Add instrumentation for MCP resources and prompts. (#1400)

* Add instrumentation for MCP resources and prompts.

* [MegaLinter] Apply linters fixes

* Address review comments.

* Remove if conditional.

Author: umaannamalai

newrelic/hooks/adapter_mcp.py

@@ -12,28 +12,72 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import logging
+
 from newrelic.api.function_trace import FunctionTrace
 from newrelic.api.transaction import current_transaction
 from newrelic.common.object_names import callable_name
 from newrelic.common.object_wrapper import wrap_function_wrapper
 from newrelic.common.signature import bind_args
 
+_logger = logging.getLogger(__name__)
+
 
 async def wrap_call_tool(wrapped, instance, args, kwargs):
     transaction = current_transaction()
     if not transaction:
         return await wrapped(*args, **kwargs)
 
+    func_name = callable_name(wrapped)
     bound_args = bind_args(wrapped, args, kwargs)
     tool_name = bound_args.get("name") or "tool"
-    func_name = callable_name(wrapped)
     function_trace_name = f"{func_name}/{tool_name}"
 
     with FunctionTrace(name=function_trace_name, group="Llm/tool/MCP", source=wrapped):
         return await wrapped(*args, **kwargs)
 
 
+async def wrap_read_resource(wrapped, instance, args, kwargs):
+    transaction = current_transaction()
+    if not transaction:
+        return await wrapped(*args, **kwargs)
+
+    func_name = callable_name(wrapped)
+    bound_args = bind_args(wrapped, args, kwargs)
+    # Set a default value in case we can't parse out the URI scheme successfully
+    resource_scheme = "resource"
+
+    try:
+        resource_uri = bound_args.get("uri")
+        resource_scheme = getattr(resource_uri, "scheme", "resource")
+    except Exception:
+        _logger.warning("Unable to parse resource URI scheme for MCP read_resource call")
+
+    function_trace_name = f"{func_name}/{resource_scheme}"
+
+    with FunctionTrace(name=function_trace_name, group="Llm/resource/MCP", source=wrapped):
+        return await wrapped(*args, **kwargs)
+
+
+async def wrap_get_prompt(wrapped, instance, args, kwargs):
+    transaction = current_transaction()
+    if not transaction:
+        return await wrapped(*args, **kwargs)
+
+    func_name = callable_name(wrapped)
+    bound_args = bind_args(wrapped, args, kwargs)
+    prompt_name = bound_args.get("name") or "prompt"
+    function_trace_name = f"{func_name}/{prompt_name}"
+
+    with FunctionTrace(name=function_trace_name, group="Llm/prompt/MCP", source=wrapped):
+        return await wrapped(*args, **kwargs)
+
+
 def instrument_mcp_client_session(module):
     if hasattr(module, "ClientSession"):
         if hasattr(module.ClientSession, "call_tool"):
             wrap_function_wrapper(module, "ClientSession.call_tool", wrap_call_tool)
+        if hasattr(module.ClientSession, "read_resource"):
+            wrap_function_wrapper(module, "ClientSession.read_resource", wrap_read_resource)
+        if hasattr(module.ClientSession, "get_prompt"):
+            wrap_function_wrapper(module, "ClientSession.get_prompt", wrap_get_prompt)

tests/adapter_mcp/test_mcp.py

@@ -0,0 +1,116 @@
+# Copyright 2010 New Relic, Inc.
+#
+# 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
+#
+#      http://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.
+
+import pytest
+from fastmcp.client import Client
+from fastmcp.client.transports import FastMCPTransport
+from fastmcp.server.server import FastMCP
+from testing_support.validators.validate_transaction_metrics import validate_transaction_metrics
+
+from newrelic.api.background_task import background_task
+
+
+@pytest.fixture
+def fastmcp_server():
+    server = FastMCP("Test Tools")
+
+    @server.tool()
+    def add_exclamation(phrase):
+        return f"{phrase}!"
+
+    @server.resource("greeting://{name}")
+    def get_greeting(name):
+        return f"Hello, {name}!"
+
+    @server.resource("files:///home/user/documents/{filename}")
+    def get_file(filename):
+        return f"Hello, Python! You requested the file: {filename}."
+
+    @server.resource("postgres://python/customers/schema")
+    def get_db_info():
+        return "Hello, Python!"
+
+    @server.prompt()
+    def echo_prompt(message: str):
+        return f"Echo this message: {message}"
+
+    return server
+
+
+@validate_transaction_metrics(
+    "test_mcp:test_tool_tracing",
+    scoped_metrics=[("Llm/tool/MCP/mcp.client.session:ClientSession.call_tool/add_exclamation", 1)],
+    rollup_metrics=[("Llm/tool/MCP/mcp.client.session:ClientSession.call_tool/add_exclamation", 1)],
+    background_task=True,
+)
+@background_task()
+def test_tool_tracing(loop, fastmcp_server):
+    async def _test():
+        async with Client(transport=FastMCPTransport(fastmcp_server)) as client:
+            # Call the MCP tool, so we can validate the trace naming is correct.
+            result = await client.call_tool("add_exclamation", {"phrase": "Python is awesome"})
+
+            content = str(result[0])
+        assert "Python is awesome!" in content
+
+    loop.run_until_complete(_test())
+
+
+# Separate out the test function to work with the transaction metrics validator
+def run_read_resources(loop, fastmcp_server, resource_uri):
+    async def _test():
+        async with Client(transport=FastMCPTransport(fastmcp_server)) as client:
+            result = await client.read_resource(resource_uri)
+            content = str(result[0])
+        assert "Hello, Python!" in content
+
+    loop.run_until_complete(_test())
+
+
+@pytest.mark.parametrize(
+    "resource_uri",
+    ("greeting://Python", "files:///home/user/documents/python.pdf", "postgres://python/customers/schema"),
+)
+def test_resource_tracing(loop, fastmcp_server, resource_uri):
+    resource_scheme = resource_uri.split(":/")[0]
+
+    @validate_transaction_metrics(
+        "test_mcp:test_resource_tracing.<locals>._test",
+        scoped_metrics=[(f"Llm/resource/MCP/mcp.client.session:ClientSession.read_resource/{resource_scheme}", 1)],
+        rollup_metrics=[(f"Llm/resource/MCP/mcp.client.session:ClientSession.read_resource/{resource_scheme}", 1)],
+        background_task=True,
+    )
+    @background_task()
+    def _test():
+        run_read_resources(loop, fastmcp_server, resource_uri)
+
+    _test()
+
+
+@validate_transaction_metrics(
+    "test_mcp:test_prompt_tracing",
+    scoped_metrics=[("Llm/prompt/MCP/mcp.client.session:ClientSession.get_prompt/echo_prompt", 1)],
+    rollup_metrics=[("Llm/prompt/MCP/mcp.client.session:ClientSession.get_prompt/echo_prompt", 1)],
+    background_task=True,
+)
+@background_task()
+def test_prompt_tracing(loop, fastmcp_server):
+    async def _test():
+        async with Client(transport=FastMCPTransport(fastmcp_server)) as client:
+            result = await client.get_prompt("echo_prompt", {"message": "Python is cool"})
+
+            content = str(result)
+        assert "Python is cool" in content
+
+    loop.run_until_complete(_test())