diff --git a/README.md b/README.md
index a3ab108c6b..9e282b3e10 100644
--- a/README.md
+++ b/README.md
@@ -176,9 +176,10 @@ Also see [architecture](docs/ARCHITECTURE.md).
 | Provider | Status | Provider | Status |
 |----------|--------|----------|--------|
 | OpenAI | ✅ | Azure OpenAI | ✅ |
-| Anthropic Claude | ✅ | Google Gemini | ✅ |
-| AWS Bedrock | ✅ | Mistral AI | ✅ |
-| Ollama (local) | ✅ | Anyscale | ✅ |
+| OpenAI Compatible | ✅ | Anthropic Claude | ✅ |
+| AWS Bedrock | ✅ | Google Gemini | ✅ |
+| Ollama (local) | ✅ | Mistral AI | ✅ |
+| Anyscale | ✅ | | |
 
 ### Vector Databases
 
diff --git a/frontend/public/icons/adapter-icons/OpenAICompatible.png b/frontend/public/icons/adapter-icons/OpenAICompatible.png
new file mode 100644
index 0000000000..ec23189d9a
Binary files /dev/null and b/frontend/public/icons/adapter-icons/OpenAICompatible.png differ
diff --git a/unstract/sdk1/src/unstract/sdk1/adapters/base1.py b/unstract/sdk1/src/unstract/sdk1/adapters/base1.py
index 8ad721c3d4..427e1d361b 100644
--- a/unstract/sdk1/src/unstract/sdk1/adapters/base1.py
+++ b/unstract/sdk1/src/unstract/sdk1/adapters/base1.py
@@ -225,6 +225,30 @@ def validate_model(adapter_metadata: dict[str, "Any"]) -> str:
             return f"openai/{model}"
 
 
+class OpenAICompatibleLLMParameters(BaseChatCompletionParameters):
+    """See https://docs.litellm.ai/docs/providers/openai_compatible/."""
+
+    api_key: str | None = None
+    api_base: str
+
+    @staticmethod
+    def validate(adapter_metadata: dict[str, "Any"]) -> dict[str, "Any"]:
+        adapter_metadata["model"] = OpenAICompatibleLLMParameters.validate_model(
+            adapter_metadata
+        )
+        api_key = adapter_metadata.get("api_key")
+        if isinstance(api_key, str) and not api_key.strip():
+            adapter_metadata["api_key"] = None
+        return OpenAICompatibleLLMParameters(**adapter_metadata).model_dump()
+
+    @staticmethod
+    def validate_model(adapter_metadata: dict[str, "Any"]) -> str:
+        model = adapter_metadata.get("model", "")
+        if model.startswith("custom_openai/"):
+            return model
+        return f"custom_openai/{model}"
+
+
 class AzureOpenAILLMParameters(BaseChatCompletionParameters):
     """See https://docs.litellm.ai/docs/providers/azure/#completion---using-azure_ad_token-api_base-api_version."""
 
diff --git a/unstract/sdk1/src/unstract/sdk1/adapters/llm1/__init__.py b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/__init__.py
index c23a33390a..1da3590f51 100644
--- a/unstract/sdk1/src/unstract/sdk1/adapters/llm1/__init__.py
+++ b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/__init__.py
@@ -8,6 +8,7 @@
 from unstract.sdk1.adapters.llm1.bedrock import AWSBedrockLLMAdapter
 from unstract.sdk1.adapters.llm1.ollama import OllamaLLMAdapter
 from unstract.sdk1.adapters.llm1.openai import OpenAILLMAdapter
+from unstract.sdk1.adapters.llm1.openai_compatible import OpenAICompatibleLLMAdapter
 from unstract.sdk1.adapters.llm1.vertexai import VertexAILLMAdapter
 
 adapters: dict[str, dict[str, Any]] = {}
@@ -22,5 +23,6 @@
     "AzureOpenAILLMAdapter",
     "OllamaLLMAdapter",
     "OpenAILLMAdapter",
+    "OpenAICompatibleLLMAdapter",
     "VertexAILLMAdapter",
 ]
diff --git a/unstract/sdk1/src/unstract/sdk1/adapters/llm1/openai_compatible.py b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/openai_compatible.py
new file mode 100644
index 0000000000..3cb3ceafc4
--- /dev/null
+++ b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/openai_compatible.py
@@ -0,0 +1,46 @@
+from typing import Any
+
+from unstract.sdk1.adapters.base1 import BaseAdapter, OpenAICompatibleLLMParameters
+from unstract.sdk1.adapters.enums import AdapterTypes
+
+DESCRIPTION = (
+    "Adapter for servers that implement the OpenAI Chat Completions API "
+    "(vLLM, LM Studio, self-hosted gateways, and third-party providers). "
+    "Use OpenAI for the official OpenAI service."
