Types in API for plugins - how to?

// server.ts

import { drizzleAdapter } from "better-auth/adapters/drizzle";
import { betterAuth, type BetterAuthOptions } from "better-auth";

import { DbConnection } from "~/database/index.server";
import { dialect } from "~/database/config";
import { config } from "~/auth/config";
import { dialectToProviderMap } from "~/auth/utils";

import type { AuthInstance, EnvConfig } from "~/auth/types";

export class Auth {
  private constructor() {}
  private static instance: AuthInstance;
  private static envOptions: EnvConfig;
  static init(opt: EnvConfig) {
    this.envOptions = opt;
  }
  static get() {
    if (!this.envOptions) {
      throw new Error("Auth must be init");
    }

    let options = {
      database: drizzleAdapter(DbConnection.get(), {
        provider: dialectToProviderMap[dialect],
      }),
      ...config,
      ...this.envOptions,
    } satisfies BetterAuthOptions;
    this.instance ??= betterAuth(options);
    return this.instance;
  }
}

// config.ts

import { type BetterAuthOptions } from "better-auth";
import { emailOTP,  openAPI } from "better-auth/plugins";
import { ___app_name___ } from "~/env/config";

/** Better Auth base app configuration */
export const config = {
  emailAndPassword: { enabled: false },
  plugins: [
    emailOTP({
      async sendVerificationOTP({ email, otp, type }) {
        console.log(`${type} ${email}: ${otp}`);
      },
    }),
    openAPI(),
  ],
  advanced: { cookiePrefix: ___app_name___ },
} satisfies BetterAuthOptions;

// server.ts

import { drizzleAdapter } from "better-auth/adapters/drizzle";
import { betterAuth, type BetterAuthOptions } from "better-auth";

import { DbConnection } from "~/database/index.server";
import { dialect } from "~/database/config";
import { config } from "~/auth/config";
import { dialectToProviderMap } from "~/auth/utils";

import type { AuthInstance, EnvConfig } from "~/auth/types";

export class Auth {
  private constructor() {}
  private static instance: AuthInstance;
  private static envOptions: EnvConfig;
  static init(opt: EnvConfig) {
    this.envOptions = opt;
  }
  static get() {
    if (!this.envOptions) {
      throw new Error("Auth must be init");
    }

    let options = {
      database: drizzleAdapter(DbConnection.get(), {
        provider: dialectToProviderMap[dialect],
      }),
      ...config,
      ...this.envOptions,
    } satisfies BetterAuthOptions;
    this.instance ??= betterAuth(options);
    return this.instance;
  }
}

// config.ts

import { type BetterAuthOptions } from "better-auth";
import { emailOTP,  openAPI } from "better-auth/plugins";
import { ___app_name___ } from "~/env/config";

/** Better Auth base app configuration */
export const config = {
  emailAndPassword: { enabled: false },
  plugins: [
    emailOTP({
      async sendVerificationOTP({ email, otp, type }) {
        console.log(`${type} ${email}: ${otp}`);
      },
    }),
    openAPI(),
  ],
  advanced: { cookiePrefix: ___app_name___ },
} satisfies BetterAuthOptions;

//types.ts
import { type DrizzleDialect } from "~/database/types";
import { config } from "~/auth/config";
// Mappings of "dialect" in drizzle to "provider" in Better Auth drizzle adapter
export type SupportedDialect = Extract<
  DrizzleDialect,
  "postgresql" | "mysql" | "sqlite"
>;

import { type BetterAuthOptions } from "better-auth";

//export type AuthInstance = ReturnType<(typeof Auth)["get"]>;
import { betterAuth } from "better-auth";

type StaticBetterAuthOptions = typeof config & EnvConfig;

export type AuthInstance = ReturnType<
  typeof betterAuth<StaticBetterAuthOptions>
>;

export type EnvConfig = Required<Pick<BetterAuthOptions, "secret" | "baseURL">>;

type BetterAuthSession = Awaited<ReturnType<AuthInstance["api"]["getSession"]>>;
export type User = NonNullable<BetterAuthSession>["user"];
export type AuthSession = { user: User };
export type MaybeAuthSession = AuthSession | null;

//types.ts
import { type DrizzleDialect } from "~/database/types";
import { config } from "~/auth/config";
// Mappings of "dialect" in drizzle to "provider" in Better Auth drizzle adapter
export type SupportedDialect = Extract<
  DrizzleDialect,
  "postgresql" | "mysql" | "sqlite"
>;

import { type BetterAuthOptions } from "better-auth";

//export type AuthInstance = ReturnType<(typeof Auth)["get"]>;
import { betterAuth } from "better-auth";

type StaticBetterAuthOptions = typeof config & EnvConfig;

export type AuthInstance = ReturnType<
  typeof betterAuth<StaticBetterAuthOptions>
>;

export type EnvConfig = Required<Pick<BetterAuthOptions, "secret" | "baseURL">>;

type BetterAuthSession = Awaited<ReturnType<AuthInstance["api"]["getSession"]>>;
export type User = NonNullable<BetterAuthSession>["user"];
export type AuthSession = { user: User };
export type MaybeAuthSession = AuthSession | null;