diff --git a/package.json b/package.json
index 8df2d82..1d6b3d3 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
     "test": "cm-runtests",
     "static": "tsc --noEmit",
     "testAll": "yarn run static && yarn run test && cd dev/cm5 && yarn run buildAndTest",
-    "build": "cm-buildhelper src/index.ts",
+    "build": "cm-buildhelper src/index.ts && node scripts/addVersion.cjs",
     "publish": "yarn run build && npm publish",
     "prepare": "yarn run build"
   },
diff --git a/scripts/addVersion.cjs b/scripts/addVersion.cjs
new file mode 100644
index 0000000..718dae8
--- /dev/null
+++ b/scripts/addVersion.cjs
@@ -0,0 +1,13 @@
+var fs = require("fs")
+var json = fs.readFileSync(__dirname + "/../package.json", "utf-8")
+var version = JSON.parse(json).version
+
+console.log(version)
+function replace(path) {
+    var value = fs.readFileSync(path, "utf-8")
+    value = value.replace("<DEV>", version);
+    fs.writeFileSync(path, value , "utf-8")
+}
+
+replace(__dirname + "/../dist/index.js")
+replace(__dirname + "/../dist/index.cjs")
\ No newline at end of file
diff --git a/src/types.d.ts b/src/types.d.ts
index 289957b..f271162 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -184,7 +184,7 @@ export type vimOption = {
 }
 
 
-export type ExFn = ()=> void;
+export type ExFn = (cm: CodeMirrorV, params: ExParams)=> void;
 
 type allCommands = {
     keys: string,
diff --git a/src/vim.js b/src/vim.js
index 31e5f61..d0e299f 100644
--- a/src/vim.js
+++ b/src/vim.js
@@ -6216,6 +6216,10 @@ export function initVim(CodeMirror) {
 
   var exCommandDispatcher = new ExCommandDispatcher();
 
+  vimApi.defineEx("version", "ve", (cm) => {
+    showConfirm(cm, "Codemirror-vim version: <DEV>");
+  });
+
 /**
  * @arg {CodeMirrorV} cm CodeMirror instance we are in.
  * @arg {boolean} confirm Whether to confirm each replace.