Test what matters.
Prioritize high-risk changes and explore real user flows. Look beyond happy paths to find where the experience breaks.
Risk analysis · Exploratory testingCARBON AGENT · CORE
Meet Jay.
Your AI test manager agent.
An AI test harness that lives in your coding agent. Jay coordinates 12 free testing commands—from risk-based checks and exploratory testing to accessibility investigations, reproducible findings and evidence-backed confidence.
Works alongside your existing test frameworks and your coding agent’s tools. Free and open source.
Install Core free →Explore the 12 commands ↓JAY + YOUR CODING AGENT
Your testing, coordinated.
MITfree & open source
Supported
CARBON can use any connection established in your AI coding agent context.
Clients & protocol
Claude
ChatGPTCodex
Cursor
MCP
ClaudeChatGPTCodexCursorMCPFrameworks & tools
Selenium
Playwright
pytest
AppiumVibium
SeleniumPlaywrightpytestAppiumVibiumLanguages
Java
Python
TypeScript
JavaScript
C#
JavaPythonTypeScriptJavaScriptC#Issues
Jira
GitHub Issues
GitLab Issues
JiraGitHub IssuesGitLab IssuesTest management
TestRailXray
TestRailXrayBrowsers & platforms
Chrome
Firefox
Safari
iOS
Android
ChromeFirefoxSafariiOSAndroidDevice & cloud testingBrowserStack
Sauce Labs
Sauce LabsONE PLUGIN. YOUR EXISTING WORKFLOW.
Choose your agent.
Install CARBON. Open your project. Give Jay one thing to test.
Step 1Add to your agent
- Open
/pluginand choose Discover. - Search CARBON. Check that the publisher is testers.ai, then install.
- Start a fresh session and choose
/carbon:carbon.
In Claude Cowork, use the plugin directory. Your organization may restrict plugins.
Installation help →Step 1Add to your agent
Open the listing, verify the testers.ai publisher, and install in your supported local Codex environment. Start a fresh session and choose CARBON in the skill picker.
Open CARBON in the marketplace ↗The local plugin needs your coding agent’s tools. Ordinary ChatGPT web chat is not the local Codex runtime.
Step 1Add to your agent
Add CARBON as a local MCP server in Cursor using this configuration, then reconnect and check that its tools are available.
{
"mcpServers": {
"carbon": {
"command": "npx",
"args": [
"-y",
"@testers-ai/carbon-mcp"
]
}
}
}Requires Node.js 22+. This runs a local stdio server, not a hosted URL. Some Windows hosts need npx.cmd. Merge the CARBON entry into your existing config; don’t replace other servers.
Once connected, ask your agent to use CARBON to test your project. MCP does not automatically add the native plugin’s slash commands.
Package & setup details ↗Step 1Add to your agent
- In Antigravity IDE, open … → MCP Servers → Manage MCP Servers → View raw config.
- Merge the configuration below into
mcp_config.jsonand save. - Refresh the MCP servers and check that CARBON connects before asking it to test.
{
"mcpServers": {
"carbon": {
"command": "npx",
"args": [
"-y",
"@testers-ai/carbon-mcp"
]
}
}
}Requires Node.js 22+. This runs a local stdio server, not a hosted URL. Some Windows hosts need npx.cmd. Merge the CARBON entry into your existing config; don’t replace other servers.
Once connected, ask your agent to use CARBON to test your project. MCP does not automatically add the native plugin’s slash commands.
Official Antigravity MCP setup ↗Step 1Add to your agent
Use any MCP host that supports local stdio servers. Server name: carbon; command: npx; arguments: -y @testers-ai/carbon-mcp.
Paste the JSON below if your host uses an mcpServers configuration. Otherwise enter the command and arguments in its MCP settings. Save, reconnect and check the available tools.
{
"mcpServers": {
"carbon": {
"command": "npx",
"args": [
"-y",
"@testers-ai/carbon-mcp"
]
}
}
}Requires Node.js 22+. This runs a local stdio server, not a hosted URL. Some Windows hosts need npx.cmd. Merge the CARBON entry into your existing config; don’t replace other servers.
Once connected, ask your agent to use CARBON to test your project. MCP does not automatically add the native plugin’s slash commands.
CARBON MCP package ↗More than “the tests passed.”
Test the change. Explore the experience. See what remains uncertain—without replacing your existing framework.
Find it. Reproduce it.
Keep the steps and evidence behind verified bugs. Get regression-test proposals to help stop the same failure returning.
Reproducible findings · Regression testsSee the evidence.
Inspect readable reports with findings, supporting evidence and coverage gaps. Know what was checked—and what wasn’t.
Rendered reports · Coverage gapsGo further with /full.
Run the comprehensive testing workflow across your project. Included free, within your edition’s capabilities and your agent’s permissions.
Comprehensive workflow · Included freeFAQ
Is the useful version really free?
Yes. The core CARBON harness is MIT-licensed and open source, including the comprehensive /full workflow within its included capabilities. Pro adds specialist controls and advanced workflows. Your coding agent’s subscription and model usage are separate.
