Merge branch 'main' into nmulepati/docs/dev-notes-push-to-huggingface-hub

Author: nabinchha

docs/code_reference/mcp.md

@@ -4,7 +4,7 @@ The `mcp` module defines configuration and execution classes for tool use via MC
 
 ## Configuration Classes
 
-[MCPProvider](#data_designer.config.mcp.MCPProvider) configures remote MCP servers via SSE transport. [LocalStdioMCPProvider](#data_designer.config.mcp.LocalStdioMCPProvider) configures local MCP servers as subprocesses via stdio transport. [ToolConfig](#data_designer.config.mcp.ToolConfig) defines which tools are available for LLM columns and how they are constrained.
+[MCPProvider](#data_designer.config.mcp.MCPProvider) configures remote MCP servers via SSE or Streamable HTTP transport. [LocalStdioMCPProvider](#data_designer.config.mcp.LocalStdioMCPProvider) configures local MCP servers as subprocesses via stdio transport. [ToolConfig](#data_designer.config.mcp.ToolConfig) defines which tools are available for LLM columns and how they are constrained.
 
 For user-facing guides, see:
 

docs/concepts/mcp/configure-mcp-cli.md

@@ -49,14 +49,15 @@ data-designer config mcp
 The wizard first asks you to choose a provider type:
 
 1. **Remote SSE**: Connect to a pre-existing MCP server via HTTP Server-Sent Events
-2. **Local stdio subprocess**: Launch an MCP server as a subprocess
+2. **Remote Streamable HTTP**: Connect to a pre-existing MCP server via Streamable HTTP
+3. **Local stdio subprocess**: Launch an MCP server as a subprocess
 
-### Remote SSE Configuration
+### Remote SSE / Streamable HTTP Configuration
 
-When configuring a Remote SSE provider, you'll be prompted for:
+When configuring a remote provider (SSE or Streamable HTTP), you'll be prompted for:
 
 - **Name**: Unique identifier (e.g., `"doc-search"`)
-- **Endpoint**: SSE endpoint URL (e.g., `"http://localhost:8080/sse"`)
+- **Endpoint**: Server endpoint URL (e.g., `"http://localhost:8080/sse"` or `"https://mcp.example.com/mcp"`)
 - **API Key**: Optional API key or environment variable name
 
 ### Local Stdio Configuration

docs/concepts/mcp/mcp-providers.md

@@ -8,36 +8,45 @@ An MCP provider defines how Data Designer connects to a tool server. Data Design
 
 | Provider Class | Connection Method | Use Case |
 |---------------|-------------------|----------|
-| `MCPProvider` | HTTP Server-Sent Events | Connect to a pre-existing MCP server |
+| `MCPProvider` | SSE or Streamable HTTP | Connect to a pre-existing MCP server |
 | `LocalStdioMCPProvider` | Subprocess via stdin/stdout | Launch an MCP server as a subprocess |
 
 When you create a `ToolConfig`, you reference providers by name, and Data Designer uses those provider settings to communicate with the appropriate MCP servers.
 
-## MCPProvider (Remote SSE)
+## MCPProvider (Remote)
 
-Use `MCPProvider` to connect to a pre-existing MCP server via Server-Sent Events:
+Use `MCPProvider` to connect to a pre-existing MCP server. Both SSE (Server-Sent Events) and Streamable HTTP transports are supported:
 
 ```python
 import data_designer.config as dd
 from data_designer.interface import DataDesigner
 
-mcp_provider = dd.MCPProvider(
+# SSE transport (default)
+sse_provider = dd.MCPProvider(
     name="remote-mcp",
     endpoint="http://localhost:8080/sse",
     api_key="MCP_API_KEY",  # Environment variable name
 )
 
-data_designer = DataDesigner(mcp_providers=[mcp_provider])
+# Streamable HTTP transport
+http_provider = dd.MCPProvider(
+    name="remote-tools",
+    endpoint="https://mcp.example.com/mcp",
+    api_key="MCP_API_KEY",
+    provider_type="streamable_http",
+)
+
+data_designer = DataDesigner(mcp_providers=[sse_provider, http_provider])
 ```
 
