PDF Viewer vs Universal File Opener CLI
PDF Viewer is a plugin bundle for AI coding tools published by Anthropic. Marketplaces we read that list it: 1 (Claude: knowledge-work-plugins). Universal File Opener CLI is an MCP server published by krauqllc. Marketplaces we read that list it: 1 (Official MCP Registry). As of our marketplace pass on 2026-10-15. 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 |  Universal File Opener CLI | |
|---|---|---|
| Claude: knowledge-work-plugins | Listed Version: 0.2.0 Forks (GitHub): 3 369 Stars (GitHub): 29 771 Not marked · First seen |
Not listed |
| Official MCP Registry | Not listed | Listed Version: 1.10.1-1 Forks (GitHub): 0 Stars (GitHub): 0 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 | PDF Viewer | Universal File Opener CLI |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 29 771 (better) | 0 (worse) |
| Forks (GitHub) (differs) | 3 369 (better) | 0 (worse) |
| Last release (differs) | Not published | 2026-10-15 |
| Where it runs (differs) | On your machine (@modelcontextprotocol/server-pdf) | On your machine (https://github.com/krauqllc/ufo-cli/releases/download/v1.10.1/ufo-cli-1.10.1-linux-x64.mcpb) |
| Transport (differs) | Not stated | stdio |
| Tools it declares | Not published | Not published |
| Environment variables it asks for | Not published | Not published |
| Parts of the bundle (differs) | 6 | Not a bundle |
| Licence | Not stated | Not stated |
| Repository (differs) | github.com/anthropics/knowledge-work-plugins | github.com/krauqllc/ufo-cli |
| Changes in the last 7 days (differs) | 0 | 2 |
| First seen | 2026-10-11 | 2026-10-11 |
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
PDF Viewer
View, annotate, and sign PDFs in a live interactive viewer. Mark up contracts, fill forms with visual feedback, stamp approvals, and place signatures — then download the annotated copy.
Universal File Opener CLI
Inspect files, extract content and make guarded edits locally. Linux x86_64, glibc 2.35+.
How to run each
PDF Viewer As a Claude Code plugin
/plugin marketplace add anthropics/knowledge-work-plugins
/plugin install pdf-viewer@knowledge-work-pluginsUniversal File Opener CLI
No data for an automatic command: what its marketplaces declare does not say unambiguously how to connect it.
Commands 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: PDF Viewer · What it can do: Universal File Opener CLI · 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 Official MCP Registry (registry.modelcontextprotocol.io), CC0 1.0. Figures come from our own regular passes over the marketplaces, last read on . We publish no contact details for plugin publishers.