github.com/ehang-io/nps

NPS is a fast reverse proxy and intranet penetration tool, but using it as a Go package presents significant challenges. The documentation is primarily in Chinese with rough English translations, making it difficult to understand configuration options and API usage patterns. The codebase lacks comprehensive examples for programmatic integration, with most documentation focused on the standalone binary usage rather than library embedding.

Error messages are often cryptic or entirely in Chinese, making debugging frustrating without language skills or translation tools. When things go wrong with tunneling or connection management, you'll spend considerable time tracing through source code to understand the issue. The package hasn't been updated since April 2021, raising concerns about compatibility with newer Go versions and security patches.

Common use cases like setting up basic tunnels require reading through the CLI implementation to understand how to properly initialize and configure components. The lack of idiomatic Go patterns and minimal community presence on English-speaking forums means you're largely on your own for troubleshooting. Stack Overflow has virtually no coverage, and GitHub issues are predominantly in Chinese.

NPS is primarily a standalone tunneling/proxy server application rather than a Go library meant for embedding. When attempting to use it as a package, you quickly encounter issues: the API surface is designed for CLI usage, not programmatic integration. Documentation is almost entirely in Chinese with sparse English translations, making it difficult to understand configuration structures and internal APIs.

The codebase lacks meaningful Go package documentation (godoc comments are minimal), and there's no clear separation between internal and public APIs. Type definitions exist but aren't designed with library consumers in mind—you'll find yourself navigating through server initialization code and configuration structs that assume you're running the binary directly. Error messages are often cryptic or untranslated, making debugging frustrating.

The project hasn't seen updates since April 2021, which is concerning for security-sensitive tunneling software. If you need an NPS tunnel in your Go application, you're better off spawning the binary as a subprocess rather than importing this package. For programmatic proxy/tunnel solutions in Go, consider purpose-built libraries instead.

NPS is a feature-rich intranet penetration proxy server with support for multiple protocols (TCP, UDP, HTTP, HTTPS). However, from a security perspective, daily use reveals significant concerns. The codebase lacks fundamental secure-by-default principles - TLS configuration options are minimal, crypto implementations use outdated patterns, and default settings prioritize convenience over security.

Input validation is inconsistent across different protocol handlers, and error messages frequently leak internal path information and configuration details. The authentication layer is basic, using simple password-based auth without modern standards like token rotation or rate limiting. Client configuration requires storing credentials in plaintext files by default.

Most concerning is the lack of maintenance since April 2021. No CVE responses, no dependency updates, and multiple known vulnerabilities in transitive dependencies remain unpatched. The project feels abandoned despite being functional for basic tunneling needs. If you must use it, deploy behind strict network controls and never expose directly to the internet.