From e1f3f1ca3b8a658e7a407a900cd2e5eaafffd6c7 Mon Sep 17 00:00:00 2001
From: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
Date: Sun, 5 Jul 2026 21:36:59 -0400
Subject: [PATCH] Select FastMCP client span by component key in session-id
 telemetry tests (SDK v2)

---
 tests/client/telemetry/test_client_tracing.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tests/client/telemetry/test_client_tracing.py b/tests/client/telemetry/test_client_tracing.py
index 54c4c08f3..908fcc789 100644
--- a/tests/client/telemetry/test_client_tracing.py
+++ b/tests/client/telemetry/test_client_tracing.py
@@ -571,13 +571,16 @@ class TestSessionIdOnSpans:
 
         spans = trace_exporter.get_finished_spans()
 
-        # Find client-side span
+        # Find the FastMCP client-side span. SDK v2 emits its own native OTel
+        # spans (also lacking `fastmcp.server.name`), so select on the
+        # `fastmcp.component.key` attribute that only our client_span sets.
         client_span = next(
             (
                 s
                 for s in spans
                 if s.name == "tools/call echo"
                 and s.attributes is not None
+                and "fastmcp.component.key" in s.attributes
                 and "fastmcp.server.name" not in s.attributes
             ),
             None,
@@ -635,13 +638,15 @@ class TestSessionIdOnSpans:
 
         spans = trace_exporter.get_finished_spans()
 
-        # Find both spans
+        # Find both spans. Select the FastMCP client span on
+        # `fastmcp.component.key` to avoid matching SDK v2's native OTel span.
         client_span = next(
             (
                 s
                 for s in spans
                 if s.name == "tools/call echo"
                 and s.attributes is not None
+                and "fastmcp.component.key" in s.attributes
                 and "fastmcp.server.name" not in s.attributes
             ),
             None,