diff --git a/agent/a2aagent/a2a_agent.go b/agent/a2aagent/a2a_agent.go
index ac72ef5926..5589e236c0 100644
--- a/agent/a2aagent/a2a_agent.go
+++ b/agent/a2aagent/a2a_agent.go
@@ -33,6 +33,7 @@ import (
 	itrace "trpc.group/trpc-go/trpc-agent-go/internal/trace"
 	"trpc.group/trpc-go/trpc-agent-go/log"
 	"trpc.group/trpc-go/trpc-agent-go/model"
+	"trpc.group/trpc-go/trpc-agent-go/platform"
 	semconvtrace "trpc.group/trpc-go/trpc-agent-go/telemetry/semconv/trace"
 	"trpc.group/trpc-go/trpc-agent-go/tool"
 )
@@ -155,6 +156,7 @@ func (r *A2AAgent) sendErrorEvent(
 	err error,
 ) *model.ResponseError {
 	respErr := model.ResponseErrorFromError(err, model.ErrorTypeRunError)
+	redactAgentResponseError(respErr)
 	agent.EmitEvent(ctx, invocation, eventChan, event.New(
 		invocation.InvocationID,
 		r.name,
@@ -166,6 +168,17 @@ func (r *A2AAgent) sendErrorEvent(
 	return respErr
 }
 
+func redactAgentResponseError(respErr *model.ResponseError) {
+	if respErr == nil {
+		return
+	}
+	redactor, err := platform.NewRedactor()
+	if err != nil {
+		return
+	}
+	respErr.Message = redactor.Redact(respErr.Message)
+}
+
 // validateA2ARequestOptions validates that all A2A request options are of the correct type
 func (r *A2AAgent) validateA2ARequestOptions(invocation *agent.Invocation) error {
 	if invocation.RunOptions.A2ARequestOptions == nil {
diff --git a/agent/a2aagent/a2a_agent_test.go b/agent/a2aagent/a2a_agent_test.go
index 0b83a5b9ce..970a62c404 100644
--- a/agent/a2aagent/a2a_agent_test.go
+++ b/agent/a2aagent/a2a_agent_test.go
@@ -2914,6 +2914,33 @@ func TestA2AAgent_sendErrorEvent_UsesRunErrorType(t *testing.T) {
 	require.Equal(t, evt.Response.Error, respErr)
 }
 
+func TestA2AAgent_sendErrorEvent_RedactsSensitiveMessage(t *testing.T) {
+	a := &A2AAgent{name: "remote-agent"}
+	eventCh := make(chan *event.Event, 1)
+	invocation := &agent.Invocation{InvocationID: "inv-test"}
+
+	respErr := a.sendErrorEvent(
+		context.Background(),
+		eventCh,
+		invocation,
+		fmt.Errorf("request failed Authorization: Bearer raw-token\napi_key=sk-1234567890abcdef\nCookie: session=abc; sid=def"),
+	)
+
+	require.NotNil(t, respErr)
+	require.Equal(t, model.ErrorTypeRunError, respErr.Type)
+	for _, secret := range []string{"raw-token", "sk-1234567890abcdef", "session=abc", "sid=def"} {
+		require.NotContains(t, respErr.Message, secret)
+	}
+	for _, redacted := range []string{"Authorization: ****", "api_key=****", "Cookie: ****"} {
+		require.Contains(t, respErr.Message, redacted)
+	}
+
+	evt := <-eventCh
+	require.NotNil(t, evt)
+	require.NotNil(t, evt.Response)
+	require.Equal(t, respErr, evt.Response.Error)
+}
+
 func TestA2AAgent_aggregateEventContent_IgnoresErrorResponses(t *testing.T) {
 	a := &A2AAgent{name: "remote-agent"}
 	builder := &strings.Builder{}