diff --git a/hyperbrowser/models/__init__.py b/hyperbrowser/models/__init__.py
index 04678b09..931c7560 100644
--- a/hyperbrowser/models/__init__.py
+++ b/hyperbrowser/models/__init__.py
@@ -134,6 +134,7 @@
     StartCuaTaskParams,
     StartCuaTaskResponse,
     CuaApiKeys,
+    CuaBaseUrls,
     CuaTaskStatus,
 )
 from .agents.hyper_agent import (
@@ -493,6 +494,7 @@
     "GeminiComputerUseApiKeys",
     "GrokComputerUseApiKeys",
     "CuaApiKeys",
+    "CuaBaseUrls",
     "HyperAgentApiKeys",
     "GrokComputerUseLlm",
     "GrokReasoningEffort",
diff --git a/hyperbrowser/models/agents/cua.py b/hyperbrowser/models/agents/cua.py
index c5990e3a..f99f4eb6 100644
--- a/hyperbrowser/models/agents/cua.py
+++ b/hyperbrowser/models/agents/cua.py
@@ -22,6 +22,18 @@ class CuaApiKeys(BaseModel):
     openai: Optional[str] = Field(default=None, serialization_alias="openai")
 
 
+class CuaBaseUrls(BaseModel):
+    """
+    Provider base URLs for the CUA task.
+    """
+
+    model_config = ConfigDict(
+        populate_by_alias=True,
+    )
+
+    openai: Optional[str] = Field(default=None, serialization_alias="openai")
+
+
 class StartCuaTaskParams(BaseModel):
     """
     Parameters for creating a new CUA task.
@@ -46,6 +58,9 @@ class StartCuaTaskParams(BaseModel):
         default=None, serialization_alias="useCustomApiKeys"
     )
     api_keys: Optional[CuaApiKeys] = Field(default=None, serialization_alias="apiKeys")
+    base_urls: Optional[CuaBaseUrls] = Field(
+        default=None, serialization_alias="baseUrls"
+    )
     use_computer_action: Optional[bool] = Field(
         default=None, serialization_alias="useComputerAction"
     )
diff --git a/hyperbrowser/types/__init__.py b/hyperbrowser/types/__init__.py
index ad886119..405b8989 100644
--- a/hyperbrowser/types/__init__.py
+++ b/hyperbrowser/types/__init__.py
@@ -16,6 +16,7 @@
     BrowserUseApiKeys,
     ClaudeComputerUseApiKeys,
     CuaApiKeys,
+    CuaBaseUrls,
     GeminiComputerUseApiKeys,
     GrokComputerUseApiKeys,
     HyperAgentApiKeys,
@@ -173,6 +174,7 @@
     "BrowserUseApiKeys",
     "ClaudeComputerUseApiKeys",
     "CuaApiKeys",
+    "CuaBaseUrls",
     "GeminiComputerUseApiKeys",
     "GrokComputerUseApiKeys",
     "HyperAgentApiKeys",
diff --git a/hyperbrowser/types/agents.py b/hyperbrowser/types/agents.py
index 5d9bd4dd..56fa9a31 100644
--- a/hyperbrowser/types/agents.py
+++ b/hyperbrowser/types/agents.py
@@ -123,6 +123,12 @@ class CuaApiKeys(TypedDict, total=False):
     openai: Optional[str]
 
 
+class CuaBaseUrls(TypedDict, total=False):
+    """Provider base URLs for an OpenAI CUA task."""
+
+    openai: Optional[str]
+
+
 class StartCuaTaskParams(TypedDict, total=False):
     """Parameters for starting an OpenAI CUA task."""
 
