Open-source alternatives to Proxygen

Beast is a C++ library for implementing low-level HTTP and WebSocket clients and servers. It functions as an asynchronous networking framework designed to compose non-blocking I/O operations and layered stream stacks for managing concurrent network traffic, specifically utilizing the Boost.Asio asynchronous model. The library provides a comprehensive implementation of the HTTP/1.1 and WebSocket protocols. For HTTP, it includes primitives for parsing and serializing messages with support for chunked transfer encoding, incremental body reading, and request pipelining. Its WebSocket implementati

Tengine is an enhanced Nginx web server distribution designed for high-traffic environments. It functions as a high-performance reverse proxy, dynamic load balancer, and HTTP/3 proxy server, integrating an embedded Lua scripting engine to allow for custom business logic and dynamic request processing. The project distinguishes itself through a focus on modern transport protocols and efficiency, featuring native support for QUIC and HTTP/3 to reduce connection latency. It implements userspace UDP forwarding to bypass the kernel for higher throughput and provides the ability to dynamically upda

Cowboy is a high-performance HTTP server for Erlang and OTP. It is designed to handle web traffic with low memory usage and can be used as a standalone server or as an embedded networking library integrated directly into an existing application. The project implements modern transport protocols, including HTTP/3, QUIC, and WebTransport, to enable faster connections and bidirectional data streaming. It also functions as a real-time communication server supporting Server-Sent Events for pushing asynchronous updates to clients. Broad capabilities include path and content-type based request rout

Fasthttp is a high-performance networking framework for Go, designed to maximize throughput and minimize memory overhead in demanding web applications. It functions as a specialized HTTP server and client library that prioritizes efficient resource management, allowing developers to build scalable services capable of handling massive concurrent traffic with minimal garbage collection pressure. The library distinguishes itself through a focus on zero-allocation processing and low-level optimization. It achieves this by recycling temporary request and response objects through managed pools and

This is a non-blocking network client for Java applications that provides asynchronous HTTP request capabilities and bidirectional WebSocket connectivity. It leverages a Netty-based architecture to handle high volumes of network input and output. The library utilizes native transport abstractions such as Epoll, KQueue, and io_uring to reduce system latency. It supports HTTP/2 multiplexing to run multiple concurrent request-response streams over a single connection and provides automatic response body decompression for various formats. Core capabilities cover the management of complex network

cpr is a C++ networking library that provides a high-level HTTP request client. It functions as a wrapper around libcurl to simplify the process of sending and receiving data from web servers, specifically managing GET and POST calls and multipart form uploads. The library provides both synchronous and asynchronous execution models, allowing network requests to run on background threads to prevent application freezing. It integrates with the C++ Standard Library to map low-level pointers to standard strings and containers, utilizing RAII for automatic resource management. The project covers

C++ is a high-level HTTP client library and wrapper for libcurl. It provides a C++ interface for making network requests, managing network sessions, and implementing data transfers. The library distinguishes itself by offering an asynchronous HTTP client capable of executing non-blocking requests via callback interfaces. It also functions as a multipart form uploader for transmitting files and structured data, as well as an SSE stream handler for processing real-time server-sent events over persistent connections. Its broader capabilities cover secure web communication through SSL encryption

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

Muduo is a C++11 event-driven network library and framework designed for building high-concurrency Linux servers. It provides a toolkit for implementing scalable network services and socket communication using non-blocking I/O and asynchronous event processing. The framework implements a multi-threaded TCP server architecture that distributes connection handling across multiple CPU threads to maximize server throughput. This is achieved through a one-loop-per-thread model and a reactor pattern implementation, which dispatch network events from a central demultiplexer to registered handler fun

libzmq is a C++ based asynchronous messaging engine and networking core designed for routing non-blocking messages between distributed nodes. It functions as a distributed message queue that implements the ZMTP wire-format framing protocol to standardize how data moves across different network transport layers. The library provides a multi-transport abstraction that allows a single interface to route data across TCP, IPC, and in-process memory. It incorporates a cryptographic layer to encrypt and authenticate transmissions between nodes and employs topology-based messaging patterns, such as p