Does it replace my test framework?
No. Jay works through the tools available to your coding agent. Keep Playwright, Selenium, Cypress, pytest, JUnit or your current runner. Tests still need the right dependencies and access; a generated test is not a passed test.
Does it test everything automatically?
No. Scope, edition, host permissions and budgets matter. MCP and public Codex-directory builds run on explicit requests. Native builds with supported hooks offer a saved testing-mode choice. Review settings before enabling automatic checks.
Where does my code go?
CARBON runs through your coding agent’s environment and tools. Your host’s model and data-handling policies still apply. Reports are local; review exports before sharing. Optional usage analytics and milestone measurement are separate settings. Never publish a protected report URL.
What do I need installed?
A supported local coding-agent environment and Node.js 22 or newer. Demo and full-workflow helpers also need Python 3.10 or newer. Your host supplies model access, terminal tools and browser capabilities; CARBON does not supply cloud VMs.
READY FOR MORE?
Pro starts at $49/month.
Specialist controls. Lean property proofs. Reusable test history.
CARBON AGENT · PRO
Meet Jay.
Your AI test manager agent.
An AI test harness that lives in your coding agent. Jay coordinates 60 testing commands—from risk analysis and specialist testing to Lean-backed proofs, reusable test history and evidence-backed confidence.
Works alongside your existing test frameworks, bug trackers, and test case management systems.
Choose Pro · $49/month →Explore the workflows ↓PICK YOUR HARNESS PLAN
More depth. A straightforward price.
Pro
$49
per month
For an individual building with AI.
- 60 testing commands
- Specialist investigations and risk analysis
- Lean property proofs
- Test inventory and cross-run history
Team
$95
per developer / month · minimum 5
For teams sharing a quality practice.
- Everything in Pro
- Email support
- Minimum $475/month
Enterprise
Contact us
Custom pricing for your organization
Private cloud and customizations.
- Everything in Team
- CARBON Cloud deployed in your private cloud
- AI agents executing in parallel at scale
- Speed up web regression runs
- Customizations and Zoom support
- AI QA experts can set everything up, run everything for you, or both
Pro and Team reference prices checked against the published harness pricing on October 28, 2026. Stripe confirms current price, quantities, taxes and subscription terms before payment. Enterprise is quoted directly—contact us to scope your private-cloud deployment, parallel capacity and customizations. No purchase occurs when you switch editions or load plans.
Continue securely with Stripe.
Select a plan below. Need help choosing? Talk to Jason →
Stripe loads only when you ask to see checkout plans.
If plans don’t appear, open the dedicated pricing page. After purchase, you’ll receive a link to install the CARBON Pro plugin. Keep your Stripe receipt. If the link doesn’t arrive or you need help, contact Jason on LinkedIn.
SEE THE WORKFLOW, NOT JUST THE COMMAND
A minute or two. A much clearer picture.
Explore CARBON’s testing workflows. Availability depends on your edition and host. These are illustrative workflows, not recordings of completed tests.
Meet CARBON
Meet Jay and the CARBON framework
Native 4K source files · English captions · No autoplay. Playback begins when you press play.
About CARBON Pro.
What is included in Pro?
60 testing commands, specialist investigations, Lean-backed property proofs, reusable test history and evidence-backed reports. Run them inside your supported AI coding agent.
How do I install Pro after purchase?
After purchase, you receive a link to install the CARBON Pro plugin. Follow the instructions for your coding agent, open your project and run /carbon. If you need help, contact Jason on LinkedIn.
Are AI model tokens included?
No. Pro is a harness license. It uses the model access configured in your coding agent or API account; your provider’s limits and usage charges apply separately.
Does Pro work with my existing tests?
Keep your existing framework, bug tracker and test management system. CARBON works through your agent’s authorized tools and configured integrations. Required dependencies and account access still apply.
Does Pro prove my entire app is correct?
No. Lean checks specific properties of a model under stated assumptions. Reports identify the selected source, verified claims, counterexamples and untested scope. A proof is not whole-app certification.
Where does my code go?
Pro runs through your coding agent’s environment. Your host may send authorized code and evidence to its model provider under that provider’s policies. Reports are local; review exports before sharing.
Does Pro include a private cloud?
No. Enterprise includes CARBON Cloud deployed in your private cloud, parallel web testing and customizations. Contact us to agree deployment scope, infrastructure and model usage.
Help improve this page? Optional Fathom measurement
If you allow it, Fathom measures the page version and fixed-name actions such as clicks and copied test requests. We remember your page version for up to 30 days, without creating a visitor ID. No email, code or report content is included in event names. Clicks are not verified installs or sign-ups. Your choice won’t affect installation. Details
Measurement off.
OPTIONAL. NEVER REQUIRED TO INSTALL.
Keep up with CARBON.
Get occasional workflow tips and release updates from Jason. This optional newsletter is separate from your plugin license.
Your name, email and permission are saved in Testers.ai’s private Google Sheet and emailed to Jason. Signup works with analytics off. No automatic welcome email. Privacy details
THE CARBON PLATFORM
