feat(provider): support custom Base URL for LiteLLM/built-in providers

cmd/opencodereview/provider_cmd.go

@@ -3,8 +3,10 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"net/url"
 	"os"
 	"path/filepath"
+	"strings"
 
 	tea "charm.land/bubbletea/v2"
 
@@ -260,6 +262,18 @@ func applyOfficialProviderConfig(configPath string, cfg *Config, result provider
 		// Confirmed empty key: clear saved api_key so resolver falls back to $ENV_VAR.
 		entry.APIKey = ""
 	}
+	// Persist a Base URL override only when it differs from the preset default.
+	// An empty/unchanged value clears any prior override so the preset BaseURL
+	// remains the default, matching the "preset is the fallback" contract.
+	trimmedURL := strings.TrimSpace(result.url)
+	if isPreset && trimmedURL != "" && trimmedURL != preset.BaseURL {
+		if err := validateBaseURL(trimmedURL); err != nil {
+			return err
+		}
+		entry.URL = trimmedURL
+	} else {
+		entry.URL = ""
+	}
 	cfg.Providers[result.provider] = entry
 
 	if cfg.Provider != result.provider {
@@ -311,6 +325,12 @@ func runConfigModel() error {
 		if entry, ok := cfg.Providers[cfg.Provider]; ok {
 			currentModel = activeModelForProvider(cfg, cfg.Provider, entry)
 			provider.Models = mergeModelLists(provider.Models, entry.Models)
+			// Surface the effective Base URL: a configured override takes
+			// precedence over the preset default so users can confirm their
+			// gateway is in use from the model picker.
+			if entry.URL != "" {
+				provider.BaseURL = entry.URL
+			}
 		}
 	} else {
 		isCustom = true
@@ -409,3 +429,20 @@ func maskKey(key string) string {
 	}
 	return key[:4] + "***" + key[len(key)-4:]
 }
+
+// validateBaseURL checks that a provider Base URL has an http or https scheme
+// and a non-empty host, giving the user immediate feedback in the TUI rather
+// than a runtime failure when the LLM client tries to use it.
+func validateBaseURL(raw string) error {
+	parsed, err := url.Parse(raw)
+	if err != nil {
+		return fmt.Errorf("invalid Base URL %q: %w", raw, err)
+	}
+	if parsed.Scheme != "http" && parsed.Scheme != "https" {
+		return fmt.Errorf("Base URL must use http or https scheme, got %q", parsed.Scheme)
+	}
+	if parsed.Host == "" {
+		return fmt.Errorf("Base URL %q must include a host", raw)
+	}
+	return nil
+}

cmd/opencodereview/provider_cmd_test.go

@@ -6,6 +6,8 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+
+	"github.com/alibaba/open-code-review/internal/llm"
 )
 
 func TestMaskKey(t *testing.T) {
@@ -376,3 +378,145 @@ func TestPrintWizardCancelled(t *testing.T) {
 		})
 	}
 }
+
+// TestApplyOfficialProviderConfig_PersistsURLOverride verifies that a custom
+// Base URL entered in the wizard is persisted to providers.<name>.url, while a
+// value equal to the preset default is cleared so the preset remains the default.
+func TestApplyOfficialProviderConfig_PersistsURLOverride(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{}
+
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      "https://gateway.internal:8000/v1",
+	})
+	if err != nil {
+		t.Fatalf("applyOfficialProviderConfig: %v", err)
+	}
+	if got := cfg.Providers["litellm"].URL; got != "https://gateway.internal:8000/v1" {
+		t.Errorf("persisted URL = %q, want https://gateway.internal:8000/v1", got)
+	}
+	diskCfg, err := loadOrCreateConfig(configPath)
+	if err != nil {
+		t.Fatalf("load config: %v", err)
+	}
+	if got := diskCfg.Providers["litellm"].URL; got != "https://gateway.internal:8000/v1" {
+		t.Errorf("disk URL = %q, want https://gateway.internal:8000/v1", got)
+	}
+}
+
+// TestApplyOfficialProviderConfig_ClearsURLWhenPresetDefault verifies that
+// submitting the preset default Base URL writes no url field, so the preset
+// BaseURL remains the resolver default.
+func TestApplyOfficialProviderConfig_ClearsURLWhenPresetDefault(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{
+		Providers: map[string]ProviderEntry{
+			"litellm": {URL: "https://old-gateway.internal:9000/v1"},
+		},
+	}
+
+	preset, _ := llm.LookupProvider("litellm")
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      preset.BaseURL,
+	})
+	if err != nil {
+		t.Fatalf("applyOfficialProviderConfig: %v", err)
+	}
+	if got := cfg.Providers["litellm"].URL; got != "" {
+		t.Errorf("persisted URL = %q, want empty (preset default should not persist a url)", got)
+	}
+}
+
+// TestApplyOfficialProviderConfig_TrimsURLWhitespace verifies that a Base URL
+// with surrounding whitespace is trimmed before comparison and persistence, so
+// whitespace-polluted values are never written to the config file.
+func TestApplyOfficialProviderConfig_TrimsURLWhitespace(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{}
+
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      "  https://gateway.internal:8000/v1  ",
+	})
+	if err != nil {
+		t.Fatalf("applyOfficialProviderConfig: %v", err)
+	}
+	if got := cfg.Providers["litellm"].URL; got != "https://gateway.internal:8000/v1" {
+		t.Errorf("persisted URL = %q, want trimmed value", got)
+	}
+}
+
+// TestApplyOfficialProviderConfig_RejectsInvalidScheme verifies that a Base URL
+// without an http/https scheme is rejected with a clear error at config time
+// rather than failing later at runtime.
+func TestApplyOfficialProviderConfig_RejectsInvalidScheme(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{}
+
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      "ftp://example.com/v1",
+	})
+	if err == nil {
+		t.Fatal("expected error for non-http scheme, got nil")
+	}
+}
+
+// TestApplyOfficialProviderConfig_RejectsMissingScheme verifies that a Base URL
+// lacking a scheme (e.g. a bare host) is rejected at config time.
+func TestApplyOfficialProviderConfig_RejectsMissingScheme(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{}
+
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      "api.example.com/v1",
+	})
+	if err == nil {
+		t.Fatal("expected error for URL missing scheme, got nil")
+	}
+}
+
+// TestApplyOfficialProviderConfig_AcceptsHTTP verifies that plain http:// URLs
+// are accepted (the default litellm preset is http://localhost:4000/v1).
+func TestApplyOfficialProviderConfig_AcceptsHTTP(t *testing.T) {
+	t.Setenv("LITELLM_API_KEY", "sk-litellm")
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	cfg := &Config{}
+
+	err := applyOfficialProviderConfig(configPath, cfg, providerTUIResult{
+		provider: "litellm",
+		model:    "openai/gpt-5.4",
+		apiKey:   "sk-litellm",
+		url:      "http://my-litellm.local:4000/v1",
+	})
+	if err != nil {
+		t.Fatalf("applyOfficialProviderConfig: %v", err)
+	}
+	if got := cfg.Providers["litellm"].URL; got != "http://my-litellm.local:4000/v1" {
+		t.Errorf("persisted URL = %q, want http URL", got)
+	}
+}