diff --git a/backend/internal/trace/context.go b/backend/internal/trace/context.go
new file mode 100644
index 0000000..e023a7a
--- /dev/null
+++ b/backend/internal/trace/context.go
@@ -0,0 +1,46 @@
+package trace
+
+import "context"
+
+type traceIDKey struct{}
+type requestIDKey struct{}
+type sessionIDKey struct{}
+
+// WithTraceID 将 trace ID 注入 context（连接级/会话级标识）
+func WithTraceID(ctx context.Context, traceID string) context.Context {
+	return context.WithValue(ctx, traceIDKey{}, traceID)
+}
+
+// GetTraceID 从 context 提取 trace ID
+func GetTraceID(ctx context.Context) string {
+	if v, ok := ctx.Value(traceIDKey{}).(string); ok {
+		return v
+	}
+	return ""
+}
+
+// WithRequestID 将 request ID 注入 context（单次请求/查询标识）
+func WithRequestID(ctx context.Context, requestID string) context.Context {
+	return context.WithValue(ctx, requestIDKey{}, requestID)
+}
+
+// GetRequestID 从 context 提取 request ID
+func GetRequestID(ctx context.Context) string {
+	if v, ok := ctx.Value(requestIDKey{}).(string); ok {
+		return v
+	}
+	return ""
+}
+
+// WithSessionID 将 session ID 注入 context（会话存储标识）
+func WithSessionID(ctx context.Context, sessionID string) context.Context {
+	return context.WithValue(ctx, sessionIDKey{}, sessionID)
+}
+
+// GetSessionID 从 context 提取 session ID
+func GetSessionID(ctx context.Context) string {
+	if v, ok := ctx.Value(sessionIDKey{}).(string); ok {
+		return v
+	}
+	return ""
+}