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CARBON MCP Server

local only

CARBON runs on your own machine — the client starts it, so there is no endpoint to ping. 211 installs a week from npm. Last commit 11 Oct 2026.

AI testing harness with Jay: risk-based checks, bug investigation, and local evidence reports.

Installs per day peak 211 · avg 7
a month agotoday
211
Installs / week
npm · @testers-ai/carbon-mcp
2
Stars
0 open issues
11 Oct 2026
Last commit
from GitHub
MIT
License
JavaScript

What the code does

We read the source, 1 d ago · rules 995398eba69f

Capabilities

What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.

File ships in the package but is absent from the source [пакет] ui/forever.html:1, [пакет] bin/carbon-mcp.mjs:1, [пакет] background/onboarding.mjs:1 и ещё 2
этот файл ставится пользователю, но в репозитории его нет
…m</option><option value="large">Large (+$0.75)</option></select></div><div class="field"><label for="milk">Milk</label><select id="milk"><option value="regular">Regular</option><option value="oat">Oat (+$0.75)</option><option value="almond">Almond (+$0.75)</option></select></div>…
  const dir=path.join(home,'.config/carbon/usage',product.edition), config=path.join(home,'.config/carbon/config.json');

Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.

This code can reach further than it looks

We found places where it runs commands, builds paths or queries from values it is given. None of that is a flaw by itself — it becomes one when the code changes, and code changes quietly between releases. We re-read it on every one.

Three servers free · no card

Connect this server

This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.

run in your terminal
claude mcp add carbon -- npx -y @testers-ai/carbon-mcp
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "carbon": {
      "command": "npx",
      "args": [
        "-y",
        "@testers-ai/carbon-mcp"
      ]
    }
  }
}
~/.codex/config.toml
[mcp_servers.carbon]
command = "npx"
args = ["-y", "@testers-ai/carbon-mcp"]
.cursor/mcp.json
{
  "mcpServers": {
    "carbon": {
      "command": "npx",
      "args": [
        "-y",
        "@testers-ai/carbon-mcp"
      ]
    }
  }
}
.vscode/mcp.json
{
  "servers": {
    "carbon": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@testers-ai/carbon-mcp"
      ]
    }
  }
}

Optional settings from the registry entry, left out of the block above: CARBON_ANALYTICS (Optional content-free analytics. Off by default; set off to force-disable), DO_NOT_TRACK (Set 1 to disable analytics regardless of preferences).

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CARBON — questions

Answers built from our own checks of this server.

Why is there no uptime for CARBON?
CARBON runs on your own machine over stdio — there is no network address to reach, so uptime cannot be measured for it by anyone. What can be measured is adoption: the npm package @testers-ai/carbon-mcp was installed 211 times last week.
How do I connect CARBON?
Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It runs locally, so the command pulls @testers-ai/carbon-mcp straight from npm; nothing to host, nothing to sign up for.
How many people use CARBON?
The npm package @testers-ai/carbon-mcp was installed 211 times in the last week. We show installs rather than GitHub stars on purpose: a star is a bookmark, an install is someone actually running it.
Is CARBON open source?
Yes — it is published under the MIT licence, written in JavaScript and 2 stars on GitHub. The source link is on this page, so you can read exactly what it does with your data before you connect it.