diff --git a/agent/pkg/handler/check_health_test.go b/agent/pkg/handler/check_health_test.go
index 4633ed6..d90d98e 100644
--- a/agent/pkg/handler/check_health_test.go
+++ b/agent/pkg/handler/check_health_test.go
@@ -1,7 +1,6 @@
 package handler_test
 
 import (
-	"encoding/json"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -9,6 +8,8 @@ import (
 	"strconv"
 	"testing"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/stretchr/testify/require"
 	"github.com/yusing/go-proxy/agent/pkg/agent"
 	"github.com/yusing/go-proxy/agent/pkg/handler"
diff --git a/internal/api/v1/auth/oidc.go b/internal/api/v1/auth/oidc.go
index 2643a99..95ae628 100644
--- a/internal/api/v1/auth/oidc.go
+++ b/internal/api/v1/auth/oidc.go
@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/rand"
 	"encoding/base64"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -15,6 +14,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/net/gphttp"
diff --git a/internal/api/v1/auth/oidc_test.go b/internal/api/v1/auth/oidc_test.go
index 0ed759f..ad2a5e2 100644
--- a/internal/api/v1/auth/oidc_test.go
+++ b/internal/api/v1/auth/oidc_test.go
@@ -5,12 +5,13 @@ import (
 	"crypto/rand"
 	"crypto/rsa"
 	"encoding/base64"
-	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/yusing/go-proxy/internal/common"
diff --git a/internal/api/v1/auth/userpass.go b/internal/api/v1/auth/userpass.go
index 239a4cc..39dae3f 100644
--- a/internal/api/v1/auth/userpass.go
+++ b/internal/api/v1/auth/userpass.go
@@ -1,11 +1,12 @@
 package auth
 
 import (
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/golang-jwt/jwt/v5"
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/gperr"
diff --git a/internal/api/v1/auth/userpass_test.go b/internal/api/v1/auth/userpass_test.go
index 9a9fbc4..cd958ed 100644
--- a/internal/api/v1/auth/userpass_test.go
+++ b/internal/api/v1/auth/userpass_test.go
@@ -2,13 +2,14 @@ package auth
 
 import (
 	"bytes"
-	"encoding/json"
 	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	. "github.com/yusing/go-proxy/internal/utils/testing"
 	"golang.org/x/crypto/bcrypt"
 )
diff --git a/internal/api/v1/certapi/cert_info.go b/internal/api/v1/certapi/cert_info.go
index 07edfd9..c99586c 100644
--- a/internal/api/v1/certapi/cert_info.go
+++ b/internal/api/v1/certapi/cert_info.go
@@ -1,9 +1,10 @@
 package certapi
 
 import (
-	"encoding/json"
 	"net/http"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	config "github.com/yusing/go-proxy/internal/config/types"
 )
 
diff --git a/internal/api/v1/dockerapi/info.go b/internal/api/v1/dockerapi/info.go
index 373895d..6aeb4de 100644
--- a/internal/api/v1/dockerapi/info.go
+++ b/internal/api/v1/dockerapi/info.go
@@ -2,10 +2,11 @@ package dockerapi
 
 import (
 	"context"
-	"encoding/json"
 	"net/http"
 	"sort"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	dockerSystem "github.com/docker/docker/api/types/system"
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/utils/strutils"
@@ -13,8 +14,8 @@ import (
 
 type dockerInfo dockerSystem.Info
 
-func (d *dockerInfo) MarshalJSON() ([]byte, error) {
-	return json.Marshal(map[string]any{
+func (d *dockerInfo) MarshalJSONTo(buf []byte) []byte {
+	return json.MarshalTo(map[string]any{
 		"name":    d.Name,
 		"version": d.ServerVersion,
 		"containers": map[string]int{
@@ -25,8 +26,8 @@ func (d *dockerInfo) MarshalJSON() ([]byte, error) {
 		},
 		"images": d.Images,
 		"n_cpu":  d.NCPU,
-		"memory": strutils.FormatByteSizeWithUnit(d.MemTotal),
-	})
+		"memory": strutils.FormatByteSize(d.MemTotal),
+	}, buf)
 }
 
 func DockerInfo(w http.ResponseWriter, r *http.Request) {
diff --git a/internal/api/v1/dockerapi/utils.go b/internal/api/v1/dockerapi/utils.go
index b25b59a..51f23cf 100644
--- a/internal/api/v1/dockerapi/utils.go
+++ b/internal/api/v1/dockerapi/utils.go
@@ -2,10 +2,11 @@ package dockerapi
 
 import (
 	"context"
-	"encoding/json"
 	"net/http"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/coder/websocket"
 	"github.com/coder/websocket/wsjson"
 	"github.com/yusing/go-proxy/agent/pkg/agent"
diff --git a/internal/api/v1/homepage_overrides.go b/internal/api/v1/homepage_overrides.go
index 6c3d303..3cd46af 100644
--- a/internal/api/v1/homepage_overrides.go
+++ b/internal/api/v1/homepage_overrides.go
@@ -1,12 +1,12 @@
 package v1
 
 import (
-	"encoding/json"
 	"io"
 	"net/http"
 
