CUBE

CUBE = Chrome URL Blocking Extension.

A modern, privacy-first request blocker built on Manifest V3 + Chrome’s declarativeNetRequest engine.

What you get

• Privacy-first defaults: block rules enabled; optional compatibility allow rules are off until you opt in.
• Fast & local: blocking happens in Chrome’s native DNR engine (no proxy, no remote service).
• Modern UX: “Fix This Site” flows (temporary tab/site bypass), per-domain allow/block, and a “Recent Activity” view.
• Transparent diagnostics: optional local match logging via onRuleMatchedDebug (unpacked/dev only).

Install (unpacked / dev)

1. Open chrome://extensions
2. Enable Developer mode
3. Click Load unpacked
4. Select this repo folder

How blocking works

CUBE ships static rulesets (generated from filter lists) and also supports dynamic rules you add from the popup:

• Static rulesets (packaged, versioned):
  • rules.json, rules.2.json, rules.3.json, rules.4.json (block shards)
  • rules.exceptions.json (optional compatibility exceptions; disabled by default)
  • rules.allowlist.json (optional support-widget allowlist; disabled by default)
• Dynamic/session rules (runtime):
  • per-domain allow/block
  • scoped allows
  • temporary bypass (tab / site) to quickly make a site work

Regenerate rulesets

Rules are generated from Adblock Plus (ABP)-style filter lists using Go:

go run ./tools/rulegen

Useful flags:

• -blocks-shards 4 writes rules.json, rules.2.json, …
• -max-rules 30000 caps each ruleset
• -source name=url adds/replaces sources (repeatable)
• -exceptions none|scoped|all controls @@ exception emission into rules.exceptions.json
• -builtin-allowlist=false disables the small support-widget allowlist ruleset
• -allow-domain example.com adds domains to the generated allowlist ruleset (repeatable)

Regenerate icons

The icon set is generated (deterministically) from Go:

go run ./tools/icongen -outdir icons

Outputs:

• icons/icon16.png
• icons/icon32.png
• icons/icon48.png
• icons/icon128.png

Diagnostics note

Diagnostics logging uses declarativeNetRequest.onRuleMatchedDebug. Per Chrome’s permission model, this is intended for debugging/unpacked extensions; CUBE keeps diagnostics off by default and stores matches locally.

License

MIT — see LICENSE.