feat (auth): CLI OAuth supports pasting callback URLs to complete login

- Added callback URL resolution and terminal prompt logic
  - Codex/Claude/iFlow/Antigravity/Gemini login supports callback URL or local callback completion
  - Update Gemini login option signature and manager call
  - CLI default prompt function is compatible with null input to continue waiting

internal/api/handlers/management/auth_files.go

@@ -1093,7 +1093,9 @@ func (h *Handler) RequestGeminiCLIToken(c *gin.Context) {
 
 		// Initialize authenticated HTTP client via GeminiAuth to honor proxy settings
 		gemAuth := geminiAuth.NewGeminiAuth()
-		gemClient, errGetClient := gemAuth.GetAuthenticatedClient(ctx, &ts, h.cfg, true)
+		gemClient, errGetClient := gemAuth.GetAuthenticatedClient(ctx, &ts, h.cfg, &geminiAuth.WebLoginOptions{
+			NoBrowser: true,
+		})
 		if errGetClient != nil {
 			log.Errorf("failed to get authenticated client: %v", errGetClient)
 			SetOAuthSessionError(state, "Failed to get authenticated client")

internal/auth/gemini/gemini_auth.go

@@ -18,6 +18,7 @@ import (
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/auth/codex"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/browser"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/misc"
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
 	log "github.com/sirupsen/logrus"
 	"github.com/tidwall/gjson"
@@ -46,6 +47,12 @@ var (
 type GeminiAuth struct {
 }
 
+// WebLoginOptions customizes the interactive OAuth flow.
+type WebLoginOptions struct {
+	NoBrowser bool
+	Prompt    func(string) (string, error)
+}
+
 // NewGeminiAuth creates a new instance of GeminiAuth.
 func NewGeminiAuth() *GeminiAuth {
 	return &GeminiAuth{}
@@ -59,12 +66,12 @@ func NewGeminiAuth() *GeminiAuth {
 //   - ctx: The context for the HTTP client
 //   - ts: The Gemini token storage containing authentication tokens
 //   - cfg: The configuration containing proxy settings
-//   - noBrowser: Optional parameter to disable browser opening
+//   - opts: Optional parameters to customize browser and prompt behavior
 //
 // Returns:
 //   - *http.Client: An HTTP client configured with authentication
 //   - error: An error if the client configuration fails, nil otherwise
-func (g *GeminiAuth) GetAuthenticatedClient(ctx context.Context, ts *GeminiTokenStorage, cfg *config.Config, noBrowser ...bool) (*http.Client, error) {
+func (g *GeminiAuth) GetAuthenticatedClient(ctx context.Context, ts *GeminiTokenStorage, cfg *config.Config, opts *WebLoginOptions) (*http.Client, error) {
 	// Configure proxy settings for the HTTP client if a proxy URL is provided.
 	proxyURL, err := url.Parse(cfg.ProxyURL)
 	if err == nil {
@@ -109,7 +116,7 @@ func (g *GeminiAuth) GetAuthenticatedClient(ctx context.Context, ts *GeminiToken
 	// If no token is found in storage, initiate the web-based OAuth flow.
 	if ts.Token == nil {
 		fmt.Printf("Could not load token from file, starting OAuth flow.\n")
-		token, err = g.getTokenFromWeb(ctx, conf, noBrowser...)
+		token, err = g.getTokenFromWeb(ctx, conf, opts)
 		if err != nil {
 			return nil, fmt.Errorf("failed to get token from web: %w", err)
 		}
@@ -205,12 +212,12 @@ func (g *GeminiAuth) createTokenStorage(ctx context.Context, config *oauth2.Conf
 // Parameters:
 //   - ctx: The context for the HTTP client
 //   - config: The OAuth2 configuration
-//   - noBrowser: Optional parameter to disable browser opening
+//   - opts: Optional parameters to customize browser and prompt behavior
 //
 // Returns:
 //   - *oauth2.Token: The OAuth2 token obtained from the authorization flow
 //   - error: An error if the token acquisition fails, nil otherwise
-func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config, noBrowser ...bool) (*oauth2.Token, error) {
+func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config, opts *WebLoginOptions) (*oauth2.Token, error) {
 	// Use a channel to pass the authorization code from the HTTP handler to the main function.
 	codeChan := make(chan string)
 	errChan := make(chan error)
@@ -250,7 +257,12 @@ func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config,
 	// Open the authorization URL in the user's browser.
 	authURL := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline, oauth2.SetAuthURLParam("prompt", "consent"))
 
-	if len(noBrowser) == 1 && !noBrowser[0] {
+	noBrowser := false
+	if opts != nil {
+		noBrowser = opts.NoBrowser
+	}
+
+	if !noBrowser {
 		fmt.Println("Opening browser for authentication...")
 
