# CARBON Free

Find real bugs inside your AI coding agent. Built by testers.ai.

Eight commands: `/carbon`, `/carbon-demo`, `/carbon-test`, `/carbon-issues`,
`/carbon-accessibility`, `/carbon-map`, `/carbon-help`, `/carbon-settings`.
Includes all recorded findings, live reports, persona journeys, current-assessment
screenshot maps, scope-qualified confidence and portable HTML/JSON exports.
No account, payment, run quota or finding unlock is required. Your coding-agent
subscription or API usage is separate. Defaults are about 20 minutes/20 checks,
not an application-wide coverage guarantee.

## Install

Requires Node.js 22+. Demo creation also requires Python 3.10+.
For Claude Code, use `claude --plugin-dir /absolute/path/to/carbon` after unzipping.
In Claude Desktop's local Cowork plugin-upload UI, select `carbon-free.zip`; local
runtime and host support are required. Ordinary Claude chat is not a local MCP host.
For Codex, download `carbon-free-codex.zip` and use `.codex-plugin/plugin.json` through your configured local
plugin marketplace. This archive does not register a marketplace automatically.
For other MCP hosts, launch `node /absolute/path/to/carbon/server/index.mjs` and expose
the included `skills/` using that host's documented skill installation mechanism.
Command names/prefixes and embedded-browser support vary by host.

Install only one CARBON edition at a time; Free and Pro intentionally share the
CARBON namespace. Uninstalling a plugin must not delete project `.carbon` evidence.

## Start

This is the Free-only guide. See [COMMANDS.md](command-reference.html) for the eight included
commands and [MCP_SERVER.md](docs-free.html#free-tools) for the six Free runtime tools.
The public guide is https://testers.ai/carbon/docs-free.html.

In a project, ask `/carbon` to assess it. Without a project, use `/carbon-demo`.
CARBON provides investigation instructions and evidence tools; the host agent does
the testing. No fabricated test results are bundled. Open the generated localhost
URL in the host's browser; HTML files remain usable when that live session ends.

## License and Pro

Free is source-available under the unmodified PolyForm Perimeter 1.0.0 license.
Internal commercial use is permitted; providing competing products is restricted.
It is not unrestricted open source. See LICENSE and NOTICE.md.

Pro adds continuous coverage and repair, deeper specialists, advanced test engineering,
confidence investigations and team workflows. Request access at
https://testers.ai/carbon/#pro; Jason reviews your needs before providing access.
No Pro implementation, private benchmarks, feedback server or unlock flag is shipped
in Free. Safety, existing findings and exports are not paywalled.

See PRIVACY.md before using sensitive projects. Analytics is enabled by default;
set CARBON_ANALYTICS=off before startup or disable it in CARBON Settings.