chore: Split MCP Server into 2 servers; One for recipe (A2UI over MCP…

samples/agent/adk/mcp_app_proxy/README.md

@@ -12,7 +12,7 @@ create a simple "MCP Apps Proxy" agent that is hosted as an A2A server.
 ## Running the sample
 
 1. Run the MCP Server that serves the MCP Apps. ([Link to
-   instructions](../../agent/mcp/README.md))
+   instructions](../../mcp/calculator/README.md))
 
 
 2. Navigate to the samples directory:

samples/agent/adk/orchestrator/README.md

@@ -45,7 +45,7 @@ Subagents are configured using RemoteA2aAgent which translates ADK events to A2A
    Optionally, run the MCP Server and MCP App Proxy Agent to MCP Apps in A2UI demo:
 
    ```bash
-   cd samples/agent/mcp
+   cd samples/agent/mcp/calculator
    uv run . --port=8000
    ```
 

samples/agent/mcp/calculator/README.md

@@ -0,0 +1,22 @@
+# Calculator MCP App Demo
+
+A demo of an MCP server exposing a Calculator as an MCP Application Resource.
+
+## Usage
+
+1. Start the server using either stdio (default) or SSE transport:
+
+```bash
+# Using SSE transport (default) on port 8000
+uv run .
+```
+
+The server exposes a resource named `ui://calculator/app`.
+
+2. Inspect the server using the [MCP Inspector](https://github.com/modelcontextprotocol/inspector)
+
+```bash
+npx @modelcontextprotocol/inspector
+```
+
+Connect to http://localhost:8000/sse using Transport Type SSE and fetch the resources.

samples/agent/mcp/__init__.py → samples/agent/mcp/calculator/__init__.py

@@ -1,4 +1,4 @@
-# Copyright 2025 Google LLC
+# Copyright 2026 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -11,3 +11,5 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+# Empty init

samples/agent/mcp/calculator/pyproject.toml

@@ -0,0 +1,53 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+[project]
+name = "a2ui-mcp-calculator-demo"
+version = "0.1.0"
+description = "A demo of exposing a calculator app via MCP"
+readme = "README.md"
+requires-python = ">=3.10"
+keywords = ["mcp", "automation", "agent"]
+license = { text = "MIT" }
+dependencies = ["anyio>=4.5", "click>=8.2.0", "httpx>=0.27", "mcp"]
+
+[project.scripts]
+a2ui-mcp-calculator-demo = "server:main"
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.wheel]
+packages = ["."]
+
+[[tool.uv.index]]
+url = "https://pypi.org/simple"
+default = true
+
+[tool.pyright]
+include = ["."]
+venvPath = "."
+venv = ".venv"
+
+[tool.ruff.lint]
+select = ["E", "F", "I"]
+ignore = []
+
+[tool.ruff]
+line-length = 120
+target-version = "py310"
+
+[dependency-groups]
+dev = ["pyright>=1.1.378", "pytest>=8.3.3", "ruff>=0.6.9"]

samples/agent/mcp/calculator/server.py

@@ -0,0 +1,101 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Any
+import anyio
+import click
+import pathlib
+import mcp.types as types
+from mcp.server.lowlevel import Server
+from starlette.requests import Request
+
+
+@click.command()
+@click.option("--port", default=8000, help="Port to listen on for SSE")
+@click.option(
+    "--transport",
+    type=click.Choice(["stdio", "sse"]),
+    default="sse",
+    help="Transport type",
+)
+def main(port: int, transport: str) -> int:
+
+  app = Server("a2ui-mcp-calculator-demo")
+
+  @app.list_resources()
+  async def list_resources() -> list[types.Resource]:
+    return [
+        types.Resource(
+            uri="ui://calculator/app",
+            name="Calculator App",
+            mimeType="text/html;profile=mcp-app",
+            description="A simple calculator application",
+        )
+    ]
+
+  @app.read_resource()
+  async def read_resource(uri: types.ResourceIdentifier) -> str | bytes:
+    if str(uri) == "ui://calculator/app":
+      try:
+        return (pathlib.Path(__file__).parent / "apps" / "calculator.html").read_text()
+      except FileNotFoundError:
+        raise ValueError(f"Resource file not found for uri: {uri}")
+    raise ValueError(f"Unknown resource: {uri}")
+
+  if transport == "sse":
+    from mcp.server.sse import SseServerTransport
+    from starlette.applications import Starlette
+    from starlette.responses import Response
+    from starlette.routing import Mount, Route
+    from starlette.middleware import Middleware
+    from starlette.middleware.cors import CORSMiddleware
+
+    sse = SseServerTransport("/messages/")
+
+    async def handle_sse(request: Request):
+      async with sse.connect_sse(request.scope, request.receive, request._send) as streams:  # type: ignore[reportPrivateUsage]
+        await app.run(streams[0], streams[1], app.create_initialization_options())
+      return Response()
+
+    starlette_app = Starlette(
+        debug=True,
+        routes=[
+            Route("/sse", endpoint=handle_sse, methods=["GET"]),
+            Mount("/messages/", app=sse.handle_post_message),
+        ],
+        middleware=[
+            Middleware(
+                CORSMiddleware,
+                allow_origins=["*"],
+                allow_methods=["*"],
+                allow_headers=["*"],
+            )
+        ],
+    )
+
+    import uvicorn
+
+    print(f"Server running at 127.0.0.1:{port} using sse")
+    uvicorn.run(starlette_app, host="127.0.0.1", port=port)
+  else:
+    from mcp.server.stdio import stdio_server
+
+    async def arun():
+      async with stdio_server() as streams:
+        await app.run(streams[0], streams[1], app.create_initialization_options())
+
+    click.echo("Server running using stdio", err=True)
+    anyio.run(arun)
+
+  return 0