 	"github.com/yusing/go-proxy/internal/homepage"
 	"github.com/yusing/go-proxy/internal/net/gphttp"
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 const (
diff --git a/internal/api/v1/new_agent.go b/internal/api/v1/new_agent.go
index 9abc627..6b6daa5 100644
--- a/internal/api/v1/new_agent.go
+++ b/internal/api/v1/new_agent.go
@@ -1,13 +1,14 @@
 package v1
 
 import (
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
 	"os"
 	"strconv"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	_ "embed"
 
 	"github.com/yusing/go-proxy/agent/pkg/agent"
diff --git a/internal/api/v1/query/query.go b/internal/api/v1/query/query.go
index 4463834..df59adc 100644
--- a/internal/api/v1/query/query.go
+++ b/internal/api/v1/query/query.go
@@ -1,11 +1,12 @@
 package query
 
 import (
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	v1 "github.com/yusing/go-proxy/internal/api/v1"
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/gperr"
diff --git a/internal/homepage/homepage.go b/internal/homepage/homepage.go
index 9ad1d81..77dc620 100644
--- a/internal/homepage/homepage.go
+++ b/internal/homepage/homepage.go
@@ -1,9 +1,10 @@
 package homepage
 
 import (
-	"encoding/json"
 	"strings"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	config "github.com/yusing/go-proxy/internal/config/types"
 	"github.com/yusing/go-proxy/internal/utils"
 )
@@ -42,7 +43,7 @@ func (cfg *ItemConfig) GetOverride(alias string) *ItemConfig {
 	return overrideConfigInstance.GetOverride(alias, cfg)
 }
 
-func (item *Item) MarshalJSON() ([]byte, error) {
+func (item *Item) MarshalJSONTo(buf []byte) []byte {
 	var url *string
 	if !strings.ContainsRune(item.Alias, '.') {
 		godoxyCfg := config.GetInstance().Value()
@@ -55,7 +56,7 @@ func (item *Item) MarshalJSON() ([]byte, error) {
 	} else {
 		url = &item.Alias
 	}
-	return json.Marshal(map[string]any{
+	return json.MarshalTo(map[string]any{
 		"show":          item.Show,
 		"alias":         item.Alias,
 		"provider":      item.Provider,
@@ -66,7 +67,7 @@ func (item *Item) MarshalJSON() ([]byte, error) {
 		"description":   item.Description,
 		"sort_order":    item.SortOrder,
 		"widget_config": item.WidgetConfig,
-	})
+	}, buf)
 }
 
 func (c Homepage) Add(item *Item) {
diff --git a/internal/homepage/icon_cache.go b/internal/homepage/icon_cache.go
index b7f68ea..ac35db3 100644
--- a/internal/homepage/icon_cache.go
+++ b/internal/homepage/icon_cache.go
@@ -1,10 +1,11 @@
 package homepage
 
 import (
-	"encoding/json"
 	"sync"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/logging"
 	"github.com/yusing/go-proxy/internal/task"
diff --git a/internal/homepage/list-icons.go b/internal/homepage/list-icons.go
index a76a87e..9979fe9 100644
--- a/internal/homepage/list-icons.go
+++ b/internal/homepage/list-icons.go
@@ -1,12 +1,13 @@
 package homepage
 
 import (
-	"encoding/json"
 	"io"
 	"net/http"
 	"sync"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/lithammer/fuzzysearch/fuzzy"
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/logging"
diff --git a/internal/metrics/period/entries.go b/internal/metrics/period/entries.go
index d9a5554..db61431 100644
--- a/internal/metrics/period/entries.go
+++ b/internal/metrics/period/entries.go
@@ -1,8 +1,9 @@
 package period
 
 import (
-	"encoding/json"
 	"time"
+
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 type Entries[T any] struct {
@@ -48,11 +49,11 @@ func (e *Entries[T]) Get() []*T {
 	return res
 }
 
-func (e *Entries[T]) MarshalJSON() ([]byte, error) {
-	return json.Marshal(map[string]any{
+func (e *Entries[T]) MarshalJSONTo(buf []byte) []byte {
+	return json.MarshalTo(map[string]any{
 		"entries":  e.Get(),
 		"interval": e.interval,
-	})
+	}, buf)
 }
 