+)
+
+
+class OpenAICompatibleLLMAdapter(OpenAICompatibleLLMParameters, BaseAdapter):
+    @staticmethod
+    def get_id() -> str:
+        return "openaicompatible|b6d10f33-2c41-49fc-a8c2-58d2b247fc09"
+
+    @staticmethod
+    def get_metadata() -> dict[str, Any]:
+        return {
+            "name": "OpenAI Compatible",
+            "version": "1.0.0",
+            "adapter": OpenAICompatibleLLMAdapter,
+            "description": DESCRIPTION,
+            "is_active": True,
+        }
+
+    @staticmethod
+    def get_name() -> str:
+        return "OpenAI Compatible"
+
+    @staticmethod
+    def get_description() -> str:
+        return DESCRIPTION
+
+    @staticmethod
+    def get_provider() -> str:
+        return "custom_openai"
+
+    @staticmethod
+    def get_icon() -> str:
+        return "/icons/adapter-icons/OpenAICompatible.png"
+
+    @staticmethod
+    def get_adapter_type() -> AdapterTypes:
+        return AdapterTypes.LLM
diff --git a/unstract/sdk1/src/unstract/sdk1/adapters/llm1/static/custom_openai.json b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/static/custom_openai.json
new file mode 100644
index 0000000000..f4720c9e92
--- /dev/null
+++ b/unstract/sdk1/src/unstract/sdk1/adapters/llm1/static/custom_openai.json
@@ -0,0 +1,61 @@
+{
+  "title": "OpenAI Compatible LLM",
+  "type": "object",
+  "required": [
+    "adapter_name",
+    "api_base"
+  ],
+  "properties": {
+    "adapter_name": {
+      "type": "string",
+      "title": "Name",
+      "default": "",
+      "description": "Provide a unique name for this adapter instance. Example: compatible-gateway-1"
+    },
+    "api_key": {
+      "type": [
+        "string",
+        "null"
+      ],
+      "title": "API Key",
+      "format": "password",
+      "description": "API key for your OpenAI-compatible endpoint. Leave empty if the endpoint does not require one."
+    },
+    "model": {
+      "type": "string",
+      "title": "Model",
+      "default": "gpt-4o-mini",
+      "description": "The model name expected by your OpenAI-compatible endpoint. Examples: gateway-model, gpt-4o-mini, openai/gpt-4o"
+    },
+    "api_base": {
+      "type": "string",
+      "format": "url",
+      "title": "API Base",
+      "description": "Base URL for the OpenAI-compatible endpoint. Examples: https://gateway.example.com/v1, https://llm.example.net/openai/v1"
+    },
+    "max_tokens": {
+      "type": "number",
+      "minimum": 0,
+      "multipleOf": 1,
+      "title": "Maximum Output Tokens",
+      "default": 4096,
+      "description": "Maximum number of output tokens to limit LLM replies. Leave it empty to use the provider default."
+    },
+    "max_retries": {
+      "type": "number",
+      "minimum": 0,
+      "multipleOf": 1,
+      "title": "Max Retries",
+      "default": 5,
+      "description": "The maximum number of times to retry a request if it fails."
+    },
+    "timeout": {
+      "type": "number",
+      "minimum": 0,
+      "multipleOf": 1,
+      "title": "Timeout",
+      "default": 900,
+      "description": "Timeout in seconds."
