Vendor mcp-ui-server to fix MIME type and unblock PyPI publishing (#130)

PyPI rejects git deps in metadata. The PyPI v1.0.0 of mcp-ui-server
has wrong MIME type (text/html instead of text/html;profile=mcp-app).
Vendor the ~80 lines we need from the git source into
sidemantic/apps/_mcp_ui.py with correct MIME type. Remove external dep.

Author: nicosuave

pyproject.toml

@@ -44,7 +44,6 @@ mcp = [
 ]
 apps = [
     "mcp[cli]>=1.25.0,<2",
-    "mcp-ui-server @ git+https://github.com/MCP-UI-Org/mcp-ui.git#subdirectory=sdks/python/server",  # PyPI v1.0.0 has wrong MIME type; switch to PyPI pin when they release
 ]
 charts = [
     "altair>=5.0.0",
@@ -119,9 +118,6 @@ full = [
 requires = ["hatchling"]
 build-backend = "hatchling.build"
 
-[tool.hatch.metadata]
-allow-direct-references = true
-
 [tool.hatch.build.targets.sdist]
 exclude = [
   "/.claude",

sidemantic/apps/__init__.py

@@ -1,6 +1,6 @@
 """MCP Apps integration for sidemantic.
 
-Uses mcp-ui-server to create vendor-neutral UI resources that render
+Creates vendor-neutral UI resources (MCP Apps standard) that render
 interactive charts in any MCP Apps-compatible host.
 """
 
@@ -45,7 +45,7 @@ def create_chart_resource(vega_spec: dict[str, Any]):
     Returns:
         UIResource (EmbeddedResource) for MCP Apps-compatible hosts.
     """
-    from mcp_ui_server import create_ui_resource
+    from sidemantic.apps._mcp_ui import create_ui_resource
 
     html = build_chart_html(vega_spec)
     return create_ui_resource(

sidemantic/apps/_mcp_ui.py

@@ -0,0 +1,83 @@
+"""Vendored subset of mcp-ui-server (https://github.com/MCP-UI-Org/mcp-ui).
+
+Provides create_ui_resource() for building MCP Apps-compatible UI resources.
+Vendored because PyPI v1.0.0 has incorrect MIME type (text/html instead of
+text/html;profile=mcp-app) and the fix hasn't been published yet.
+
+License: Apache-2.0 (MCP UI Contributors)
+"""
+
+import base64
+from typing import Any, Literal
+
+from mcp.types import BlobResourceContents, EmbeddedResource, TextResourceContents
+from pydantic import AnyUrl, BaseModel
+
+# MIME type for MCP Apps resources
+RESOURCE_MIME_TYPE = "text/html;profile=mcp-app"
+
+
+class UIResource(EmbeddedResource):
+    """A UI resource that can be included in tool results."""
+
+    def __init__(self, resource: TextResourceContents | BlobResourceContents, **kwargs: Any):
+        super().__init__(type="resource", resource=resource, **kwargs)
+
+
+class RawHtmlPayload(BaseModel):
+    type: Literal["rawHtml"]
+    htmlString: str  # noqa: N815
+
+
+class ExternalUrlPayload(BaseModel):
+    type: Literal["externalUrl"]
+    iframeUrl: str  # noqa: N815
+
+
+class CreateUIResourceOptions(BaseModel):
+    uri: str
+    content: RawHtmlPayload | ExternalUrlPayload
+    encoding: Literal["text", "blob"]
+
+
+def create_ui_resource(options_dict: dict[str, Any]) -> UIResource:
+    """Create a UIResource for inclusion in MCP tool results.
+
+    Args:
+        options_dict: Configuration with keys:
+            - uri: Resource identifier starting with 'ui://'
+            - content: {"type": "rawHtml", "htmlString": "..."} or {"type": "externalUrl", "iframeUrl": "..."}
+            - encoding: "text" or "blob"
+
+    Returns:
+        UIResource (EmbeddedResource subclass) with correct MCP Apps MIME type.
+    """
+    options = CreateUIResourceOptions.model_validate(options_dict)
+
+    if not options.uri.startswith("ui://"):
+        raise ValueError(f"URI must start with 'ui://' but got: {options.uri}")
+
+    content = options.content
+    if isinstance(content, RawHtmlPayload):
+        content_string = content.htmlString
+    elif isinstance(content, ExternalUrlPayload):
+        content_string = content.iframeUrl
+    else:
+        raise ValueError(f"Invalid content type: {content.type}")
+
+    if options.encoding == "text":
+        resource: TextResourceContents | BlobResourceContents = TextResourceContents(
+            uri=AnyUrl(options.uri),
+            mimeType=RESOURCE_MIME_TYPE,
+            text=content_string,
+        )
+    elif options.encoding == "blob":
+        resource = BlobResourceContents(
+            uri=AnyUrl(options.uri),
+            mimeType=RESOURCE_MIME_TYPE,
+            blob=base64.b64encode(content_string.encode("utf-8")).decode("ascii"),
+        )
+    else:
+        raise ValueError(f"Invalid encoding: {options.encoding}")
+
+    return UIResource(resource=resource)

sidemantic/cli.py

@@ -330,19 +330,10 @@ def mcp_serve(
 
         # Enable apps mode if requested
         if apps:
-            try:
-                import mcp_ui_server  # noqa: F401
-
-                import sidemantic.mcp_server as _mcp_mod
+            import sidemantic.mcp_server as _mcp_mod
 
-                _mcp_mod._apps_enabled = True
-                typer.echo("Interactive UI widgets enabled", err=True)
-            except ImportError:
-                typer.echo(
-                    "Error: mcp-ui-server not installed. Install with: uv add mcp-ui-server",
-                    err=True,
-                )
-                raise typer.Exit(1)
+            _mcp_mod._apps_enabled = True
+            typer.echo("Interactive UI widgets enabled", err=True)
 
         # Determine transport
         if http or apps:

tests/test_mcp_apps.py

@@ -1,9 +1,8 @@
-"""Tests for MCP Apps (mcp-ui-server) integration."""
+"""Tests for MCP Apps UI integration."""
 
 import pytest
 
-pytest.importorskip("mcp_ui_server")  # Skip if apps extra not installed
-pytest.importorskip("mcp")
+pytest.importorskip("mcp")  # Skip if mcp extra not installed
 
 from sidemantic.apps import build_chart_html, create_chart_resource
 from sidemantic.mcp_server import create_chart, initialize_layer