diff --git a/relay/channel/aws/constants.go b/relay/channel/aws/constants.go
index ff1f377e..d24e02eb 100644
--- a/relay/channel/aws/constants.go
+++ b/relay/channel/aws/constants.go
@@ -19,6 +19,7 @@ var awsModelIDMap = map[string]string{
 	"claude-opus-4-5-20251101":   "anthropic.claude-opus-4-5-20251101-v1:0",
 	"claude-opus-4-6":            "anthropic.claude-opus-4-6-v1",
 	"claude-opus-4-7":            "anthropic.claude-opus-4-7",
+	"claude-opus-4-8":            "anthropic.claude-opus-4-8",
 	// Nova models
 	"nova-micro-v1:0":   "amazon.nova-micro-v1:0",
 	"nova-lite-v1:0":    "amazon.nova-lite-v1:0",
@@ -97,6 +98,11 @@ var awsModelCanCrossRegionMap = map[string]map[string]bool{
 		"ap": true,
 		"eu": true,
 	},
+	"anthropic.claude-opus-4-8": {
+		"us": true,
+		"ap": true,
+		"eu": true,
+	},
 	"anthropic.claude-haiku-4-5-20251001-v1:0": {
 		"us": true,
 		"ap": true,
diff --git a/relay/channel/claude/constants.go b/relay/channel/claude/constants.go
index 3c516aef..0e7ba865 100644
--- a/relay/channel/claude/constants.go
+++ b/relay/channel/claude/constants.go
@@ -33,6 +33,13 @@ var ModelList = []string{
 	"claude-opus-4-7-medium",
 	"claude-opus-4-7-low",
 	"claude-opus-4-7-thinking",
+	"claude-opus-4-8",
+	"claude-opus-4-8-max",
+	"claude-opus-4-8-xhigh",
+	"claude-opus-4-8-high",
+	"claude-opus-4-8-medium",
+	"claude-opus-4-8-low",
+	"claude-opus-4-8-thinking",
 }
 
 var ChannelName = "claude"
diff --git a/relay/channel/claude/relay-claude.go b/relay/channel/claude/relay-claude.go
index 6356cd35..18d7455e 100644
--- a/relay/channel/claude/relay-claude.go
+++ b/relay/channel/claude/relay-claude.go
@@ -154,14 +154,17 @@ func RequestOpenAI2ClaudeMessage(c *gin.Context, textRequest dto.GeneralOpenAIRe
 	}
 
 	if baseModel, effortLevel, ok := reasoning.TrimEffortSuffix(textRequest.Model); ok && effortLevel != "" &&
-		(strings.HasPrefix(textRequest.Model, "claude-opus-4-6") || strings.HasPrefix(textRequest.Model, "claude-opus-4-7")) {
+		(strings.HasPrefix(textRequest.Model, "claude-opus-4-6") ||
+			strings.HasPrefix(textRequest.Model, "claude-opus-4-7") ||
+			strings.HasPrefix(textRequest.Model, "claude-opus-4-8")) {
 		claudeRequest.Model = baseModel
 		claudeRequest.Thinking = &dto.Thinking{
 			Type: "adaptive",
 		}
 		claudeRequest.OutputConfig = json.RawMessage(fmt.Sprintf(`{"effort":"%s"}`, effortLevel))
-		if strings.HasPrefix(baseModel, "claude-opus-4-7") {
-			// Opus 4.7 rejects non-default temperature/top_p/top_k with 400
+		if strings.HasPrefix(baseModel, "claude-opus-4-7") ||
+			strings.HasPrefix(baseModel, "claude-opus-4-8") {
+			// Opus 4.7/4.8 reject non-default temperature/top_p/top_k with 400
 			// and defaults display to "omitted"; restore the 4.6 visible summary.
 			claudeRequest.Thinking.Display = "summarized"
 			claudeRequest.Temperature = nil
@@ -175,8 +178,9 @@ func RequestOpenAI2ClaudeMessage(c *gin.Context, textRequest dto.GeneralOpenAIRe
 		strings.HasSuffix(textRequest.Model, "-thinking") {
 
