Voidcast

Voidcast is a programmable blackhole proxy and honeypot toolkit that lets developers, security engineers, and network explorers simulate, sink, replay, or redirect traffic all while staying invisible.

Features

Feature	Description
Sink Mode (Blackhole Sink)	Silently drop traffic at socket or layer-7, with optional metadata logging for analysis
Mirage Mode (Fake Replay Server)	Replay fake responses to emulate real services (HTTP, TCP, etc.)
Drift Mode (Dynamic Proxy)	Dynamically proxy or redirect requests to real or decoy backends
Traffic Introspection	CLI tool to inspect, tail, and filter traffic in real time
Programmable Rules	Define matching/mutation logic via JS/Lua/DSL
Deception Hooks	Trap bots, scanners, and pentesters; log behavior or redirect to bait endpoints

Use Cases

• Security teams building deceptive perimeters
• Developers needing traffic mirroring, mutation, or controlled failure zones
• Interview demos to simulate misbehaving or unreleased APIs
• Capture-the-flag (CTF) hosts setting up traps or lures
• Testing networks for faulty clients, retries, edge-case handling

Architecture

Voidcast uses a hybrid architecture:

• Go Core: Handles raw sockets, TCP/HTTP listeners, and performance-critical proxying
• Node.js/TypeScript CLI: Provides configuration, scripting, and rule engine
• Next.js Web Interface: React-based UI for traffic playback and analysis

This split optimizes for performance where it matters while keeping Voidcast highly programmable and approachable for users writing rules and automation.

Project Structure

voidcast/
├── cmd/                    # Go executables
│   └── voidcastd/         # Core daemon
├── internal/               # Go internal packages
│   ├── engine/            # Core traffic engine
│   ├── proxy/             # Proxy logic
│   └── sink/              # Sink mode implementation
├── pkg/                    # Go public packages
│   └── api/               # RPC/API interfaces
├── cli/                    # Node.js/TypeScript CLI
├── web/                    # Next.js web interface
└── scripts/                # Bash scripts

Getting Started

Prerequisites

• Go 1.21 or later
• Node.js 18 or later
• Yarn package manager

Installation

1. Clone the repository:

git clone https://github.com/s4tvara/voidcast.git
cd voidcast

2. Install all dependencies:

make install

Or manually:

go mod download
cd cli && yarn install
cd ../web && yarn install

Building

Build all components:

make build

Or use the build script:

./scripts/build.sh

Build individual components:

make build-go    # Build Go daemon
make build-cli   # Build Node.js CLI
make build-web   # Build Next.js web app

Development

Start development servers:

make dev

Or use the dev script:

./scripts/dev.sh

This will start:

• Next.js dev server at http://localhost:3000
• CLI in watch mode

Usage

CLI Commands

# Sink mode - silently drop traffic
voidcast sink --port 8080

# Mirage mode - replay fake responses
voidcast mirage --port 8080

# Drift mode - dynamic proxy
voidcast drift --port 8080

# Inspect traffic
voidcast inspect --filter "method=GET"

Go Daemon

# Run the daemon
./bin/voidcastd start