diff --git a/tests/test_litellm/llms/openai_like/test_byesu_provider.py b/tests/test_litellm/llms/openai_like/test_byesu_provider.py
new file mode 100644
index 00000000000..3c75e8f9d1f
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+++ b/tests/test_litellm/llms/openai_like/test_byesu_provider.py
@@ -0,0 +1,97 @@
+"""
+Tests for the `byesu` JSON-configured OpenAI-compatible provider.
+
+byesu is registered purely via litellm/llms/openai_like/providers.json, so these
+tests exercise the JSON registry, provider routing, and the dynamically generated
+config class. No network calls are made.
+"""
+
+import os
+import sys
+
+try:
+    import pytest  # noqa: F401
+except ImportError:
+    pytest = None  # allow standalone execution
+
+sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../../../..")))
+
+import litellm  # noqa: E402
+from litellm import get_llm_provider  # noqa: E402
+
+
+class TestByesuProvider:
+    def test_byesu_loaded_from_json(self):
+        """byesu is discovered by the JSON provider registry."""
+        from litellm.llms.openai_like.json_loader import JSONProviderRegistry
+
+        assert JSONProviderRegistry.exists("byesu")
+
+        cfg = JSONProviderRegistry.get("byesu")
+        assert cfg is not None
+        assert cfg.base_url == "https://byesu.com/v1"
+        assert cfg.api_key_env == "BYESU_API_KEY"
+        assert cfg.api_base_env == "BYESU_API_BASE"
+
+    def test_byesu_in_openai_compatible_providers(self):
+        """byesu is registered as an OpenAI-compatible provider."""
+        from litellm.constants import openai_compatible_providers
+
+        assert "byesu" in openai_compatible_providers
+
+    def test_byesu_get_llm_provider_routing(self):
+        """`byesu/<model>` resolves to custom_llm_provider == 'byesu'."""
+        model, custom_llm_provider, _, _ = get_llm_provider(model="byesu/gpt-4o-mini")
+        assert custom_llm_provider == "byesu"
+        assert model == "gpt-4o-mini"
+
+    def test_byesu_api_base_and_key_resolution(self):
+        """The dynamic config resolves the byesu base URL and honors overrides."""
+        from litellm.llms.openai_like.dynamic_config import create_config_class
+        from litellm.llms.openai_like.json_loader import JSONProviderRegistry
+
+        config_class = create_config_class(JSONProviderRegistry.get("byesu"))
+        config = config_class()
+
+        # Defaults to the byesu base URL
+        api_base, _ = config._get_openai_compatible_provider_info(None, "test-key")
+        assert api_base == "https://byesu.com/v1"
+
+        # Explicit overrides win
+        api_base, api_key = config._get_openai_compatible_provider_info(
+            "https://custom.example.com/v1", "override-key"
+        )
+        assert api_base == "https://custom.example.com/v1"
+        assert api_key == "override-key"
+
+    def test_byesu_param_mapping(self):
+        """max_completion_tokens is mapped to max_tokens per providers.json."""
+        from litellm.llms.openai_like.dynamic_config import create_config_class
+        from litellm.llms.openai_like.json_loader import JSONProviderRegistry
+
+        config_class = create_config_class(JSONProviderRegistry.get("byesu"))
+        config = config_class()
+
+        result = config.map_openai_params(
+            {"max_completion_tokens": 128},
+            {},
+            "gpt-4o-mini",
+            False,
+        )
+        assert result.get("max_tokens") == 128
+        assert "max_completion_tokens" not in result
+
+    def test_byesu_declares_responses_api(self):
+        """byesu declares /v1/responses support."""
+        from litellm.llms.openai_like.json_loader import JSONProviderRegistry
+
+        assert JSONProviderRegistry.supports_responses_api("byesu")
+
+
+if __name__ == "__main__":
+    t = TestByesuProvider()
+    for name in dir(t):
+        if name.startswith("test_"):
+            getattr(t, name)()
+            print(f"PASS {name}")
+    print("All byesu provider tests passed.")