diff --git a/core/zerr/implementation.go b/core/zerr/implementation.go
index 9a75d95..adad7fb 100644
--- a/core/zerr/implementation.go
+++ b/core/zerr/implementation.go
@@ -193,12 +193,12 @@ func (mu *Err) GetID() string {
 }
 
 func (mu *Err) Log(ctx context.Context) Error {
-	mu.logger.Log(ctx, mu)
+	mu.logger.LogError(ctx, mu)
 	return mu
 }
 
 func (mu *Err) Notify(ctx context.Context, opts ...zoptions.NotifyOption) Error {
-	mu.notifier.Notify(ctx, mu, opts...)
+	mu.notifier.NotifyError(ctx, mu, opts...)
 	return mu
 }
 
diff --git a/core/zerr/wrap.go b/core/zerr/wrap.go
index d9306f2..168b547 100644
--- a/core/zerr/wrap.go
+++ b/core/zerr/wrap.go
@@ -23,11 +23,11 @@ type Wrapper interface {
 }
 
 type Logger interface {
-	Log(ctx context.Context, err Error)
+	LogError(ctx context.Context, err Error)
 }
 
 type Notifier interface {
-	Notify(ctx context.Context, err Error, opts ...zoptions.NotifyOption)
+	NotifyError(ctx context.Context, err Error, opts ...zoptions.NotifyOption)
 }
 
 type WrapperFunc func(input WrapInitialInput) Error
diff --git a/core/zlog/buffer.go b/core/zlog/buffer.go
new file mode 100644
index 0000000..546770b
--- /dev/null
+++ b/core/zlog/buffer.go
@@ -0,0 +1,75 @@
+package zlog
+
+import (
+	"bytes"
+	"log/slog"
+	"sync"
+)
+
+type jsonHandlerPool struct {
+	*sync.Pool
+}
+
+func newJsonHandlerPool(handlerOption *slog.HandlerOptions) *jsonHandlerPool {
+	var handlerPool *jsonHandlerPool
+	generator := &sync.Pool{
+		New: func() any {
+			buf := new(bytes.Buffer)
+			return &jsonHandler{
+				Buffer:      buf,
+				pool:        handlerPool,
+				JSONHandler: slog.NewJSONHandler(buf, handlerOption),
+			}
+		},
+	}
+	handlerPool = &jsonHandlerPool{
+		generator,
+	}
+	return handlerPool
+}
+
+func (jhp *jsonHandlerPool) Get() *jsonHandler {
+	handler := jhp.Pool.Get().(*jsonHandler)
+	return handler
+}
+
+type jsonHandler struct {
+	*bytes.Buffer
+	pool *jsonHandlerPool
+	*slog.JSONHandler
+}
+
+func (j *jsonHandler) Put() {
+	// Only put back to pool if buffer is smaller than 4MB in RAM size.
+	if j.Buffer.Cap() < 1024*1024*4 {
+		j.Buffer.Reset()
+		j.pool.Put(j)
+	}
+}
+
+type bufferPool struct {
+	*sync.Pool
+}
+
+func newBufferPool() *bufferPool {
+	return &bufferPool{
+		&sync.Pool{
+			New: func() any {
+				buf := new(bytes.Buffer)
+				buf.Grow(1024)
+				return buf
+			},
+		},
+	}
+}
+
+func (bp *bufferPool) Get() *bytes.Buffer {
+	return bp.Pool.Get().(*bytes.Buffer)
+}
+
+func (bp *bufferPool) Put(buf *bytes.Buffer) {
+	if buf.Cap() < 1024*1024*4 {
+		buf.Reset()
+		bp.Pool.Put(buf)
+	}
+}
diff --git a/core/zlog/caller.go b/core/zlog/caller.go
new file mode 100644
index 0000000..d3e6811
--- /dev/null
+++ b/core/zlog/caller.go
@@ -0,0 +1 @@
+package zlog
diff --git a/core/zlog/null.go b/core/zlog/null.go
new file mode 100644
index 0000000..d3e6811
--- /dev/null
+++ b/core/zlog/null.go
@@ -0,0 +1 @@
+package zlog
diff --git a/core/zlog/zlog.go b/core/zlog/zlog.go
index ade69da..aaabadb 100644
--- a/core/zlog/zlog.go
+++ b/core/zlog/zlog.go
@@ -1,7 +1,141 @@
 package zlog
 
