feat(client): add support for endpoint-specific base URLs in python

This also changes how `WithEnvironmentProduction()` and `WithBaseURL()` interact. Previously, `WithBaseURL()` would be overridden by `WithEnvironmentProduction()` if `WithEnvironmentProduction()` was later in the list of options; now, `WithBaseURL()` always takes precedence.

Author: stainless-app[bot]

internal/requestconfig/requestconfig.go

@@ -205,6 +205,9 @@ type RequestConfig struct {
 	Context        context.Context
 	Request        *http.Request
 	BaseURL        *url.URL
+	// DefaultBaseURL will be used if BaseURL is not explicitly overridden using
+	// WithBaseURL.
+	DefaultBaseURL *url.URL
 	CustomHTTPDoer HTTPDoer
 	HTTPClient     *http.Client
 	Middlewares    []middleware
@@ -373,7 +376,11 @@ func retryDelay(res *http.Response, retryCount int) time.Duration {
 
 func (cfg *RequestConfig) Execute() (err error) {
 	if cfg.BaseURL == nil {
-		return fmt.Errorf("requestconfig: base url is not set")
+		if cfg.DefaultBaseURL != nil {
+			cfg.BaseURL = cfg.DefaultBaseURL
+		} else {
+			return fmt.Errorf("requestconfig: base url is not set")
+		}
 	}
 
 	cfg.Request.URL, err = cfg.BaseURL.Parse(strings.TrimLeft(cfg.Request.URL.String(), "/"))
@@ -610,3 +617,17 @@ func PreRequestOptions(opts ...RequestOption) (RequestConfig, error) {
 	}
 	return cfg, nil
 }
+
+// WithDefaultBaseURL returns a RequestOption that sets the client's default Base URL.
+// This is always overridden by setting a base URL with WithBaseURL.
+// WithBaseURL should be used instead of WithDefaultBaseURL except in internal code.
+func WithDefaultBaseURL(baseURL string) RequestOption {
+	u, err := url.Parse(baseURL)
+	return RequestOptionFunc(func(r *RequestConfig) error {
+		if err != nil {
+			return err
+		}
+		r.DefaultBaseURL = u
+		return nil
+	})
+}

option/requestoption.go

@@ -262,7 +262,7 @@ func WithRequestTimeout(dur time.Duration) RequestOption {
 // environment to be the "production" environment. An environment specifies which base URL
 // to use by default.
 func WithEnvironmentProduction() RequestOption {
-	return WithBaseURL("https://api.openai.com/v1/")
+	return requestconfig.WithDefaultBaseURL("https://api.openai.com/v1/")
 }
 
 // WithAPIKey returns a RequestOption that sets the client setting "api_key".