 func (e *Entries[T]) UnmarshalJSON(data []byte) error {
diff --git a/internal/metrics/period/poller.go b/internal/metrics/period/poller.go
index f60014d..0e36e0d 100644
--- a/internal/metrics/period/poller.go
+++ b/internal/metrics/period/poller.go
@@ -2,7 +2,6 @@ package period
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"net/url"
 	"os"
@@ -15,6 +14,7 @@ import (
 	"github.com/yusing/go-proxy/internal/logging"
 	"github.com/yusing/go-proxy/internal/task"
 	"github.com/yusing/go-proxy/internal/utils/atomic"
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 type (
diff --git a/internal/metrics/period/tests.go b/internal/metrics/period/tests.go
new file mode 100644
index 0000000..94abac4
--- /dev/null
+++ b/internal/metrics/period/tests.go
@@ -0,0 +1,71 @@
+package period
+
+import (
+	"context"
+	"net/http"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/yusing/go-proxy/pkg/json"
+)
+
+func (p *Poller[T, AggregateT]) Test(t *testing.T, query url.Values) {
+	t.Helper()
+	for range 3 {
+		require.NoError(t, p.testPoll())
+	}
+	t.Run("periods", func(t *testing.T) {
+		assert.NoError(t, p.testMarshalPeriods(query))
+	})
+	t.Run("no period", func(t *testing.T) {
+		assert.NoError(t, p.testMarshalNoPeriod())
+	})
+}
+
+func (p *Poller[T, AggregateT]) testPeriod(period string, query url.Values) (any, error) {
+	query.Set("period", period)
+	return p.getRespData(&http.Request{URL: &url.URL{RawQuery: query.Encode()}})
+}
+
+func (p *Poller[T, AggregateT]) testPoll() error {
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	data, err := p.poll(ctx, p.lastResult.Load())
+	if err != nil {
+		return err
+	}
+	for _, period := range p.period.Entries {
+		period.Add(time.Now(), data)
+	}
+	p.lastResult.Store(data)
+	return nil
+}
+
+func (p *Poller[T, AggregateT]) testMarshalPeriods(query url.Values) error {
+	for period := range p.period.Entries {
+		data, err := p.testPeriod(string(period), query)
+		if err != nil {
+			return err
+		}
+		_, err = json.Marshal(data)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (p *Poller[T, AggregateT]) testMarshalNoPeriod() error {
+	data, err := p.getRespData(&http.Request{URL: &url.URL{}})
+	if err != nil {
+		return err
+	}
+	_, err = json.Marshal(data)
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/internal/metrics/systeminfo/system_info.go b/internal/metrics/systeminfo/system_info.go
index abe37b9..1d44c50 100644
--- a/internal/metrics/systeminfo/system_info.go
+++ b/internal/metrics/systeminfo/system_info.go
@@ -3,7 +3,6 @@ package systeminfo
 import (
 	"bytes"
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"net/url"
@@ -20,6 +19,7 @@ import (
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/logging"
 	"github.com/yusing/go-proxy/internal/metrics/period"
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 // json tags are left for tests
@@ -55,7 +55,7 @@ type (
 		DownloadSpeed float64 `json:"download_speed"`
 	}
 	Sensors    []sensors.TemperatureStat
-	Aggregated []map[string]any
+	Aggregated = json.MapSlice[any]
 )
 
 type SystemInfo struct {
@@ -295,8 +295,8 @@ func (s *SystemInfo) collectSensorsInfo(ctx context.Context) error {
 }
 
 // explicitly implement MarshalJSON to avoid reflection
-func (s *SystemInfo) MarshalJSON() ([]byte, error) {
-	b := bytes.NewBuffer(make([]byte, 0, 1024))
+func (s *SystemInfo) MarshalJSONTo(buf []byte) []byte {
+	b := bytes.NewBuffer(buf)
 
 	b.WriteRune('{')
 
@@ -315,7 +315,7 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 	// memory
 	b.WriteString(`,"memory":`)
 	if s.Memory != nil {
-		b.WriteString(fmt.Sprintf(
+		b.Write(fmt.Appendf(nil,
 			`{"total":%d,"available":%d,"used":%d,"used_percent":%s}`,
 			s.Memory.Total,
 			s.Memory.Available,
@@ -329,13 +329,13 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 	// disk
 	b.WriteString(`,"disks":`)
 	if len(s.Disks) > 0 {
-		b.WriteString("{")
+		b.WriteRune('{')
 		first := true
 		for device, disk := range s.Disks {
 			if !first {
 				b.WriteRune(',')
 			}
-			b.WriteString(fmt.Sprintf(
+			b.Write(fmt.Appendf(nil,
 				`"%s":{"device":%q,"path":%q,"fstype":%q,"total":%d,"free":%d,"used":%d,"used_percent":%s}`,
 				device,
 				device,
@@ -362,7 +362,7 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 			if !first {
 				b.WriteRune(',')
 			}
-			b.WriteString(fmt.Sprintf(
+			b.Write(fmt.Appendf(nil,
 				`"%s":{"name":%q,"read_bytes":%d,"write_bytes":%d,"read_speed":%s,"write_speed":%s,"iops":%d}`,
 				name,
 				name,
@@ -382,7 +382,7 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 	// network
 	b.WriteString(`,"network":`)
 	if s.Network != nil {
-		b.WriteString(fmt.Sprintf(
+		b.Write(fmt.Appendf(nil,
 			`{"bytes_sent":%d,"bytes_recv":%d,"upload_speed":%s,"download_speed":%s}`,
 			s.Network.BytesSent,
 			s.Network.BytesRecv,
@@ -396,13 +396,13 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 	// sensors
 	b.WriteString(`,"sensors":`)
 	if len(s.Sensors) > 0 {
-		b.WriteString("{")
+		b.WriteRune('{')
 		first := true
 		for _, sensor := range s.Sensors {
 			if !first {
 				b.WriteRune(',')
 			}
-			b.WriteString(fmt.Sprintf(
+			b.Write(fmt.Appendf(nil,
 				`%q:{"name":%q,"temperature":%s,"high":%s,"critical":%s}`,
 				sensor.SensorKey,
 				sensor.SensorKey,
@@ -418,7 +418,7 @@ func (s *SystemInfo) MarshalJSON() ([]byte, error) {
 	}
 
