Add BaseURL for Anthropic configuration. (#336)

This will allow Anthropic requests to be issued via a proxy.

app/pkg/anthropic/client.go

@@ -48,7 +48,14 @@ func NewClient(cfg config.Config) (*anthropic.Client, error) {
 		return nil, err
 	}
 
-	client := anthropic.NewClient(apiKey, anthropic.WithHTTPClient(httpClient))
+	opts := make([]anthropic.ClientOption, 0)
+
+	if cfg.Anthropic.BaseURL != "" {
+		log.Info("Using custom Anthropic base URL", "baseURL", cfg.Anthropic.BaseURL)
+		opts = append(opts, anthropic.WithBaseURL(cfg.Anthropic.BaseURL))
+	}
+	opts = append(opts, anthropic.WithHTTPClient(httpClient))
+	client := anthropic.NewClient(apiKey, opts...)
 	return client, nil
 }
 

app/pkg/anthropic/client_test.go

@@ -0,0 +1,57 @@
+package anthropic
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/jlewi/foyle/app/pkg/config"
+	"github.com/liushuangls/go-anthropic/v2"
+	"google.golang.org/protobuf/proto"
+)
+
+func Test_AnthropicClient(t *testing.T) {
+	if os.Getenv("GITHUB_ACTIONS") != "" {
+		t.Skipf("TestAnthropicClient is a manual test that is skipped in CICD")
+	}
+
+	// N.B since this test isn't using a valid endpoint we don't expect it to succceed
+	// But hopefully the error message will let us confirm that the baseURL is being used
+
+	// Test non standard base URL
+	cfg := config.Config{
+		Anthropic: &config.AnthropicConfig{
+			APIKeyFile: "/Users/jlewi/secrets/anthropic.key",
+			BaseURL:    "https://localhost:8844",
+		},
+	}
+
+	client, err := NewClient(cfg)
+	if err != nil {
+		t.Fatalf("Failed to create Anthropic client: %v", err)
+	}
+
+	message := "Say hello a funny way"
+	messages := []anthropic.Message{
+		{Role: anthropic.RoleUser,
+			Content: []anthropic.MessageContent{
+				{Type: anthropic.MessagesContentTypeText,
+					Text: proto.String(message),
+				},
+			},
+		},
+	}
+
+	request := anthropic.MessagesRequest{
+		Model:       cfg.GetModel(),
+		Messages:    messages,
+		MaxTokens:   2000,
+		Temperature: proto.Float32(temperature),
+		System:      "You are a helper",
+	}
+
+	_, err = client.CreateMessages(context.Background(), request)
+	if err != nil {
+		t.Logf("Error: %+v", err)
+	}
+}

app/pkg/config/config.go

@@ -130,6 +130,9 @@ type OpenAIConfig struct {
 type AnthropicConfig struct {
 	// APIKeyFile is the path to the file containing the API key
 	APIKeyFile string `json:"apiKeyFile" yaml:"apiKeyFile"`
+
+	// BaseURL is the baseURL for the API.
+	BaseURL string `json:"baseURL" yaml:"baseURL"`
 }
 
 type ReplicateConfig struct {