diff --git a/pyproject.toml b/pyproject.toml
index ac2982f..5330829 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -63,7 +63,7 @@ dev = [
     "agentrust-trace-tests>=0.4,<0.6",
     # The bridge and real HTTP loopback run in the normal CI matrix. Pin the
     # tested SDK/server surface here; the public a2a-sdk extra remains a range.
-    "a2a-sdk[http-server]==1.1.5",
+    "a2a-sdk[http-server]==1.2.1",
     "uvicorn==0.53.0",
     "aiohttp>=3.14.3",
 ]
diff --git a/requirements/dev.in b/requirements/dev.in
index 1ca18a1..b9ace4c 100644
--- a/requirements/dev.in
+++ b/requirements/dev.in
@@ -21,7 +21,7 @@ types-pyyaml
 bandit[toml]>=1.7
 pip-audit>=2.6
 agentrust-trace-tests>=0.4,<0.6
-a2a-sdk[http-server]==1.1.5
+a2a-sdk[http-server]==1.2.1
 uvicorn==0.53.0
 aiohttp>=3.14.3
 setuptools>=83.0.0