Cross-platform proxy resolution with support for Linux, macOS, & Windows.

Read the Documentation

• Read the user's proxy configuration from the operating system.
• Execute a PAC script using JavaScriptCore or Windows Script Host.
• Get the proxies for a URL asynchronously using WinHTTP, ProxyConfiguration, and CFNetwork.
  • Or with a fallback proxy resolver featuring:
    • Support for WPAD using DHCP and DNS.
    • Support for PAC file execution using system scripting libraries.
    • Support for downloading PAC scripts using HTTPS with curl.
• Example command line utility.

• Windows XP+, RT (UWP)
• Ubuntu 18
• macOS 10.13

Source code examples can be found in the docs for each class or in the command line test application proxycli.

Use CMake to generate project and solution files for your environment:

cmake -S . -B build
cmake --build build

To run CMake tests use the following command:

ctest --verbose -C Debug

Portions of the code for this library started many years ago as part of a custom HTTP/HTTPS stack we developed at Solid State Networks. Recently we made the decision to switch over to libcurl but realized that we still needed to implement our own proxy resolution code. We investigated using libproxy, however it did not allow us to statically link the library for closed source commerical purposes.

• Wikipedia - Proxy Auto-config
• Mozilla - Proxy Auto-Configuration (PAC)
• RFC Drafts
  • Web Proxy Auto-Discovery Protocol
  • Generalize Client UDP Port Number of DHCP Relay
• Windows Proxy Setting "Bypass proxy server for local addresses"