CoreSend

Temporary email service with Ed25519 signature-based authentication.

Overview

CoreSend provides disposable email addresses with cryptographic authentication. Each address is derived from an Ed25519 public key, ensuring only the key holder can access the inbox.

Features

• Cryptographic Authentication - Ed25519 signature-based auth, no passwords
• Disposable Addresses - Self-destructing emails after 24 hours
• Rate Limiting - Prevents abuse with configurable limits
• REST API - Full REST API with OpenAPI/Swagger documentation
• SMTP Server - Standard SMTP for receiving emails

Project Structure

coresend/
├── backend/          # Go HTTP API + SMTP server
│   ├── cmd/server/   # Entry point
│   ├── internal/     # API, SMTP, storage, validation
│   └── docs/         # Swagger documentation
└── app/              # React frontend (Vite + TypeScript)

Quick Start

Prerequisites

• Go 1.21+
• Node.js 18+ (or Bun)
• Redis 6.0+

1. Start Redis

redis-server

2. Start Backend

cd backend
make deps
make run

Backend runs on:

• HTTP API: http://localhost:8080
• SMTP: localhost:1025
• Swagger UI: http://localhost:8080/docs/

3. Start Frontend

cd app
bun install
bun run dev

Frontend runs on http://localhost:5173

Documentation

• Backend README - Backend setup, configuration, and API
• API Documentation - Authentication flow and usage examples

Architecture

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   Client    │────▶│  HTTP API   │────▶│    Redis    │
│  (Frontend) │     │  (Go/8080)  │     │  (Storage)  │
└─────────────┘     └─────────────┘     └─────────────┘
                           │
                           ▼
                    ┌─────────────┐
                    │ SMTP Server │
                    │  (Go/1025)  │
                    └─────────────┘

Authentication

CoreSend uses Ed25519 signatures instead of passwords:

1. Generate Ed25519 keypair
2. Derive address: sha256(publicKey)[:20] (hex)
3. Sign each request: timestamp:method:path
4. Include headers: X-Public-Key, X-Signature, X-Timestamp

See API Documentation for detailed examples.

API Endpoints

Method	Path	Description
POST	/api/register/{address}	Register address
GET	/api/inbox/{address}	Get all emails
GET	/api/inbox/{address}/{id}	Get specific email
DELETE	/api/inbox/{address}/{id}	Delete email
DELETE	/api/inbox/{address}	Clear inbox
GET	/api/health	Health check

Development

Backend

cd backend
make test           # Run tests
make swagger        # Generate swagger docs
make build          # Build binary

Frontend

cd app
bun run lint        # Run linter
bun run build       # Build for production

License

AGLP-3.0 License. See LICENSE for details.