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perch skillA

perch is agent-read markdown (skill) from lakeday-org/perch: Semantic linting with perch. Use it to verify code changes in flight. Scan a branch or a diff. Check one method right after editing it. Confirm a fix landed before opening a pull request. Use it to lint behavior a compiler cannot check: bugs, vulnerabilities, swallowed errors, and a method that does not do what its name says. Use it to act on what a scan found. Use it to write rules that turn a repeated mistake into verifiable behavior..

Indexed from public GitHub and served as immutable, content-addressed versions. Install it pinned to an exact SHA-256 with the mdr CLI, and every file is verified against the hash recorded here before it reaches your agent. The deterministic audit below grades the latest version, and the same file always earns the same grade.

What the file says

# perch

perch asks a model about the code in a repository. It reports what it believes, as a probability on
every finding.

## Scan what changed

```console
$ perch scan --since origin/main
checkout.py
  ID        Line  Severity  Type    Confidence  Problem      Method
  bdc67421    14  P1 (0.8)  defect         81%  wrong_order  place_order

✖ 1 problem in 1 file, all failing
perch at commit 5e9d910: 3 methods, read 3
3 requests  10k tokens in / 2k out  $0.0004
```

`--since <ref>` covers what moved since that ref. That is what you want on a branch
and in CI. `--paths a,b` covers named files or directories. Add `--json` for the full
detail: `perch scan --since origin/main --json`.

A whole repository is hundreds of model requests. A branch is a handful. Never scan
everything to check one change.

A method whose code and neighbours have not moved is skipped next run. Scanning again
after a fix costs almost nothing.

| Exit | |
| --- | --- |
| `0` | Nothing to act on. |
| `3` | Something that fails was found. |
| `1` | perch could not run. |
| `2` | The command was typed wrong. |

`3` is a result rather than an error, so report what it found. Only `1` and `2` are
failures.
…

Read the whole file at its exact version.

How to install

Latest version
mdr add lakeday-org/perch/perch@git:20260918.3c5d842
Exact content
mdr add lakeday-org/perch/perch@sha256:b25496798545384c

Pin to a label to follow the author's releases, or to a sha256 to freeze the exact bytes forever. Either way the resolved hash is written to mdr.lock, and mdr install reproduces it on any machine.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_wlwr4wlubp4hrrfx.svg)](https://markdownregistry.com/a/art_wlwr4wlubp4hrrfx)

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Versions

versioncommittedcommitsizeaudit
git:20260918.3c5d842 latest2026-09-18 3c5d842 7,562 BA view

Audit of the latest version

A  17 of 17 checks passed. Deterministic, no model, same answer every run.
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (7562 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No instruction to read or print local credentials
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Source

GitHub

lakeday-org/perch · 175 stars · license MIT · pushed 2026-09-24 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_wlwr4wlubp4hrrfx
GET https://markdownregistry.com/api/v1/resolve?ref=lakeday-org/perch/perch
GET https://markdownregistry.com/api/v1/blob/b25496798545384c2e8da7ef1ba6bf277ff9476bd6c7aa07d15c0a243d8e1442

Your agent does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

More from lakeday-org/perch

AGENTS.md agents
lakeday-org/perch · AGENTS.md
git:20260920.aa3f08c · audit A · 175 stars
CLAUDE.md claude
lakeday-org/perch · CLAUDE.md
git:20260918.221ab9a · audit B · 175 stars

Every file in lakeday-org/perch

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