diff --git a/tests/cli/test_oidc_utils.py b/tests/cli/test_oidc_utils.py
new file mode 100644
index 000000000..69e760a38
--- /dev/null
+++ b/tests/cli/test_oidc_utils.py
@@ -0,0 +1,96 @@
+"""
+Unit tests for OidcUtils.get_auth_config() method.
+
+IMPORTANT: Backwards Compatibility Notice
+=========================================
+If any values in auth_config.json are changed, we MUST maintain backwards
+compatibility with release/2025.10 branches or later.
+"""
+
+import json
+import os
+
+
+class TestOidcUtils:
+    """Test suite for OidcUtils class."""
+
+    def test_auth_config_backwards_compatibility_v2025_10(self):
+        """
+        Test that auth_config.json maintains backwards compatibility with release/v2025.10.
+
+        This test validates that the authentication configuration values remain
+        unchanged to ensure compatibility with release/v2025.10 and later branches.
+
+        CRITICAL: Any failure indicates a breaking change that requires coordination
+        across all supported release branches.
+        """
+        # Read the actual auth_config.json file
+        config_path = os.path.join(
+            os.path.dirname(__file__),
+            "..",
+            "..",
+            "src",
+            "uipath",
+            "_cli",
+            "_auth",
+            "auth_config.json",
+        )
+
+        with open(config_path, "r") as f:
+            actual_config = json.load(f)
+
+        # Assert exact values for non-scope fields
+        assert actual_config["client_id"] == "36dea5b8-e8bb-423d-8e7b-c808df8f1c00", (
+            f"BACKWARDS COMPATIBILITY VIOLATION: client_id has changed! "
+            f"Expected: 36dea5b8-e8bb-423d-8e7b-c808df8f1c00, Got: {actual_config['client_id']}"
+        )
+
+        assert (
+            actual_config["redirect_uri"]
+            == "http://localhost:__PY_REPLACE_PORT__/oidc/login"
+        ), (
+            f"BACKWARDS COMPATIBILITY VIOLATION: redirect_uri has changed! "
+            f"Expected: http://localhost:__PY_REPLACE_PORT__/oidc/login, Got: {actual_config['redirect_uri']}"
+        )
+
+        assert actual_config["port"] == 8104, (
+            f"BACKWARDS COMPATIBILITY VIOLATION: port has changed! "
+            f"Expected: 8104, Got: {actual_config['port']}"
+        )
+
+        # For scopes, ensure actual scopes are a subset of the allowed scopes (no new scopes allowed)
+        allowed_scopes = set(
+            [
+                "offline_access",
+                "ProcessMining",
+                "OrchestratorApiUserAccess",
+                "StudioWebBackend",
+                "IdentityServerApi",
+                "ConnectionService",
+                "DataService",
+                "DocumentUnderstanding",
+                "Du.Digitization.Api",
+                "Du.Classification.Api",
+                "Du.Extraction.Api",
+                "Du.Validation.Api",
+                "EnterpriseContextService",
+                "Directory",
+                "JamJamApi",
+                "LLMGateway",
+                "LLMOps",
+                "OMS",
+                "RCS.FolderAuthorization",
+                "TM.Projects",
+                "TM.TestCases",
+                "TM.Requirements",
+                "TM.TestSets",
+            ]
+        )
+
+        actual_scopes = set(actual_config["scope"].split())
+
+        assert actual_scopes.issubset(allowed_scopes), (
+            f"BACKWARDS COMPATIBILITY VIOLATION: New scopes detected that are not allowed on v2025.10! "
+            f"New scopes: {actual_scopes - allowed_scopes}. "
+            f"Only subsets of the following scopes are permitted: {sorted(allowed_scopes)}"
+        )