diff --git a/src/base_cmd.h b/src/base_cmd.h
index 17ff6b432..f36f9079b 100644
--- a/src/base_cmd.h
+++ b/src/base_cmd.h
@@ -25,6 +25,10 @@ namespace pikiwidb {
 const std::string kCmdNameSet = "set";
 const std::string kCmdNameGet = "get";
 const std::string kCmdNameIncrby = "incrby";
+const std::string kCmdNameStrlen = "strlen";
+const std::string kCmdNameSetex = "setex";
+const std::string kCmdNamePsetex = "psetex";
+const std::string kCmdNameSetnx = "setnx";
 
 // multi
 const std::string kCmdNameMulti = "multi";
diff --git a/src/cmd_kv.cc b/src/cmd_kv.cc
index b9f7aa970..da9249780 100644
--- a/src/cmd_kv.cc
+++ b/src/cmd_kv.cc
@@ -7,6 +7,7 @@
 
 #include "cmd_kv.h"
 #include "pstd_string.h"
+#include "pstd_util.h"
 #include "store.h"
 
 namespace pikiwidb {
@@ -215,6 +216,78 @@ void BitCountCmd::DoCmd(PClient* client) {
   client->AppendInteger(static_cast<int64_t>(count));
 }
 
+StrlenCmd::StrlenCmd(const std::string& name, int16_t arity)
+    : BaseCmd(name, arity, CmdFlagsReadonly, AclCategoryRead | AclCategoryString) {}
+
+bool StrlenCmd::DoInitial(PClient* client) {
+  client->SetKey(client->argv_[1]);
+  return true;
+}
+
+void StrlenCmd::DoCmd(PClient* client) {
+  PObject* value = nullptr;
+  PError err = PSTORE.GetValueByType(client->Key(), value, PType_string);
+
+  switch (err) {
+    case PError_ok: {
+      auto str = GetDecodedString(value);
+      size_t len = str->size();
+      client->AppendInteger(static_cast<int64_t>(len));
+      break;
+    }
+    case PError_notExist: {
+      client->AppendInteger(0);
+      break;
+    }
+    default: {
+      client->SetRes(CmdRes::kErrOther, "error other");
+      break;
+    }
+  }
+}
+
+SetexCmd::SetexCmd(const std::string& name, int16_t arity)
+    : BaseCmd(name, arity, CmdFlagsWrite, AclCategoryWrite | AclCategoryString) {}
+
+bool SetexCmd::DoInitial(PClient* client) {
+  client->SetKey(client->argv_[1]);
+  int64_t sec = 0;
+  if (pstd::String2int(client->argv_[2], &sec) == 0) {
+    client->SetRes(CmdRes::kInvalidInt);
+    return false;
+  }
+  return true;
+}
+
+void SetexCmd::DoCmd(PClient* client) {
+  PSTORE.SetValue(client->argv_[1], PObject::CreateString(client->argv_[3]));
+  int64_t sec = 0;
+  pstd::String2int(client->argv_[2], &sec);
+  PSTORE.SetExpire(client->argv_[1], pstd::UnixMilliTimestamp() + sec * 1000);
+  client->SetRes(CmdRes::kOk);
+}
+
+PsetexCmd::PsetexCmd(const std::string& name, int16_t arity)
+    : BaseCmd(name, arity, CmdFlagsWrite, AclCategoryWrite | AclCategoryString) {}
+
+bool PsetexCmd::DoInitial(PClient* client) {
+  client->SetKey(client->argv_[1]);
+  int64_t msec = 0;
+  if (pstd::String2int(client->argv_[2], &msec) == 0) {
+    client->SetRes(CmdRes::kInvalidInt);
+    return false;
+  }
+  return true;
+}
+
+void PsetexCmd::DoCmd(PClient* client) {
+  PSTORE.SetValue(client->argv_[1], PObject::CreateString(client->argv_[3]));
+  int64_t msec = 0;
+  pstd::String2int(client->argv_[2], &msec);
+  PSTORE.SetExpire(client->argv_[1], pstd::UnixMilliTimestamp() + msec);
+  client->SetRes(CmdRes::kOk);
+}
+
 IncrbyCmd::IncrbyCmd(const std::string& name, int16_t arity)
     : BaseCmd(name, arity, CmdFlagsWrite, AclCategoryWrite | AclCategoryString) {}
 
