diff --git a/package.json b/package.json
index 939bda6..a1394b3 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@dudko.dev/agent-web",
-  "version": "0.0.11",
+  "version": "0.0.12",
   "description": "Headless, configurable in-browser LLM agent on the Vercel AI SDK: multi-provider bring-your-own-key (OpenAI, Anthropic, Google, xAI, DeepSeek, gateway, openai-compatible) AND local WebGPU/WebLLM, native + prompted tool-calling, structured output, an encrypted IndexedDB token vault, and a plan \u2192 execute \u2192 replan \u2192 synthesize loop. UI-agnostic.",
   "type": "module",
   "sideEffects": false,
diff --git a/src/mcp/index.ts b/src/mcp/index.ts
index 6140c15..957d815 100644
--- a/src/mcp/index.ts
+++ b/src/mcp/index.ts
@@ -1,4 +1,9 @@
 export { connectMcpHttp, flattenContent } from './http.js'
+// Re-exported so a host can identify an authorization failure by identity.
+// The SDK's class does not set `name`, so `err.name === 'UnauthorizedError'`
+// is always false — string sniffing is not an option, and a host that only
+// depends on this package has no other handle on the class.
+export { UnauthorizedError } from '@modelcontextprotocol/sdk/client/auth.js'
 export type {
   McpHttpServerConfig,
   McpCatalogEntry,
diff --git a/tests/mcp.test.ts b/tests/mcp.test.ts
index 77d685e..404881e 100644
--- a/tests/mcp.test.ts
+++ b/tests/mcp.test.ts
@@ -9,6 +9,7 @@ import {
   flattenContent,
   MemoryOAuthStorage,
   readOAuthCallback,
+  UnauthorizedError,
   VaultOAuthStorage,
 } from '../dist/mcp.js'
 
@@ -849,3 +850,20 @@ test('OAuth: a dead refresh token falls back to a fresh authorization', async ()
   // the same doomed refresh.
   assert.equal(await provider.tokens(), undefined)
 })
+
+test('the subpath re-exports UnauthorizedError so a host can identify auth failures', async () => {
+  const mock = createMockServer({ requireAuth: true })
+  const provider = makeProvider()
+  const mcp = await connectMcpHttp({
+    docs: { url: MCP_URL, authProvider: provider, fetch: mock.fetchFn },
+  })
+  assert.equal(mcp.results[0].needsAuthorization, true)
+
+  // The SDK's class never assigns `this.name`, so it reads as "Error" —
+  // a host checking err.name would silently never match. Identity is the
+  // only reliable handle, and it has to be reachable from this package.
+  const err = new UnauthorizedError()
+  assert.equal(err.name, 'Error', 'guards the assumption this export exists for')
+  assert.ok(err instanceof UnauthorizedError)
+  assert.ok(err instanceof Error)
+})