Claude Sonnet 4 and Opus 4 Support for VertexAI Provider

README.md

@@ -269,6 +269,8 @@ OpenCode supports a variety of AI models from different providers:
 
 - Gemini 2.5
 - Gemini 2.5 Flash
+- Claude Sonnet 4
+- Claude Opus 4
 
 ## Usage
 

go.mod

@@ -33,6 +33,14 @@ require (
 	github.com/stretchr/testify v1.10.0
 )
 
+require (
+	cloud.google.com/go/auth/oauth2adapt v0.2.6 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.54.0 // indirect
+	golang.org/x/oauth2 v0.30.0 // indirect
+	golang.org/x/time v0.8.0 // indirect
+	google.golang.org/api v0.215.0 // indirect
+)
+
 require (
 	cloud.google.com/go v0.116.0 // indirect
 	cloud.google.com/go/auth v0.13.0 // indirect

go.sum

@@ -2,6 +2,8 @@ cloud.google.com/go v0.116.0 h1:B3fRrSDkLRt5qSHWe40ERJvhvnQwdZiHu0bJOpldweE=
 cloud.google.com/go v0.116.0/go.mod h1:cEPSRWPzZEswwdr9BxE6ChEn01dWlTaF05LiC2Xs70U=
 cloud.google.com/go/auth v0.13.0 h1:8Fu8TZy167JkW8Tj3q7dIkr2v4cndv41ouecJx0PAHs=
 cloud.google.com/go/auth v0.13.0/go.mod h1:COOjD9gwfKNKz+IIduatIhYJQIc0mG3H102r/EMxX6Q=
+cloud.google.com/go/auth/oauth2adapt v0.2.6 h1:V6a6XDu2lTwPZWOawrAa9HUK+DB2zfJyTuciBG5hFkU=
+cloud.google.com/go/auth/oauth2adapt v0.2.6/go.mod h1:AlmsELtlEBnaNTL7jCj8VQFLy6mbZv0s4Q7NGBeQ5E8=
 cloud.google.com/go/compute/metadata v0.6.0 h1:A6hENjEsCDtC1k8byVsgwvVcioamEHvZ4j01OwKxG9I=
 cloud.google.com/go/compute/metadata v0.6.0/go.mod h1:FjyFAW1MW0C203CEOMDTu3Dk1FlqW3Rga40jzHL4hfg=
 github.com/Azure/azure-sdk-for-go/sdk/azcore v1.17.0 h1:g0EZJwz7xkXQiZAI5xi9f3WWFYBlX1CPTrR+NDToRkQ=
@@ -250,6 +252,8 @@ github.com/yuin/goldmark-emoji v1.0.5 h1:EMVWyCGPlXJfUXBXpuMu+ii3TIaxbVBnEX9uaDC
 github.com/yuin/goldmark-emoji v1.0.5/go.mod h1:tTkZEbwu5wkPmgTcitqddVxY9osFZiavD+r4AzQrh1U=
 go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.54.0 h1:r6I7RJCN86bpD/FQwedZ0vSixDpwuWREjW9oRMsmqDc=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.54.0/go.mod h1:B9yO6b04uB80CzjedvewuqDhxJxi11s7/GtiGa8bAjI=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.54.0 h1:TT4fX+nBOA/+LUkobKGW1ydGcn+G3vRw9+g5HwCphpk=
 go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.54.0/go.mod h1:L7UH0GbB0p47T4Rri3uHjbpCFYrVrwc1I25QhNPiGK8=
 go.opentelemetry.io/otel v1.35.0 h1:xKWKPxrxB6OtMCbmMY021CqC45J+3Onta9MqjhnusiQ=
@@ -289,6 +293,8 @@ golang.org/x/net v0.24.0/go.mod h1:2Q7sJY5mzlzWjKtYUEXSlBWCdyaioyXzRB2RtU8KVE8=
 golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
 golang.org/x/net v0.39.0 h1:ZCu7HMWDxpXpaiKdhzIfaltL9Lp31x/3fCP11bc6/fY=
 golang.org/x/net v0.39.0/go.mod h1:X7NRbYVEA+ewNkCNyJ513WmMdQ3BineSwVtN2zD/d+E=
+golang.org/x/oauth2 v0.30.0 h1:dnDm7JmhM45NNpd8FDDeLhK6FwqbOf4MLCM9zb1BOHI=
+golang.org/x/oauth2 v0.30.0/go.mod h1:B++QgG3ZKulg6sRPGD/mqlHQs5rB3Ml9erfeDY7xKlU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
@@ -329,11 +335,15 @@ golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.24.0 h1:dd5Bzh4yt5KYA8f9CJHCP4FB4D51c2c6JvN37xJJkJ0=
 golang.org/x/text v0.24.0/go.mod h1:L8rBsPeo2pSS+xqN0d5u2ikmjtmoJbDBT1b7nHvFCdU=
+golang.org/x/time v0.8.0 h1:9i3RxcPv3PZnitoVGMPDKZSq1xW1gK1Xy3ArNOGZfEg=
+golang.org/x/time v0.8.0/go.mod h1:3BpzKBy/shNhVucY/MWOyx10tF3SFh9QdLuxbVysPQM=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+google.golang.org/api v0.215.0 h1:jdYF4qnyczlEz2ReWIsosNLDuzXyvFHJtI5gcr0J7t0=
+google.golang.org/api v0.215.0/go.mod h1:fta3CVtuJYOEdugLNWm6WodzOS8KdFckABwN4I40hzY=
 google.golang.org/genai v1.3.0 h1:tXhPJF30skOjnnDY7ZnjK3q7IKy4PuAlEA0fk7uEaEI=
 google.golang.org/genai v1.3.0/go.mod h1:TyfOKRz/QyCaj6f/ZDt505x+YreXnY40l2I6k8TvgqY=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20250324211829-b45e905df463 h1:e0AIkUUhxyBKh6ssZNrAMeqhA7RKUj42346d1y02i2g=