@@ -250,4 +323,26 @@ void IncrbyCmd::DoCmd(PClient* client) {
       break;
   }
 }
+
+SetnxCmd::SetnxCmd(const std::string& name, int16_t arity)
+    : BaseCmd(name, arity, CmdFlagsWrite, AclCategoryWrite | AclCategoryString) {}
+
+bool SetnxCmd::DoInitial(PClient* client) {
+  client->SetKey(client->argv_[1]);
+  return true;
+}
+
+void SetnxCmd::DoCmd(PClient* client) {
+  int iSuccess = 1;
+  PObject* value = nullptr;
+  PError err = PSTORE.GetValue(client->argv_[1], value);
+  if (err == PError_notExist) {
+    PSTORE.ClearExpire(client->argv_[1]);  // clear key's old ttl
+    PSTORE.SetValue(client->argv_[1], PObject::CreateString(client->argv_[2]));
+    client->AppendInteger(iSuccess);
+  } else {
+    client->AppendInteger(!iSuccess);
+  }
+}
+
 }  // namespace pikiwidb
diff --git a/src/cmd_kv.h b/src/cmd_kv.h
index e3ef2bab7..94114af42 100644
--- a/src/cmd_kv.h
+++ b/src/cmd_kv.h
@@ -33,6 +33,50 @@ class SetCmd : public BaseCmd {
   void DoCmd(PClient *client) override;
 };
 
+class StrlenCmd : public BaseCmd {
+ public:
+  StrlenCmd(const std::string &name, int16_t arity);
+
+ protected:
+  bool DoInitial(PClient *client) override;
+
+ private:
+  void DoCmd(PClient *client) override;
+};
+
+class SetexCmd : public BaseCmd {
+ public:
+  SetexCmd(const std::string &name, int16_t arity);
+
+ protected:
+  bool DoInitial(PClient *client) override;
+
+ private:
+  void DoCmd(PClient *client) override;
+};
+
+class PsetexCmd : public BaseCmd {
+ public:
+  PsetexCmd(const std::string &name, int16_t arity);
+
+ protected:
+  bool DoInitial(PClient *client) override;
+
+ private:
+  void DoCmd(PClient *client) override;
+};
+
+class SetnxCmd : public BaseCmd {
+ public:
+  SetnxCmd(const std::string &name, int16_t arity);
+
+ protected:
+  bool DoInitial(PClient *client) override;
+
+ private:
+  void DoCmd(PClient *client) override;
+};
+
 class AppendCmd : public BaseCmd {
  public:
   AppendCmd(const std::string &name, int16_t arity);
diff --git a/src/cmd_table_manager.cc b/src/cmd_table_manager.cc
index 92215f1be..1b37ca780 100644
--- a/src/cmd_table_manager.cc
+++ b/src/cmd_table_manager.cc
@@ -42,9 +42,16 @@ void CmdTableManager::InitCmdTable() {
   cmds_->insert(std::make_pair(kCmdNameMset, std::move(msetPtr)));
   std::unique_ptr<BaseCmd> bitcountPtr = std::make_unique<BitCountCmd>(kCmdNameBitCount, -2);
   cmds_->insert(std::make_pair(kCmdNameBitCount, std::move(bitcountPtr)));
-
   std::unique_ptr<BaseCmd> incrbyPtr = std::make_unique<IncrbyCmd>(kCmdNameIncrby, 3);
   cmds_->insert(std::make_pair(kCmdNameIncrby, std::move(incrbyPtr)));
+  std::unique_ptr<BaseCmd> strlenPtr = std::make_unique<StrlenCmd>(kCmdNameStrlen, 2);
+  cmds_->insert(std::make_pair(kCmdNameStrlen, std::move(strlenPtr)));
+  std::unique_ptr<BaseCmd> setexPtr = std::make_unique<SetexCmd>(kCmdNameSetex, 4);
+  cmds_->insert(std::make_pair(kCmdNameSetex, std::move(setexPtr)));
+  std::unique_ptr<BaseCmd> psetexPtr = std::make_unique<PsetexCmd>(kCmdNamePsetex, 4);
+  cmds_->insert(std::make_pair(kCmdNamePsetex, std::move(psetexPtr)));
+  std::unique_ptr<BaseCmd> setnxPtr = std::make_unique<SetnxCmd>(kCmdNameSetnx, 3);
+  cmds_->insert(std::make_pair(kCmdNameSetnx, std::move(setnxPtr)));
 }
 
 std::pair<BaseCmd*, CmdRes::CmdRet> CmdTableManager::GetCommand(const std::string& cmdName, PClient* client) {