Open-source alternatives to Cow

Mitmproxy is an interactive, programmable network proxy engine designed for traffic analysis and protocol manipulation. It functions as a gateway that intercepts, inspects, and modifies network traffic in real-time, supporting HTTP, HTTPS, WebSocket, DNS, and generic TCP or UDP streams. By acting as a trusted certificate authority, the proxy can dynamically generate and sign certificates to decrypt and analyze secure TLS-encrypted connections. The project distinguishes itself through a highly extensible, event-driven architecture that allows users to automate traffic transformation using cust

Proxyee is a Java-based network proxy library designed for building custom proxy servers that support traffic interception, inspection, and modification. It functions as a programmable framework for handling HTTP, HTTPS, and WebSocket traffic, providing the necessary tools to analyze and alter request and response data in real time. The project distinguishes itself through its man-in-the-middle capabilities, which include dynamic certificate generation to facilitate the decryption and re-encryption of secure traffic streams. This allows for granular control over network communications, suppor

Sish is a reverse SSH proxy and tunneling server designed to expose local services to the internet. It functions as an SSH tunneling proxy that routes HTTP, WebSocket, and TCP traffic from a remote server to a local machine, enabling the creation of public URLs for local applications. The project distinguishes itself through a combination of an SNI proxy for routing encrypted TLS traffic without decryption and a TCP load balancer that distributes incoming requests across multiple backend targets. It also includes a dedicated service console for real-time inspection and debugging of forwarded

CodeIgniter is a PHP web framework built on the Model-View-Controller pattern, designed for building full-stack web applications. It provides a lightweight toolkit with minimal configuration, organizing application logic into controllers, models, and views for clean separation of concerns. The framework includes a fluent query builder for constructing SQL statements programmatically, PSR-4 autoloading with namespace mapping, and a service-based dependency injection container for managing shared class instances. The framework distinguishes itself through its comprehensive set of built-in tools

Surge is a network traffic routing and configuration system designed to categorize and steer network requests using curated rule sets, domain lists, and IP databases. It provides the data structures and filtering logic necessary to manage how application traffic is directed across proxies, direct connections, or regional gateways. The project distinguishes itself through granular traffic identification and steering. It identifies network requests by matching them against system process names, user-agent strings, and geographic IP ranges to apply specific routing policies. This allows for the

This project is a proxy server designed to intercept and modify HTTP and HTTPS traffic for Netease Cloud Music. It functions as network middleware to restore playback for songs and albums restricted by geographic regions and to unlock premium account features, such as high-fidelity audio. The server utilizes header-based privilege injection to spoof premium status and employs conditional content redirection to route requests for unavailable media to alternative source providers. It also incorporates upstream proxy routing and IP parameters to bypass regional access restrictions. Additional c

This project is a cloud storage link resolver and direct link generator that transforms sharing links from various cloud and music sharing platforms into direct download URLs. It functions as a programmatic interface that returns file metadata and download paths in JSON format for use in external applications and download managers. The system features a JavaScript parser framework that allows for the implementation of new link conversion logic via dynamic scripts without requiring application recompilation. To maintain service availability, it includes a request router that distributes outgoi

MTProxy is a proxy server that routes traffic to Telegram servers using the MTProto protocol to bypass network restrictions. It functions as a system for managing secure connections and forwarding protocol traffic between clients and destination servers. The project implements traffic obfuscation by adding random padding to packets to mask data patterns and hide proxy usage from internet service providers. It also includes a connection manager that restricts user access through the validation of specific authentication secrets. The system provides operational observability by exposing real-t

tg-ws-proxy is a local proxy server and network tool designed to route Telegram traffic through WebSocket connections. It functions as a bridge that tunnels MTProto protocol traffic to bypass network restrictions and circumvent firewalls that block direct connections to messaging services. The project includes a system tray proxy manager that provides a desktop interface for controlling the server state. This manager allows for updating connection secrets, viewing server logs, and restarting services through a native OS desktop tray icon. The system supports establishing proxy connections vi

HAProxy is a high-performance TCP and HTTP proxy that distributes traffic across multiple backend servers to ensure availability and fault tolerance for critical services. It operates in either TCP or HTTP mode, with an event-driven, single-threaded reactor that handles tens of thousands of connections without context switching, and supports kernel-level data transfer to minimize memory usage and latency. What distinguishes HAProxy is its configuration-file-first design, where all load-balancing rules and runtime behavior are defined in a declarative text file parsed at startup. It embeds a L

This project is a Python-based proxy pool manager that collects, validates, and serves free proxy IP addresses through an HTTP API. It consists of an automated scraper to gather addresses from multiple online sources, a persistent database-backed store for organization, and a delivery interface for retrieving validated proxies. The system features a pluggable scraper architecture that allows for the integration of custom discovery methods and source expansion via generator functions. It employs decorator-based validation logic, enabling the definition of custom connectivity and HTTPS criteria

youtube-transcript-api is a Python library designed to retrieve and download subtitles and captions from YouTube videos using video IDs. It functions as an API client that extracts text and timing data for video content. The project includes a wrapper for automated translation, allowing transcripts to be converted into different target languages. It also features a retrieval system that supports routing requests through HTTP, HTTPS, or SOCKS proxies to avoid IP blocking and regional restrictions. The library provides tools for identifying available subtitle tracks and converting raw transcri

This project is a censorship circumvention utility designed to maintain connectivity to restricted online services by evading deep packet inspection. It functions as a network traffic redirection service that manipulates packet headers at the transport layer to bypass regional network filters and censorship systems. The tool distinguishes itself by providing granular control over traffic management, allowing users to define specific lists of domains and IP addresses for targeted interception. By applying custom bypass strategies only to these designated hosts, the utility ensures that the rem

