CARBON
Free
MIT open source. Real assessments, focused tests, exploration, accessibility and /full within free capabilities. Every finding stays visible.
Install freeCARBON Test Harness
Keep free capable.
Add Pro when it matters.
More precise investigations and reusable evidence for people who test more than once.
CARBON Pro
$49 / month
Advanced specialist commands, property proofs, test inventory and cross-run quality history.
Choose Pro →Team & Enterprise
Team: $95/developer/month
Minimum 5 developers. Pro capabilities plus email support.
Enterprise: $195/developer/month
Minimum 5 developers. Team plus Zoom support and customizations.
Prices checked October 22, 2026. Stripe confirms current pricing, quantities, taxes and terms before payment. Host model costs are separate.
What changes when you upgrade?
| Outcome | CARBON free | CARBON Pro |
|---|---|---|
| Find bugs and retain evidence | Included | Included |
| Comprehensive /full workflow | Included, free capabilities | Included, Pro capabilities |
| Focused security, privacy, performance and other specialist workflows | Basic risk-based investigation | Dedicated controls and commands |
| Formally verify a suitable code property | Not included | /proof; supported scope and assumptions required |
| Test inventory, cross-run evidence and history | Individual assessment reports | Project-level workflow |
| Jira/Xray and TestRail workflows | Use host tools manually | Dedicated guarded integration flows |
Choose your harness plan.
Loads Stripe’s secure pricing component. Loading or clicking a plan is interest—not a verified purchase.
After purchase
- Use the purchaser email at checkout. Keep your Stripe receipt.
- Use the customer download instructions sent to that email. Pro is a separate package—not an unlock code inside the free npm build.
- Disable the free edition in that host, install Pro and keep your project’s .carbon evidence. Don’t run duplicate CARBON servers.
If the welcome message is missing, check spam, then email Jason with the purchaser email and receipt reference. Never email payment card details.
Does this include CARBON Cloud?
No. These are coding-agent harness plans. CARBON Cloud and Private Cloud are separate services.
Does proof guarantee my whole application works?
No. Formal verification establishes a specific property within an explicit model and assumptions. Jay should report counterexamples, limitations and unsupported scope.
How do I manage billing?
Open the Stripe customer portal using your purchaser email.