# Install onioncat with Homebrew, apk, MacPorts, zypper, scoop, winget VPN-adapter that provides location privacy using Tor or I2P. Version 4.11.0 via Homebrew; verified 2026-07-28. Also installable with apk: sudo apk add onioncat. ## Install ```sh sudo av install brew:onioncat ``` Additional install commands: ### macOS - Homebrew (100%): ```sh brew install onioncat ``` Evidence: local Homebrew formula metadata - MacPorts (94%): ```sh sudo port install onioncat ``` Evidence: MacPorts ports tree: net/onioncat/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 ### Linux - apk (92%): ```sh sudo apk add onioncat ``` Evidence: Alpine Linux edge package indexes: onioncat from https://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz - zypper (92%): ```sh sudo zypper install onioncat ``` Evidence: openSUSE Tumbleweed package metadata: onioncat from https://download.opensuse.org/tumbleweed/repo/oss/repodata/50b07339cb64c8ed4091bdbabddadc1ff5737b090e478818a195b40d8a3292861a879139b4a3987c31109699fde9fbf4a716367ddf4eef77da75f96e3193d6ed-primary.xml.zst ### Windows - Scoop (92%): ```sh scoop install extras/ocat ``` Evidence: Scoop official bucket manifest trees: bucket/ocat.json from https://api.github.com/repos/ScoopInstaller/Extras/git/trees/master?recursive=1 - winget (92%): ```sh winget install --id ic005k.OCAuxiliaryTools -e ``` Evidence: Windows Package Manager source index: ic005k.OCAuxiliaryTools from https://cdn.winget.microsoft.com/cache/source.msix ## Package facts - **Package key:** brew:onioncat - **Package manager:** Homebrew - **Version:** 4.11.0 - **Source summary:** VPN-adapter that provides location privacy using Tor or I2P - **Homepage:** - **Repository:** - **Last updated:** 2026-07-28T14:05:35+09:00 - **Generated:** 2026-08-03T19:37:03+00:00 ## Executables - ocat (alias) ## Install behavior - Bottle: not available ## Freshness - Page generated: 2026-08-03 - Package-manager version: 4.11.0 ## Project history and usage OnionCat is a long-running networking experiment that maps Tor hidden services or I2P tunnels into an IPv6 TUN interface. It makes onion/I2P endpoints look like peers on an IP network, so ordinary IP-based protocols can travel over Tor or I2P hidden-service transports. ### Project history OnionCat development began in 2008, when Tor hidden-service v2 identifiers were short enough to be reversibly mapped into IPv6 addresses under a special prefix. Its own documentation describes the core trick as translating between OnionCat IPv6 addresses and .onion hostnames, then forwarding packets between a local TUN device and remote OnionCat peers. The move from Tor v2 hidden services to v3 onion services challenged OnionCat's original design because v3 identifiers no longer fit inside an IPv6 address. OnionCat4 added lookup machinery to preserve the virtual-network model after the identifier-size change. ### Adoption history OnionCat has been packaged beyond a single ecosystem: Debian documented an ocat(1) man page by the Jessie era, and Homebrew packages onioncat for macOS and Linux users. Its GitHub repository is the official upstream and had an onioncat-4.11.0 release dated March 9, 2023. ### How it is used Users run ocat with a local onion or I2P identifier, and OnionCat opens a TUN device, assigns it a derived IPv6 address, and relays packets through Tor or I2P. The tool can carry TCP, UDP, and other IP-based traffic, making it resemble a peer-to-peer VPN between hidden services rather than a web-only Tor client. The README also exposes OnionCat's operational rough edges: it is a userland connector, depends on Tor/I2P setup, and does not add its own encryption on top of the transport. That makes it a tool for operators who understand the underlying anonymity network rather than a general-purpose consumer VPN. ### Why package nerds care OnionCat matters because it is one of the more literal attempts to package 'IP over onion services' as a Unix-style command. It combines old-school TUN-device networking, IPv6 address mapping, Tor/I2P naming, and distro packaging into a compact but unusual formula. ### Timeline - 2008: OnionCat development began around Tor hidden-service v2 identifiers. - 2015: Debian Jessie shipped an onioncat man page documenting ocat as an IP-transparent Tor/I2P connector. - 2023-03-09: onioncat-4.11.0 was published as a GitHub release. - 2023-10-25: the upstream README/man-page text identified ocat and documented OnionCat4 behavior. ### Related projects - Related projects and technologies include Tor onion services, I2P server tunnels, TUN/TAP virtual network interfaces, and VPN-style tunneling tools. ### Sources - - - - ## Security Notes narrow executable package without higher-risk signals. - **Geiger risk:** green / low - narrow executable package without higher-risk signals ## Other Package-Manager Records - apk - onioncat - 4.11.0-r1: normalized package name match | Alpine Linux edge package indexes: onioncat from https://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz | OnionCat is a VPN-adapter, which uses Tor or I2P as its transport. | https://www.onioncat.org/ - apk - onioncat-doc - 4.11.0-r1: normalized package name match | Alpine Linux edge package indexes: onioncat-doc from https://dl-cdn.alpinelinux.org/alpine/edge/testing/x86_64/APKINDEX.tar.gz | OnionCat is a VPN-adapter, which uses Tor or I2P as its transport. (documentation) | https://www.onioncat.org/ - zypper - onioncat - 4.11.0-1.12: normalized package name match | openSUSE Tumbleweed package metadata: onioncat from https://download.opensuse.org/tumbleweed/repo/oss/repodata/50b07339cb64c8ed4091bdbabddadc1ff5737b090e478818a195b40d8a3292861a879139b4a3987c31109699fde9fbf4a716367ddf4eef77da75f96e3193d6ed-primary.xml.zst | VPN adapter for Tor and I2P | https://www.onioncat.org/ - MacPorts - onioncat: normalized package name match | MacPorts ports tree: net/onioncat/Portfile from https://api.github.com/repos/macports/macports-ports/git/trees/master?recursive=1 - Scoop - extras/ocat: installed executable or alias match | Scoop official bucket manifest trees: bucket/ocat.json from https://api.github.com/repos/ScoopInstaller/Extras/git/trees/master?recursive=1 - winget - ic005k.OCAuxiliaryTools: installed executable or alias match | Windows Package Manager source index: ic005k.OCAuxiliaryTools from https://cdn.winget.microsoft.com/cache/source.msix ## Combined YAML source View the package source record on GitHub. [combined/onioncat.yml](https://github.com/mxcl/pkgdb/blob/main/combined/onioncat.yml) ## Sources - pkg.so package database - Geiger risk classifier - curated package history - pkgdb category and tag curation - external package-manager database matches - cross-ecosystem install command graph