legacy SKILL.md skillA
legacy from alexander-danilenko/cortex-claude-code-plugins is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add alexander-danilenko/cortex-claude-code-plugins/legacy@git:20261013.ecfffa1Pins git:20261013.ecfffa1 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- alexander-danilenko/cortex-claude-code-plugins
- Path
plugins/engineering/cortex-modernization/skills/legacy/SKILL.md- Versions recorded
- 1
- Latest version
- git:20261013.ecfffa1, committed Oct 13, 2026
- Size
- 4,191 bytes
- Repository stars
- 17
- License
- MIT
Apply this opinionated workflow when modernizing legacy systems: strangler fig pattern, branch by abstraction, characterization tests, incremental monolith decomposition, framework upgrades, feature-flagged migration with rollback.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Legacy Modernization
Incremental migration of running systems. The constraint that shapes every decision here: the system is in production and must keep working while it changes.
## The sequence
Order matters more than the individual techniques — each step exists to make the next one safe.
1. **Characterize before changing.** Write tests that pin current behaviour, bugs included. You are not testing what the code _should_ do; you are recording what it _does_, so a behaviour diff becomes visible. When an assertion looks wrong, that is the point — write it down and say so:
```python
def test_domestic_lightweight():
order = {"weight": 5, "destination": "domestic", "priority": False}
# Current behaviour: nothing charged under 10kg. Looks like a bug —
# pin it here, fix it as its own change after the migration lands.
assert calculate_shipping_cost(order) == 0.0
```
Golden-master or approval tests (approvaltests, syrupy) get coverage over gnarly code fastest, because they capture output wholesale instead of requiring you to understand it first.
…Read the whole file at its exact version.
How to install
mdr add alexander-danilenko/cortex-claude-code-plugins/legacy@sha256:6db933fbd3fc7ec8The line at the top of this page pins the label git:20261013.ecfffa1, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_m6czg22ys6uu2rsd)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Oct 13, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4191 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
alexander-danilenko/cortex-claude-code-plugins · 17 stars · license MIT · pushed 2026-10-19 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_m6czg22ys6uu2rsd GET https://markdownregistry.com/api/v1/resolve?ref=alexander-danilenko/cortex-claude-code-plugins/legacy GET https://markdownregistry.com/api/v1/blob/6db933fbd3fc7ec80cf4cba0fe9a0b4ddcf1545b20725e0133dee67b9e8b46ea
Your AI assistant 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.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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