 	b.WriteRune('}')
-	return []byte(b.String()), nil
+	return b.Bytes()
 }
 
 func (s *Sensors) UnmarshalJSON(data []byte) error {
@@ -560,43 +560,3 @@ func aggregate(entries []*SystemInfo, query url.Values) (total int, result Aggre
 	}
 	return len(aggregated), aggregated
 }
-
-func (result Aggregated) MarshalJSON() ([]byte, error) {
-	buf := bytes.NewBuffer(make([]byte, 0, 1024))
-
-	buf.WriteByte('[')
-	i := 0
-	n := len(result)
-	for _, entry := range result {
-		buf.WriteRune('{')
-		j := 0
-		m := len(entry)
-		for k, v := range entry {
-			buf.WriteByte('"')
-			buf.WriteString(k)
-			buf.WriteByte('"')
-			buf.WriteByte(':')
-			switch v := v.(type) {
-			case float64:
-				buf.WriteString(strconv.FormatFloat(v, 'f', 2, 64))
-			case uint64:
-				buf.WriteString(strconv.FormatUint(v, 10))
-			case int64:
-				buf.WriteString(strconv.FormatInt(v, 10))
-			default:
-				panic(fmt.Sprintf("unexpected type: %T", v))
-			}
-			if j != m-1 {
-				buf.WriteByte(',')
-			}
-			j++
-		}
-		buf.WriteByte('}')
-		if i != n-1 {
-			buf.WriteByte(',')
-		}
-		i++
-	}
-	buf.WriteByte(']')
-	return buf.Bytes(), nil
-}
diff --git a/internal/metrics/systeminfo/system_info_test.go b/internal/metrics/systeminfo/system_info_test.go
index 6579069..8c1906f 100644
--- a/internal/metrics/systeminfo/system_info_test.go
+++ b/internal/metrics/systeminfo/system_info_test.go
@@ -1,15 +1,23 @@
 package systeminfo
 
 import (
-	"encoding/json"
 	"net/url"
 	"reflect"
 	"testing"
 
 	"github.com/shirou/gopsutil/v4/sensors"
 	. "github.com/yusing/go-proxy/internal/utils/testing"
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
+func TestPoller(t *testing.T) {
+	for _, query := range allQueries {
+		t.Run(query, func(t *testing.T) {
+			Poller.Test(t, url.Values{"aggregate": []string{query}})
+		})
+	}
+}
+
 func TestExcludeDisks(t *testing.T) {
 	tests := []struct {
 		name          string
@@ -191,8 +199,7 @@ func TestSerialize(t *testing.T) {
 	for _, query := range allQueries {
 		t.Run(query, func(t *testing.T) {
 			_, result := aggregate(entries, url.Values{"aggregate": []string{query}})
-			s, err := result.MarshalJSON()
-			ExpectNoError(t, err)
+			s := result.MarshalJSONTo(nil)
 			var v []map[string]any
 			ExpectNoError(t, json.Unmarshal(s, &v))
 			ExpectEqual(t, len(v), len(result))
@@ -206,31 +213,3 @@ func TestSerialize(t *testing.T) {
 		})
 	}
 }
-
-func BenchmarkJSONMarshal(b *testing.B) {
-	entries := make([]*SystemInfo, b.N)
-	for i := range b.N {
-		entries[i] = testInfo
-	}
-	queries := map[string]Aggregated{}
-	for _, query := range allQueries {
-		_, result := aggregate(entries, url.Values{"aggregate": []string{query}})
-		queries[query] = result
-	}
-	b.ReportAllocs()
-	b.ResetTimer()
-	b.Run("optimized", func(b *testing.B) {
-		for b.Loop() {
-			for _, query := range allQueries {
-				_, _ = queries[query].MarshalJSON()
-			}
-		}
-	})
-	b.Run("json", func(b *testing.B) {
-		for b.Loop() {
-			for _, query := range allQueries {
-				_, _ = json.Marshal([]map[string]any(queries[query]))
-			}
-		}
-	})
-}
diff --git a/internal/metrics/uptime/status.go b/internal/metrics/uptime/status.go
new file mode 100644
index 0000000..f101ae1
--- /dev/null
+++ b/internal/metrics/uptime/status.go
@@ -0,0 +1,22 @@
+package uptime
+
+import (
+	"fmt"
+
+	"github.com/yusing/go-proxy/internal/watcher/health"
+)
+
+type Status struct {
+	Status    health.Status
+	Latency   int64
+	Timestamp int64
+}
+
+type RouteStatuses map[string][]*Status
+
+func (s *Status) MarshalJSONTo(buf []byte) []byte {
+	return fmt.Appendf(buf,
+		`{"status":"%s","latency":"%d","timestamp":"%d"}`,
+		s.Status, s.Latency, s.Timestamp,
+	)
+}
diff --git a/internal/metrics/uptime/uptime.go b/internal/metrics/uptime/uptime.go
index 3162e3d..41b0732 100644
--- a/internal/metrics/uptime/uptime.go
+++ b/internal/metrics/uptime/uptime.go
@@ -2,7 +2,6 @@ package uptime
 
