Plugin Eval vs IndieML Substance API
Plugin Eval is a plugin bundle for AI coding tools published by OpenAI Codex. Marketplaces we read that list it: 1 (Codex: openai-curated (openai/plugins)). IndieML Substance API is an MCP server published by ezchx. Marketplaces we read that list it: 1 (Official MCP Registry). As of our marketplace pass on 2026-10-13. 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 |  IndieML Substance API | |
|---|---|---|
| Codex: openai-curated (openai/plugins) | Listed Version: 0.1.2 Forks (GitHub): 963 Stars (GitHub): 7 415 Not marked · First seen |
Not listed |
| Official MCP Registry | Not listed | Listed Version: 0.1.14 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 | Plugin Eval | IndieML Substance API |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 7 415 (better) | 0 (worse) |
| Forks (GitHub) (differs) | 963 (better) | 0 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | Installs as a plugin bundle | Remote server (indieml.app/mcp) |
| Transport (differs) | Not stated | Streamable HTTP |
| Tools it declares | Not published | Not published |
| Environment variables it asks for | Not published | Not published |
| Parts of the bundle (differs) | 5 | Not a bundle |
| Licence (differs) | MIT | Not stated |
| Repository (differs) | github.com/openai/plugins | github.com/ezchx/indieml |
| Changes in the last 7 days | 0 | 0 |
| First seen | 2026-10-11 | 2026-10-11 |
| Endpoint at the last check (differs) | no remote endpoint we check | not checked yet |
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
Plugin Eval
Evaluate Codex skills and plugins from chat with a beginner-friendly start command, local-first reports, token budget explanations, and guided benchmarking.
IndieML Substance API
Scores text for substance, depth, and clarity in under 25ms.
How to run each
Plugin Eval As a Codex plugin
codex plugin marketplace add openai/pluginsIndieML Substance API As a remote MCP server
claude mcp add --transport http indieml https://indieml.app/mcp/ --header "X-Api-Key: <YOUR_X_API_KEY>"Requires: X-Api-Key header
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: Plugin Eval · What it can do: IndieML Substance API · Compare two other plugins
Data comes from the public marketplace file https://github.com/openai/plugins/blob/HEAD/.agents/plugins/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.