 ### MCPProvider Fields
 
 | Field | Type | Required | Description |
 |-------|------|----------|-------------|
 | `name` | `str` | Yes | Unique identifier for the provider |
-| `endpoint` | `str` | Yes | SSE endpoint URL (e.g., `"http://localhost:8080/sse"`) |
+| `endpoint` | `str` | Yes | Endpoint URL for the remote MCP server |
 | `api_key` | `str` | No | API key or environment variable name |
-| `provider_type` | `str` | No | Always `"sse"` (set automatically) |
+| `provider_type` | `str` | No | Transport type: `"sse"` (default) or `"streamable_http"` |
 
 ## LocalStdioMCPProvider (Subprocess)
 
@@ -103,6 +112,12 @@ providers:
     endpoint: http://localhost:8080/sse
     api_key: ${MCP_API_KEY}
 
+  # Remote Streamable HTTP provider
+  - name: remote-tools
+    provider_type: streamable_http
+    endpoint: https://mcp.example.com/mcp
+    api_key: ${MCP_API_KEY}
+
   # Local stdio provider
   - name: local-tools
     provider_type: stdio

packages/data-designer-config/pyproject.toml

@@ -22,7 +22,7 @@ dependencies = [
     "jinja2>=3.1.6,<4",
     "numpy>=1.23.5,<3",
     "pandas>=2.3.3,<3",
-    "pillow>=12.0.0,<13",
+    "pillow>=12.1.1,<13",
     "pyarrow>=19.0.1,<20", # Required for parquet I/O operations
     "pydantic[email]>=2.9.2,<3",
     "pygments>=2.19.2,<3",

packages/data-designer-config/src/data_designer/config/config_builder.py

@@ -705,7 +705,7 @@ def __repr__(self) -> str:
         Returns:
             A formatted string showing the builder's configuration including seed dataset and column information grouped by type.
         """
-        if len(self._column_configs) == 0:
+        if len(self._column_configs) == 0 and self._seed_config is None:
             return f"{self.__class__.__name__}()"
 
         props_to_repr = {

packages/data-designer-config/src/data_designer/config/mcp.py

@@ -15,25 +15,36 @@ class MCPProvider(ConfigBase):
     """Configuration for a remote MCP server connection.
 
     MCPProvider is used to connect to pre-existing MCP servers via SSE (Server-Sent Events)
-    transport. For local subprocess-based MCP servers, use LocalStdioMCPProvider instead.
+    or Streamable HTTP transport. For local subprocess-based MCP servers, use
+    LocalStdioMCPProvider instead.
 
     Attributes:
         name (str): Unique name used to reference this MCP provider.
-        endpoint (str): SSE endpoint URL for connecting to the remote MCP server.
+        endpoint (str): Endpoint URL for connecting to the remote MCP server.
         api_key (str | None): Optional API key for authentication. Defaults to None.
-        provider_type (Literal["sse"]): Transport type discriminator, always "sse".
+        provider_type (Literal["sse", "streamable_http"]): Transport type discriminator.
+            Defaults to ``"sse"``.
 
     Examples:
-        Remote SSE transport:
+        Remote SSE transport (default):
 
         >>> MCPProvider(
         ...     name="remote-mcp",
         ...     endpoint="http://localhost:8080/sse",
         ...     api_key="your-api-key",
         ... )
+
+        Remote Streamable HTTP transport:
+
+        >>> MCPProvider(
+        ...     name="remote-mcp",
+        ...     endpoint="https://api.example.com/mcp",
+        ...     api_key="your-api-key",
+        ...     provider_type="streamable_http",
+        ... )
     """
 
-    provider_type: Literal["sse"] = "sse"
+    provider_type: Literal["sse", "streamable_http"] = "sse"
     name: str
     endpoint: str
     api_key: str | None = None

packages/data-designer-config/tests/config/test_config_builder.py

@@ -768,6 +768,16 @@ def test_with_seed_dataset_sampling_strategy(stub_empty_builder):
     assert seed_config.sampling_strategy == SamplingStrategy.SHUFFLE
 
 
+def test_repr_includes_seed_dataset_when_no_columns(stub_empty_builder) -> None:
+    """repr should still show seed dataset when it is the only configured item."""
+    source = HuggingFaceSeedSource(path="datasets/test-repo/testing/data.csv")
+    stub_empty_builder.with_seed_dataset(source)
+
+    repr_string = repr(stub_empty_builder)
+
+    assert "seed_dataset: hf seed" in repr_string
+
+
 def test_add_model_config(stub_empty_builder):
     assert len(stub_empty_builder.model_configs) == 1
     assert stub_empty_builder.model_configs[0].alias == "stub-model"

packages/data-designer-config/tests/config/test_mcp.py

@@ -14,11 +14,32 @@ def test_mcp_provider_requires_endpoint() -> None:
     provider = MCPProvider(name="sse", endpoint="http://localhost:8080")
     assert provider.endpoint == "http://localhost:8080"
     assert provider.api_key is None
+    assert provider.provider_type == "sse"
 
     provider_with_key = MCPProvider(name="sse-auth", endpoint="http://localhost:8080", api_key="secret")
     assert provider_with_key.api_key == "secret"
 