 		trimmedModel := strings.TrimSuffix(textRequest.Model, "-thinking")
-		if strings.HasPrefix(trimmedModel, "claude-opus-4-7") {
-			// Opus 4.7 rejects thinking.type="enabled"; use adaptive at high effort.
+		if strings.HasPrefix(trimmedModel, "claude-opus-4-7") ||
+			strings.HasPrefix(trimmedModel, "claude-opus-4-8") {
+			// Opus 4.7/4.8 reject thinking.type="enabled"; use adaptive at high effort.
 			claudeRequest.Thinking = &dto.Thinking{Type: "adaptive", Display: "summarized"}
 			claudeRequest.OutputConfig = json.RawMessage(`{"effort":"high"}`)
 			claudeRequest.Temperature = nil
diff --git a/relay/channel/claude/relay_claude_test.go b/relay/channel/claude/relay_claude_test.go
index fdc7b38e..495c500b 100644
--- a/relay/channel/claude/relay_claude_test.go
+++ b/relay/channel/claude/relay_claude_test.go
@@ -9,6 +9,10 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func commonPointer[T any](value T) *T {
+	return &value
+}
+
 func TestFormatClaudeResponseInfo_MessageStart(t *testing.T) {
 	claudeInfo := &ClaudeResponseInfo{
 		Usage: &dto.Usage{},
@@ -310,6 +314,58 @@ func TestRequestOpenAI2ClaudeMessage_IgnoresUnsupportedFileContent(t *testing.T)
 	require.Equal(t, "see attachment", *content[0].Text)
 }
 
+func TestRequestOpenAI2ClaudeMessage_ClaudeOpus48HighUsesAdaptiveThinking(t *testing.T) {
+	request := dto.GeneralOpenAIRequest{
+		Model:       "claude-opus-4-8-high",
+		Temperature: commonPointer(0.7),
+		TopP:        commonPointer(0.9),
+		TopK:        commonPointer(40),
+		Messages: []dto.Message{
+			{
+				Role:    "user",
+				Content: "hello",
+			},
+		},
+	}
+
+	claudeRequest, err := RequestOpenAI2ClaudeMessage(nil, request)
+	require.NoError(t, err)
+	require.Equal(t, "claude-opus-4-8", claudeRequest.Model)
+	require.NotNil(t, claudeRequest.Thinking)
+	require.Equal(t, "adaptive", claudeRequest.Thinking.Type)
+	require.Equal(t, "summarized", claudeRequest.Thinking.Display)
+	require.JSONEq(t, `{"effort":"high"}`, string(claudeRequest.OutputConfig))
+	require.Nil(t, claudeRequest.Temperature)
+	require.Nil(t, claudeRequest.TopP)
+	require.Nil(t, claudeRequest.TopK)
+}
+
+func TestRequestOpenAI2ClaudeMessage_ClaudeOpus48ThinkingUsesAdaptiveHighEffort(t *testing.T) {
+	request := dto.GeneralOpenAIRequest{
+		Model:       "claude-opus-4-8-thinking",
+		Temperature: commonPointer(0.7),
+		TopP:        commonPointer(0.9),
+		TopK:        commonPointer(40),
+		Messages: []dto.Message{
+			{
+				Role:    "user",
+				Content: "hello",
+			},
+		},
+	}
+
+	claudeRequest, err := RequestOpenAI2ClaudeMessage(nil, request)
+	require.NoError(t, err)
+	require.Equal(t, "claude-opus-4-8", claudeRequest.Model)
+	require.NotNil(t, claudeRequest.Thinking)
+	require.Equal(t, "adaptive", claudeRequest.Thinking.Type)
+	require.Equal(t, "summarized", claudeRequest.Thinking.Display)
+	require.JSONEq(t, `{"effort":"high"}`, string(claudeRequest.OutputConfig))
+	require.Nil(t, claudeRequest.Temperature)
+	require.Nil(t, claudeRequest.TopP)
+	require.Nil(t, claudeRequest.TopK)
+}
+
 func TestRequestOpenAI2ClaudeMessage_SupportsPDFFileContent(t *testing.T) {
 	request := dto.GeneralOpenAIRequest{
 		Model: "claude-3-5-sonnet",
diff --git a/relay/channel/vertex/adaptor.go b/relay/channel/vertex/adaptor.go
index 0d91032d..7f087c21 100644
--- a/relay/channel/vertex/adaptor.go
+++ b/relay/channel/vertex/adaptor.go
@@ -45,6 +45,7 @@ var claudeModelMap = map[string]string{
 	"claude-opus-4-5-20251101":   "claude-opus-4-5@20251101",
 	"claude-opus-4-6":            "claude-opus-4-6",
 	"claude-opus-4-7":            "claude-opus-4-7",
+	"claude-opus-4-8":            "claude-opus-4-8",
 }
 
 const anthropicVersion = "vertex-2023-10-16"
diff --git a/relay/claude_handler.go b/relay/claude_handler.go
index 7ec934f9..d72218de 100644
--- a/relay/claude_handler.go
+++ b/relay/claude_handler.go
@@ -53,14 +53,17 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 	}
 
