@vieltalk/core

Shared core utilities, enums, types, constants, and error codes for VielTalk applications — backend, web, and mobile.

Table of Contents

• @vieltalk/core
  • Table of Contents
  • Overview
  • Features
  • Installation
  • Folder Structure
  • Usage
    • Enums
    • Error Codes
    • Types
    • Constants
    • Utils
  • NestJS Exception Example
  • Contributing
  • License

Overview

@vieltalk/core is a centralized shared library for the VielTalk app. It contains:

• Standardized enums (message types, user roles, etc.)
• Error codes for backend/frontend consistency
• Shared types and interfaces
• Common constants (Redis keys, system events)
• Utility functions (formatting, helpers)

It ensures single source of truth across backend, web, and mobile apps.

Features

• ✅ Consistent enums across all platforms
• ✅ Centralized error codes (AppErrorCode)
• ✅ Strongly-typed TypeScript interfaces
• ✅ Shared constants for Redis, system events, etc.
• ✅ Utility helpers for common tasks
• ✅ Ready for NestJS, React, React Native, or Node.js

Installation

npm install @vieltalk/core
# or using yarn
yarn add @vieltalk/core

Folder Structure

src/
├── enums/
│   ├── message.enum.ts
│   ├── user.enum.ts
│   └── index.ts
├── constants/
│   ├── redis-keys.ts
│   ├── system-events.ts
│   └── index.ts
├── types/
│   ├── message.type.ts
│   ├── user.type.ts
│   └── index.ts
├── utils/
│   ├── format.ts
│   └── index.ts
├── errors/
│   ├── app-error.ts
│   └── index.ts
└── index.ts

Usage

Enums

import { MessageType } from '@vieltalk/core/enums';

const type: MessageType = MessageType.TEXT;

Error Codes

import { AppErrorCode } from '@vieltalk/core/errors';

throw new Error(AppErrorCode.DEVICE_ALREADY_REGISTERED);

Types

import { Message } from '@vieltalk/core/types';

const newMessage: Message = {
  id: '123',
  type: 'TEXT',
  content: 'Hello!',
  senderId: 'user_1',
  createdAt: new Date(),
};

Constants

import { REDIS_KEYS, SYSTEM_EVENTS } from '@vieltalk/core/constants';

const key = REDIS_KEYS.USER_SOCKET('user1', 'device1');
console.log(SYSTEM_EVENTS.CONTACT_SYNCED);

Utils

import { formatDate } from '@vieltalk/core/utils';

console.log(formatDate(new Date())); // ISO string

NestJS Exception Example

import { BadRequestException } from '@nestjs/common';
import { AppErrorCode } from '@vieltalk/core/errors';

throw new BadRequestException({
  message: 'Device is already registered.',
  code: AppErrorCode.DEVICE_ALREADY_REGISTERED,
});

This standardizes error handling across backend, web, and mobile.

Contributing

1. Fork the repository
2. Create a branch (feature/my-feature)
3. Commit your changes
4. Open a pull request

License

MIT © VielTalk