internal/llm/models/models.go

@@ -93,6 +93,6 @@ func init() {
 	maps.Copy(SupportedModels, AzureModels)
 	maps.Copy(SupportedModels, OpenRouterModels)
 	maps.Copy(SupportedModels, XAIModels)
-	maps.Copy(SupportedModels, VertexAIGeminiModels)
+	maps.Copy(SupportedModels, VertexAIModels)
 	maps.Copy(SupportedModels, CopilotModels)
 }

internal/llm/models/vertexai.go

@@ -3,12 +3,16 @@ package models
 const (
 	ProviderVertexAI ModelProvider = "vertexai"
 
-	// Models
+	// Gemini Models
 	VertexAIGemini25Flash ModelID = "vertexai.gemini-2.5-flash"
 	VertexAIGemini25      ModelID = "vertexai.gemini-2.5"
+
+	// Claude Models
+	VertexAIClaude4Sonnet ModelID = "vertexai.claude-sonnet-4"
+	VertexAIClaude4Opus   ModelID = "vertexai.claude-opus-4"
 )
 
-var VertexAIGeminiModels = map[ModelID]Model{
+var VertexAIModels = map[ModelID]Model{
 	VertexAIGemini25Flash: {
 		ID:                  VertexAIGemini25Flash,
 		Name:                "VertexAI: Gemini 2.5 Flash",
@@ -35,4 +39,32 @@ var VertexAIGeminiModels = map[ModelID]Model{
 		DefaultMaxTokens:    GeminiModels[Gemini25].DefaultMaxTokens,
 		SupportsAttachments: true,
 	},
+	VertexAIClaude4Sonnet: {
+		ID:                  VertexAIClaude4Sonnet,
+		Name:                "VertexAI: Claude Sonnet 4",
+		Provider:            ProviderVertexAI,
+		APIModel:            "claude-sonnet-4",
+		CostPer1MIn:         AnthropicModels[Claude4Sonnet].CostPer1MIn,
+		CostPer1MInCached:   AnthropicModels[Claude4Sonnet].CostPer1MInCached,
+		CostPer1MOut:        AnthropicModels[Claude4Sonnet].CostPer1MOut,
+		CostPer1MOutCached:  AnthropicModels[Claude4Sonnet].CostPer1MOutCached,
+		ContextWindow:       AnthropicModels[Claude4Sonnet].ContextWindow,
+		DefaultMaxTokens:    AnthropicModels[Claude4Sonnet].DefaultMaxTokens,
+		CanReason:           AnthropicModels[Claude4Sonnet].CanReason,
+		SupportsAttachments: AnthropicModels[Claude4Sonnet].SupportsAttachments,
+	},
+	VertexAIClaude4Opus: {
+		ID:                  VertexAIClaude4Opus,
+		Name:                "VertexAI: Claude Opus 4",
+		Provider:            ProviderVertexAI,
+		APIModel:            "claude-opus-4",
+		CostPer1MIn:         AnthropicModels[Claude4Opus].CostPer1MIn,
+		CostPer1MInCached:   AnthropicModels[Claude4Opus].CostPer1MInCached,
+		CostPer1MOut:        AnthropicModels[Claude4Opus].CostPer1MOut,
+		CostPer1MOutCached:  AnthropicModels[Claude4Opus].CostPer1MOutCached,
+		ContextWindow:       AnthropicModels[Claude4Opus].ContextWindow,
+		DefaultMaxTokens:    AnthropicModels[Claude4Opus].DefaultMaxTokens,
+		CanReason:           AnthropicModels[Claude4Opus].CanReason,
+		SupportsAttachments: AnthropicModels[Claude4Opus].SupportsAttachments,
+	},
 }

