Ensure proxy components forward meta dicts (#1282)

src/fastmcp/server/proxy.py

@@ -255,6 +255,8 @@ class ProxyTool(Tool, MirroredComponent):
             parameters=mcp_tool.inputSchema,
             annotations=mcp_tool.annotations,
             output_schema=mcp_tool.outputSchema,
+            meta=mcp_tool.meta,
+            tags=(mcp_tool.meta or {}).get("tags", []),
             _mirrored=True,
         )
 
@@ -309,6 +311,8 @@ class ProxyResource(Resource, MirroredComponent):
             name=mcp_resource.name,
             description=mcp_resource.description,
             mime_type=mcp_resource.mimeType or "text/plain",
+            meta=mcp_resource.meta,
+            tags=(mcp_resource.meta or {}).get("tags", []),
             _mirrored=True,
         )
 
@@ -348,6 +352,8 @@ class ProxyTemplate(ResourceTemplate, MirroredComponent):
             description=mcp_template.description,
             mime_type=mcp_template.mimeType or "text/plain",
             parameters={},  # Remote templates don't have local parameters
+            meta=mcp_template.meta,
+            tags=(mcp_template.meta or {}).get("tags", []),
             _mirrored=True,
         )
 
@@ -380,6 +386,8 @@ class ProxyTemplate(ResourceTemplate, MirroredComponent):
             name=self.name,
             description=self.description,
             mime_type=result[0].mimeType,
+            meta=self.meta,
+            tags=(self.meta or {}).get("tags", []),
             _value=value,
         )
 
@@ -413,6 +421,8 @@ class ProxyPrompt(Prompt, MirroredComponent):
             name=mcp_prompt.name,
             description=mcp_prompt.description,
             arguments=arguments,
+            meta=mcp_prompt.meta,
+            tags=(mcp_prompt.meta or {}).get("tags", []),
             _mirrored=True,
         )
 

tests/server/proxy/test_proxy_client.py

@@ -18,6 +18,10 @@ from fastmcp.server.proxy import ProxyClient
 def fastmcp_server():
     mcp = FastMCP("TestServer")
 
+    @mcp.tool(tags={"echo"})
+    def echo(message: str) -> str:
+        return f"echo: {message}"
+
     @mcp.tool
     async def list_roots(context: Context) -> list[str]:
         roots = await context.list_roots()
@@ -80,6 +84,15 @@ async def proxy_server(fastmcp_server: FastMCP):
 
 
 class TestProxyClient:
+    async def test_forward_tool_meta(self, proxy_server: FastMCP):
+        """
+        Test that the proxy client correctly forwards the `echo` tool meta.
+        """
+        async with Client(proxy_server) as client:
+            tools = await client.list_tools()
+            echo_tool = next(t for t in tools if t.name == "echo")
+            assert echo_tool.meta == {"tags": ["echo"]}
+
     async def test_forward_error_response(self, proxy_server: FastMCP):
         """
         Test that the proxy client correctly forwards an error response.

tests/server/proxy/test_proxy_server.py

@@ -29,7 +29,7 @@ def fastmcp_server():
 
     # --- Tools ---
 
-    @server.tool
+    @server.tool(tags={"greet"})
     def greet(name: str) -> str:
         """Greet someone by name."""
         return f"Hello, {name}!"
@@ -50,7 +50,7 @@ def fastmcp_server():
 
     # --- Resources ---
 
-    @server.resource(uri="resource://wave")
+    @server.resource(uri="resource://wave", tags={"wave"})
     def wave() -> str:
         return "👋"
 
@@ -58,13 +58,13 @@ def fastmcp_server():
     async def get_users() -> list[dict[str, Any]]:
         return USERS
 
-    @server.resource(uri="data://user/{user_id}")
+    @server.resource(uri="data://user/{user_id}", tags={"users"})
     async def get_user(user_id: str) -> dict[str, Any] | None:
         return next((user for user in USERS if user["id"] == user_id), None)
 
     # --- Prompts ---
 
-    @server.prompt
+    @server.prompt(tags={"welcome"})
     def welcome(name: str) -> str:
         return f"Welcome to FastMCP, {name}!"
 
@@ -121,6 +121,11 @@ class TestTools:
         assert "error_tool" in tools
         assert "tool_without_description" in tools
 
+    async def test_get_tools_meta(self, proxy_server):
+        tools = await proxy_server.get_tools()
+        greet_tool = tools["greet"]
+        assert greet_tool.meta == {"tags": ["greet"]}
+
     async def test_get_transformed_tools(
         self, fastmcp_server: FastMCP, proxy_server: FastMCPProxy
     ):
@@ -238,6 +243,11 @@ class TestResources:
         )
         assert [r.name for r in resources.values()] == Contains("get_users", "wave")
 
+    async def test_get_resources_meta(self, proxy_server):
+        resources = await proxy_server.get_resources()
+        wave_resource = resources["resource://wave"]
+        assert wave_resource.meta == {"tags": ["wave"]}
+
     async def test_list_resources_same_as_original(self, fastmcp_server, proxy_server):
         assert (
             await proxy_server._mcp_list_resources()
@@ -332,6 +342,11 @@ class TestResourceTemplates:
         templates = await proxy_server.get_resource_templates()
         assert [t.name for t in templates.values()] == Contains("get_user")
 
+    async def test_get_resource_templates_meta(self, proxy_server):
+        templates = await proxy_server.get_resource_templates()
+        get_user_template = templates["data://user/{user_id}"]
+        assert get_user_template.meta == {"tags": ["users"]}
+
     async def test_list_resource_templates_same_as_original(
         self, fastmcp_server, proxy_server
     ):
@@ -431,6 +446,11 @@ class TestPrompts:
         prompts = await proxy_server.get_prompts()
         assert [p.name for p in prompts.values()] == Contains("welcome")
 
+    async def test_get_prompts_meta(self, proxy_server):
+        prompts = await proxy_server.get_prompts()
+        welcome_prompt = prompts["welcome"]
+        assert welcome_prompt.meta == {"tags": ["welcome"]}
+
     async def test_list_prompts_same_as_original(self, fastmcp_server, proxy_server):
         async with Client(fastmcp_server) as client:
             result = await client.list_prompts()