diff --git a/packages/devframe/src/adapters/__tests__/dev.test.ts b/packages/devframe/src/adapters/__tests__/dev.test.ts
index a471a346..744f9234 100644
--- a/packages/devframe/src/adapters/__tests__/dev.test.ts
+++ b/packages/devframe/src/adapters/__tests__/dev.test.ts
@@ -442,6 +442,99 @@ describe('adapters/dev', () => {
     }
   })
 
+  it('the `auth: false` option overrides a gated `def.cli.auth` (hosted adapter defers to the host)', async () => {
+    const devframe = defineDevframe({
+      id: 'devframe-auth-option-off',
+      name: 'Auth Option Off',
+      version: '0.0.0',
+      packageName: 'devframe-test',
+      homepage: 'https://example.test',
+      description: 'Test devframe.',
+      // Standalone would gate; a hosted caller passes `auth: false` to defer.
+      cli: { auth: true },
+      setup: (ctx: DevframeNodeContext) => {
+        ctx.rpc.register({ name: 'test:probe', type: 'query', handler: () => 'ok' })
+      },
+    })
+    const host = '127.0.0.1'
+    const port = await getPort({ port: 19440, host })
+    const handle = await createDevServer(devframe, { host, port, openBrowser: false, auth: false })
+
+    try {
+      const client = connectWsClient(host, port)
+      const handshake = await client.$call('anonymous:devframe:auth' as any, HANDSHAKE)
+      expect(handshake).toEqual({ isTrusted: true })
+      await expect(client.$call('test:probe' as any)).resolves.toBe('ok')
+      client.$close()
+    }
+    finally {
+      await handle.close()
+    }
+  })
+
+  it('the `auth: true` option forces the gate on even when `def.cli.auth` is false', async () => {
+    const devframe = defineDevframe({
+      id: 'devframe-auth-option-on',
+      name: 'Auth Option On',
+      version: '0.0.0',
+      packageName: 'devframe-test',
+      homepage: 'https://example.test',
+      description: 'Test devframe.',
+      cli: { auth: false },
+      setup: (ctx: DevframeNodeContext) => {
+        ctx.rpc.register({ name: 'test:probe', type: 'query', handler: () => 'ok' })
+      },
+    })
+    const host = '127.0.0.1'
+    const port = await getPort({ port: 19450, host })
+    // Silence the default OTP stdout banner for the test run.
+    const spy = vi.spyOn(console, 'log').mockImplementation(() => {})
+    const handle = await createDevServer(devframe, { host, port, openBrowser: false, auth: true })
+
+    try {
+      const client = connectWsClient(host, port)
+      // Gated: an empty handshake token is refused until a code is exchanged.
+      const handshake = await client.$call('anonymous:devframe:auth' as any, HANDSHAKE)
+      expect(handshake).toEqual({ isTrusted: false })
+      const code = getTempAuthCode()
+      const exchange = await client.$call('anonymous:devframe:auth:exchange' as any, { code, ua: 'test', origin: 'http://localhost' }) as { authToken: string | null }
+      expect(exchange.authToken).toBeTruthy()
+      client.$close()
+    }
+    finally {
+      spy.mockRestore()
+      await handle.close()
+    }
+  })
+
+  it('the `--no-auth` flag forces the gate off even when the `auth: true` option opts in', async () => {
+    const devframe = defineDevframe({
+      id: 'devframe-auth-flag-wins',
+      name: 'Auth Flag Wins',
+      version: '0.0.0',
+      packageName: 'devframe-test',
+      homepage: 'https://example.test',
+      description: 'Test devframe.',
+      setup: (ctx: DevframeNodeContext) => {
+        ctx.rpc.register({ name: 'test:probe', type: 'query', handler: () => 'ok' })
+      },
+    })
+    const host = '127.0.0.1'
+    const port = await getPort({ port: 19460, host })
+    const handle = await createDevServer(devframe, { host, port, openBrowser: false, auth: true, flags: { auth: false } })
+
+    try {
+      const client = connectWsClient(host, port)
+      const handshake = await client.$call('anonymous:devframe:auth' as any, HANDSHAKE)
+      expect(handshake).toEqual({ isTrusted: true })
+      await expect(client.$call('test:probe' as any)).resolves.toBe('ok')
+      client.$close()
+    }
+    finally {
+      await handle.close()
+    }
+  })
+
   it('resolveDevServerPort honors def.cli.port as the preferred default', async () => {
     const preferred = await getPort({ port: 19500, host: '127.0.0.1' })
     const devframe = defineDevframe({
diff --git a/packages/devframe/src/adapters/dev.ts b/packages/devframe/src/adapters/dev.ts
index 706d04b5..a6143567 100644
--- a/packages/devframe/src/adapters/dev.ts
+++ b/packages/devframe/src/adapters/dev.ts
@@ -68,6 +68,17 @@ export interface CreateDevServerOptions {
    * sources; a string opens that relative path.
    */
   openBrowser?: boolean | string
+  /**
+   * Override how authentication resolves, taking precedence over
+   * `def.cli?.auth`. Pass `false` to skip the gate entirely (the standard
+   * choice for a **hosted** deployment where the host manages auth — see
+   * {@link viteDevBridge}); a {@link DevframeAuthHandler} to install a custom
+   * scheme; or `true` to force devframe's interactive OTP gate on. When
+   * omitted, auth resolves from `flags.auth` / `def.cli?.auth` (the standalone
+   * default: gated). The `--no-auth` flag (`flags.auth === false`) still forces
+   * the gate off regardless of this option.
+   */
+  auth?: boolean | DevframeAuthHandler
   /**
    * Expose a route-based MCP server on the dev server (Streamable-HTTP).
    * Overrides `def.cli?.mcp`; `undefined` falls through to it. `false`
@@ -212,8 +223,15 @@ export async function createDevServer(
   // interactive OTP handler and print its code + magic-link banner once the
   // server is listening (a gate is useless without surfacing the code). A
   // `false` (including the `--no-auth` flag) opts out; a handler object is
-  // passed straight through to `startHttpAndWs`.
-  const authOption = flags.auth === false ? false : def.cli?.auth
+  // passed straight through to `startHttpAndWs`. An explicit `options.auth`
+  // wins over the definition default — a hosted adapter (e.g. `viteDevBridge`)
+  // passes `false` so the plugin's own gate never fires and the host owns auth
+  // — but the `--no-auth` flag can still force the gate off.
+  const authOption = flags.auth === false
+    ? false
+    : options.auth !== undefined
+      ? options.auth
+      : def.cli?.auth
   let authHandler: DevframeAuthHandler | undefined
   let resolvedAuth: boolean | DevframeAuthHandler
   if (authOption === false) {
diff --git a/packages/devframe/src/helpers/vite.ts b/packages/devframe/src/helpers/vite.ts
index 57f00f21..82accb7b 100644
--- a/packages/devframe/src/helpers/vite.ts
+++ b/packages/devframe/src/helpers/vite.ts
@@ -1,3 +1,4 @@
+import type { DevframeAuthHandler } from '../node/auth/handler'
 import type { DevframeDefinition } from '../types/devframe'
 import { serveStaticNodeMiddleware } from 'devframe/utils/serve-static'
 import { resolve } from 'pathe'
@@ -36,6 +37,19 @@ export interface ViteDevBridgeOptions {
     /** Flag bag forwarded to `def.setup(ctx, { flags })`. */
     flags?: Record<string, unknown>
   }
+  /**
+   * Whether the bridged devframe runs its own auth gate. This is a **hosted**
+   * adapter — the devframe shares the host app's origin and the host owns
+   * authentication — so it defaults to `false`: the plugin's own gate never
+   * fires and its `cli.auth` default is ignored (matching devframe's
+   * hosted-deployment contract). Pass `true` to force devframe's interactive
+   * OTP gate on, or a {@link DevframeAuthHandler} to install a custom scheme.
+   * Only applies in bridge mode (`devMiddleware`); the static-mount mode
+   * starts no RPC server.
+   *
+   * @default false
+   */
+  auth?: boolean | DevframeAuthHandler
 }
 
