# Installation

> Install Supercov for your language and run your first measurement.

Web page: https://supercov.com/docs/installation
All Supercov pages for agents: https://supercov.com/llms.txt · Full text: https://supercov.com/llms-full.txt

Your coding agent can install Supercov for you. If you'd like to set it up
yourself, choose your language above and follow these steps in your project.

For setup, runner support and a runnable example in one place, use the
[JavaScript / TypeScript](https://supercov.com/docs/javascript.md), [Python](https://supercov.com/docs/python.md),
[Ruby](https://supercov.com/docs/ruby.md), [Rust](https://supercov.com/docs/rust.md), [Go](https://supercov.com/docs/go.md), [Java](https://supercov.com/docs/java.md) or
[Kotlin](https://supercov.com/docs/kotlin.md) guide.

## Before you start

Node.js 22 or newer is required for the npm package. Your project's test
dependencies and any services used by the suite must already be available.

The native CLI supports macOS, Linux and Windows on arm64 and x64. See
[Runner support](https://supercov.com/docs/supported-suites.md) for environment-specific limits.

## Get Supercov

The npm package runs on demand with npx; a global installation isn't needed. This command downloads Supercov if necessary and prints its version:

```sh
npx supercov --version
```

npx uses the npm registry. The package provides a prebuilt native CLI; it doesn't compile Supercov on install.

No account or Supercov configuration file is required.

## Run your tests

From the project root, put Supercov before your normal test command:

```sh
npx supercov -- npm test
```

Everything after `--` is your existing test command. Use the command you
normally run for the full suite, including its usual flags.
Supercov measures that run; it doesn't add tests by itself.

Read the result:

```sh
npx supercov runs latest
```

You'll see line, branch and MC/DC coverage where measurement is supported.
For [assertion coverage](https://supercov.com/docs/assertions.md), run `npx supercov runs latest assertions assess`;
Jev judges, test by test, which executed statements a change could break unnoticed.

Run `npx supercov report` to open an [interactive HTML report](https://supercov.com/docs/reports.md)
from the saved run. [Security checks](https://supercov.com/docs/security.md) and code quality assessments
use Jev and need an API key; coverage and the report itself do not.

## Continue with your agent

Use the prompt in [Getting started](https://supercov.com/docs/getting-started.md) to add one missing
test, or ask the agent to inspect the run you've just made. Reports stay local
in `.supercov/`; see [Files and privacy](https://supercov.com/docs/workspace-isolation.md) for details.

If installation or the test command fails, start with [Troubleshooting](https://supercov.com/docs/troubleshooting.md).