 
+def test_mcp_provider_streamable_http() -> None:
+    provider = MCPProvider(
+        name="streamable",
+        endpoint="https://api.example.com/mcp",
+        provider_type="streamable_http",
+    )
+    assert provider.provider_type == "streamable_http"
+    assert provider.endpoint == "https://api.example.com/mcp"
+    assert provider.api_key is None
+
+    provider_with_key = MCPProvider(
+        name="streamable-auth",
+        endpoint="https://api.example.com/mcp",
+        provider_type="streamable_http",
+        api_key="secret",
+    )
+    assert provider_with_key.api_key == "secret"
+    assert provider_with_key.provider_type == "streamable_http"
+
+
 def test_local_stdio_mcp_provider_requires_command() -> None:
     with pytest.raises(ValidationError):
         LocalStdioMCPProvider(name="missing-command")

packages/data-designer-engine/src/data_designer/engine/mcp/io.py

@@ -39,8 +39,9 @@
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.sse import sse_client
 from mcp.client.stdio import stdio_client
+from mcp.client.streamable_http import streamablehttp_client
 
-from data_designer.config.mcp import LocalStdioMCPProvider, MCPProviderT
+from data_designer.config.mcp import LocalStdioMCPProvider, MCPProvider, MCPProviderT
 from data_designer.engine.mcp.errors import MCPToolError
 from data_designer.engine.mcp.registry import MCPToolDefinition, MCPToolResult
 
@@ -211,11 +212,15 @@ async def create_session() -> ClientSession:
                         env=provider.env,
                     )
                     ctx = stdio_client(params)
+                elif isinstance(provider, MCPProvider) and provider.provider_type == "streamable_http":
+                    headers = _build_auth_headers(provider.api_key)
+                    ctx = streamablehttp_client(provider.endpoint, headers=headers)
                 else:
                     headers = _build_auth_headers(provider.api_key)
                     ctx = sse_client(provider.endpoint, headers=headers)
 
-                read, write = await ctx.__aenter__()
+                ctx_result = await ctx.__aenter__()
+                read, write = ctx_result[0], ctx_result[1]
                 new_session = ClientSession(read, write)
                 await new_session.__aenter__()
                 await new_session.initialize()
@@ -399,6 +404,11 @@ def list_tools(provider: MCPProviderT, timeout_sec: float | None = None) -> tupl
     return _MCP_IO_SERVICE.list_tools(provider, timeout_sec=timeout_sec)
 
 
+def list_tool_names(provider: MCPProviderT, timeout_sec: float) -> list[str]:
+    """Return the names of all tools available on an MCP provider."""
+    return [t.name for t in _MCP_IO_SERVICE.list_tools(provider, timeout_sec=timeout_sec)]
+
+
 def call_tools(
     calls: list[tuple[MCPProviderT, str, dict[str, Any]]],
     *,
@@ -434,7 +444,7 @@ def get_session_pool_info() -> dict[str, Any]:
 
 
 def _build_auth_headers(api_key: str | None) -> dict[str, Any] | None:
-    """Build authentication headers for SSE client."""
+    """Build authentication headers for remote MCP clients."""
     if not api_key:
         return None
     return {"Authorization": f"Bearer {api_key}"}

packages/data-designer-engine/src/data_designer/engine/testing/fixtures.py

@@ -81,6 +81,17 @@ def stub_sse_provider() -> MCPProvider:
     )
 
 
+@pytest.fixture
+def stub_streamable_http_provider() -> MCPProvider:
+    """Create a stub Streamable HTTP MCP provider for testing."""
+    return MCPProvider(
+        name="test-streamable-http",
+        endpoint="https://api.example.com/mcp",
+        api_key="test-key",
+        provider_type="streamable_http",
+    )
+
+
 # =============================================================================
 # Tool config fixtures
 # =============================================================================