llms/anthropic: Implement WithBaseURL and WithHTTPClient for Anthropi…

…c LLM (#671)

* implement WithBaseUrl and WithHttpClient for anthropic model

* fix build errors

* URL not url

* fix more errors

llms/anthropic/anthropicllm.go

@@ -3,6 +3,7 @@ package anthropic
 import (
 	"context"
 	"errors"
+	"net/http"
 	"os"
 
 	"github.com/tmc/langchaingo/callbacks"
@@ -34,7 +35,9 @@ func New(opts ...Option) (*LLM, error) {
 
 func newClient(opts ...Option) (*anthropicclient.Client, error) {
 	options := &options{
-		token: os.Getenv(tokenEnvVarName),
+		token:      os.Getenv(tokenEnvVarName),
+		baseURL:    anthropicclient.DefaultBaseURL,
+		httpClient: http.DefaultClient,
 	}
 
 	for _, opt := range opts {
@@ -45,7 +48,7 @@ func newClient(opts ...Option) (*anthropicclient.Client, error) {
 		return nil, ErrMissingToken
 	}
 
-	return anthropicclient.New(options.token, options.model)
+	return anthropicclient.New(options.token, options.model, options.baseURL, options.httpClient)
 }
 
 // Call requests a completion for the given prompt.

llms/anthropic/anthropicllm_option.go

@@ -1,12 +1,18 @@
 package anthropic
 
+import (
+	"github.com/tmc/langchaingo/llms/anthropic/internal/anthropicclient"
+)
+
 const (
 	tokenEnvVarName = "ANTHROPIC_API_KEY" //nolint:gosec
 )
 
 type options struct {
-	token string
-	model string
+	token      string
+	model      string
+	baseURL    string
+	httpClient anthropicclient.Doer
 }
 
 type Option func(*options)
@@ -25,3 +31,19 @@ func WithModel(model string) Option {
 		opts.model = model
 	}
 }
+
+// WithBaseUrl passes the Anthropic base URL to the client.
+// If not set, the default base URL is used.
+func WithBaseURL(baseURL string) Option {
+	return func(opts *options) {
+		opts.baseURL = baseURL
+	}
+}
+
+// WithHTTPClient allows setting a custom HTTP client. If not set, the default value
+// is http.DefaultClient.
+func WithHTTPClient(client anthropicclient.Doer) Option {
+	return func(opts *options) {
+		opts.httpClient = client
+	}
+}

llms/anthropic/internal/anthropicclient/anthropicclient.go

@@ -4,10 +4,11 @@ import (
 	"context"
 	"errors"
 	"net/http"
+	"strings"
 )
 
 const (
-	defaultBaseURL = "https://api.anthropic.com/v1"
+	DefaultBaseURL = "https://api.anthropic.com/v1"
 )
 
 // ErrEmptyResponse is returned when the Anthropic API returns an empty response.
@@ -40,12 +41,12 @@ func WithHTTPClient(client Doer) Option {
 }
 
 // New returns a new Anthropic client.
-func New(token string, model string, opts ...Option) (*Client, error) {
+func New(token string, model string, baseURL string, httpClient Doer, opts ...Option) (*Client, error) {
 	c := &Client{
 		Model:      model,
 		token:      token,
-		baseURL:    defaultBaseURL,
-		httpClient: http.DefaultClient,
+		baseURL:    strings.TrimSuffix(baseURL, "/"),
+		httpClient: httpClient,
 	}
 
 	for _, opt := range opts {

llms/anthropic/internal/anthropicclient/completions.go

@@ -80,7 +80,7 @@ func (c *Client) createCompletion(ctx context.Context, payload *completionPayloa
 	}
 
 	if c.baseURL == "" {
-		c.baseURL = defaultBaseURL
+		c.baseURL = DefaultBaseURL
 	}
 
 	url := fmt.Sprintf("%s/complete", c.baseURL)