diff --git a/litellm/llms/openai_like/dynamic_config.py b/litellm/llms/openai_like/dynamic_config.py
index fac453447fa..abe9974d550 100644
--- a/litellm/llms/openai_like/dynamic_config.py
+++ b/litellm/llms/openai_like/dynamic_config.py
@@ -4,6 +4,8 @@ Dynamic configuration class generator for JSON-based providers.
 
 from typing import Any, Coroutine, List, Literal, Optional, Tuple, Union, overload
 
+import httpx
+
 from litellm._logging import verbose_logger
 from litellm.litellm_core_utils.prompt_templates.common_utils import (
     handle_messages_with_content_list_to_str_conversion,
@@ -165,6 +167,61 @@ def create_config_class(provider: SimpleProviderConfig):
 
             return optional_params
 
+        def should_retry_llm_api_inside_llm_translation_on_http_error(
+            self, e: httpx.HTTPStatusError, litellm_params: dict
+        ) -> bool:
+            """
+            Retry on 422 UnprocessableEntity when drop_params is enabled.
+
+            OpenAI-compatible providers may reject unknown parameters.
+            When drop_params is set, strip the offending params and retry.
+            """
+            import litellm as _litellm
+
+            should_drop = litellm_params.get("drop_params") or _litellm.drop_params
+            if should_drop and e.response.status_code == 422:
+                error_text = e.response.text
+                if "Extra inputs are not permitted" in error_text:
+                    return True
+            return super().should_retry_llm_api_inside_llm_translation_on_http_error(
+                e=e, litellm_params=litellm_params
+            )
+
+        @property
+        def max_retry_on_unprocessable_entity_error(self) -> int:
+            return 2
+
+        def transform_request_on_unprocessable_entity_error(
+            self, e: httpx.HTTPStatusError, request_data: dict
+        ) -> dict:
+            """
+            On 422, attempt to extract the offending field name from the error
+            response and remove it from the request data before retrying.
+            """
+            import json as _json
+
+            try:
+                error_body = _json.loads(e.response.text)
+                error_msg = str(error_body)
+            except Exception:
+                error_msg = e.response.text
+
+            if "Extra inputs are not permitted" in error_msg:
+                # Try to extract field name from error message pattern like:
+                # "field_name: Extra inputs are not permitted"
+                for line in error_msg.split(","):
+                    line = line.strip()
+                    if "Extra inputs are not permitted" in line:
+                        field = line.split(":")[0].strip().strip("'\"{ ")
+                        if field and field in request_data:
+                            verbose_logger.debug(
+                                f"Removing unsupported param '{field}' from "
+                                f"request to {provider.slug} on retry"
+                            )
+                            request_data.pop(field, None)
+
+            return request_data
+
         @property
         def custom_llm_provider(self) -> Optional[str]:
             return provider.slug
diff --git a/litellm/types/utils.py b/litellm/types/utils.py
index ed29d49fc29..7b8abcbbdd0 100644
--- a/litellm/types/utils.py
+++ b/litellm/types/utils.py
@@ -3327,6 +3327,13 @@ class LlmProviders(str, Enum):
     NANOGPT = "nano-gpt"
     POE = "poe"
     CHUTES = "chutes"
+    AVIAN = "avian"
+    ABLITERATION = "abliteration"
+    LLAMAGATE = "llamagate"
+    GMI = "gmi"
+    SARVAM = "sarvam"
+    AIHUBMIX = "aihubmix"
+    VENICEAI = "veniceai"
     XIAOMI_MIMO = "xiaomi_mimo"
     LITELLM_AGENT = "litellm_agent"
     CURSOR = "cursor"
diff --git a/tests/litellm/llms/openai_like/test_avian_provider.py b/tests/litellm/llms/openai_like/test_avian_provider.py
index 410b68a8341..7271ef4d434 100644
--- a/tests/litellm/llms/openai_like/test_avian_provider.py
+++ b/tests/litellm/llms/openai_like/test_avian_provider.py
@@ -5,6 +5,9 @@ Unit tests for the Avian OpenAI-like provider.
 import os
 import sys
 
+import httpx
+import pytest
+
 sys.path.insert(
     0, os.path.abspath(os.path.join(os.path.dirname(__file__), "../../../.."))
 )
@@ -48,3 +51,63 @@ def test_avian_complete_url_appends_endpoint():
         stream=False,
     )
     assert url == f"{AVIAN_BASE_URL}/chat/completions"
+
+
+def test_avian_in_provider_list():
+    from litellm.types.utils import LlmProviders
+
+    assert LlmProviders.AVIAN.value == "avian"
+
+
+def test_avian_retry_on_422_with_drop_params():
+    config = _get_config()
+    mock_request = httpx.Request(method="POST", url=AVIAN_BASE_URL)
+    mock_response = httpx.Response(
+        status_code=422,
+        text='{"detail": "max_completion_tokens: Extra inputs are not permitted"}',
+        request=mock_request,
+    )
+    error = httpx.HTTPStatusError(
+        message="422", request=mock_request, response=mock_response
+    )
+    assert config.should_retry_llm_api_inside_llm_translation_on_http_error(
+        e=error, litellm_params={"drop_params": True}
+    )
+
+
+def test_avian_no_retry_without_drop_params():
+    config = _get_config()
+    mock_request = httpx.Request(method="POST", url=AVIAN_BASE_URL)
+    mock_response = httpx.Response(
+        status_code=422,
+        text='{"detail": "Extra inputs are not permitted"}',
+        request=mock_request,
+    )
+    error = httpx.HTTPStatusError(
+        message="422", request=mock_request, response=mock_response
+    )
+    assert not config.should_retry_llm_api_inside_llm_translation_on_http_error(
+        e=error, litellm_params={}
+    )
+
+
+def test_avian_max_retry_count():
+    config = _get_config()
+    assert config.max_retry_on_unprocessable_entity_error == 2
+
+
+@pytest.mark.flaky(retries=3, delay=1)
+@pytest.mark.skipif(
+    not os.environ.get("AVIAN_API_KEY"),
+    reason="AVIAN_API_KEY not set",
+)
+def test_avian_chat_completion():
+    """Live API test — requires AVIAN_API_KEY."""
+    import litellm
+
+    response = litellm.completion(
+        model="avian/deepseek/deepseek-v3.2",
+        messages=[{"role": "user", "content": "Say hello in one word."}],
+        max_tokens=10,
+    )
+    assert response.choices[0].message.content is not None