diff --git a/cli.py b/cli.py
index 79383f2..edf259a 100644
--- a/cli.py
+++ b/cli.py
@@ -5,6 +5,20 @@ import subprocess
 import sys
 import os
 
+def updateIssue(issuePath: str, verbose = False):
+    if verbose:
+        print("get issues")
+    p = subprocess.run(["deno", "run", "-A","tools/getIssue.ts", "--path",issuePath])
+    p.check_returncode()
+
+def printDocument(issuePath:str, outDir:str, watch = False, verbose = False):
+    if verbose:
+        print("build document")
+    cmd = ["deno", "run", "-A","tools/printDocument.ts", "--issue_path", issuePath, "--outDir", outDir]
+    if watch:
+        cmd.append("--watch")
+    p = subprocess.run(cmd)
+    p.check_returncode()
 
 def build(args):
     parser = argparse.ArgumentParser(description='Compiling the documentation', prog="cli.py build")
@@ -19,17 +33,26 @@ def build(args):
 
     issuePath = os.path.join(args.outDir,"issues.json")
     if args.update_issues:
-        if args.verbose:
-            print("get issues")
-        p = subprocess.run(["deno", "run", "-A","tools/getIssue.ts", "--path",issuePath])
-        p.check_returncode()
+        updateIssue(issuePath, args.verbose)
+    printDocument(issuePath, args.outDir, args.watch, args.verbose)
+
+def serve(args):
+    """serve the documentation and reload on changes"""
+    parser = argparse.ArgumentParser(description='Serve the documentation and reload changes', prog="cli.py serve")
+    parser.add_argument('-v', '--verbose', action='store_true', help='verbose mode')
+    parser.add_argument('-p', '--port', default=8000, help='port')
+    parser.add_argument('--update_issues', action='store_true', help='update issues')
+    outDir = "build"
+    issuePath = os.path.join(outDir,"issues.json")
+    args = parser.parse_args(args)
     if args.verbose:
-        print("build issues")
-    cmd = ["deno", "run", "-A","tools/printDocument.ts", "--issue_path", issuePath, "--outDir", args.outDir]
-    if args.watch:
-        cmd.append("--watch")
-    p = subprocess.run(cmd)
-    p.check_returncode()
+        print("serve start")
+    cmd = ["mdbook", "serve", "--port", str(args.port)]
+    p = subprocess.Popen(cmd)
+    printDocument(issuePath, outDir, True, args.verbose)
+    p.wait()
+    if p.returncode != 0:
+        sys.exit(p.returncode)
 
 def help(_args):
     global commandList
@@ -42,16 +65,14 @@ def issueUpdate(args):
     parser.add_argument('-v', '--verbose', action='store_true', help='verbose mode')
     parser.add_argument('--outDir', default="build", help='output directory')
     args = parser.parse_args(args)
-    if args.verbose:
-        print("update issues")
     issuePath = os.path.join(args.outDir,"issues.json")
-    p = subprocess.run(["deno", "run", "-A","tools/getIssue.ts", "--path",issuePath])
-    p.check_returncode()
+    updateIssue(issuePath, args.verbose)
 
 commandList = {
     'build': build,
     'help': help,
-    'issueUpdate': issueUpdate
+    'issueUpdate': issueUpdate,
+    'serve': serve
 }
 
 def main():