@@ -71,6 +71,8 @@ You can configure OpenCode using environment variables:
 | `ANTHROPIC_API_KEY`        | For Claude models                                      |
 | `OPENAI_API_KEY`           | For OpenAI models                                      |
 | `GEMINI_API_KEY`           | For Google Gemini models                               |
+| `VERTEXAI_PROJECT`         | For Google Cloud VertexAI (Gemini)                     |
+| `VERTEXAI_LOCATION`        | For Google Cloud VertexAI (Gemini)                     |
 | `GROQ_API_KEY`             | For Groq models                                        |
 | `AWS_ACCESS_KEY_ID`        | For AWS Bedrock (Claude)                               |
 | `AWS_SECRET_ACCESS_KEY`    | For AWS Bedrock (Claude)                               |
 
@@ -0,0 +1,38 @@
+package models
+
+const (
+	ProviderVertexAI ModelProvider = "vertexai"
+
+	// Models
+	VertexAIGemini25Flash ModelID = "vertexai.gemini-2.5-flash"
+	VertexAIGemini25      ModelID = "vertexai.gemini-2.5"
+)
+
+var VertexAIGeminiModels = map[ModelID]Model{
+	VertexAIGemini25Flash: {
+		ID:                  VertexAIGemini25Flash,
+		Name:                "VertexAI: Gemini 2.5 Flash",
+		Provider:            ProviderVertexAI,
+		APIModel:            "gemini-2.5-flash-preview-04-17",
+		CostPer1MIn:         GeminiModels[Gemini25Flash].CostPer1MIn,
+		CostPer1MInCached:   GeminiModels[Gemini25Flash].CostPer1MInCached,
+		CostPer1MOut:        GeminiModels[Gemini25Flash].CostPer1MOut,
+		CostPer1MOutCached:  GeminiModels[Gemini25Flash].CostPer1MOutCached,
+		ContextWindow:       GeminiModels[Gemini25Flash].ContextWindow,
+		DefaultMaxTokens:    GeminiModels[Gemini25Flash].DefaultMaxTokens,
+		SupportsAttachments: true,
+	},
+	VertexAIGemini25: {
+		ID:                  VertexAIGemini25,
+		Name:                "VertexAI: Gemini 2.5 Pro",
+		Provider:            ProviderVertexAI,
+		APIModel:            "gemini-2.5-pro-preview-03-25",
+		CostPer1MIn:         GeminiModels[Gemini25].CostPer1MIn,
+		CostPer1MInCached:   GeminiModels[Gemini25].CostPer1MInCached,
+		CostPer1MOut:        GeminiModels[Gemini25].CostPer1MOut,
+		CostPer1MOutCached:  GeminiModels[Gemini25].CostPer1MOutCached,
+		ContextWindow:       GeminiModels[Gemini25].ContextWindow,
+		DefaultMaxTokens:    GeminiModels[Gemini25].DefaultMaxTokens,
+		SupportsAttachments: true,
+	},
+}
@@ -102,6 +102,11 @@ func NewProvider(providerName models.ModelProvider, opts ...ProviderClientOption
 			options: clientOptions,
 			client:  newGeminiClient(clientOptions),
 		}, nil
+	case models.ProviderVertexAI:
+		return &baseProvider[VertexAIClient]{
+			options: clientOptions,
+			client:  newVertexAIClient(clientOptions),
+		}, nil
 	case models.ProviderBedrock:
 		return &baseProvider[BedrockClient]{
 			options: clientOptions,
 
@@ -0,0 +1,34 @@
+package provider
+
+import (
+	"context"
+	"os"
+
+	"github.com/opencode-ai/opencode/internal/logging"
+	"google.golang.org/genai"
+)
+
+type VertexAIClient ProviderClient
+
+func newVertexAIClient(opts providerClientOptions) VertexAIClient {
+	geminiOpts := geminiOptions{}
+	for _, o := range opts.geminiOptions {
+		o(&geminiOpts)
+	}
+
+	client, err := genai.NewClient(context.Background(), &genai.ClientConfig{
+		Project:  os.Getenv("VERTEXAI_PROJECT"),
+		Location: os.Getenv("VERTEXAI_LOCATION"),
+		Backend:  genai.BackendVertexAI,
+	})
+	if err != nil {
+		logging.Error("Failed to create Gemini client", "error", err)
+		return nil
+	}
+
+	return &geminiClient{
+		providerOptions: opts,
+		options:         geminiOpts,
+		client:          client,
+	}
+}