auth/config.ts
+++ b/packages/cli/src/core/auth/config.ts
@@ -1,16 +1,27 @@
+import { mkdir, open, stat, unlink } from "node:fs/promises";
+import { dirname } from "node:path";
+import { setTimeout as sleep } from "node:timers/promises";
 import jwt, { type JwtPayload } from "jsonwebtoken";
 import { renewAccessToken } from "@/core/auth/api.js";
 import type { AuthData } from "@/core/auth/schema.js";
 import { AuthDataSchema } from "@/core/auth/schema.js";
 import { getAuthFilePath } from "@/core/config.js";
-import { FileReadError, SchemaValidationError } from "@/core/errors.js";
+import {
+  ApiError,
+  FileReadError,
+  SchemaValidationError,
+} from "@/core/errors.js";
 import { deleteFile, readJsonFile, writeJsonFile } from "@/core/utils/fs.js";
 
 // Buffer time before expiration to trigger proactive refresh (60 seconds)
 const TOKEN_REFRESH_BUFFER_MS = 60 * 1000;
 const WORKSPACE_API_KEY_PREFIX = "b44k_";
 
-// Lock to prevent concurrent token refreshes
+// A lock older than this belongs to a process that died mid-refresh
+const REFRESH_LOCK_STALE_MS = 30 * 1000;
+const REFRESH_LOCK_RETRY_MS = 50;
+
+// Lock to prevent concurrent token refreshes within this process
 let refreshPromise: Promise<string | null> | null = null;
 
 export function getWorkspaceApiKeyFromEnv(): string | null {
@@ -131,6 +142,34 @@ export function isTokenExpired(auth: AuthData): boolean {
   return Date.now() >= auth.expiresAt - TOKEN_REFRESH_BUFFER_MS;
 }
 
+// Refresh tokens rotate on use, so parallel CLI processes must not refresh
+// with the same one: the losers would be rejected and log the user out.
+async function withRefreshLock<T>(fn: () => Promise<T>): Promise<T> {
+  const lockPath = `${getAuthFilePath()}.lock`;
+  await mkdir(dirname(lockPath), { recursive: true });
+  for (;;) {
+    try {
+      await (await open(lockPath, "wx")).close();
+      break;
+    } catch (error) {
+      if ((error as NodeJS.ErrnoException).code !== "EEXIST") {
+        throw error;
+      }
+      const lock = await stat(lockPath).catch(() => null);
+      if (lock && Date.now() - lock.mtimeMs > REFRESH_LOCK_STALE_MS) {
+        await unlink(lockPath).catch(() => {});
+      } else {
+        await sleep(REFRESH_LOCK_RETRY_MS);
+      }
+    }
+  }
+  try {
+    return await fn();
+  } finally {
+    await unlink(lockPath).catch(() => {});
+  }
+}
+
 export async function refreshAndSaveTokens(): Promise<string | null> {
   // If a refresh is already in progress, wait for it
   if (refreshPromise) {
@@ -139,20 +178,32 @@ export async function refreshAndSaveTokens(): Promise<string | null> {
 
   refreshPromise = (async () => {
     try {
-      const auth = await readAuth();
-      const tokenResponse = await renewAccessToken(auth.refreshToken);
-
-      await writeAuth({
-        ...auth,
-        accessToken: tokenResponse.accessToken,
-        refreshToken: tokenResponse.refreshToken,
-        expiresAt: Date.now() + tokenResponse.expiresIn * 1000,
+      const staleRefreshToken = (await readAuth()).refreshToken;
+      return await withRefreshLock(async () => {
+        const auth = await readAuth();
+        if (auth.refreshToken !== staleRefreshToken) {
+          // Another process refreshed while we waited for the lock
+          return auth.accessToken;
+        }
+
+        const tokenResponse = await renewAccessToken(auth.refreshToken);
+        await writeAuth({
+          ...auth,
+          accessToken: tokenResponse.accessToken,
+          refreshToken: tokenResponse.refreshToken,
+          expiresAt: Date.now() + tokenResponse.expiresIn * 1000,
+        });
+        return tokenResponse.accessToken;
       });
-
-      return tokenResponse.accessToken;
-    } catch {
-      // Refresh failed - delete auth, user needs to login again
-      await deleteAuth();
+    } catch (error) {
+      // Only a rejected refresh token means the user must log in again;
+      // keep auth on network or server errors.
+      if (
+        error instanceof ApiError &&
+        (error.statusCode === 400 || error.statusCode === 401)
+      ) {
+        await deleteAuth();
+      }
       return null;
     } finally {
       refreshPromise = null;
diff --git a/packages/cli/tests/cli/authorization.spec.ts b/packages/cli/tests/cli/authorization.spec.ts
index e15a1e6ec..7582bc99c 100644
--- a/packages/cli/tests/cli/authorization.spec.ts
+++ b/packages/cli/tests/cli/authorization.spec.ts
@@ -1,4 +1,4 @@
-import { describe, it } from "vitest";
+import { describe, expect, it } from "vitest";
 import { fixture, setupCLITests } from "./testkit/index.js";
 
 const APP_ID = "test-app-id";
@@ -65,6 +65,57 @@ describe("token refresh on 401", () => {
     t.expectResult(result).toContain("Entities pushed");
   });
 
+  it("keeps parallel commands logged in when they refresh with the same rotating token", async () => {
+    await t.givenLoggedInWithProject(fixture("with-agents"));
+
+    // The server rotates refresh tokens: the original works once, then is rejected.
+    const tokenRequests: Array<() => void> = [];
+    let refreshTokenUsed = false;
+    t.api.mockRoute("POST", "/oauth/token", (_req, res) => {
+      const respond = () => {
+        if (refreshTokenUsed) {
+          res.status(400).json({ error: "invalid_grant" });
+          return;
+        }
+        refreshTokenUsed = true;
+        res.json({
+          access_token: "rotated-access-token",
+          refresh_token: "rotated-refresh-token",
+          expires_in: 3600,
+          token_type: "Bearer",
+        });
+      };
+      const releaseAll = () => {
+        for (const held of tokenRequests.splice(0)) held();
+      };
+      // Hold the first refresh until the second process asks too (or 2s pass).
+      tokenRequests.push(respond);
+      if (tokenRequests.length === 1) {
+        setTimeout(releaseAll, 2000);
+      } else {
+        releaseAll();
+      }
+    });
+    t.api.mockRoute("PUT", `/api/apps/${APP_ID}/agent-configs`, (req, res) => {
+      if (req.headers.authorization !== "Bearer rotated-access-token") {
+        res.status(401).json({ error: "Unauthorized" });
+        return;
+      }
+      res.json({ created: [], updated: [], deleted: [] });
+    });
+
+    const results = await Promise.all([
+      t.run("agents", "push", "--yes"),
+      t.run("agents", "push", "--yes"),
+    ]);
+
+    for (const result of results) {
+      t.expectResult(result).toSucceed();
+    }
+    const auth = await t.readAuthFile();
+    expect(auth?.refreshToken).toBe("rotated-refresh-token");
+  });
+
   it("fails with actual error when token refresh also fails", async () => {
     await t.givenLoggedInWithProject(fixture("with-agents"));