diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..02a30bb
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,5 @@
+# Changelog
+
+## 0.1.0 (2023-02-02)
+
+- The first release which uses a UDP socket on a loopback address. ([#1](https://github.com/tonyseek/trapit/pull/1))
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 13b0bba..d1075ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,10 +1,12 @@
 cmake_minimum_required(VERSION 3.22..3.25)
-project(trapit)
+project(trapit VERSION 0.1.0)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 add_executable(trapit trapit.cc)
+target_compile_definitions(
+  trapit PRIVATE TRAPIT_VERSION="${CMAKE_PROJECT_VERSION}")
 install(TARGETS trapit)
 
 set(CPACK_PACKAGE_VENDOR "Jiangge Zhang <tonyseek@gmail.com>")
diff --git a/trapit.cc b/trapit.cc
index 175bf38..9b449bb 100644
--- a/trapit.cc
+++ b/trapit.cc
@@ -16,7 +16,14 @@
 #define TRAPIT_PORT 26842
 #endif
 
+#ifndef TRAPIT_VERSION
+#define TRAPIT_VERSION "unstable"
+#endif
+
+const std::string version(TRAPIT_VERSION);
+
 int cmd_usage(const char *prog) noexcept;
+int cmd_version(const char *prog) noexcept;
 int cmd_trap(const char *prog, int argc, char **argv) noexcept;
 int cmd_wake(const char *prog, int argc, char **argv) noexcept;
 
@@ -56,6 +63,8 @@ int main(int argc, char **argv) {
     } else if (strcmp(argv[1], "help") == 0) {
         cmd_usage(argv[0]);
         return 0;
+    } else if (strcmp(argv[1], "version") == 0) {
+        return cmd_version(argv[0]);
     } else {
         return cmd_usage(argv[0]);
     }
@@ -65,12 +74,17 @@ int main(int argc, char **argv) {
 int cmd_usage(const char *prog) noexcept {
     const char *hl = "Usage: ";
     const char *pr = "       ";
-    std::cerr << hl << prog << " [exec|wake|help]" << std::endl;
+    std::cerr << hl << prog << " [exec|wake|version|help]" << std::endl;
     std::cerr << pr << prog << " exec -- [argument ...]" << std::endl;
     std::cerr << pr << prog << " wake" << std::endl;
     return 2;
 }
 
+int cmd_version(const char *prog) noexcept {
+    std::cout << version << std::endl;
+    return 0;
+}
+
 int cmd_trap(const char *prog, int argc, char **argv) noexcept {
     /*
      * Layout: [ARG 0] [ARG 0] [ARG 1] ... [NULL]