 import (
 	"context"
-	"encoding/json"
 	"net/url"
 	"sort"
 	"time"
@@ -13,20 +12,15 @@ import (
 	"github.com/yusing/go-proxy/internal/route/routes"
 	"github.com/yusing/go-proxy/internal/route/routes/routequery"
 	"github.com/yusing/go-proxy/internal/watcher/health"
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 type (
 	StatusByAlias struct {
-		Map       map[string]*routequery.HealthInfoRaw `json:"statuses"`
-		Timestamp int64                                `json:"timestamp"`
+		Map       json.Map[*routequery.HealthInfoRaw] `json:"statuses"`
+		Timestamp int64                               `json:"timestamp"`
 	}
-	Status struct {
-		Status    health.Status `json:"status"`
-		Latency   int64         `json:"latency"`
-		Timestamp int64         `json:"timestamp"`
-	}
-	RouteStatuses map[string][]*Status
-	Aggregated    []map[string]any
+	Aggregated = json.MapSlice[any]
 )
 
 var Poller = period.NewPoller("uptime", getStatuses, aggregateStatuses)
@@ -124,7 +118,3 @@ func (rs RouteStatuses) aggregate(limit int, offset int) Aggregated {
 	}
 	return result
 }
-
-func (result Aggregated) MarshalJSON() ([]byte, error) {
-	return json.Marshal([]map[string]any(result))
-}
diff --git a/internal/metrics/uptime/uptime_test.go b/internal/metrics/uptime/uptime_test.go
new file mode 100644
index 0000000..8182aad
--- /dev/null
+++ b/internal/metrics/uptime/uptime_test.go
@@ -0,0 +1,10 @@
+package uptime
+
+import (
+	"net/url"
+	"testing"
+)
+
+func TestPoller(t *testing.T) {
+	Poller.Test(t, url.Values{"limit": []string{"1"}})
+}
diff --git a/internal/net/gphttp/accesslog/access_logger.go b/internal/net/gphttp/accesslog/access_logger.go
index 1637377..3f56fa2 100644
--- a/internal/net/gphttp/accesslog/access_logger.go
+++ b/internal/net/gphttp/accesslog/access_logger.go
@@ -194,6 +194,6 @@ func (l *AccessLogger) write(data []byte) {
 	if err != nil {
 		l.handleErr(err)
 	} else {
-		logging.Debug().Msg("access log flushed to " + l.io.Name())
+		logging.Trace().Msg("access log flushed to " + l.io.Name())
 	}
 }
diff --git a/internal/net/gphttp/accesslog/access_logger_test.go b/internal/net/gphttp/accesslog/access_logger_test.go
index 7e7af45..ee903c4 100644
--- a/internal/net/gphttp/accesslog/access_logger_test.go
+++ b/internal/net/gphttp/accesslog/access_logger_test.go
@@ -2,13 +2,14 @@ package accesslog_test
 
 import (
 	"bytes"
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/url"
 	"testing"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	. "github.com/yusing/go-proxy/internal/net/gphttp/accesslog"
 	"github.com/yusing/go-proxy/internal/task"
 	. "github.com/yusing/go-proxy/internal/utils/testing"
diff --git a/internal/net/gphttp/accesslog/formatter.go b/internal/net/gphttp/accesslog/formatter.go
index d0fcd68..deca013 100644
--- a/internal/net/gphttp/accesslog/formatter.go
+++ b/internal/net/gphttp/accesslog/formatter.go
@@ -2,13 +2,14 @@ package accesslog
 
 import (
 	"bytes"
-	"encoding/json"
 	"net"
 	"net/http"
 	"net/url"
 	"strconv"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/logging"
 )
 
diff --git a/internal/net/gphttp/body.go b/internal/net/gphttp/body.go
index 3a94023..45d78e7 100644
--- a/internal/net/gphttp/body.go
+++ b/internal/net/gphttp/body.go
@@ -2,11 +2,12 @@ package gphttp
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"net/http"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/logging"
 )
 
