diff --git a/pkg/uuid/internal_generator.go b/pkg/uuid/internal_generator.go
new file mode 100644
index 00000000..db96dc43
--- /dev/null
+++ b/pkg/uuid/internal_generator.go
@@ -0,0 +1,100 @@
+package uuid
+
+import (
+	"sync/atomic"
+	"time"
+
+	"github.com/mayswind/lab/pkg/settings"
+)
+
+const (
+	INTERNAL_UUID_UNIX_TIME_BITS = 32
+	INTERNAL_UUID_UNIX_TIME_MASK = (1 << INTERNAL_UUID_UNIX_TIME_BITS) - 1
+
+	INTERNAL_UUID_TYPE_BITS = 4
+	INTERNAL_UUID_TYPE_MASK = (1 << INTERNAL_UUID_TYPE_BITS) - 1
+
+	INTERNAL_UUID_SERVER_ID_BITS = 8
+	INTERNAL_UUID_SERVER_ID_MASK = (1 << INTERNAL_UUID_SERVER_ID_BITS) - 1
+
+	INTERNAL_UUID_SEQ_ID_BITS = 19
+	INTERNAL_UUID_SEQ_ID_MASK = (1 << INTERNAL_UUID_SEQ_ID_BITS) - 1
+
+	SEQ_NUMBER_ID_BITS = 32
+	SEQ_NUMBER_ID_MASK = (1 << SEQ_NUMBER_ID_BITS) - 1
+)
+
+type InternalUuidInfo struct {
+	UnixTime     uint32
+	UuidType     uint8
+	UuidServerId uint8
+	SequentialId uint32
+}
+
+type InternalUuidGenerator struct {
+	uuidServerId   uint8
+	uuidSeqNumbers [1 << INTERNAL_UUID_TYPE_BITS]uint64
+}
+
+func NewInternalUuidGenerator(config *settings.Config) (*InternalUuidGenerator, error) {
+	generator := &InternalUuidGenerator{
+		uuidServerId: config.UuidServerId,
+	}
+
+	return generator, nil
+}
+
+func (u *InternalUuidGenerator) GenerateUuid(idType UuidType) int64 {
+	// 63bits = unixTime(32bits) + uuidType(4bits) + uuidServerId(8bits) + sequentialNumber(19bits)
+
+	var unixTime uint64
+	var newSeqId uint64
+	uuidType := uint8(idType)
+
+	for {
+		unixTime = uint64(time.Now().Unix())
+		newSeqId = atomic.AddUint64(&u.uuidSeqNumbers[uuidType], 1)
+
+		if newSeqId>>SEQ_NUMBER_ID_BITS == unixTime {
+			break
+		}
+
+		currentSeqId := newSeqId
+		newSeqId = unixTime << SEQ_NUMBER_ID_BITS
+
+		if atomic.CompareAndSwapUint64(&u.uuidSeqNumbers[uuidType], currentSeqId, newSeqId) {
+			break
+		}
+	}
+
+	seqId := newSeqId & SEQ_NUMBER_ID_MASK
+
+	unixTimePart := (int64(unixTime) & INTERNAL_UUID_UNIX_TIME_MASK) << (INTERNAL_UUID_TYPE_BITS + INTERNAL_UUID_SERVER_ID_BITS + INTERNAL_UUID_SEQ_ID_BITS)
+	uuidTypePart := (int64(uuidType) & INTERNAL_UUID_TYPE_MASK) << (INTERNAL_UUID_SERVER_ID_BITS + INTERNAL_UUID_SEQ_ID_BITS)
+	uuidServerIdPart := (int64(u.uuidServerId) & INTERNAL_UUID_SERVER_ID_MASK) << INTERNAL_UUID_SEQ_ID_BITS
+	seqIdPart := int64(seqId) & INTERNAL_UUID_SEQ_ID_MASK
+
+	uuid := unixTimePart | uuidTypePart | uuidServerIdPart | seqIdPart
+
+	return uuid
+}
+
+func (u *InternalUuidGenerator) ParseUuidInfo(uuid int64) *InternalUuidInfo {
+	seqId := uint32(uuid & INTERNAL_UUID_SEQ_ID_MASK)
+	uuid = uuid >> INTERNAL_UUID_SEQ_ID_BITS
+
+	uuidServerId := uint8(uuid & INTERNAL_UUID_SERVER_ID_MASK)
+	uuid = uuid >> INTERNAL_UUID_SERVER_ID_BITS
+
+	uuidType := uint8(uuid & INTERNAL_UUID_TYPE_MASK)