 export interface DevframeVitePlugin {
@@ -62,6 +76,12 @@ export interface DevframeVitePlugin {
  *     host-served SPA can discover the WS endpoint via
  *     {@link connectDevframe}.
  *
+ * As a hosted adapter the bridge defers authentication to the host: its
+ * side-car RPC server runs with the plugin's own auth gate **off** by
+ * default (ignoring `def.cli?.auth`), so a plugin mounted this way never
+ * triggers its standalone OTP prompt. Opt back in per-mount with
+ * `options.auth` (`true` for devframe's interactive gate, or a handler).
+ *
  * Use bridge mode when integrating with frameworks that own the SPA
  * (Nuxt, Astro, SolidStart, plain Vite apps). For the all-in-one
  * `dev` / `build` / `mcp` shell, reach for {@link createCac} instead.
@@ -103,6 +123,9 @@ export function viteDevBridge(d: DevframeDefinition, options: ViteDevBridgeOptio
           port,
           flags: mw.flags,
           openBrowser: false,
+          // Hosted adapter: the host owns auth, so the bridged devframe's own
+          // gate stays off unless the caller explicitly opts back in.
+          auth: options.auth ?? false,
         })
       }
       catch (e) {
diff --git a/plugins/og/src/spa/vite.config.ts b/plugins/og/src/spa/vite.config.ts
index ba285d2b..745400c8 100644
--- a/plugins/og/src/spa/vite.config.ts
+++ b/plugins/og/src/spa/vite.config.ts
@@ -12,7 +12,7 @@ export default defineConfig({
   plugins: [
     vue(),
     UnoCSS(),
-    ogVitePlugin({ devMiddleware: true, base: '/', auth: false }),
+    ogVitePlugin({ devMiddleware: true, base: '/' }),
   ],
   optimizeDeps: { exclude: ['@antfu/design'] },
   build: {
diff --git a/plugins/og/src/vite.ts b/plugins/og/src/vite.ts
index cf17e5f5..e609509c 100644
--- a/plugins/og/src/vite.ts
+++ b/plugins/og/src/vite.ts
@@ -1,16 +1,16 @@
 import type { DevframeVitePlugin, ViteDevBridgeOptions } from 'devframe/helpers/vite'
 import { viteDevBridge } from 'devframe/helpers/vite'
-import ogDevframe, { createOgDevframe } from './index'
+import ogDevframe from './index'
 
