perch

perchscan.com</a> &nbsp;&middot;&nbsp;
  <a href="https://docs.perchscan.com">docs</a> &nbsp;&middot;&nbsp;
  <a href=".benchmarks">benchmarks</a> &nbsp;&middot;&nbsp;
  <a href="https://discord.gg/znTcuKRK">Discord</a>
</p>

Semantic code and security scanner.

<picture>
  <source media="(prefers-color-scheme: dark)" srcset=".github/greptile-dark.svg">
  <img alt="Known bugs caught on the Greptile benchmark and the cost of a pull request: Greptile 82% at about $1, perch on OpenAI Decisions 76% at $0.007, Cursor Bugbot 58% at about $1.50, GitHub Copilot 54%, CodeRabbit 44% at $1–3, perch on Jev 44% at $0.003, Graphite 6% at about $2" src=".github/greptile-light.svg" width="880">
</picture>

## Getting started

```sh
npm install -g @lakeday/perch
perch login
perch scan
```

`perch login` signs you in to [Perch Cloud](https://perchscan.com), where the first $5 is free. Since decisions are cached,
running perch again on unchanged code is free. Perch Cloud also scans pull requests in CI, without writing
any workflows.

```console
$ perch scan
checkout.py
  ID        Line  Severity  Type    Confidence  Problem                     Method
  bdc67421    14  P1 (0.8)  defect         81%  wrong_order                 place_order
  ddc5c917    24  P1 (0.8)  defect         92%  inverted_condition          can_fulfil

cart.py
  ID        Line  Severity  Type    Confidence  Problem             Method
  287bfb9d     9  P1 (1.0)  defect         90%  off_by_one          subtotal
  80d6ebbb    29  P1 (1.4)  defect         89%  unhandled_null      cheapest

✖ 20 problems in 5 files, all failing
```

Run `perch issues` to see them worst first, and `perch issues <id>` to view one.

`perch check <id>` asks again after you think you've fixed it. It doesn't record anything.

## Agent skills

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