ZeroOmega is a web-based proxy orchestrator and manager designed for real-time updates to active network gateways. It functions as a system for configuring, storing, and switching between different network proxy profiles to direct internet traffic. The project features a PAC script generator that translates structured proxy profile data into auto-configuration files. These scripts automate network routing decisions by matching requested URLs against defined patterns. Administration is handled through a browser-based interface that allows for the modification of routing rules and the manageme

Unblock-Youku is a geo-blocking circumvention tool and proxy server designed to grant access to region-locked video streaming and web services. It functions as a regional content unblocker that masks a user's location to bypass geographic restrictions. The system operates as an SNI proxy server, forwarding HTTPS traffic based on the Server Name Indication without decrypting the payload. It also serves as a transparent proxy gateway and a DNS-based request router that directs network traffic to specific proxy servers by modifying name resolution records for regional domains. Its capabilities

Pingora is a Rust-based framework for building high-performance network services, including HTTP reverse proxies, layer seven load balancers, and TLS termination proxies. It serves as an asynchronous network library designed to intercept and route HTTP, gRPC, and WebSocket traffic between clients and upstream backend servers. The project enables zero-downtime service updates by handing over listening sockets between processes during binary or configuration upgrades. It utilizes a programmable multi-phase pipeline to modify request and response bodies and headers, and it provides a pluggable T

Requests is a Python HTTP client library used for sending HTTP requests and handling responses. It serves as a network client providing fundamental components for session management, proxy routing, multi-part uploading, and SSL/TLS certificate verification. The project distinguishes itself through a session manager that maintains cookies and reuses TCP connections to improve network performance. It also includes a dedicated multi-part form uploader for transmitting binary data and an integrated SSL/TLS certificate verifier to ensure encrypted and trusted communication. The library covers a b

This project provides a comprehensive collection of curated configuration files and rule sets designed for the Shadowrocket proxy client. It functions as a centralized repository for managing network traffic, enabling users to implement granular routing policies, content filtering, and connection management across their devices. The repository distinguishes itself by offering advanced traffic orchestration capabilities, including domain-suffix pattern matching and rule-based interception. It supports complex network configurations such as proxy group load balancing, custom DNS resolution, and

This project provides predefined configuration profiles and rule sets for ad filtering, geographic traffic steering, and proxy routing. It specifically offers curated rule sets and configuration lists for Shadowrocket to filter advertising domains and manage network traffic on iOS devices. The project specializes in converting industry-standard ad-blocking filter lists into a proprietary rule format compatible with proxy client configurations. These rule sets facilitate the separation of domestic and foreign network requests to optimize connection paths and bypass regional restrictions. The

A Rust port of shadowsocks

Stoatchat is a real-time chat server and messaging backend that utilizes WebSockets to handle instant communication, live event updates, and user presence tracking. The project incorporates an encrypted file storage system and cloud storage layer that applies AES encryption to binary data before upload. It also functions as an HTTP content proxy server to mask user IP addresses when fetching media from third-party services and as a push notification gateway to ensure reliable alert delivery via a background dispatch queue. The system includes role-based access control to manage user permissi

Mutagen is a cross-platform file synchronization engine and development environment orchestrator. It provides real-time bidirectional file synchronization between local machines, remote servers, and Docker containers, often utilizing SSH for transport. The tool functions as a high-performance alternative to Docker bind mounts by mirroring files between a local host and a running container. It also operates as a network port forwarding utility, routing TCP traffic and Unix domain sockets between local and remote environments via SSH. Its capability surface includes filesystem event monitoring

SSH.NET is a .NET library that implements the SSH-2 protocol for encrypted remote connections and secure file transfers. It provides a complete SSH-2 protocol stack implementation with a channel multiplexing engine that manages multiple concurrent channels over a single connection, supporting simultaneous shell sessions, remote command execution, SFTP transfers, and port forwarding tunnels. The library includes a pluggable authentication pipeline supporting password, public key, certificate, keyboard-interactive, and multi-factor authentication combinations. The library distinguishes itself t

This project is an asynchronous network framework for Python that provides both a client and a server for HTTP communication. It is designed to handle high-concurrency network operations by leveraging cooperative multitasking, allowing for the management of thousands of simultaneous connections without the overhead of traditional thread-per-request models. The framework distinguishes itself through its focus on efficient resource management and persistent communication. It utilizes connection pooling to reuse network sockets, which reduces latency during sequential requests, and supports full

VictoriaMetrics is a high-performance, scalable time series database and observability platform designed for long-term storage and analysis of metric, log, and trace data. It functions as a unified backend for monitoring ecosystems, offering full compatibility with industry-standard protocols and query languages. The system is built to handle massive data volumes through a distributed architecture that supports horizontal scaling and efficient data lifecycle management. The platform distinguishes itself through a storage engine that utilizes consistent hashing for data sharding and log-struct

libhv is a high-performance C/C++ network library and event-driven I/O framework used to build TCP, UDP, SSL, HTTP, WebSocket, and MQTT clients and servers. It provides a non-blocking event loop for managing network sockets, timers, and system signals across multiple threads. The project is distinguished by its integrated support for specialized network roles, including a full HTTP web server with RESTful routing and middleware, an MQTT messaging client for IoT communication, and the ability to implement SOCKS5 and HTTP proxies. It also features a reliable UDP implementation to ensure ordered

Better Errors is a Rack middleware exception handler and interactive application state inspector for Ruby web applications. It intercepts unhandled exceptions to render developer-friendly error pages that provide detailed stack traces and variable inspection. The tool provides a debugging interface that allows for live code evaluation at every stack frame of an exception. It maps stack trace entries to local filesystem paths for direct navigation to source code in an editor and restricts interface access via IP-based validation. The project covers error response formatting for API and AJAX c