-import notifyv1 "gitlab.bareksa.com/backend/zen/internal/gen/proto/notify/v1"
+import (
+	"context"
+	"io"
+	"log/slog"
+	"sync"
 
-func log() {
-	notifyv1.Payload
+	"github.com/fatih/color"
+)
+
+type WriteLocker interface {
+	io.Writer
+	sync.Locker
+}
+
+func WrapLocker(w io.Writer) WriteLocker {
+	if wl, ok := w.(WriteLocker); ok {
+		return wl
+	}
+	return &writeLocker{Writer: w}
+}
+
+type writeLocker struct {
+	io.Writer
+	sync.Mutex
+}
+
+type Log struct {
+	level         slog.Level
+	bufPool       *bufferPool
+	jsonPool      *jsonHandlerPool
+	withAttrs     []slog.Attr
+	withGroup     []string
+	handlerOption *slog.HandlerOptions
+	pretty        bool
+	color         bool
+	writer        WriteLocker
+}
+
+// Clone clones the Logger, replacing the output writer with w.
+//
+// If w is nil, the clone shares the original Logger's output writer.
+func (log *Log) Clone(w io.Writer) *Log {
+	var output WriteLocker
+	if w == nil {
+		output = log.writer
+	} else {
+		output = WrapLocker(w)
+	}
+	withAttrs := make([]slog.Attr, len(log.withAttrs))
+	copy(withAttrs, log.withAttrs)
+	withGroup := make([]string, len(log.withGroup))
+	copy(withGroup, log.withGroup)
+	return &Log{
+		level:         log.level,
+		withAttrs:     withAttrs,
+		withGroup:     withGroup,
+		handlerOption: log.handlerOption,
+		pretty:        log.pretty,
+		bufPool:       newBufferPool(),
+		jsonPool:      newJsonHandlerPool(log.handlerOption),
+		writer:        output,
+	}
+}
+
+// Enabled implements the slog.Handler interface.
+func (lo *Log) Enabled(ctx context.Context, lvl slog.Level) bool {
+	return lvl >= lo.level
+}
+
+// Handle implements the slog.Handler interface.
+func (lo *Log) Handle(ctx context.Context, record slog.Record) error {
+	if !lo.pretty {
+		j := lo.jsonPool.Get()
+		defer j.Put()
+		return j.Handle(ctx, record)
+	}
+
+	var levelColor *color.Color
+	switch {
+	case record.Level >= slog.LevelError:
+		levelColor = color.New(color.FgRed)
+	case record.Level >= slog.LevelWarn:
+		levelColor = color.New(color.FgYellow)
+	case record.Level >= slog.LevelInfo:
+		levelColor = color.New(color.FgGreen)
+	default:
+		levelColor = color.New(color.FgWhite)
+	}
+
+	_ = levelColor
+
+	buf := lo.bufPool.Get()
+	defer lo.bufPool.Put(buf)
+
+	panic("not implemented")
+
+	// if record.PC != 0 && pr.opts.AddSource {
+	// 	frame := caller.From(record.PC).Frame
+	// 	levelColor.Fprint(buf, frame.File)
+	// 	levelColor.Fprint(buf, ":")
+	// 	levelColor.Fprint(buf, frame.Line)
+	// 	levelColor.Fprint(buf, " -- ")
+	// 	split := strings.Split(frame.Function, string(os.PathSeparator))
+	// 	fnName := split[len(split)-1]
+	// 	levelColor.Fprint(buf, fnName)
+	// 	buf.WriteByte('\n')
+	// }
+}
+
+// WithAttrs implements the slog.Handler interface.
+func (lo *Log) WithAttrs(attrs []slog.Attr) slog.Handler {
+	l := lo.Clone(nil)
+	l.withAttrs = append(l.withAttrs, attrs...)
+	return l
+}
+
+// WithGroup implements the slog.Handler interface.
+func (lo *Log) WithGroup(name string) slog.Handler {
+	l := lo.Clone(nil)
+	l.withGroup = append(l.withGroup, name)
+	return l
+}
+
+type replaceAttrFunc = func([]string, slog.Attr) slog.Attr
+
+// wrapReplaceAttr disables adding Time, Level, Source, Message
+// fields when pretty mode is enabled.
+func (lo *Log) wrapReplaceAttr(f replaceAttrFunc) replaceAttrFunc {
+	return func(s []string, a slog.Attr) slog.Attr {
+		if !lo.pretty {
+			return f(s, a)
+		}
+		switch a.Key {
+		case slog.TimeKey, slog.LevelKey, slog.SourceKey, slog.MessageKey:
+			return slog.Attr{}
+		}
+		return f(s, a)
+	}
 }
diff --git a/core/zoptions/notify.go b/core/zoptions/notify.go
index d9601bd..e8d3f14 100644
--- a/core/zoptions/notify.go
+++ b/core/zoptions/notify.go
@@ -1,6 +1,7 @@
 package zoptions
 
