B12 vs plugin-builder
B12 is a plugin bundle for AI coding tools published by b12io. Marketplaces we read that list it: 3 (Claude: knowledge-work-plugins, Claude Code: claude-plugins-community, Community GitHub marketplaces). plugin-builder is a plugin bundle for AI coding tools published by Daniel Kovacs. Marketplaces we read that list it: 1 (Community GitHub marketplaces). As of our marketplace pass on 2026-10-18. 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 |  B12 | |
|---|---|---|
| Claude: knowledge-work-plugins | Listed Version: 1.0.0 Forks (GitHub): 0 Stars (GitHub): 10 Not marked · First seen |
Not listed |
| Claude Code: claude-plugins-community | Listed Version: 1.0.0 Forks (GitHub): 0 Stars (GitHub): 10 Not marked · First seen |
Not listed |
| Community marketplace claude-market/marketplace | Not listed | Listed Version: 1.3.2 Forks (GitHub): 31 Stars (GitHub): 26 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 | B12 | plugin-builder |
|---|---|---|
| Marketplaces that list it (differs) | 3 (better) | 1 (worse) |
| Stars (GitHub) (differs) | 10 (worse) | 26 (better) |
| Forks (GitHub) (differs) | 0 (worse) | 31 (better) |
| Last release (differs) | 2026-10-16 | Not published |
| 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 |
| Parts of the bundle (differs) | 2 | 5 |
| Licence (differs) | Apache-2.0 | MIT |
| Repository (differs) | github.com/b12io/b12-claude-plugin | github.com/claude-market/marketplace |
| Changes in the last 7 days (differs) | 3 | 2 |
| First seen (differs) | 2026-10-11 | 2026-10-15 |
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
B12
B12 plugin with two skills: Website Generator (create a B12 website from a brief description) and B12 Website Editor (edit a live B12 website using Claude's browser access in Claude Cowork).
plugin-builder
Interactive plugin builder for Claude Code - serves as both an example plugin and a tool to create new plugins through guided prompts with specialized builder skills for each component type
How to run each
B12 As a Claude Code plugin
/plugin marketplace add anthropics/knowledge-work-plugins
/plugin install b12-claude-plugin@knowledge-work-pluginsplugin-builder As a Claude Code plugin
/plugin marketplace add claude-market/marketplace
/plugin install plugin-builder@claude-marketCommands 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: B12 · What it can do: plugin-builder · Compare two other plugins
Data comes from the public marketplace file https://github.com/anthropics/knowledge-work-plugins/blob/HEAD/.claude-plugin/marketplace.json. Data comes from the public marketplace file https://github.com/anthropics/claude-plugins-community/blob/HEAD/.claude-plugin/marketplace.json. 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.