This is a header-only C++ library and asynchronous network framework used to implement WebSocket clients and servers. It provides a full implementation of the WebSocket protocol, including handshakes, subprotocol negotiation, and frame parsing. The framework is distinguished by a policy-based transport layer and template-driven protocol negotiation, allowing the underlying network implementation to be swapped between raw buffers, streams, or custom policies. It supports per-message deflate compression to reduce data transmission volume and integrates Transport Layer Security for encrypted bid

The C++ REST SDK is a library for asynchronous HTTP and RESTful communication in native C++ applications. It provides a non-blocking network client for sending requests and receiving responses, a JSON parser for serializing and deserializing data, and a WebSocket client library for real-time, full-duplex communication. The project includes a dedicated OAuth2 authentication client to manage access tokens and authorization flows for secure communication with protected cloud resources. It utilizes a task-based asynchronous model to coordinate background operations and keep application interfaces

This project is a C++ HTTP web server designed for the Linux environment. It functions as a high-performance network server that processes HTTP requests and delivers static files. The server utilizes a reactor model and a thread pool to handle high volumes of simultaneous connections. It employs a state machine and regular expressions for request parsing, while a min-heap timer system manages connection timeouts to automatically close inactive sockets. Additional capabilities include a database connection pooler to reduce handshake overhead and an integrated user authentication system for re

Hyper is a low-level networking library designed for building high-performance HTTP clients and servers. It provides a foundational toolkit for creating network services that leverage asynchronous execution and memory-safe data handling, supporting both HTTP/1 and HTTP/2 protocols. The library distinguishes itself through a protocol-agnostic architecture that separates transport logic from HTTP semantics. It utilizes a service-trait abstraction to decouple network logic from the underlying transport, enabling developers to inject custom middleware for request interception and response transfo

MsQuic is a cross-platform, C-based implementation of the QUIC protocol. It provides a network library for establishing encrypted and authenticated transport links over UDP, integrating TLS to ensure all data flows between endpoints are encrypted. The implementation utilizes a language-agnostic binding layer to support high-level languages including C#, Rust, and C++. It features connection-ID based migration to maintain active sessions when IP addresses or ports change, and employs multi-stream multiplexing to manage independent data flows within a single connection. The library covers netw

This is a high-performance C++ HTTP web server designed for delivering static content. It operates as an asynchronous event loop server that combines IO multiplexing with worker thread pools to handle concurrent requests without blocking. The server specializes in TCP connection management, featuring keep-alive sessions, request pipelining, and timer-based timeout tracking for idle sockets. To ensure high throughput, it utilizes double-buffered asynchronous logging and background threads to prevent disk I/O latency from impacting network traffic. The system covers broad capability areas incl

Salvo is a comprehensive Rust web framework for building asynchronous HTTP servers and web applications. It features a hierarchical web router that uses a tree-based structure to map requests to handlers and an asynchronous middleware pipeline based on the onion model for request and response pre- and post-processing. The framework is distinguished by its native support for modern network protocols, including a QUIC-based HTTP/3 implementation alongside HTTP/1 and HTTP/2. It includes an integrated OpenAPI documentation generator that extracts schemas directly from handler signatures to produc

aiohttp is an asynchronous networking framework for Python that provides both an HTTP client and an HTTP server. It utilizes the asyncio library to handle network requests and server-side routing through a non-blocking event loop. The framework includes a dedicated toolkit for establishing persistent bidirectional communication channels, enabling the implementation of both WebSocket servers and clients for real-time data exchange. It covers a broad range of asynchronous network programming capabilities, including the development of web servers with customizable routing and the ability to sen