diff --git a/internal/net/gphttp/error.go b/internal/net/gphttp/error.go
index f269e3f..fc37077 100644
--- a/internal/net/gphttp/error.go
+++ b/internal/net/gphttp/error.go
@@ -2,11 +2,12 @@ package gphttp
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"net/http"
 	"syscall"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/net/gphttp/httpheaders"
 )
diff --git a/internal/net/gphttp/gpwebsocket/utils.go b/internal/net/gphttp/gpwebsocket/utils.go
index cc98592..be4fa74 100644
--- a/internal/net/gphttp/gpwebsocket/utils.go
+++ b/internal/net/gphttp/gpwebsocket/utils.go
@@ -12,7 +12,6 @@ import (
 	"github.com/yusing/go-proxy/internal/logging"
 	"github.com/yusing/go-proxy/internal/net/gphttp"
 	"github.com/yusing/go-proxy/internal/net/gphttp/httpheaders"
-	"github.com/yusing/go-proxy/internal/utils"
 )
 
 func warnNoMatchDomains() {
@@ -95,7 +94,7 @@ func WriteText(r *http.Request, conn *websocket.Conn, msg string) bool {
 func DynamicJSONHandler[ResultType any](w http.ResponseWriter, r *http.Request, getter func() ResultType, interval time.Duration) {
 	if httpheaders.IsWebsocket(r.Header) {
 		Periodic(w, r, interval, func(conn *websocket.Conn) error {
-			return wsjson.Write(r.Context(), conn, utils.ToJSONObject(getter()))
+			return wsjson.Write(r.Context(), conn, getter())
 		})
 	} else {
 		gphttp.RespondJSON(w, r, getter())
diff --git a/internal/net/gphttp/middleware/middleware.go b/internal/net/gphttp/middleware/middleware.go
index c6b5fd8..cc12aa9 100644
--- a/internal/net/gphttp/middleware/middleware.go
+++ b/internal/net/gphttp/middleware/middleware.go
@@ -1,12 +1,13 @@
 package middleware
 
 import (
-	"encoding/json"
 	"net/http"
 	"reflect"
 	"sort"
 	"strings"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/logging"
 	gphttp "github.com/yusing/go-proxy/internal/net/gphttp"
@@ -158,12 +159,12 @@ func (m *Middleware) String() string {
 	return m.name
 }
 
-func (m *Middleware) MarshalJSON() ([]byte, error) {
-	return json.MarshalIndent(map[string]any{
+func (m *Middleware) MarshalJSONTo(buf []byte) []byte {
+	return json.MarshalTo(map[string]any{
 		"name":     m.name,
 		"options":  m.impl,
 		"priority": m.priority,
-	}, "", "  ")
+	}, buf)
 }
 
 func (m *Middleware) ModifyRequest(next http.HandlerFunc, w http.ResponseWriter, r *http.Request) {
diff --git a/internal/net/gphttp/middleware/middleware_builder_test.go b/internal/net/gphttp/middleware/middleware_builder_test.go
index 08e8402..3036ca6 100644
--- a/internal/net/gphttp/middleware/middleware_builder_test.go
+++ b/internal/net/gphttp/middleware/middleware_builder_test.go
@@ -2,9 +2,10 @@ package middleware
 
 import (
 	_ "embed"
-	"encoding/json"
 	"testing"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/gperr"
 	. "github.com/yusing/go-proxy/internal/utils/testing"
 )
@@ -16,7 +17,7 @@ func TestBuild(t *testing.T) {
 	errs := gperr.NewBuilder("")
 	middlewares := BuildMiddlewaresFromYAML("", testMiddlewareCompose, errs)
 	ExpectNoError(t, errs.Error())
-	Must(json.MarshalIndent(middlewares, "", "  "))
+	json.Marshal(middlewares)
 	// t.Log(string(data))
 	// TODO: test
 }
diff --git a/internal/net/gphttp/middleware/test_utils.go b/internal/net/gphttp/middleware/test_utils.go
index edb5e24..a3eb34d 100644
--- a/internal/net/gphttp/middleware/test_utils.go
+++ b/internal/net/gphttp/middleware/test_utils.go
@@ -3,12 +3,13 @@ package middleware
 import (
 	"bytes"
 	_ "embed"
-	"encoding/json"
 	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/common"
 	"github.com/yusing/go-proxy/internal/gperr"
 	"github.com/yusing/go-proxy/internal/net/gphttp/reverseproxy"
diff --git a/internal/notif/format.go b/internal/notif/format.go
index f54d897..da51763 100644
--- a/internal/notif/format.go
+++ b/internal/notif/format.go
@@ -2,7 +2,8 @@ package notif
 
 import (
 	"bytes"
-	"encoding/json"
+
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 func formatMarkdown(extras LogFields) string {
diff --git a/internal/notif/gotify.go b/internal/notif/gotify.go
index bb2d951..390d4af 100644
--- a/internal/notif/gotify.go
+++ b/internal/notif/gotify.go
@@ -2,11 +2,12 @@ package notif
 
 import (
 	"bytes"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/gotify/server/v2/model"
 	"github.com/rs/zerolog"
 )
diff --git a/internal/notif/webhook.go b/internal/notif/webhook.go
index 13fd23c..bccd5fc 100644
--- a/internal/notif/webhook.go
+++ b/internal/notif/webhook.go
@@ -2,12 +2,13 @@ package notif
 
 import (
 	_ "embed"
-	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
 	"strings"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/yusing/go-proxy/internal/gperr"
 )
 