 		// Check if browser is available
@@ -281,11 +293,47 @@ func (g *GeminiAuth) getTokenFromWeb(ctx context.Context, config *oauth2.Config,
 
 	// Wait for the authorization code or an error.
 	var authCode string
+	manualCodeChan := make(chan string, 1)
+	manualErrChan := make(chan error, 1)
+	if opts != nil && opts.Prompt != nil {
+		go func() {
+			input, err := opts.Prompt("Paste the Gemini callback URL (or press Enter to keep waiting): ")
+			if err != nil {
+				manualErrChan <- err
+				return
+			}
+			parsed, err := misc.ParseOAuthCallback(input)
+			if err != nil {
+				manualErrChan <- err
+				return
+			}
+			if parsed == nil {
+				return
+			}
+			if parsed.Error != "" {
+				manualErrChan <- fmt.Errorf("authentication failed via callback: %s", parsed.Error)
+				return
+			}
+			if parsed.Code == "" {
+				manualErrChan <- fmt.Errorf("code not found in callback")
+				return
+			}
+			manualCodeChan <- parsed.Code
+		}()
+	} else {
+		manualCodeChan = nil
+		manualErrChan = nil
+	}
+
 	select {
 	case code := <-codeChan:
 		authCode = code
 	case err := <-errChan:
 		return nil, err
+	case code := <-manualCodeChan:
+		authCode = code
+	case err := <-manualErrChan:
+		return nil, err
 	case <-time.After(5 * time.Minute): // Timeout
 		return nil, fmt.Errorf("oauth flow timed out")
 	}

internal/cmd/anthropic_login.go

@@ -24,12 +24,17 @@ func DoClaudeLogin(cfg *config.Config, options *LoginOptions) {
 		options = &LoginOptions{}
 	}
 
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+	}
+
 	manager := newAuthManager()
 
 	authOpts := &sdkAuth.LoginOptions{
 		NoBrowser: options.NoBrowser,
 		Metadata:  map[string]string{},
-		Prompt:    options.Prompt,
+		Prompt:    promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "claude", cfg, authOpts)

internal/cmd/antigravity_login.go

@@ -15,11 +15,16 @@ func DoAntigravityLogin(cfg *config.Config, options *LoginOptions) {
 		options = &LoginOptions{}
 	}
 
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+	}
+
 	manager := newAuthManager()
 	authOpts := &sdkAuth.LoginOptions{
 		NoBrowser: options.NoBrowser,
 		Metadata:  map[string]string{},
-		Prompt:    options.Prompt,
+		Prompt:    promptFn,
 	}
 
 	record, savedPath, err := manager.Login(context.Background(), "antigravity", cfg, authOpts)

internal/cmd/iflow_login.go

@@ -20,13 +20,7 @@ func DoIFlowLogin(cfg *config.Config, options *LoginOptions) {
 
 	promptFn := options.Prompt
 	if promptFn == nil {
-		promptFn = func(prompt string) (string, error) {
-			fmt.Println()
-			fmt.Println(prompt)
-			var value string
-			_, err := fmt.Scanln(&value)
-			return value, err
-		}
+		promptFn = defaultProjectPrompt()
 	}
 
 	authOpts := &sdkAuth.LoginOptions{

internal/cmd/login.go

@@ -55,11 +55,17 @@ func DoLogin(cfg *config.Config, projectID string, options *LoginOptions) {
 
 	ctx := context.Background()
 
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+		options.Prompt = promptFn
+	}
+
 	loginOpts := &sdkAuth.LoginOptions{
 		NoBrowser: options.NoBrowser,
 		ProjectID: strings.TrimSpace(projectID),
 		Metadata:  map[string]string{},
-		Prompt:    options.Prompt,
+		Prompt:    promptFn,
 	}
 
 	authenticator := sdkAuth.NewGeminiAuthenticator()
@@ -76,7 +82,10 @@ func DoLogin(cfg *config.Config, projectID string, options *LoginOptions) {
 	}
 
 	geminiAuth := gemini.NewGeminiAuth()
-	httpClient, errClient := geminiAuth.GetAuthenticatedClient(ctx, storage, cfg, options.NoBrowser)
+	httpClient, errClient := geminiAuth.GetAuthenticatedClient(ctx, storage, cfg, &gemini.WebLoginOptions{
+		NoBrowser: options.NoBrowser,
+		Prompt:    promptFn,
+	})
 	if errClient != nil {
 		log.Errorf("Gemini authentication failed: %v", errClient)
 		return
@@ -90,11 +99,6 @@ func DoLogin(cfg *config.Config, projectID string, options *LoginOptions) {
 		return
 	}
 