internal/llm/models/vertexai_test.go

@@ -0,0 +1,162 @@
+package models
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestVertexAIClaudeModels(t *testing.T) {
+	// Test that Claude Sonnet 4 model is correctly defined
+	claude4Sonnet, exists := SupportedModels[VertexAIClaude4Sonnet]
+	if !exists {
+		t.Errorf("VertexAI Claude Sonnet 4 model not found in SupportedModels")
+		return
+	}
+
+	// Verify model properties
+	if claude4Sonnet.ID != VertexAIClaude4Sonnet {
+		t.Errorf("Expected ID %s, got %s", VertexAIClaude4Sonnet, claude4Sonnet.ID)
+	}
+	if claude4Sonnet.Name != "VertexAI: Claude Sonnet 4" {
+		t.Errorf("Expected name 'VertexAI: Claude Sonnet 4', got %s", claude4Sonnet.Name)
+	}
+	if claude4Sonnet.Provider != ProviderVertexAI {
+		t.Errorf("Expected provider %s, got %s", ProviderVertexAI, claude4Sonnet.Provider)
+	}
+	if claude4Sonnet.APIModel != "claude-sonnet-4" {
+		t.Errorf("Expected API model 'claude-sonnet-4', got %s", claude4Sonnet.APIModel)
+	}
+	if !claude4Sonnet.CanReason {
+		t.Errorf("Expected Claude Sonnet 4 to support reasoning")
+	}
+	if !claude4Sonnet.SupportsAttachments {
+		t.Errorf("Expected Claude Sonnet 4 to support attachments")
+	}
+
+	// Test that Claude Opus 4 model is correctly defined
+	claude4Opus, exists := SupportedModels[VertexAIClaude4Opus]
+	if !exists {
+		t.Errorf("VertexAI Claude Opus 4 model not found in SupportedModels")
+		return
+	}
+
+	// Verify model properties
+	if claude4Opus.ID != VertexAIClaude4Opus {
+		t.Errorf("Expected ID %s, got %s", VertexAIClaude4Opus, claude4Opus.ID)
+	}
+	if claude4Opus.Name != "VertexAI: Claude Opus 4" {
+		t.Errorf("Expected name 'VertexAI: Claude Opus 4', got %s", claude4Opus.Name)
+	}
+	if claude4Opus.Provider != ProviderVertexAI {
+		t.Errorf("Expected provider %s, got %s", ProviderVertexAI, claude4Opus.Provider)
+	}
+	if claude4Opus.APIModel != "claude-opus-4" {
+		t.Errorf("Expected API model 'claude-opus-4', got %s", claude4Opus.APIModel)
+	}
+	if !claude4Opus.SupportsAttachments {
+		t.Errorf("Expected Claude Opus 4 to support attachments")
+	}
+
+	// Check reasoning capability - should match the Anthropic model
+	anthropicOpusModel := AnthropicModels[Claude4Opus]
+	if claude4Opus.CanReason != anthropicOpusModel.CanReason {
+		t.Errorf("Expected CanReason to match Anthropic model: %v, got %v", anthropicOpusModel.CanReason, claude4Opus.CanReason)
+	}
+
+	// Test that pricing is inherited correctly from Anthropic models
+	anthropicSonnet := AnthropicModels[Claude4Sonnet]
+	if claude4Sonnet.CostPer1MIn != anthropicSonnet.CostPer1MIn {
+		t.Errorf("Expected inherited input cost %f, got %f", anthropicSonnet.CostPer1MIn, claude4Sonnet.CostPer1MIn)
+	}
+	if claude4Sonnet.ContextWindow != anthropicSonnet.ContextWindow {