@@ -101,10 +102,7 @@ func (webhook *Webhook) makeRespError(resp *http.Response) error {
 }
 
 func (webhook *Webhook) MakeBody(logMsg *LogMessage) (io.Reader, error) {
-	title, err := json.Marshal(logMsg.Title)
-	if err != nil {
-		return nil, err
-	}
+	title := json.String(logMsg.Title)
 	fields, err := formatDiscord(logMsg.Extras)
 	if err != nil {
 		return nil, err
@@ -115,13 +113,10 @@ func (webhook *Webhook) MakeBody(logMsg *LogMessage) (io.Reader, error) {
 	} else {
 		color = logMsg.Color.DecString()
 	}
-	message, err := json.Marshal(formatMarkdown(logMsg.Extras))
-	if err != nil {
-		return nil, err
-	}
+	message := json.String(formatMarkdown(logMsg.Extras))
 	plTempl := strings.NewReplacer(
-		"$title", string(title),
-		"$message", string(message),
+		"$title", title,
+		"$message", message,
 		"$fields", fields,
 		"$color", color,
 	)
diff --git a/internal/route/routes/routequery/query.go b/internal/route/routes/routequery/query.go
index f1b3037..d1bcf7f 100644
--- a/internal/route/routes/routequery/query.go
+++ b/internal/route/routes/routequery/query.go
@@ -26,8 +26,8 @@ func getHealthInfo(r route.Route) map[string]string {
 }
 
 type HealthInfoRaw struct {
-	Status  health.Status
-	Latency time.Duration
+	Status  health.Status `json:"status,string"`
+	Latency time.Duration `json:"latency"`
 }
 
 func getHealthInfoRaw(r route.Route) *HealthInfoRaw {
diff --git a/internal/route/rules/do.go b/internal/route/rules/do.go
index f113a4c..336a90b 100644
--- a/internal/route/rules/do.go
+++ b/internal/route/rules/do.go
@@ -300,7 +300,3 @@ func (cmd *Command) isBypass() bool {
 func (cmd *Command) String() string {
 	return cmd.raw
 }
-
-func (cmd *Command) MarshalText() ([]byte, error) {
-	return []byte(cmd.String()), nil
-}
diff --git a/internal/route/rules/on.go b/internal/route/rules/on.go
index f69e7a8..da3e453 100644
--- a/internal/route/rules/on.go
+++ b/internal/route/rules/on.go
@@ -261,10 +261,6 @@ func (on *RuleOn) String() string {
 	return on.raw
 }
 
-func (on *RuleOn) MarshalText() ([]byte, error) {
-	return []byte(on.String()), nil
-}
-
 func parseOn(line string) (Checker, gperr.Error) {
 	ors := strutils.SplitRune(line, '|')
 
diff --git a/internal/route/rules/rules.go b/internal/route/rules/rules.go
index 4d1dbcc..032c523 100644
--- a/internal/route/rules/rules.go
+++ b/internal/route/rules/rules.go
@@ -1,8 +1,9 @@
 package rules
 
 import (
-	"encoding/json"
 	"net/http"
+
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 type (
@@ -40,8 +41,8 @@ type (
 	*/
 	Rule struct {
 		Name string  `json:"name"`
-		On   RuleOn  `json:"on"`
-		Do   Command `json:"do"`
+		On   RuleOn  `json:"on,string"`
+		Do   Command `json:"do,string"`
 	}
 )
 
@@ -102,12 +103,12 @@ func (rules Rules) BuildHandler(caller string, up http.Handler) http.HandlerFunc
 	}
 }
 
-func (rules Rules) MarshalJSON() ([]byte, error) {
+func (rules Rules) MarshalJSONTo(buf []byte) []byte {
 	names := make([]string, len(rules))
 	for i, rule := range rules {
 		names[i] = rule.Name
 	}
-	return json.Marshal(names)
+	return json.MarshalTo(names, buf)
 }
 
 func (rule *Rule) String() string {
diff --git a/internal/utils/atomic/value.go b/internal/utils/atomic/value.go
index 65140fe..d05f80b 100644
--- a/internal/utils/atomic/value.go
+++ b/internal/utils/atomic/value.go
@@ -1,8 +1,9 @@
 package atomic
 
 import (
-	"encoding/json"
 	"sync/atomic"
+
+	"github.com/yusing/go-proxy/pkg/json"
 )
 
 type Value[T any] struct {
@@ -29,6 +30,6 @@ func (a *Value[T]) Swap(v T) T {
 	return zero
 }
 
