diff --git a/src/lib/providers/validation/webProvidersA.ts b/src/lib/providers/validation/webProvidersA.ts
index 1a6aa00380..a1b20f1df9 100644
--- a/src/lib/providers/validation/webProvidersA.ts
+++ b/src/lib/providers/validation/webProvidersA.ts
@@ -116,6 +116,7 @@ export async function validateDeepSeekWebProvider({ apiKey }: any) {
       return {
         valid: false,
         error: "userToken is invalid or expired — get a fresh one from localStorage",
+        statusCode: resp.status,
       };
     }
     if (!resp.ok) {
@@ -123,6 +124,20 @@ export async function validateDeepSeekWebProvider({ apiKey }: any) {
     }
     const json = await resp.json();
     const bizData = json?.data?.biz_data || json?.biz_data;
+
+    // DeepSeek's web endpoint can report auth rejection as HTTP 200 with an
+    // application-level error envelope. Code 40003 is the observed
+    // "Authorization Failed" signal. Preserve the real HTTP behavior while
+    // returning an auth-classifiable status to OmniRoute's connection-test
+    // layer so it is not collapsed into a generic upstream_error.
+    if (Number(json?.code) === 40003) {
+      return {
+        valid: false,
+        error: "userToken is invalid or expired — get a fresh one from localStorage",
+        statusCode: 401,
+      };
+    }
+
     if (!bizData?.token) {
       return {
         valid: false,
diff --git a/tests/unit/deepseek-web-auth-semantics.test.ts b/tests/unit/deepseek-web-auth-semantics.test.ts
new file mode 100644
index 0000000000..2e34a87dac
--- /dev/null
+++ b/tests/unit/deepseek-web-auth-semantics.test.ts
@@ -0,0 +1,132 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { validateDeepSeekWebProvider } = await import(
+  "../../src/lib/providers/validation/webProvidersA.ts"
+);
+const { classifyFailure } = await import(
+  "../../src/app/api/providers/[id]/test/route.ts"
+);
+
+const SYNTHETIC_INVALID_TOKEN = "omniroute-auth-keeper-invalid-session-deepseek";
+
+type DeepSeekValidationResult = Awaited<ReturnType<typeof validateDeepSeekWebProvider>>;
+
+function statusCodeOf(result: DeepSeekValidationResult): number | undefined {
+  if ("statusCode" in result && typeof result.statusCode === "number") {
+    return result.statusCode;
+  }
+  return undefined;
+}
+
+async function withFetchResponse(body: unknown, status: number, fn: () => Promise<void>) {
+  const originalFetch = globalThis.fetch;
+  globalThis.fetch = async () =>
+    new Response(JSON.stringify(body), {
+      status,
+      headers: { "Content-Type": "application/json" },
+    });
+
+  try {
+    await fn();
+  } finally {
+    globalThis.fetch = originalFetch;
+  }
+}
+
+test("DeepSeek HTTP 200 code 40003 is surfaced as auth-classifiable 401", async () => {
+  await withFetchResponse(
+    {
+      code: 40003,
+      msg: "Authorization Failed",
+      data: { biz_data: null },
+    },
+    200,
+    async () => {
+      const result = await validateDeepSeekWebProvider({
+        apiKey: SYNTHETIC_INVALID_TOKEN,
+      });
+      const statusCode = statusCodeOf(result);
+
+      assert.equal(result.valid, false);
+      assert.equal(statusCode, 401);
+      assert.match(String(result.error ?? ""), /invalid or expired/i);
+      assert.doesNotMatch(String(result.error ?? ""), new RegExp(SYNTHETIC_INVALID_TOKEN));
+
+      const diagnosis = classifyFailure({
+        error: result.error,
+        statusCode,
+        provider: "deepseek-web",
+      });
+      assert.equal(diagnosis.type, "upstream_auth_error");
+      assert.equal(diagnosis.code, "401");
+    }
+  );
+});
+
+test("DeepSeek unknown HTTP 200 business failure is not synthesized into 401", async () => {
+  await withFetchResponse(
+    {
+      code: 49999,
+      msg: "Temporary provider condition",
+      data: { biz_data: null },
+    },
+    200,
+    async () => {
+      const result = await validateDeepSeekWebProvider({
+        apiKey: SYNTHETIC_INVALID_TOKEN,
+      });
+      const statusCode = statusCodeOf(result);
+
+      assert.equal(result.valid, false);
+      assert.equal(statusCode, undefined);
+
+      const diagnosis = classifyFailure({
+        error: result.error,
+        statusCode,
+        provider: "deepseek-web",
+      });
+      assert.equal(diagnosis.type, "upstream_error");
+      assert.equal(diagnosis.code, "upstream_error");
+    }
+  );
+});
+
+test("DeepSeek literal 401 and 403 preserve their HTTP auth status", async () => {
+  for (const status of [401, 403]) {
+    await withFetchResponse({}, status, async () => {
+      const result = await validateDeepSeekWebProvider({
+        apiKey: SYNTHETIC_INVALID_TOKEN,
+      });
+      const statusCode = statusCodeOf(result);
+
+      assert.equal(result.valid, false);
+      assert.equal(statusCode, status);
+
+      const diagnosis = classifyFailure({
+        error: result.error,
+        statusCode,
+        provider: "deepseek-web",
+      });
+      assert.equal(diagnosis.type, "upstream_auth_error");
+      assert.equal(diagnosis.code, String(status));
+    });
+  }
+});
+
+test("DeepSeek valid HTTP 200 response with derived token remains healthy", async () => {
+  await withFetchResponse(
+    {
+      code: 0,
+      msg: "",
+      data: { biz_data: { token: "synthetic-derived-access-token" } },
+    },
+    200,
+    async () => {
+      const result = await validateDeepSeekWebProvider({
+        apiKey: "synthetic-valid-user-token",
+      });
+      assert.deepEqual(result, { valid: true, error: null });
+    }
+  );
+});