22120 bets your browsing history becomes your offline internet; HN 537, now paid TDF

22120 is a self-hosted personal web archive: a tool that attaches to Chrome through the DevTools Protocol, caches the pages a user visits while they browse, and replays the archive back from the user's own disk, so browsing history becomes an offline, searchable internet.

That your own browsing history is enough internet: capture pages as you browse, replay them fully offline, then sell that personal library as software.

The author, posting on HN as graderjs, said the idea came to him suddenly while he was doing lots of work in Chrome DevTools: he built it to see if it was possible, and the first version took very little time. He launched the repo c9fe/22120 on 2020-11-11 with a Show HN promising a self-hosted offline internet built from your browsing history, with archives you could organise yourself and version in git.

The launch drew 537 points and 158 comments. Commenters said they wanted it for planes and camping, tested it on a highly interactive site and found it worked, and pressed on the gaps: no Firefox support, no video, audio or websockets, and an archive that needs the browser running to capture. One commenter traced the licence churning MIT to AGPL to a commercial-only licence within weeks of launch. Over the following years the project grew into DownloadNet (dn), and by the 2026-09-05 crawl the repository, now at DO-SAY-GO/tdf with 3.9k stars and 146 forks, announced that dn had grown into TDF: a new client, a new archive format and a new capture architecture.

The project is not gone, it is productized: the README states the repo is no longer an open-source codebase and is the public home of the TDF product line, sold under DOSAYGO Corporation. Tree Grower captures live browsing sessions into .tdf archives as a $39 one-time purchase (three-year licence, up to three devices), Tree Player opens them for free, and the old dn v4.5 is preserved as unsupported legacy.

The wedge was Chrome's own DevTools Protocol: no proxy, no extension, no re-fetching — every response was captured inside the browser's own fetch cycle, which is why even interactive pages replayed.

It answered a felt problem, not a hypothetical one: commenters described flights, camping trips and unstable connections where a self-hosted copy of recent browsing was exactly what they wanted.

The author rode the attention instead of forcing a business model: Patreon-style support and a later paid native product grew out of a tool that first proved people loved it.

The licence churn that a commenter flagged within weeks showed the commercial tension from day one — free love from HN versus the author's stated wish to make some money from it.

A tool that surprises its own author can outgrow its first form: 22120's DevTools trick became DownloadNet and then a paid, closed-source TDF product line without venture money.

As of 2026-09-05 the project lives as TDF 1.0 under DOSAYGO Corporation: trees.dosaygo.com sells Tree Grower at $39 one-time (up to three devices, three-year term, v1.1.3 current) and a free Tree Player for macOS, Windows and Linux, while github.com/DO-SAY-GO/tdf (3.9k stars, 146 forks, 240 commits) documents the lineage from dn v4.5, preserved as unsupported legacy, to the closed-source .tdf format. The material records no revenue or funding figures beyond the $39 licence price.