Effect vs claude-code-harness
Effect is an MCP server published by tim-smart. Marketplaces we read that list it: 1 (Docker MCP Catalog). claude-code-harness is a plugin bundle for AI coding tools published by Yuanhong Yu. Marketplaces we read that list it: 1 (Community GitHub marketplaces). As of our marketplace pass on 2026-10-17. 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 |   Effect | |
|---|---|---|
| Docker MCP Catalog | Listed Version: sha256:a0e077abc890 Forks (GitHub): 13 Pulls (Docker Hub): 12 916 Stars (Docker Hub): 0 Stars (GitHub): 239 Not marked · First seen |
Not listed |
| Community marketplace dadwadw233/claude-code-harness | Not listed | Listed Version: 0.1.0 Forks (GitHub): 1 Stars (GitHub): 12 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 | Effect | claude-code-harness |
|---|---|---|
| Marketplaces that list it | 1 | 1 |
| Stars (GitHub) (differs) | 239 (better) | 12 (worse) |
| Pulls (Docker Hub) (differs) | 12 916 | No figure on Docker Hub |
| Forks (GitHub) (differs) | 13 (better) | 1 (worse) |
| Last release | Not published | Not published |
| Where it runs (differs) | On your machine (mcp/effect-mcp) | Installs as a plugin bundle |
| Transport (differs) | stdio | Not stated |
| Tools it declares (differs) | 2 | Not published |
| Environment variables it asks for | Not published | Not published |
| Parts of the bundle (differs) | Not a bundle | 1 |
| Licence | MIT | MIT |
| Repository (differs) | github.com/tim-smart/effect-mcp | github.com/dadwadw233/claude-code-harness |
| Changes in the last 7 days (differs) | 0 | 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
Effect
Tools and resources for writing Effect code in Typescript.
claude-code-harness
A single-skill package for generating harness blueprints for agentic systems.
How to run each
Effect As a local MCP server: Docker image
claude mcp add --transport stdio effect-mcp -- docker run -i --rm mcp/effect-mcpclaude-code-harness As a Claude Code plugin
/plugin marketplace add dadwadw233/claude-code-harness
/plugin install claude-code-harness@claude-code-harnessCommands built only from what the marketplaces declare; the full set for every client is on each card.
Tools each declares
The marketplaces of claude-code-harness publish no list of tools, so we do not compare tools.
Settings each asks for
Neither one's marketplaces publish the settings it asks for.
What it can do: Effect · What it can do: claude-code-harness · Compare two other plugins
Data comes from the Docker MCP Catalog (desktop.docker.com/mcp/catalog) and Docker Hub. 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.