ai-second-brain vs open-second-brain
ai-second-brain is a plugin bundle for AI coding tools published by fuuuuuuma. Marketplaces we read that list it: 1 (Community GitHub marketplaces). open-second-brain is a plugin bundle for AI coding tools published by Open Second Brain contributors. Marketplaces we read that list it: 1 (Community GitHub marketplaces). As of our marketplace pass on 2026-10-24. This pair was picked by a reader, not by our comparison rule, so search engines are asked not to index the page.
Where each is published
| Marketplace | ||
|---|---|---|
| Community marketplace fuuuuuuma/ai-second-brain-kit | Listed Version: 1.1.0 Forks (GitHub): 14 Stars (GitHub): 41 Not marked · First seen |
Not listed |
| Community marketplace itechmeat/open-second-brain | Not listed | Listed Version: 1.93.0 Forks (GitHub): 63 Stars (GitHub): 493 Not marked · First seen |
Each figure is the marketplace's own and is never added up across marketplaces. A marketplace that publishes no figure shows none: no number is not zero.
The facts side by side
| Fact | ai-second-brain | open-second-brain |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 41 (worse) | 493 (better) |
| Forks (GitHub) (differs) | 14 (worse) | 63 (better) |
| Last release (differs) | Not published | 2026-10-23 |
| Where it runs | Installs as a plugin bundle | Installs as a plugin bundle |
| Transport | Not stated | Not stated |
| Tools it declares | Not published | Not published |
| Environment variables it asks for | Not published | Not published |
| Hooks it runs (differs) | Not published | 26 |
| Parts of the bundle (differs) | 3 | 17 |
| Licence | MIT | MIT |
| Repository (differs) | github.com/fuuuuuuma/ai-second-brain-kit | github.com/itechmeat/open-second-brain |
| Changes in the last 7 days (differs) | 2 | 4 |
| First seen (differs) | 2026-10-19 | 2026-10-22 |
Lines where the two differ have a tinted background and bold values. Where the data itself says which value is better (more marketplaces, a larger figure of the same marketplace, a fresher release, a verified mark on a marketplace that lists both), the better one is also marked green with ▲ and the worse one red with ▼. Where it runs, the transport, the tools, the settings, hooks, the bundle's parts, the licence and the week's changes are marked only as different: more or fewer is not better in itself.
What each says it does
ai-second-brain
AIが記憶喪失しない第二の脳(Obsidian Vault)を自動構築する Agent Skills。second-brain / obsidian-flavored-markdown / web-clip を同梱。
open-second-brain
Plugin-first second brain for AI agents and humans (Obsidian-compatible Markdown vaults).
How to run each
ai-second-brain As a Claude Code plugin
/plugin marketplace add fuuuuuuma/ai-second-brain-kit
/plugin install ai-second-brain@ai-second-brain-kitopen-second-brain As a Claude Code plugin
/plugin marketplace add itechmeat/open-second-brain
/plugin install open-second-brain@open-second-brainCommands built only from what the marketplaces declare; the full set for every client is on each card.
Tools each declares
Neither one's marketplaces publish a list of tools, so there is nothing to compare.
Settings each asks for
Neither one's marketplaces publish the settings it asks for.
What it can do: ai-second-brain · What it can do: open-second-brain · Compare two other plugins
Data comes from public marketplace files in GitHub repositories of their authors. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.