+	uuid = uuid >> INTERNAL_UUID_TYPE_BITS
+
+	unixTime := uint32(uuid & INTERNAL_UUID_UNIX_TIME_MASK)
+
+	return &InternalUuidInfo{
+		UnixTime:     unixTime,
+		UuidType:     uuidType,
+		UuidServerId: uuidServerId,
+		SequentialId: seqId,
+	}
+}
diff --git a/pkg/uuid/internal_generator_test.go b/pkg/uuid/internal_generator_test.go
new file mode 100644
index 00000000..1f7b941e
--- /dev/null
+++ b/pkg/uuid/internal_generator_test.go
@@ -0,0 +1,122 @@
+package uuid
+
+import (
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/mayswind/lab/pkg/settings"
+)
+
+func TestGenerateUuid(t *testing.T) {
+	expectedUnixTime := time.Now().Unix()
+	expectedUuidServerId := uint8(90)
+	expectedUuidType := UUID_TYPE_JOURNAL
+
+	generator, _ := NewInternalUuidGenerator(&settings.Config{UuidServerId: expectedUuidServerId})
+	uuid := generator.GenerateUuid(expectedUuidType)
+	uuidInfo := generator.ParseUuidInfo(uuid)
+
+	actualUnixTime := uuidInfo.UnixTime
+	assert.Equal(t, uint32(expectedUnixTime), actualUnixTime)
+
+	actualUuidServerId := uuidInfo.UuidServerId
+	assert.Equal(t, expectedUuidServerId, actualUuidServerId)
+
+	actualUuidType := uuidInfo.UuidType
+	assert.Equal(t, uint8(expectedUuidType), actualUuidType)
+
+	expectedSeqId := 0
+	actualSeqId := uuidInfo.SequentialId
+	assert.Equal(t, uint32(expectedSeqId), actualSeqId)
+}
+
+func TestGenerateUuid_MultiType(t *testing.T) {
+	generator, _ := NewInternalUuidGenerator(&settings.Config{UuidServerId: 1})
+	uuid := generator.GenerateUuid(UUID_TYPE_USER)
+	uuidInfo := generator.ParseUuidInfo(uuid)
+
+	expectedSeqId := 0
+	actualSeqId := uuidInfo.SequentialId
+	assert.Equal(t, uint32(expectedSeqId), actualSeqId)
+
+	uuid = generator.GenerateUuid(UUID_TYPE_ACCOUNT)
+	uuidInfo = generator.ParseUuidInfo(uuid)
+	actualSeqId = uuidInfo.SequentialId
+	assert.Equal(t, uint32(expectedSeqId), actualSeqId)
+
+	uuid = generator.GenerateUuid(UUID_TYPE_JOURNAL)
+	uuidInfo = generator.ParseUuidInfo(uuid)
+	actualSeqId = uuidInfo.SequentialId
+	assert.Equal(t, uint32(expectedSeqId), actualSeqId)
+}
+
+func TestGenerateUuid_1000Times(t *testing.T) {
+	generator, _ := NewInternalUuidGenerator(&settings.Config{UuidServerId: 2})
+	expectedUnixTime := time.Now().Unix()
+
+	for i := 0; i < 1000; i++ {
+		uuid := generator.GenerateUuid(UUID_TYPE_USER)
+		uuidInfo := generator.ParseUuidInfo(uuid)
+
+		assert.Equal(t, uint32(expectedUnixTime), uuidInfo.UnixTime)
+		assert.Equal(t, uint32(i), uuidInfo.SequentialId)
+	}
+
+	time.Sleep(1 * time.Second)
+	expectedUnixTime = time.Now().Unix()
+
+	for i := 0; i < 1000; i++ {
+		uuid := generator.GenerateUuid(UUID_TYPE_USER)
+		uuidInfo := generator.ParseUuidInfo(uuid)
+
+		assert.Equal(t, uint32(expectedUnixTime), uuidInfo.UnixTime)