+    }
+  }
+}
diff --git a/unstract/sdk1/src/unstract/sdk1/llm.py b/unstract/sdk1/src/unstract/sdk1/llm.py
index 8ff29a89d5..ce5819c9ec 100644
--- a/unstract/sdk1/src/unstract/sdk1/llm.py
+++ b/unstract/sdk1/src/unstract/sdk1/llm.py
@@ -539,10 +539,22 @@ def _record_usage(
         usage: Mapping[str, int] | None,
         llm_api: str,
     ) -> None:
-        prompt_tokens = token_counter(model=model, messages=messages)
         usage_data: Mapping[str, int] = usage or {}
+        prompt_tokens = usage_data.get("prompt_tokens")
+        if prompt_tokens is None:
+            try:
+                prompt_tokens = token_counter(model=model, messages=messages)
+            except Exception as e:
+                prompt_tokens = 0
+                logger.warning(
+                    "[sdk1][LLM][%s][%s] Failed to estimate prompt tokens; "
+                    "recording 0 prompt tokens for usage audit: %s",
+                    model,
+                    llm_api,
+                    e,
+                )
         all_tokens = TokenCounterCompat(
-            prompt_tokens=usage_data.get("prompt_tokens", 0),
+            prompt_tokens=prompt_tokens or 0,
             completion_tokens=usage_data.get("completion_tokens", 0),
             total_tokens=usage_data.get("total_tokens", 0),
         )
diff --git a/unstract/sdk1/tests/test_openai_compatible_adapter.py b/unstract/sdk1/tests/test_openai_compatible_adapter.py
new file mode 100644
index 0000000000..53eade4601
--- /dev/null
+++ b/unstract/sdk1/tests/test_openai_compatible_adapter.py
@@ -0,0 +1,192 @@
+import json
+from functools import lru_cache
+from importlib import import_module
+from unittest.mock import MagicMock, patch
+
+from unstract.sdk1.adapters.base1 import OpenAICompatibleLLMParameters
+from unstract.sdk1.adapters.constants import Common
+from unstract.sdk1.adapters.llm1 import adapters
+from unstract.sdk1.adapters.llm1.openai_compatible import OpenAICompatibleLLMAdapter
+
+OPENAI_COMPATIBLE_DESCRIPTION = (
+    "Adapter for servers that implement the OpenAI Chat Completions API "
+    "(vLLM, LM Studio, self-hosted gateways, and third-party providers). "
+    "Use OpenAI for the official OpenAI service."
+)
+
+
+@lru_cache(maxsize=1)
+def _load_llm_module() -> object:
+    import sys
+    from types import ModuleType
+
+    with patch.dict(
+        sys.modules,
+        {
+            # Stub python-magic so importing LLM does not depend on libmagic
+            # being available in the test environment.
+            "magic": ModuleType("magic")
+        },
+    ):
+        return import_module("unstract.sdk1.llm")
+
+
+def _load_llm_class() -> type:
+    return _load_llm_module().LLM
+
+
+def test_openai_compatible_adapter_is_registered() -> None:
+    adapter_id = OpenAICompatibleLLMAdapter.get_id()
+
+    assert adapter_id in adapters
+    assert adapters[adapter_id][Common.MODULE] is OpenAICompatibleLLMAdapter
+
+
+def test_openai_compatible_validate_prefixes_model() -> None:
+    validated = OpenAICompatibleLLMParameters.validate(
+        {
+            "api_base": "https://gateway.example.com/v1",
+            "api_key": "test-key",
+            "model": "gateway-model",
+        }
+    )
+
+    assert validated["model"] == "custom_openai/gateway-model"
+
+
+def test_openai_compatible_validate_preserves_prefixed_model() -> None:
+    validated = OpenAICompatibleLLMParameters.validate(
+        {
+            "api_base": "https://gateway.example.com/v1",
+            "model": "custom_openai/openai/gpt-4o",
+        }
+    )
+
+    assert validated["model"] == "custom_openai/openai/gpt-4o"
+    assert validated["api_key"] is None
+
+
+def test_openai_compatible_validate_normalizes_blank_api_key_to_none() -> None:
+    validated = OpenAICompatibleLLMParameters.validate(
+        {
+            "api_base": "https://gateway.example.com/v1",
+            "api_key": "   ",
+            "model": "gateway-model",
+        }
+    )
+
+    assert validated["api_key"] is None
+
+
+def test_openai_compatible_schema_is_loadable() -> None:
+    schema = json.loads(OpenAICompatibleLLMAdapter.get_json_schema())
