Dev Tools & GitMCP RegistrynpmB · 75

DiffCI MCP server

Name: DiffCI
Author: DiffCI

io.github.DiffCI · Updated today

Fail-closed, change-aware verification for AI coding agents with affected-test guidance.

At a glance

DiffCI is an MCP server in the Dev Tools & Git category. It runs locally over stdio via `npx -y @diffci.com/diffci`, and declares no required credentials. It scores B (75/100) on the MCP Skills Hub health score as of Oct 28, 2026.

Source 0

One-click install

VS Code VS Code Insiders Cursor

Opens your editor and pre-fills the config. Your editor will ask before adding it.

How to install DiffCI in your AI client

Setup for Claude Code, Claude Desktop, Cursor, Codex, Windsurf, Cline and VS Code — copy-paste ready.

How to install DiffCI in Claude CodeAnthropic's agentic CLI

Add the server

bash

claude mcp add diffci -- npx -y @diffci.com/diffci

2
Verify it's connected
bash
```
claude mcp list
```
Sharing it with your team?
Add `--scope project` to write it to .mcp.json in the repository root, which you can commit (with the secrets left as environment variables).
Use it in a session
Ask Claude to use the tools this server exposes. It discovers them automatically.

How to install DiffCI in Claude DesktopDesktop app (MCP config)

Open your MCP config
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

Add this server

json

{
  "mcpServers": {
    "diffci": {
      "command": "npx",
      "args": [
        "-y",
        "@diffci.com/diffci"
      ]
    }
  }
}

Restart Claude Desktop
The tools appear under the 🔌 menu once the app reloads.

How to install DiffCI in CursorAI-first code editor

Create / edit .cursor/mcp.json in your project

json

{
  "mcpServers": {
    "diffci": {
      "command": "npx",
      "args": [
        "-y",
        "@diffci.com/diffci"
      ]
    }
  }
}

Enable it
Cursor Settings → MCP → toggle the server on. Tools become available to the Composer/Agent.

How to install DiffCI in Codex CLIOpenAI coding agent

Add to ~/.codex/config.toml

toml

[mcp_servers.diffci]
command = "npx"
args = ["-y", "@diffci.com/diffci"]

Run Codex
Codex loads MCP servers from config.toml on startup and exposes their tools to the agent.

How to install DiffCI in WindsurfCodeium's agentic IDE

Edit ~/.codeium/windsurf/mcp_config.json

json

{
  "mcpServers": {
    "diffci": {
      "command": "npx",
      "args": [
        "-y",
        "@diffci.com/diffci"
      ]
    }
  }
}

Reload
Windsurf → Cascade → refresh MCP servers. Cascade can now call the tools.

How to install DiffCI in ClineVS Code autonomous agent

Open Cline → MCP Servers → Configure
Adds to cline_mcp_settings.json.

Add the server

json

{
  "mcpServers": {
    "diffci": {
      "command": "npx",
      "args": [
        "-y",
        "@diffci.com/diffci"
      ]
    }
  }
}

How to install DiffCI in VS CodeCopilot / MCP support

Create .vscode/mcp.json

json

{
  "servers": {
    "diffci": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@diffci.com/diffci"
      ]
    }
  }
}

Start it
VS Code shows a ▶ Start action above the server entry. Agent mode (Copilot Chat) can then use the tools.

What tools does DiffCI expose?

This server runs as a local package. We only query remote servers for their tool list — asking this one would mean executing it, so its tools are listed in the documentation below.

What the code can do

Read from the published package source — never executed. Parsed 30 of 30 source files.

This server can run other programs on your machine, read and write files and read your environment variables.

How it was published

Published by a verified CI identity (github trusted publishing) rather than a personal token.
Has a provenance attestation tying this artifact to the commit it was built from.
1 npm maintainer — a single point of compromise · last published by GitHub Actions.

Maintainer of this package and think something here is wrong? Tell us and we'll correct it.

Before you install

Signals gathered from the source repo and package registry — not a safety verdict.

What it can reach

Runs code on your machine — Executes as a local process with your user's permissions, including filesystem access.
Downloads at launch — The package is fetched from its registry each run unless you pin a version.

Last commit today — Actively maintained.
Repository created 1 month ago — Very new project with little track record yet.
0 GitHub stars — Very little community usage so far.

Client compatibility

Claude Code: NativeClaude Desktop: NativeCursor: NativeCodex CLI: NativeWindsurf: NativeCline: NativeVS Code: Native

Health score

B · 75

Maintenance, adoption, transparency and packaging — not a safety audit. How this is calculated

Maintenance30%100%
Last commit 0 days ago.
Adoption20%0%
0 stars.
Transparency20%75%
3/4: ✓ public source repo, ✓ declared license, ✓ documentation, ✗ discoverable tool list.
Provenance15%100%
Package and registry entry point at the same repository.
Packaging15%100%
Publishes a pinned version (0.3.16).

Documentation

Full README

DiffCI Core

Open-source test-impact analysis for faster CI. For developers and maintainers evaluating which tests a change affects, with conservative full-run fallbacks. Licensed under the MIT License.

Coding-agent plugins

The public `integrations/agent-plugin` package makes the published DiffCI CLI available as a checkout-aware local MCP plugin. It contains only public marketplace metadata, skills, and a pinned npm launcher; it does not include product services or private source. The cross-agent installation guide covers Codex, Claude Code, Cursor, Grok, Meta Muse Code, and generic MCP hosts.

# Codex
codex plugin marketplace add DiffCI/core
codex plugin add diffci@diffci-local

# Claude Code
claude plugin marketplace add DiffCI/core
claude plugin install diffci@diffci-marketplace

Cursor Marketplace reads `.cursor-plugin/marketplace.json` from this repository. Meta Muse Code reads the native root `marketplace.json`. Before a public listing is approved, use the local MCP configuration in the agent-plugin package or visit https://diffci.com/mcp-server.

GitHub Action

The public `action.yml` is an observation-only GitHub Action wrapper. It runs the pinned published DiffCI CLI outside the observed checkout, retains existing CI jobs, and uploads an advisory report. See the observer Action guide and workflow example.

The v0.3.10 corresponding source remains publicly available at tagged Core commit 4c76be14 (cli-v0.3.10-source) while distribution migrates to the Core-native CLI package.

Try the published CLI in an existing Git checkout with Git and Node.js 22.5+:

npx "@diffci.com/diffci@latest" check

It compares full and selected runtime when safe to measure, writes reports outside the checkout, and sends nothing by default. Test commands can generate files; keep required CI authoritative.

Measured example: one controlled Cal.com sandbox replay measured 44.2% net reduction in install + pretest + test runtime including analysis overhead. This is a job-equivalent comparison, not production savings or a forecast for your repository. Method and limitations.

Star Core · Volunteer a pilot repository · Find a first contribution. Watch → Custom → Releases and Discussions for benchmark results and support updates. Public roadmap.

Excerpt — the full document is on GitHub.

Alternatives to DiffCI

Maintain DiffCI? Add a badge to your README

Shows its health grade, and links readers to install steps for every client.

markdown

[![DiffCI on MCP Skills Hub](https://mcp-skills-hub.vercel.app/badge/io-github-diffci-diffci)](https://mcp-skills-hub.vercel.app/mcps/io-github-diffci-diffci)

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