diff --git a/server/internal/adapter/http/user.go b/server/internal/adapter/http/user.go
index ba7452d0ec..3f351ad4b1 100644
--- a/server/internal/adapter/http/user.go
+++ b/server/internal/adapter/http/user.go
@@ -2,10 +2,7 @@ package http
 
 import (
 	"context"
-	"errors"
 
-	"github.com/reearth/reearth/server/internal/adapter"
-	"github.com/reearth/reearth/server/pkg/id"
 	"github.com/reearth/reearthx/account/accountdomain"
 	"github.com/reearth/reearthx/account/accountdomain/user"
 	"github.com/reearth/reearthx/account/accountusecase/accountinterfaces"
@@ -32,14 +29,14 @@ type SignupInput struct {
 	Sub         *string                    `json:"sub"`
 	Secret      *string                    `json:"secret"`
 	UserID      *accountdomain.UserID      `json:"userId"`
-	WorkspaceID *accountdomain.WorkspaceID `json:"teamId"`
-	Name        *string                    `json:"name"`
-	// Username is an alias of Name
-	Username *string       `json:"username"`
-	Email    *string       `json:"email"`
-	Password *string       `json:"password"`
-	Theme    *user.Theme   `json:"theme"`
-	Lang     *language.Tag `json:"lang"`
+	WorkspaceID *accountdomain.WorkspaceID `json:"workspaceId"`
+	TeamID      *accountdomain.WorkspaceID `json:"teamId"` // TeamID is an alias of WorkspaceID
+	Name        string                     `json:"name"`
+	Username    string                     `json:"username"` // ysername is an alias of Name
+	Email       string                     `json:"email"`
+	Password    string                     `json:"password"`
+	Theme       *user.Theme                `json:"theme"`
+	Lang        *language.Tag              `json:"lang"`
 }
 
 type CreateVerificationInput struct {
@@ -51,13 +48,6 @@ type VerifyUserOutput struct {
 	Verified bool   `json:"verified"`
 }
 
-type CreateUserInput struct {
-	Sub         string                     `json:"sub"`
-	Secret      string                     `json:"secret"`
-	UserID      *id.UserID                 `json:"userId"`
-	WorkspaceID *accountdomain.WorkspaceID `json:"teamId"`
-}
-
 type SignupOutput struct {
 	ID    string `json:"id"`
 	Name  string `json:"name"`
@@ -65,52 +55,43 @@ type SignupOutput struct {
 }
 
 func (c *UserController) Signup(ctx context.Context, input SignupInput) (SignupOutput, error) {
-	var u *user.User
-	var err error
-
-	name := input.Name
-	if name == nil {
-		name = input.Username
+	if input.Name == "" && input.Username != "" {
+		input.Name = input.Username
 	}
-	if name == nil {
-		name = input.Email
+	if input.WorkspaceID == nil && input.TeamID != nil {
+		input.WorkspaceID = input.TeamID
 	}
 
-	if au := adapter.GetAuthInfo(ctx); au != nil {
-		var name2 string
-		if name != nil {
-			name2 = *name
+	if input.Sub != nil && *input.Sub != "" && input.Email != "" && input.Name != "" {
+		u, err := c.usecase.SignupOIDC(ctx, accountinterfaces.SignupOIDCParam{
+			Name:   input.Name,
+			Email:  input.Email,
+			Sub:    *input.Sub,
+			Secret: input.Secret,
+		})
+
+		if err != nil {
+			return SignupOutput{}, err
 		}
 
-		u, err = c.usecase.SignupOIDC(ctx, accountinterfaces.SignupOIDCParam{
-			Sub:         au.Sub,
-			AccessToken: au.Token,
-			Issuer:      au.Iss,
-			Email:       au.Email,
-			Name:        name2,
-			Secret:      input.Secret,
-			User: accountinterfaces.SignupUserParam{
-				UserID:      input.UserID,
-				WorkspaceID: input.WorkspaceID,
-				Lang:        input.Lang,
-				Theme:       input.Theme,
-			},
-		})
-	} else if name != nil && input.Email != nil {
-		u, err = c.usecase.Signup(ctx, accountinterfaces.SignupParam{
-			Name:        *name,
-			Email:       *input.Email,
-			Password:    *input.Password,
-			Secret:      input.Secret,
-			UserID:      input.UserID,
-			WorkspaceID: input.WorkspaceID,
-			Lang:        input.Lang,
-			Theme:       input.Theme,
-		})
-	} else {
-		err = errors.New("invalid params")
+		return SignupOutput{
+			ID:    u.ID().String(),
+			Name:  u.Name(),
+			Email: u.Email(),
+		}, nil
 	}
 
+	u, err := c.usecase.Signup(ctx, accountinterfaces.SignupParam{
+		Name:        input.Name,
+		Email:       input.Email,
+		Password:    input.Password,
+		Secret:      input.Secret,
+		UserID:      input.UserID,
+		WorkspaceID: input.WorkspaceID,
+		Lang:        input.Lang,
+		Theme:       input.Theme,
+	})
+
 	if err != nil {
 		return SignupOutput{}, err
 	}