# CARBON AI Test Harness

CARBON is the first AI Agentic Verification Harness: a private, local
verification harness for Claude, Codex, Cursor, Antigravity, MCP-compatible
agents, and other coding-agent environments.
It helps the agent inspect risk, design checks, execute through available local
tools and test frameworks, preserve evidence, and report what remains unknown.

## Start here

Run `/carbon`, `$carbon`, or the CARBON command exposed by your host from the
project you want to verify. CARBON keeps durable state under `.carbon/` and
does not treat planned, blocked, or unmeasured work as a pass.

Use `$carbon-help` when you want project-aware recommendations, or
`$carbon-settings` to configure local test credentials, output detail, browser
control, context documents, integrations, and optional model-assisted
screenshot review.

Use `$carbon-human` near a confidence or readiness decision when CARBON needs
the smallest set of answers that code and tests cannot establish: customer
outcome, release context, risk appetite, domain invariants, real-workflow fit,
failure consequences, experience judgment, and accountability. Questions and
answers remain in `.carbon/human/decision-context.json`. Unanswered questions
qualify a confidence result; they never prevent CARBON from reporting the
technical evidence it has.

CARBON Human opens an interactive, protected local workspace beside chat. A
person can choose fast multiple-choice decision starters, add a written answer
or comment to any question, and add a project-level note. Each save refreshes a
durable branded HTML report snapshot and carries the context into later agent
work without sending it to a cloud service.

Use `$carbon-feedback` when a developer needs qualitative feedback on a URL,
image, document, API, code surface, or other artifact. It opens a protected
local feedback workspace where the developer can record a rating, observation,
and context note, then produces a durable report in `.carbon/feedback/`.
External invitations are optional and require the bundled self-hosted
`feedback-service/`; CARBON does not use a public feedback cloud. A rich HTML
email invitation opens the private reviewer page because embedded email forms
are not dependable across modern email clients.

## Why CARBON is a harness

CARBON is a specialized software-testing harness, not a replacement for the
coding-agent runtime. It connects a coding agent's project context to planning,
execution adapters, durable evidence, expert-style evaluation, and readiness
decisions. The host agent writes and operates software; CARBON supplies the
repeatable verification loop around it.

## Why it is agentic

CARBON maps the available artifact and execution context, chooses a bounded
set of decision-relevant checks, adapts to observed evidence, and makes its
unknowns explicit. It can suggest, plan, run, learn, and report, while keeping
approvals and human release authority with people.

## How a command begins

Every CARBON workflow starts in chat with a short `CARBON will:` preview before
inspection, planning, execution, or a tool call. It then opens a protected
project-local live checklist beside the coding agent. The workflow updates that
page honestly as it gathers evidence, asks for an approval, reaches a blocker,
or completes a report.

## Local execution

CARBON can coordinate the frameworks already available to your coding agent,
including Vibium, Playwright, Selenium, Cypress, pytest, JUnit, Gherkin, Robot
Framework, TestRail/Xray imports, manual cases, and mixed-framework projects.
It can help migrate durable test intent between frameworks and languages.

By default, code, prompts, credentials, screenshots, evidence, reports, and
test data stay in the local coding-agent environment. Provider calls made by
your chosen coding agent or an explicitly configured model-review key remain
subject to that provider's configuration and terms.

## Evidence boundary

CARBON distinguishes observed results from planned, inferred, blocked,
`NOT ASSESSED`, and `NOT MEASURED` dimensions. Human release authority remains
explicit. A report is evidence for the measured scope, not a claim that every
possible risk passed.

Human input is not ceremonial sign-off. CARBON asks for it only where a person
can materially improve the oracle or decision: intent, taste, experience,
consequence, domain expertise, risk appetite, and accountability. Models can
contribute to those questions; they do not quietly make the final decision.

See [COMMANDS.md](COMMANDS.md), [MCP_SERVER.md](MCP_SERVER.md), and
[TESTING_GUIDE.md](TESTING_GUIDE.md).

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