-func (a *Value[T]) MarshalJSON() ([]byte, error) {
-	return json.Marshal(a.Load())
+func (a *Value[T]) MarshalJSONTo(buf []byte) []byte {
+	return json.MarshalTo(a.Load(), buf)
 }
diff --git a/internal/utils/serialization.go b/internal/utils/serialization.go
index ea0f0c8..c150a84 100644
--- a/internal/utils/serialization.go
+++ b/internal/utils/serialization.go
@@ -2,7 +2,6 @@ package utils
 
 import (
 	"bytes"
-	"encoding/json"
 	"errors"
 	"net"
 	"net/url"
@@ -12,6 +11,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	"github.com/go-playground/validator/v10"
 	"github.com/goccy/go-yaml"
 	"github.com/yusing/go-proxy/internal/gperr"
@@ -22,12 +23,15 @@ import (
 type SerializedObject = map[string]any
 
 type (
-	MapMarshaller interface {
+	MapMarshaler interface {
 		MarshalMap() map[string]any
 	}
-	MapUnmarshaller interface {
-	UnmarshalMap(m map[string]any) gperr.Error
-}
+	MapUnmarshaler interface {
+		UnmarshalMap(m map[string]any) gperr.Error
+	}
+	Marshaler interface {
+		MarshalJSONTo(buf *bytes.Buffer) error
+	}
 )
 
 var (
@@ -51,11 +55,8 @@ var (
 	typeURL      = reflect.TypeFor[url.URL]()
 	typeCIDR     = reflect.TypeFor[net.IPNet]()
 
-	typeMapMarshaller  = reflect.TypeFor[MapMarshaller]()
-	typeMapUnmarshaler = reflect.TypeFor[MapUnmarshaller]()
-	typeJSONMarshaller = reflect.TypeFor[json.Marshaler]()
-
-	typeAny = reflect.TypeOf((*any)(nil)).Elem()
+	typeMapUnmarshaler = reflect.TypeFor[MapUnmarshaler]()
+	typeStrParser      = reflect.TypeFor[strutils.Parser]()
 )
 
 var defaultValues = functional.NewMapOf[reflect.Type, func() any]()
@@ -92,14 +93,14 @@ func extractFields(t reflect.Type) (all, anonymous []reflect.StructField) {
 		if !field.IsExported() {
 			continue
 		}
+		// not checking tagJSON because json:"-" is for skipping json.Marshal
 		if field.Tag.Get(tagDeserialize) == "-" {
 			continue
 		}
 		if field.Anonymous {
-			f1, f2 := extractFields(field.Type)
-			fields = append(fields, f1...)
+			nested, _ := extractFields(field.Type)
+			fields = append(fields, nested...)
 			anonymous = append(anonymous, field)
-			anonymous = append(anonymous, f2...)
 		} else {
 			fields = append(fields, field)
 		}
@@ -215,7 +216,7 @@ func MapUnmarshalValidate(src SerializedObject, dst any) (err gperr.Error) {
 		if err != nil {
 			return err
 		}
-		return dstV.Addr().Interface().(MapUnmarshaller).UnmarshalMap(src)
+		return dstV.Addr().Interface().(MapUnmarshaler).UnmarshalMap(src)
 	}
 
 	dstV, dstT, err = dive(dstV)
diff --git a/internal/watcher/health/monitor/agent_proxied.go b/internal/watcher/health/monitor/agent_proxied.go
index 67db85c..b8aa102 100644
--- a/internal/watcher/health/monitor/agent_proxied.go
+++ b/internal/watcher/health/monitor/agent_proxied.go
@@ -1,11 +1,12 @@
 package monitor
 
 import (
-	"encoding/json"
 	"errors"
 	"net/http"
 	"net/url"
 
+	"github.com/yusing/go-proxy/pkg/json"
+
 	agentPkg "github.com/yusing/go-proxy/agent/pkg/agent"
 	"github.com/yusing/go-proxy/internal/watcher/health"
 )
diff --git a/internal/watcher/health/status.go b/internal/watcher/health/status.go
index 355dd70..f58022c 100644
--- a/internal/watcher/health/status.go
+++ b/internal/watcher/health/status.go
@@ -1,6 +1,8 @@
 package health
 
-import "encoding/json"
+import (
+	"github.com/yusing/go-proxy/pkg/json"
+)
 
 type Status uint8
 
@@ -35,10 +37,6 @@ func (s Status) String() string {
 	}
 }
 
-func (s Status) MarshalJSON() ([]byte, error) {
-	return []byte(`"` + s.String() + `"`), nil
-}
-
 func (s *Status) UnmarshalJSON(data []byte) error {
 	var str string
 	if err := json.Unmarshal(data, &str); err != nil {
diff --git a/internal/watcher/health/types.go b/internal/watcher/health/types.go
index de7ab11..8f83143 100644
--- a/internal/watcher/health/types.go
+++ b/internal/watcher/health/types.go
@@ -24,7 +24,7 @@ type (
 		task.TaskStarter
 		task.TaskFinisher
 		fmt.Stringer
-		utils.MapMarshaller
+		utils.MapMarshaler
 		WithHealthInfo
 		Name() string
 	}