feat(go): add modelgarden and anthropic support

go/plugins/vertexai/modelgarden/anthropic.go

@@ -0,0 +1,56 @@
+// Copyright 2025 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package modelgarden
+
+import (
+	"log"
+
+	"github.com/firebase/genkit/go/ai"
+	"github.com/firebase/genkit/go/plugins/internal/gemini"
+)
+
+var AnthropicModels = map[string]ai.ModelInfo{
+	"claude-3-5-sonnet-v2": {
+		Label:    "Vertex AI Model Garden - Claude 3.5 Sonnet",
+		Supports: &gemini.Multimodal,
+		Versions: []string{"claude-3-5-sonnet-v2@20241022"},
+	},
+	"claude-3-5-sonnet": {
+		Label:    "Vertex AI Model Garden - Claude 3.5 Sonnet",
+		Supports: &gemini.Multimodal,
+		Versions: []string{"claude-3-5-sonnet@20240620"},
+	},
+	"claude-3-sonnet": {
+		Label:    "Vertex AI Model Garden - Claude 3 Sonnet",
+		Supports: &gemini.Multimodal,
+		Versions: []string{"claude-3-sonnet@20240229"},
+	},
+	"claude-3-haiku": {
+		Label:    "Vertex AI Model Garden - Claude 3 Haiku",
+		Supports: &gemini.Multimodal,
+		Versions: []string{"claude-3-haiku@20240307"},
+	},
+	"claude-3-opus": {
+		Label:    "Vertex AI Model Garden - Claude 3 Opus",
+		Supports: &gemini.Multimodal,
+		Versions: []string{"claude-3-opus@20240229"},
+	},
+}
+
+type AnthropicCloudClient struct {
+	region  string
+	project string
+}
+
+var AnthropicClient = func(region string, project string) (Client, error) {
+	return &AnthropicCloudClient{
+		region:  region,
+		project: project,
+	}, nil
+}
+
+func (a *AnthropicCloudClient) DefineModel(name string, info *ai.ModelInfo) error {
+	log.Printf("created an anthropic model: %s, versions: %#v", name, info.Versions)
+	return nil
+}

go/plugins/vertexai/modelgarden/anthropic_test.go

@@ -0,0 +1,30 @@
+// Copyright 2025 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package modelgarden_test
+
+import (
+	"testing"
+
+	"github.com/firebase/genkit/go/ai"
+	"github.com/firebase/genkit/go/plugins/vertexai/modelgarden"
+)
+
+// keep track of all clients
+var clients = modelgarden.NewClientFactory()
+
+func TestAnthropicClient(t *testing.T) {
+	anthropicClient, err := clients.CreateClient(&modelgarden.ClientConfig{
+		Region:   "us-west-1",
+		Provider: "anthropic",
+		Project:  "project-123",
+	})
+	if err != nil {
+		t.Fatalf("unable to create anthropic client")
+	}
+
+	err = anthropicClient.DefineModel("foo_model", &ai.ModelInfo{})
+	if err != nil {
+		t.Fatalf("unable to define model: %v", err)
+	}
+}

go/plugins/vertexai/modelgarden/client.go

@@ -0,0 +1,73 @@
+// Copyright 2025 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package modelgarden
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+
+	"github.com/firebase/genkit/go/ai"
+)
+
+// Generic Client interface for supported provider clients
+type Client interface {
+	DefineModel(name string, info *ai.ModelInfo) error
+}
+
+type ClientFactory struct {
+	clients map[string]Client // cache for provider clients
+	mu      sync.Mutex
+}
+
+func NewClientFactory() *ClientFactory {
+	return &ClientFactory{
+		clients: make(map[string]Client),
+	}
+}
+
+const (
+	Anthropic string = "anthropic"
+)
+
+// Function type for creating clients from supported providers
+type ClientCreator func(region string, project string) (Client, error)
+
+// Basic client configuration
+type ClientConfig struct {
+	Creator  ClientCreator
+	Provider string
+	Project  string
+	Region   string
+}
+
+func (f *ClientFactory) CreateClient(config *ClientConfig) (Client, error) {
+	if config == nil {
+		return nil, errors.New("empty client config")
+	}
+
+	f.mu.Lock()
+	defer f.mu.Unlock()
+
+	// every client will be identified by its provider-region combination
+	key := fmt.Sprintf("%s-%s", config.Provider, config.Region)
+	if client, ok := f.clients[key]; ok {
+		return client, nil // return from cache
+	}
+
+	var client Client
+	var err error
+
+	switch config.Provider {
+	case Anthropic:
+		client, err = AnthropicClient(config.Region, config.Project)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	f.clients[key] = client
+
+	return client, nil
+}

go/plugins/vertexai/modelgarden/modelgarden.go

@@ -0,0 +1,42 @@
+// Copyright 2025 Google LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package modelgarden
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/firebase/genkit/go/genkit"
+)
+
+type ModelGardenOptions struct {
+	ProjectID string
+	Region    string
+	Models    []string
+}
+
+// Init initializes the ModelGarden plugin
+// After calling Init, you may call [DefineModel] to create and register
+// any additional generative models
+func Init(ctx context.Context, g *genkit.Genkit, cfg *ModelGardenOptions) error {
+	clients := NewClientFactory()
+	for _, m := range cfg.Models {
+		// ANTHROPIC
+		if info, ok := AnthropicModels[m]; ok {
+			anthropicClient, err := clients.CreateClient(&ClientConfig{
+				Provider: "anthropic",
+				Project:  "anthropic-project",
+				Region:   "us-west-1",
+			})
+			if err != nil {
+				return fmt.Errorf("unable to create client: %v", err)
+			}
+
+			anthropicClient.DefineModel(m, &info)
+			continue
+		}
+	}
+
+	return nil
+}