Browser Extension

The SpaceRouter Onion browser extension provides a one-click interface for controlling the SpaceRouter Onion SOCKS5 proxy. It connects to the proxy's HTTP API, starts and stops circuits, displays the active relay path with country flags and IP addresses, and manages preferences such as hop count and node selection mode. The proxy must be running and reachable before the extension can do anything; see Prerequisites.

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Installation

Install from the SpaceRouter Onion Proxy page on the Chrome Web Store. Click "Add to Chrome". The extension works in Chrome, Edge, Brave, Arc, and other Chromium-based browsers.

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Prerequisites

The extension controls a running proxy instance. The proxy must be running and its HTTP API must be reachable (default: http://127.0.0.1:2080). Install the proxy through the SpaceRouter Onion App.

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Main view

The main view is the first screen you see when you open the extension popup. It contains a start/stop button, a status indicator showing whether the proxy is connected, a circuit visualization displaying the guard, middle, and exit nodes (each with a country flag and IP address), and a selection mode dropdown.

When you click Start, the extension:

1. Sends POST /api/start to the proxy.

2. Sets the browser's proxy to SOCKS5 on 127.0.0.1:<port> (default 1080).

3. On Chrome, disables non-proxied UDP to prevent WebRTC leaks.

4. Fetches the active circuit from GET /api/status and displays it.

When you click Stop, the extension:

1. Sends POST /api/stop to the proxy.

2. Clears the browser's proxy settings.

3. Restores default WebRTC behavior (Chrome only).

Selection modes

Mode	Behavior
Random (default)	Nodes chosen at random from the network
Fast	Prefers geographically nearby nodes as a proxy for lower latency
Privacy	Maximises geographic diversity across hops

You can change the selection mode from the dropdown on the main view or from the configuration view.

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Configuration view

Open the configuration view by clicking the gear icon. All settings are listed below.

Setting	Default	Description
Network	(from discovery)	Network to connect to
Proxy API URL	http://127.0.0.1:2080	Address of the proxy's HTTP API
SOCKS5 port	1080	Port the proxy listens on for SOCKS5 connections
Hops	3	Number of relay hops per circuit (1 to 5)
Selection mode	Random	How nodes are selected for circuits

Changes to network, hops, or selection mode require the proxy to be stopped first. The extension stops the proxy automatically, applies changes via POST /api/preferences, then restarts it.

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Nodes view

The nodes view lists every node in the selected network. Open it from the navigation bar.

Column	Description
Country	Geographic location (flag icon)
IP	Node IP address
TCP	TCP listen port
QUIC	QUIC listen port
Exit	Whether the node accepts exit traffic
Public key	Truncated Ed25519 identity key fingerprint

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Background behavior

The extension runs a background service worker that polls GET /api/status every 30 seconds. If the proxy stops unexpectedly while the browser's SOCKS5 proxy settings are still active, the service worker clears those settings and shows a notification badge on the extension icon. If the proxy is running, the service worker keeps the browser proxy settings pointed at the configured SOCKS5 port.

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API endpoints

The extension communicates with the proxy binary through these HTTP endpoints:

Method	Endpoint	Description
GET	/api/status	Proxy state and active circuit
POST	/api/start	Build circuit and start SOCKS5
POST	/api/stop	Tear down circuit and stop SOCKS5
GET	/api/preferences	Current preferences and available networks
POST	/api/preferences	Update preferences (proxy must be stopped)
GET	/api/nodes	Node list for the selected network

The proxy exposes additional endpoints for advanced tooling (POST /api/guard to pin a specific guard node, POST /api/guard/rotate to re-select guard/middle/exit). The extension does not use these; node selection is driven entirely through the selectionMode preference.

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Appendix: browser compatibility

Browser	SOCKS5 proxy	WebRTC protection	Notes
Chrome	Yes (chrome.proxy API)	Yes (disables non-proxied UDP)	Primary target
Edge	Yes (chrome.proxy API)	Yes	Same as Chrome