-	promptFn := options.Prompt
-	if promptFn == nil {
-		promptFn = defaultProjectPrompt()
-	}
-
 	selectedProjectID := promptForProjectSelection(projects, strings.TrimSpace(projectID), promptFn)
 	projectSelections, errSelection := resolveProjectSelections(selectedProjectID, projects)
 	if errSelection != nil {

internal/cmd/openai_login.go

@@ -35,12 +35,17 @@ func DoCodexLogin(cfg *config.Config, options *LoginOptions) {
 		options = &LoginOptions{}
 	}
 
+	promptFn := options.Prompt
+	if promptFn == nil {
+		promptFn = defaultProjectPrompt()
+	}
+
 	manager := newAuthManager()
 
 	authOpts := &sdkAuth.LoginOptions{
 		NoBrowser: options.NoBrowser,
 		Metadata:  map[string]string{},
-		Prompt:    options.Prompt,
+		Prompt:    promptFn,
 	}
 
 	_, savedPath, err := manager.Login(context.Background(), "codex", cfg, authOpts)

internal/misc/oauth.go

@@ -4,6 +4,8 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"fmt"
+	"net/url"
+	"strings"
 )
 
 // GenerateRandomState generates a cryptographically secure random state parameter
@@ -19,3 +21,81 @@ func GenerateRandomState() (string, error) {
 	}
 	return hex.EncodeToString(bytes), nil
 }
+
+// OAuthCallback captures the parsed OAuth callback parameters.
+type OAuthCallback struct {
+	Code             string
+	State            string
+	Error            string
+	ErrorDescription string
+}
+
+// ParseOAuthCallback extracts OAuth parameters from a callback URL.
+// It returns nil when the input is empty.
+func ParseOAuthCallback(input string) (*OAuthCallback, error) {
+	trimmed := strings.TrimSpace(input)
+	if trimmed == "" {
+		return nil, nil
+	}
+
+	candidate := trimmed
+	if !strings.Contains(candidate, "://") {
+		if strings.HasPrefix(candidate, "?") {
+			candidate = "http://localhost" + candidate
+		} else if strings.Contains(candidate, "=") {
+			candidate = "http://localhost/?" + candidate
+		} else {
+			return nil, fmt.Errorf("invalid callback URL")
+		}
+	}
+
+	parsedURL, err := url.Parse(candidate)
+	if err != nil {
+		return nil, err
+	}
+
+	query := parsedURL.Query()
+	code := strings.TrimSpace(query.Get("code"))
+	state := strings.TrimSpace(query.Get("state"))
+	errCode := strings.TrimSpace(query.Get("error"))
+	errDesc := strings.TrimSpace(query.Get("error_description"))
+
+	if parsedURL.Fragment != "" {
+		if fragQuery, errFrag := url.ParseQuery(parsedURL.Fragment); errFrag == nil {
+			if code == "" {
+				code = strings.TrimSpace(fragQuery.Get("code"))
+			}
+			if state == "" {
+				state = strings.TrimSpace(fragQuery.Get("state"))
+			}
+			if errCode == "" {
+				errCode = strings.TrimSpace(fragQuery.Get("error"))
+			}
+			if errDesc == "" {
+				errDesc = strings.TrimSpace(fragQuery.Get("error_description"))
+			}
+		}
+	}
+
+	if code != "" && state == "" && strings.Contains(code, "#") {
+		parts := strings.SplitN(code, "#", 2)
+		code = parts[0]
+		state = parts[1]
+	}
+
+	if errCode == "" && errDesc != "" {
+		errCode = errDesc
+		errDesc = ""
+	}
+
+	if code == "" && errCode == "" {
+		return nil, fmt.Errorf("callback URL missing code")
+	}
+
+	return &OAuthCallback{
+		Code:             code,
+		State:            state,
+		Error:            errCode,
+		ErrorDescription: errDesc,
+	}, nil
+}