ecto-patterns SKILL.md skillA
ecto-patterns from oliver-kriska/claude-elixir-phoenix is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add oliver-kriska/claude-elixir-phoenix/ecto-patterns@git:20260929.c08ad14Pins git:20260929.c08ad14 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- oliver-kriska/claude-elixir-phoenix
- Path
plugins/elixir-phoenix/skills/ecto-patterns/SKILL.md- Versions recorded
- 7
- Latest version
- git:20260929.c08ad14, committed Sep 29, 2026
- First version recorded
- Mar 21, 2026
- Size
- 3,645 bytes
- Repository stars
- 573
- License
- MIT
Use when a task touches Ecto, even a how-to question: schemas, changesets, validations, queries, preloads, Multi, migrations, constraints, money fields. Load it before writing Ecto code. Skip for Ash.
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
# Ecto Patterns Reference Reference for working with Ecto schemas, queries, and migrations. ## Iron Laws — Never Violate These 1. **CHANGESETS ARE FOR EXTERNAL DATA** — Use `cast/4` for user/API input, `change/2` or `put_change/3` for internal trusted data 2. **NEVER USE `:float` FOR MONEY** — Always use `:decimal` or `:integer` (cents) 3. **NO RAILS-STYLE POLYMORPHIC ASSOCIATIONS** — They break foreign key constraints; use multiple nullable FKs or separate join tables 4. **ALWAYS PIN VALUES IN QUERIES** — `u.name == ^user_input` is safe, string interpolation causes SQL injection 5. **PRELOAD COLLECTIONS, NOT INDIVIDUALS** — Preloading in loops = N+1 queries 6. **CONSTRAINTS BEAT VALIDATIONS FOR RACE CONDITIONS** — Validations provide quick feedback, constraints provide DB-level safety 7. **SEPARATE QUERIES FOR `has_many`, JOIN FOR `belongs_to`** — Avoids row multiplication 8. **NO IMPLICIT CROSS JOINS** — `from(a in A, b in B)` without `on:` creates Cartesian product 9. **DEDUP BEFORE `cast_assoc` WITH SHARED DATA** — When multiple parents share child data, deduplicate child records BEFORE building changesets. Dedup only works within a single changeset …
Read the whole file at its exact version.
How to install
mdr add oliver-kriska/claude-elixir-phoenix/ecto-patterns@sha256:3d7f0e835b849c15The line at the top of this page pins the label git:20260929.c08ad14, 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_fqrpzz6wtuwpfvt7)
4 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 7 versions of this file, between Mar 21, 2026 and Sep 29, 2026, about one every 32 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260929.c08ad14 latest | 2026-09-29 | c08ad14 | 3,645 B | A | view · diff |
| git:20260921.69af5df | 2026-09-21 | 69af5df | 3,651 B | A | view · diff |
| git:20260720.42d1e41 | 2026-07-20 | 42d1e41 | 3,617 B | A | view · diff |
| git:20260402.ab98357 | 2026-04-02 | ab98357 | 3,498 B | A | view · diff |
| git:20260401.f2ab67a | 2026-04-01 | f2ab67a | 3,420 B | A | view · diff |
| git:20260325.d20c8dd | 2026-03-25 | d20c8dd | 3,597 B | A | view · diff |
| git:20260321.4e9d9e9 | 2026-03-21 | 4e9d9e9 | 3,575 B | A | view |
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 (3645 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
oliver-kriska/claude-elixir-phoenix · 573 stars · license MIT · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_fqrpzz6wtuwpfvt7 GET https://markdownregistry.com/api/v1/resolve?ref=oliver-kriska/claude-elixir-phoenix/ecto-patterns GET https://markdownregistry.com/api/v1/blob/3d7f0e835b849c157bca596d869a791d43164012af6e0f0e415e0ee54a92610f
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.
More from oliver-kriska/claude-elixir-phoenix
Every file in oliver-kriska/claude-elixir-phoenix