@@ -135,6 +141,7 @@ class StartCuaTaskParams(TypedDict, total=False):
     session_options: Optional[CreateSessionParams]
     use_custom_api_keys: Optional[bool]
     api_keys: Optional[CuaApiKeys]
+    base_urls: Optional[CuaBaseUrls]
     use_computer_action: Optional[bool]
 
 
@@ -165,6 +172,7 @@ class StartHyperAgentTaskParams(TypedDict, total=False):
     "BrowserUseApiKeys",
     "ClaudeComputerUseApiKeys",
     "CuaApiKeys",
+    "CuaBaseUrls",
     "GeminiComputerUseApiKeys",
     "GrokComputerUseApiKeys",
     "HyperAgentApiKeys",
diff --git a/pyproject.toml b/pyproject.toml
index 203a172d..955e8319 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "hyperbrowser"
-version = "1.2.2"
+version = "1.2.3"
 description = "Python SDK for hyperbrowser"
 authors = ["Nikhil Shahi <nshahi1998@gmail.com>"]
 license = "MIT"
diff --git a/tests/test_request_compat.py b/tests/test_request_compat.py
index 9217d8c4..b052881f 100644
--- a/tests/test_request_compat.py
+++ b/tests/test_request_compat.py
@@ -8,9 +8,11 @@
     normalize_pydantic_schema,
 )
 from hyperbrowser.models import (
+    CuaBaseUrls,
     CreateSandboxParams,
     CreateSessionParams,
     StartBrowserUseTaskParams,
+    StartCuaTaskParams,
 )
 from hyperbrowser.tools import _normalize_extract_tool_params
 
@@ -76,6 +78,36 @@ def test_mapping_uses_existing_cross_field_validation():
         )
 
 
+def test_cua_custom_base_url_serializes_for_mapping_and_legacy_model():
+    mapping = {
+        "task": "Complete the task",
+        "use_custom_api_keys": True,
+        "api_keys": {"openai": "openai-key"},
+        "base_urls": {
+            "openai": "https://example.openai.azure.com/openai/v1/",
+        },
+    }
+    legacy = StartCuaTaskParams(
+        task="Complete the task",
+        use_custom_api_keys=True,
+        api_keys={"openai": "openai-key"},
+        base_urls=CuaBaseUrls(openai="https://example.openai.azure.com/openai/v1/"),
+    )
+
+    assert dump_request(mapping, StartCuaTaskParams) == dump_request(
+        legacy,
+        StartCuaTaskParams,
+    )
+    assert dump_request(mapping, StartCuaTaskParams) == {
+        "task": "Complete the task",
+        "useCustomApiKeys": True,
+        "apiKeys": {"openai": "openai-key"},
+        "baseUrls": {
+            "openai": "https://example.openai.azure.com/openai/v1/",
+        },
+    }
+
+
 def test_raw_json_schema_is_copied_without_rewriting_or_dereferencing():
     schema = {
         "$defs": {
diff --git a/tests/typecheck/valid_requests.py b/tests/typecheck/valid_requests.py
index 34e9fdcd..6f4eeb1b 100644
--- a/tests/typecheck/valid_requests.py
+++ b/tests/typecheck/valid_requests.py
@@ -96,6 +96,16 @@ def valid_sync_requests(client: Hyperbrowser) -> None:
             "session_options": {"use_stealth": True},
         }
     )
+    client.agents.cua.start(
+        {
+            "task": "Complete the task",
+            "use_custom_api_keys": True,
+            "api_keys": {"openai": "openai-key"},
+            "base_urls": {
+                "openai": "https://example.openai.azure.com/openai/v1/",
+            },
+        }
+    )
     client.sandboxes.create(
         {
             "image_name": "node",
@@ -182,6 +192,16 @@ async def valid_async_requests(client: AsyncHyperbrowser) -> None:
             },
         }
     )
+    await client.agents.cua.start(
+        {
+            "task": "Complete the task",
+            "use_custom_api_keys": True,
+            "api_keys": {"openai": "openai-key"},
+            "base_urls": {
+                "openai": "https://example.openai.azure.com/openai/v1/",
+            },
+        }
+    )
     await client.sandboxes.create(
         {
             "snapshot_name": "ready-to-run",