 import (
+	"fmt"
 	"io"
 	"os"
 	"time"
@@ -237,7 +238,12 @@ func NewNamedReaderFromFile(path string, mimetype string) NamedReader {
 	if err != nil {
 		rc = &errorReader{err}
 	} else {
-		rc = f
+		if stat, err := f.Stat(); err == nil && stat.IsDir() {
+			f.Close()
+			rc = &errorReader{fmt.Errorf("file %s is a directory", path)}
+		} else {
+			rc = f
+		}
 	}
 	return &namedReader{
 		filename: path,
diff --git a/go.mod b/go.mod
index e1dd7b6..69708bd 100644
--- a/go.mod
+++ b/go.mod
@@ -5,8 +5,14 @@ go 1.23
 require (
 	connectrpc.com/connect v1.16.2
 	connectrpc.com/grpcreflect v1.2.0
+	github.com/fatih/color v1.17.0
 	golang.org/x/net v0.23.0
 	google.golang.org/protobuf v1.34.2
 )
 
-require golang.org/x/text v0.14.0 // indirect
+require (
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	golang.org/x/sys v0.18.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+)
diff --git a/go.sum b/go.sum
index e0f11ee..0605658 100644
--- a/go.sum
+++ b/go.sum
@@ -2,10 +2,21 @@ connectrpc.com/connect v1.16.2 h1:ybd6y+ls7GOlb7Bh5C8+ghA6SvCBajHwxssO2CGFjqE=
 connectrpc.com/connect v1.16.2/go.mod h1:n2kgwskMHXC+lVqb18wngEpF95ldBHXjZYJussz5FRc=
 connectrpc.com/grpcreflect v1.2.0 h1:Q6og1S7HinmtbEuBvARLNwYmTbhEGRpHDhqrPNlmK+U=
 connectrpc.com/grpcreflect v1.2.0/go.mod h1:nwSOKmE8nU5u/CidgHtPYk1PFI3U9ignz7iDMxOYkSY=
+github.com/fatih/color v1.17.0 h1:GlRw1BRJxkpqUCBKzKOw098ed57fEsKeNjpTe3cSjK4=
+github.com/fatih/color v1.17.0/go.mod h1:YZ7TlrGPkiz6ku9fK3TLD/pl3CpsiFyu8N92HLgmosI=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 golang.org/x/net v0.23.0 h1:7EYJ93RZ9vYSZAIb2x3lnuvqO5zneoD6IvWjuhfxjTs=
 golang.org/x/net v0.23.0/go.mod h1:JKghWKKOSdJwpW2GEx0Ja7fmaKnMsbu+MWVZTokSYmg=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
+golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=