+
+    assert schema["title"] == "OpenAI Compatible LLM"
+    assert schema["properties"]["api_key"]["type"] == ["string", "null"]
+    assert "gateway-model" in schema["properties"]["model"]["description"]
+    assert "ERNIE" not in schema["properties"]["model"]["description"]
+    assert "qianfan" not in schema["properties"]["api_base"]["description"].lower()
+    assert "default" not in schema["properties"]["api_base"]
+
+
+def test_openai_compatible_adapter_uses_distinct_description_and_icon() -> None:
+    metadata = OpenAICompatibleLLMAdapter.get_metadata()
+
+    assert OpenAICompatibleLLMAdapter.get_description() == OPENAI_COMPATIBLE_DESCRIPTION
+    assert metadata["description"] == OPENAI_COMPATIBLE_DESCRIPTION
+    assert OpenAICompatibleLLMAdapter.get_icon() == (
+        "/icons/adapter-icons/OpenAICompatible.png"
+    )
+
+
+def test_record_usage_uses_reported_prompt_tokens_without_estimating() -> None:
+    llm_module = _load_llm_module()
+    llm_cls = llm_module.LLM
+
+    llm = llm_cls.__new__(llm_cls)
+    llm._platform_api_key = "platform-key"
+    llm.platform_kwargs = {"run_id": "run-1"}
+    llm.adapter = MagicMock()
+    llm.adapter.get_provider.return_value = "custom_openai"
+
+    with (
+        patch.object(llm_module, "token_counter") as mock_token_counter,
+        patch.object(llm_module, "Audit") as mock_audit,
+    ):
+        llm._record_usage(
+            model="custom_openai/gateway-model",
+            messages=[{"role": "user", "content": "hello"}],
+            usage={"prompt_tokens": 3, "completion_tokens": 4, "total_tokens": 7},
+            llm_api="complete",
+        )
+
+    mock_token_counter.assert_not_called()
+    mock_audit.return_value.push_usage_data.assert_called_once()
+    assert (
+        mock_audit.return_value.push_usage_data.call_args.kwargs[
+            "token_counter"
+        ].prompt_llm_token_count
+        == 3
+    )
+
+
+def test_record_usage_tolerates_unmapped_models_without_prompt_tokens() -> None:
+    llm_module = _load_llm_module()
+    llm_cls = llm_module.LLM
+
+    llm = llm_cls.__new__(llm_cls)
+    llm._platform_api_key = "platform-key"
+    llm.platform_kwargs = {"run_id": "run-1"}
+    llm.adapter = MagicMock()
+    llm.adapter.get_provider.return_value = "custom_openai"
+
+    with (
+        patch.object(llm_module, "token_counter", side_effect=Exception("unmapped")),
+        patch.object(llm_module, "Audit") as mock_audit,
+        patch.object(llm_module.logger, "warning") as mock_warning,
+    ):
+        llm._record_usage(
+            model="custom_openai/gateway-model",
+            messages=[{"role": "user", "content": "hello"}],
+            usage={"completion_tokens": 4, "total_tokens": 7},
+            llm_api="complete",
+        )
+
+    mock_audit.return_value.push_usage_data.assert_called_once()
+    assert (
+        mock_audit.return_value.push_usage_data.call_args.kwargs[
+            "token_counter"
+        ].prompt_llm_token_count
+        == 0
+    )
+    assert "recording 0 prompt tokens for usage audit" in mock_warning.call_args.args[0]
+
+
+def test_record_usage_uses_estimated_prompt_tokens_when_usage_has_none() -> None:
+    llm_module = _load_llm_module()
+    llm_cls = llm_module.LLM
+
+    llm = llm_cls.__new__(llm_cls)
+    llm._platform_api_key = "platform-key"
+    llm.platform_kwargs = {"run_id": "run-1"}
+    llm.adapter = MagicMock()
+    llm.adapter.get_provider.return_value = "custom_openai"
+
+    with (
+        patch.object(llm_module, "token_counter", return_value=9) as mock_token_counter,
+        patch.object(llm_module, "Audit") as mock_audit,
+    ):
+        llm._record_usage(
+            model="custom_openai/gateway-model",
+            messages=[{"role": "user", "content": "hello"}],
+            usage={"prompt_tokens": None, "completion_tokens": 4, "total_tokens": 13},
+            llm_api="complete",
+        )
+
+    mock_token_counter.assert_called_once()
+    assert (
+        mock_audit.return_value.push_usage_data.call_args.kwargs[
+            "token_counter"
+        ].prompt_llm_token_count
+        == 9
+    )