Port Buddy is an Apache-2.0 licensed, Java-based localhost tunneling tool that exposes local HTTP, TCP and UDP services to the public internet through a reverse tunnel created with a single command, and it is aimed at developers and operators who need a public endpoint for a local web app, database, SSH session or game server without configuring router port forwarding.

What it is

Port Buddy is a self-hostable tunneling system built as a multi-modular Java project. The repository is split into a cli module (a GraalVM-native command-line application on Java 25), a server module (Spring Boot 3.5.7 handling the API and tunnel management), a net-proxy module for high-performance TCP and UDP proxying, a Webflux-based gateway, a React dashboard written in TypeScript and TailwindCSS, a eureka service-discovery component, an ssl-service for automated certificate management, and a common module of shared DTOs and utilities. The README describes the project as a lightweight, high-performance ngrok alternative, and the topic list places it in the localhost-tunnel, reverse-proxy and port-forwarding corner of the networking tooling ecosystem.

The concrete problem it solves is the one that normally requires either router port forwarding or a hosted third-party tunnel: getting a service that only listens on localhost reachable from the public internet. Port Buddy replaces the router configuration step entirely, and it also stands in for a hosted tunneling service, because the server, proxy, gateway and certificate components are all published in the same repository and can be run by the operator. The README draws a specific contrast with standard tunneling tools on protocol coverage, describing native, zero-configuration support for HTTP/HTTPS, raw TCP and UDP out of the box rather than HTTP alone, which is what makes it usable for databases, SSH, VoIP and game traffic and not just webhooks.

Key capabilities

• HTTP and HTTPS tunnels with auto-generated SSL certificates: portbuddy 3000 returns a public URL in the form https://my-web-site.portbuddy.dev.
• Raw TCP port forwarding for services such as PostgreSQL, MySQL, SSH or custom TCP protocols, via portbuddy tcp 5432, returning an endpoint such as net-proxy-1.portbuddy.dev:43452.
• Native UDP tunneling through portbuddy udp 19132, intended for game servers, VoIP services and IoT protocol debugging.
• Custom and static domains through the -d, --domain= option, plus port reservation with -pr, --port-reservation= taking a host:port argument for TCP and UDP, so endpoints stay permanent across restarts.
• Passcode protection for a tunnel with -pc, --passcode=, alongside verbose logging via -v.
• WebSocket and Server-Sent Events support for real-time streaming, chat applications and live data connections.
• A background daemon mode for running Port Buddy as a system service under systemd or Windows Task Scheduler, with the CLI also distributed as the container image amaktech/portbuddy:latest.

Who uses it and how

• Web and API developers who need to test inbound webhooks or share a local application running on a port such as 3000, using the default HTTP mode.
• Developers and DBAs who expose a local database or an SSH service for remote debugging with portbuddy tcp, avoiding inbound firewall rules on the local network.
• Teams debugging UDP workloads such as IoT protocols, VoIP or self-hosted game servers, which the HTTP-only tools in this space do not cover.
• Operators who run the whole stack on their own infrastructure: docker-compose up -d starts the server, gateway, net-proxy, Eureka and SSL services together with the React dashboard, and the CLI authenticates by mounting a token file at /root/.port-buddy/token.
• Windows users who prefer a desktop interface can use the community-built PortBuddy GUI, listed in the README's community projects section.

Getting started

The shortest path is to install the Port Buddy CLI and run portbuddy 3000, portbuddy tcp 5432 or portbuddy udp 19132; alternatively pull amaktech/portbuddy:latest and mount the token at /root/.port-buddy/token. Self-hosters build with ./mvnw clean install and start the stack with docker-compose up -d.

How it compares

The README positions Port Buddy as an ngrok alternative rather than a companion tool, and the difference the facts support is one of licence and custody: Port Buddy is Apache-2.0 and ships its own server, gateway, net-proxy and ssl-service modules for self-hosting, so tunnels, tokens and static domain assignments stay on infrastructure the operator controls instead of terminating at a third-party endpoint. The cost model follows from that — the software itself is free under Apache-2.0, and the running cost is whatever infrastructure the operator already provisions for the compose stack.

When to use it — and when not to

Choose Port Buddy when TCP or UDP exposure is a requirement alongside HTTP, or when tunnel traffic must terminate on infrastructure you run; a self-hoster must operate a Java 25 and Spring Boot environment, Docker and Compose, Maven 3.9+, a Node.js toolchain for the web module, and the Eureka-based service discovery that ties the modules together. It is a poor fit for teams wanting a fully managed service with no operational surface, or for anyone who needs documented production hardening — the README covers installation and build steps but not deployment topology, scaling or the security model beyond the --passcode option, and with 537 stars, 46 forks and two open issues the project is small enough that support depends on the community and the code itself.

portbuddy 3000

portbuddy tcp 5432

portbuddy udp 19132

docker pull amaktech/portbuddy:latest

Usage: portbuddy [options] [mode] [host:][port]

Modes:
  http (default), tcp, udp

Options:
  -d,  --domain=<domain>        Requested static subdomain (e.g. my-app)
  -pr, --port-reservation=<hp>  Use specific port reservation host:port for TCP/UDP
  -pc, --passcode=<passcode>    Protect tunnel with a passcode
  -v,  --verbose                Enable verbose logging
  -h,  --help                   Show help message
  -V,  --version                Show version info

./mvnw clean install

docker-compose up -d