+		assert.Equal(t, uint32(i), uuidInfo.SequentialId)
+	}
+}
+
+func TestGenerateUuid_1000000TimesConcurrent(t *testing.T) {
+	generator, _ := NewInternalUuidGenerator(&settings.Config{UuidServerId: 3})
+	var mutex sync.Mutex
+	var generatedIds sync.Map
+	var waitGroup sync.WaitGroup
+
+	for i := 0; i < 50; i++ {
+		go func() {
+			waitGroup.Add(1)
+
+			for j := 0; j < 40000; j++ {
+				if j%10000 == 0 { // echo server can only generate 500,000 (50 * 10000) uuids in one second
+					time.Sleep(1000 * time.Millisecond)
+				}
+
+				expectedUnixTime := time.Now().Unix()
+				uuid := generator.GenerateUuid(UUID_TYPE_USER)
+				uuidInfo := generator.ParseUuidInfo(uuid)
+
+				if uint32(expectedUnixTime) != uuidInfo.UnixTime {
+					mutex.Lock()
+					assert.Equal(t, uint32(expectedUnixTime), uuidInfo.UnixTime)
+					mutex.Unlock()
+				}
+
+				if uuidInfo.SequentialId == 0 {
+					if existedUnixTime, exists := generatedIds.Load(uuid); exists {
+						mutex.Lock()
+						assert.Fail(t, fmt.Sprintf("uuid \"%d\" conflicts, seq id is %d, existed unixtime is %d, current unix time is %d", uuid, uuidInfo.SequentialId, existedUnixTime, uuidInfo.UnixTime))
+						mutex.Unlock()
+					}
+
+					generatedIds.Store(uuid, uuidInfo.UnixTime)
+				}
+			}
+
+			waitGroup.Done()
+		}()
+	}
+
+	waitGroup.Wait()
+}
diff --git a/pkg/uuid/uuid_container.go b/pkg/uuid/uuid_container.go
new file mode 100644
index 00000000..2f9242c5
--- /dev/null
+++ b/pkg/uuid/uuid_container.go
@@ -0,0 +1,29 @@
+package uuid
+
+import (
+	"github.com/mayswind/lab/pkg/errs"
+	"github.com/mayswind/lab/pkg/settings"
+)
+
+type UuidContainer struct {
+	Current UuidGenerator
+}
+
+var (
+	Container = &UuidContainer{}
+)
+
+func InitializeUuidGenerator(config *settings.Config) error {
+	if config.UuidGeneratorType == settings.UUID_GENERATOR_TYPE_INTERNAL {
+		generator, err := NewInternalUuidGenerator(config)
+		Container.Current = generator
+
+		return err
+	}
+
+	return errs.ErrInvalidUuidMode
+}
+
+func (u *UuidContainer) GenerateUuid(uuidType UuidType) int64 {
+	return u.Current.GenerateUuid(uuidType)
+}
diff --git a/pkg/uuid/uuid_generator.go b/pkg/uuid/uuid_generator.go
new file mode 100644
index 00000000..e673a0ac
--- /dev/null
+++ b/pkg/uuid/uuid_generator.go
@@ -0,0 +1,5 @@
+package uuid
+
+type UuidGenerator interface {
+	GenerateUuid(uuidType UuidType) int64
+}
diff --git a/pkg/uuid/uuid_type.go b/pkg/uuid/uuid_type.go
new file mode 100644
index 00000000..85add5a8
--- /dev/null
+++ b/pkg/uuid/uuid_type.go
@@ -0,0 +1,12 @@
+package uuid
+
+type UuidType uint8
+
+const (
+	UUID_TYPE_DEFAULT  UuidType = 0
+	UUID_TYPE_USER     UuidType = 1
+	UUID_TYPE_ACCOUNT  UuidType = 2
+	UUID_TYPE_JOURNAL  UuidType = 3
+	UUID_TYPE_CATEGORY UuidType = 4
+	UUID_TYPE_TAG      UuidType = 5
+)