 export type { ViteDevBridgeOptions }
 
-export interface OgVitePluginOptions extends ViteDevBridgeOptions {
-  /** Override standalone trust for the bridge; useful for local SPA development. */
-  auth?: boolean
-}
+export type OgVitePluginOptions = ViteDevBridgeOptions
 
+/**
+ * Mount the OG image preview into an existing Vite dev server. As a hosted
+ * adapter it defers authentication to the host, so the bridged devframe's own
+ * gate stays off by default — opt back in with `{ auth: true }`.
+ */
 export function ogVitePlugin(options: OgVitePluginOptions = {}): DevframeVitePlugin {
-  const { auth, ...bridgeOptions } = options
-  const definition = auth === undefined ? ogDevframe : createOgDevframe({ auth })
-  return viteDevBridge(definition, bridgeOptions)
+  return viteDevBridge(ogDevframe, options)
 }
diff --git a/tests/__snapshots__/tsnapi/@devframes/plugin-og/vite.snapshot.d.ts b/tests/__snapshots__/tsnapi/@devframes/plugin-og/vite.snapshot.d.ts
index 883cfcd8..da6b18f3 100644
--- a/tests/__snapshots__/tsnapi/@devframes/plugin-og/vite.snapshot.d.ts
+++ b/tests/__snapshots__/tsnapi/@devframes/plugin-og/vite.snapshot.d.ts
@@ -1,10 +1,8 @@
 /**
  * Generated by tsnapi — public API snapshot of `@devframes/plugin-og/vite`
  */
-// #region Interfaces
-export interface OgVitePluginOptions extends ViteDevBridgeOptions {
-  auth?: boolean;
-}
+// #region Types
+export type OgVitePluginOptions = ViteDevBridgeOptions;
 // #endregion
 
 // #region Functions
diff --git a/tests/__snapshots__/tsnapi/devframe/adapters/dev.snapshot.d.ts b/tests/__snapshots__/tsnapi/devframe/adapters/dev.snapshot.d.ts
index 17c29a5e..45f23a19 100644
--- a/tests/__snapshots__/tsnapi/devframe/adapters/dev.snapshot.d.ts
+++ b/tests/__snapshots__/tsnapi/devframe/adapters/dev.snapshot.d.ts
@@ -11,6 +11,7 @@ export interface CreateDevServerOptions {
   ws?: DevframeWsOptions;
   app?: H3;
   openBrowser?: boolean | string;
+  auth?: boolean | DevframeAuthHandler;
   mcp?: boolean | McpRouteOptions;
   onReady?: (_: {
     origin: string;
diff --git a/tests/__snapshots__/tsnapi/devframe/helpers/vite.snapshot.d.ts b/tests/__snapshots__/tsnapi/devframe/helpers/vite.snapshot.d.ts
index a4efd70d..bfdaa265 100644
--- a/tests/__snapshots__/tsnapi/devframe/helpers/vite.snapshot.d.ts
+++ b/tests/__snapshots__/tsnapi/devframe/helpers/vite.snapshot.d.ts
@@ -22,6 +22,7 @@ export interface ViteDevBridgeOptions {
     host?: string;
     flags?: Record<string, unknown>;
   };
+  auth?: boolean | DevframeAuthHandler;
 }
 // #endregion