Serve the Finance Database icon from the MCP server

financedatabase/mcp_server/config.yaml

@@ -3,6 +3,8 @@
 # Server name and the instructions sent to the client on initialisation.
 server:
   name: "Finance Database"
+  website_url: "https://www.jeroenbouma.com/projects/financedatabase/mcp"
+  icon_url: "https://financedatabase.jeroenbouma.com/icon.png"
   instructions: >-
     The Finance Database categorises financial symbols: equities, ETFs, indices,
     currencies and cryptocurrencies. It holds classifications (sector, industry,

financedatabase/mcp_server/mcp_controller.py

@@ -15,6 +15,7 @@
 import uvicorn
 import yaml
 from mcp.server.fastmcp import FastMCP
+from mcp.types import Icon
 from starlette.middleware.cors import CORSMiddleware
 from starlette.requests import Request
 from starlette.responses import JSONResponse
@@ -26,6 +27,7 @@
     DatabaseProvider,
 )
 from financedatabase.mcp_server.registry_model import AssetToolRegistry
+from financedatabase.mcp_server.site_model import register_site_routes
 from financedatabase.mcp_server.tools_model import UtilityToolRegistry
 from financedatabase.utilities.logger_model import get_logger
 
@@ -70,9 +72,12 @@ def _build_mcp_app() -> tuple[FastMCP, DatabaseProvider]:
         synonyms=configuration.get("synonyms", {}),
     )
 
+    server = configuration["server"]
     mcp = FastMCP(
-        name=configuration["server"]["name"],
-        instructions=configuration["server"]["instructions"],
+        name=server["name"],
+        instructions=server["instructions"],
+        website_url=server["website_url"],
+        icons=[Icon(src=server["icon_url"], mimeType="image/png", sizes=["512x512"])],
         log_level="CRITICAL",
         # All interfaces for Docker, which also leaves the DNS-rebinding guard off.
         host="0.0.0.0",  # noqa: S104
@@ -105,6 +110,8 @@ def _build_mcp_app() -> tuple[FastMCP, DatabaseProvider]:
     if analytics is not None:
         analytics.register_route(mcp)
 
+    register_site_routes(mcp, server["website_url"])
+
     @mcp.custom_route("/health", methods=["GET"])
     async def check_health(request: Request) -> JSONResponse:  # noqa: ARG001
         return JSONResponse({"status": "ok"})

financedatabase/mcp_server/site_model.py

@@ -0,0 +1,67 @@
+"""Site Model"""
+
+__docformat__ = "google"
+
+from pathlib import Path
+from typing import Any
+
+from starlette.requests import Request
+from starlette.responses import HTMLResponse, Response
+
+ICON_DIRECTORY = Path(__file__).parent / "icons"
+FULL_ICON = Path(__file__).parent / "mcpb" / "finance_database_icon.png"
+ICONS = {
+    "/favicon.ico": (ICON_DIRECTORY / "favicon.ico", "image/x-icon"),
+    "/favicon-32.png": (ICON_DIRECTORY / "favicon-32.png", "image/png"),
+    "/apple-touch-icon.png": (ICON_DIRECTORY / "apple-touch-icon.png", "image/png"),
+    "/icon.png": (FULL_ICON, "image/png"),
+}
+PAGE = """<!doctype html>
+<html lang="en">
+<head>
+<meta charset="utf-8">
+<title>Finance Database MCP</title>
+<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32.png">
+<link rel="icon" type="image/png" sizes="512x512" href="/icon.png">
+<link rel="apple-touch-icon" href="/apple-touch-icon.png">
+</head>
+<body>
+<p>This is the Finance Database MCP server; MCP clients connect at <code>/mcp</code>.
+See <a href="{website}">{website}</a> for how to add it.</p>
+</body>
+</html>
+"""
+
+
+def register_site_routes(mcp: Any, website: str) -> None:
+    """
+    Serve the icons and a short page at the root, so browsers and favicon lookups find the
+    Finance Database icon.
+
+    Args:
+        mcp (Any): The FastMCP server.
+        website (str): The documentation page the root page links to.
+    """
+    if not hasattr(mcp, "custom_route"):
+        return
+
+    for path, (file, media_type) in ICONS.items():
+        content = file.read_bytes()
+
+        @mcp.custom_route(path, methods=["GET"])
+        async def show_icon(
+            request: Request,  # noqa: ARG001
+            content: bytes = content,
+            media_type: str = media_type,
+        ) -> Response:
+            return Response(
+                content,
+                media_type=media_type,
+                headers={"Cache-Control": "public, max-age=86400"},
+            )
+
+    page = PAGE.format(website=website)
+
+    @mcp.custom_route("/", methods=["GET"])
+    async def show_page(request: Request) -> HTMLResponse:  # noqa: ARG001
+        return HTMLResponse(page)

tests/mcp_server/test_site_model.py

@@ -0,0 +1,27 @@
+"""Site Model Tests"""
+
+from mcp.server.fastmcp import FastMCP
+from starlette.testclient import TestClient
+
+from financedatabase.mcp_server.site_model import register_site_routes
+
+
+def test_icons_and_root_page_are_served() -> None:
+    """Test that the icons and the root page are served for browsers and favicon lookups."""
+    mcp = FastMCP(name="Finance Database")
+    register_site_routes(mcp, "https://example.com/mcp")
+    client = TestClient(mcp.streamable_http_app())
+
+    icon = client.get("/favicon.ico")
+    assert icon.status_code == 200
+    assert icon.headers["content-type"] == "image/x-icon"
+    assert icon.content[:4] == b"\x00\x00\x01\x00"  # ICO header
+    for path in ("/favicon-32.png", "/apple-touch-icon.png", "/icon.png"):
+        response = client.get(path)
+        assert response.status_code == 200 and response.content[:4] == b"\x89PNG"
+
+    page = client.get("/", follow_redirects=False)
+    assert page.status_code == 200
+    assert "<title>Finance Database MCP</title>" in page.text
+    assert 'href="/favicon-32.png"' in page.text
+    assert "https://example.com/mcp" in page.text