Axios is a promise-based HTTP client used to make asynchronous network requests in both browser and Node.js environments. It functions as a multi-environment network adapter that abstracts the transport layer to ensure consistent behavior across different runtimes. The project distinguishes itself through a request lifecycle management system that allows for the cancellation of active requests, the setting of timeouts, and the monitoring of upload and download transfer progress. It includes a mechanism for intercepting network traffic, enabling the transformation of outgoing requests and inco

Koa is a lightweight web framework for Node.js designed for building HTTP applications and servers. It functions as an asynchronous middleware engine that processes network requests through a sequence of functions sharing a common context. The framework distinguishes itself by using an onion-model middleware stack and promise-based flow control. This architecture allows requests to flow downstream and responses to flow back upstream through the same chain, enabling non-blocking request cycles and a modular approach to handling network traffic. The system provides high-level capabilities for

r2 is a JavaScript HTTP client library and asynchronous request library used for executing network calls. It provides a runtime-agnostic network layer that abstracts underlying HTTP implementations to ensure consistent behavior across different JavaScript execution environments. The library functions as a JSON API client, automatically parsing response bodies and formatting outgoing payloads. It utilizes a promise-based interface to manage the lifecycle of HTTP requests and responses. The project covers REST API integration and HTTP header management, allowing users to attach custom key-valu

Vibora is an asynchronous Python web framework and built-in HTTP server designed for building high-performance web applications. It utilizes an asynchronous event loop and coroutines to process network requests and serve responses without requiring external server wrappers. The project features a high-performance asynchronous schema validator for request integrity, a non-blocking template engine with support for hot-reloading, and a WebSocket communication server for bidirectional real-time data exchange. The framework covers a broad range of capabilities, including modular route management

Coost is a concurrent network framework and coroutine scheduler designed for building high-performance TCP, HTTP, and RPC services. It provides a set of tools for handling non-blocking IPv4 and IPv6 communication, integrating SSL encryption and a lightweight execution engine that manages concurrent tasks using shared stacks. The project features a specialized JSON RPC implementation for exchanging structured data over encrypted connections and a high-performance logging system. This logging infrastructure supports topic-based routing, frequency filtering, and automated stack trace capture for

h2o is a high-performance content delivery server and HTTP/3 web server. It functions as a network gateway and reverse proxy that forwards client requests to upstream servers to manage traffic flow and load. The project distinguishes itself as a protocol fuzzing tool, utilizing a testing framework to execute automated stress tests against network protocols to identify memory leaks and crashes. The server provides capabilities for secure web traffic management through encrypted data transmission and high-performance web serving across HTTP/1, HTTP/2, and HTTP/3. It includes tools for server r

This is an asynchronous HTTP client for Android that simplifies network requests by wrapping Apache HttpClient. It provides a callback-based networking library for fetching remote data and communicating with servers without blocking the user interface. The project includes a multipart HTTP uploader for sending binary files and large data payloads, as well as a JSON parser to convert raw response text into structured data objects. It features a session manager that persists cookies in local application preferences to maintain state across multiple requests. Additional capabilities include aut

AFNetworking is an Objective-C networking library for Apple platforms, including iOS, macOS, watchOS, and tvOS. It functions as an HTTP client that manages remote server communication by wrapping the system loading framework to handle requests and responses. The library provides specialized security and identity tools, featuring SSL certificate pinning for server trust validation and the implementation of standardized OAuth authentication flows. It further distinguishes itself with network reachability monitoring to track interface availability and request mocking capabilities to simulate ser

OkHttp is an HTTP client for the JVM and Android that enables network communication via synchronous and asynchronous requests. It provides a core identity as a comprehensive networking toolkit featuring a WebSocket client for bidirectional data synchronization, a TLS security toolkit for encrypted communication, and a programmable HTTP mock server for simulating backend responses. The project distinguishes itself through a specialized security and performance architecture. It implements mutual TLS, certificate pinning, and DNS over HTTPS to secure data in transit, while utilizing connection p