+		t.Errorf("Expected inherited context window %d, got %d", anthropicSonnet.ContextWindow, claude4Sonnet.ContextWindow)
+	}
+
+	anthropicOpus := AnthropicModels[Claude4Opus]
+	if claude4Opus.CostPer1MIn != anthropicOpus.CostPer1MIn {
+		t.Errorf("Expected inherited input cost %f, got %f", anthropicOpus.CostPer1MIn, claude4Opus.CostPer1MIn)
+	}
+	if claude4Opus.ContextWindow != anthropicOpus.ContextWindow {
+		t.Errorf("Expected inherited context window %d, got %d", anthropicOpus.ContextWindow, claude4Opus.ContextWindow)
+	}
+}
+
+func TestVertexAIProviderPriority(t *testing.T) {
+	// Test that VertexAI provider is included in the popularity rankings
+	priority, exists := ProviderPopularity[ProviderVertexAI]
+	if !exists {
+		t.Errorf("VertexAI provider not found in ProviderPopularity")
+		return
+	}
+
+	// VertexAI should have a reasonable priority (not 0)
+	if priority <= 0 {
+		t.Errorf("Expected positive priority for VertexAI provider, got %d", priority)
+	}
+}
+
+// Test model routing for all defined models
+func TestVertexAI_AllModelRouting(t *testing.T) {
+	claudeModels := []ModelID{
+		VertexAIClaude4Sonnet,
+		VertexAIClaude4Opus,
+	}
+
+	geminiModels := []ModelID{
+		VertexAIGemini25Flash,
+		VertexAIGemini25,
+	}
+
+	// Test Claude models route correctly
+	for _, modelID := range claudeModels {
+		t.Run(string(modelID), func(t *testing.T) {
+			model := SupportedModels[modelID]
+			if !strings.HasPrefix(model.APIModel, "claude-") {
+				t.Errorf("Claude model %s should have 'claude-' prefix, got %s", modelID, model.APIModel)
+			}
+		})
+	}
+
+	// Test Gemini models route correctly  
+	for _, modelID := range geminiModels {
+		t.Run(string(modelID), func(t *testing.T) {
+			model := SupportedModels[modelID]
+			if strings.HasPrefix(model.APIModel, "claude-") {
+				t.Errorf("Gemini model %s should not have 'claude-' prefix, got %s", modelID, model.APIModel)
+			}
+		})
+	}
+}
+
+// Test model definitions for required fields
+func TestVertexAI_ClaudeModelDefinitions(t *testing.T) {
+	claudeModels := []ModelID{
+		VertexAIClaude4Sonnet,
+		VertexAIClaude4Opus,
+	}
+
+	for _, modelID := range claudeModels {
+		t.Run(string(modelID), func(t *testing.T) {
+			model := SupportedModels[modelID]
+
+			// Verify required fields
+			if model.APIModel == "" {
+				t.Errorf("API model should not be empty")
+			}
+			if model.Name == "" {
+				t.Errorf("Display name should not be empty")
+			}
+			if model.ContextWindow <= 0 {
+				t.Errorf("Context window should be positive, got %d", model.ContextWindow)
+			}
+			if model.DefaultMaxTokens <= 0 {
+				t.Errorf("Max output tokens should be positive, got %d", model.DefaultMaxTokens)
+			}
+
+			// Verify Claude-specific requirements
+			if !model.SupportsAttachments {
+				t.Errorf("Claude models should support attachments")
+			}
+		})
+	}
+}