 	if baseModel, effortLevel, ok := reasoning.TrimEffortSuffix(request.Model); ok && effortLevel != "" &&
-		(strings.HasPrefix(request.Model, "claude-opus-4-6") || strings.HasPrefix(request.Model, "claude-opus-4-7")) {
+		(strings.HasPrefix(request.Model, "claude-opus-4-6") ||
+			strings.HasPrefix(request.Model, "claude-opus-4-7") ||
+			strings.HasPrefix(request.Model, "claude-opus-4-8")) {
 		request.Model = baseModel
 		request.Thinking = &dto.Thinking{
 			Type: "adaptive",
 		}
 		request.OutputConfig = json.RawMessage(fmt.Sprintf(`{"effort":"%s"}`, effortLevel))
-		if strings.HasPrefix(request.Model, "claude-opus-4-7") {
-			// Opus 4.7 rejects non-default temperature/top_p/top_k with 400
+		if strings.HasPrefix(request.Model, "claude-opus-4-7") ||
+			strings.HasPrefix(request.Model, "claude-opus-4-8") {
+			// Opus 4.7/4.8 reject non-default temperature/top_p/top_k with 400
 			// and defaults display to "omitted"; restore the 4.6 visible summary.
 			request.Thinking.Display = "summarized"
 			request.Temperature = nil
@@ -74,8 +77,9 @@ func ClaudeHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *typ
 		strings.HasSuffix(request.Model, "-thinking") {
 		if request.Thinking == nil {
 			baseModel := strings.TrimSuffix(request.Model, "-thinking")
-			if strings.HasPrefix(baseModel, "claude-opus-4-7") {
-				// Opus 4.7 rejects thinking.type="enabled"; use adaptive at high effort.
+			if strings.HasPrefix(baseModel, "claude-opus-4-7") ||
+				strings.HasPrefix(baseModel, "claude-opus-4-8") {
+				// Opus 4.7/4.8 reject thinking.type="enabled"; use adaptive at high effort.
 				request.Thinking = &dto.Thinking{Type: "adaptive", Display: "summarized"}
 				request.OutputConfig = json.RawMessage(`{"effort":"high"}`)
 				request.Temperature = nil
diff --git a/setting/ratio_setting/cache_ratio.go b/setting/ratio_setting/cache_ratio.go
index fe6e3b32..89d0bfc2 100644
--- a/setting/ratio_setting/cache_ratio.go
+++ b/setting/ratio_setting/cache_ratio.go
@@ -71,6 +71,13 @@ var defaultCacheRatio = map[string]float64{
 	"claude-opus-4-7-high":                0.1,
 	"claude-opus-4-7-medium":              0.1,
 	"claude-opus-4-7-low":                 0.1,
+	"claude-opus-4-8":                     0.1,
+	"claude-opus-4-8-thinking":            0.1,
+	"claude-opus-4-8-max":                 0.1,
+	"claude-opus-4-8-xhigh":               0.1,
+	"claude-opus-4-8-high":                0.1,
+	"claude-opus-4-8-medium":              0.1,
+	"claude-opus-4-8-low":                 0.1,
 }
 
 var defaultCreateCacheRatio = map[string]float64{
@@ -106,6 +113,13 @@ var defaultCreateCacheRatio = map[string]float64{
 	"claude-opus-4-7-high":                1.25,
 	"claude-opus-4-7-medium":              1.25,
 	"claude-opus-4-7-low":                 1.25,
+	"claude-opus-4-8":                     1.25,
+	"claude-opus-4-8-thinking":            1.25,
+	"claude-opus-4-8-max":                 1.25,
+	"claude-opus-4-8-xhigh":               1.25,
+	"claude-opus-4-8-high":                1.25,
+	"claude-opus-4-8-medium":              1.25,
+	"claude-opus-4-8-low":                 1.25,
 }
 
 //var defaultCreateCacheRatio = map[string]float64{}
diff --git a/setting/ratio_setting/model_ratio.go b/setting/ratio_setting/model_ratio.go
index 80702ee4..23fd360e 100644
--- a/setting/ratio_setting/model_ratio.go
+++ b/setting/ratio_setting/model_ratio.go
@@ -152,6 +152,12 @@ var defaultModelRatio = map[string]float64{
 	"claude-opus-4-7-high":                      2.5,
 	"claude-opus-4-7-medium":                    2.5,
 	"claude-opus-4-7-low":                       2.5,
+	"claude-opus-4-8":                           2.5,
+	"claude-opus-4-8-max":                       2.5,
+	"claude-opus-4-8-xhigh":                     2.5,
+	"claude-opus-4-8-high":                      2.5,
+	"claude-opus-4-8-medium":                    2.5,
+	"claude-opus-4-8-low":                       2.5,
 	"claude-3-opus-20240229":                    7.5, // $15 / 1M tokens
 	"claude-opus-4-20250514":                    7.5,
 	"claude-opus-4-1-20250805":                  7.5,