elixir-idioms
OTP/BEAM patterns and Elixir idioms — GenServer, Supervisor, Task, Registry, pattern matching, with chains, pipes. Use when designing processes or debugging BEAM issues.
npx skills add oliver-kriska/claude-elixir-phoenix --skill elixir-idioms --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# Elixir Idioms Reference for writing idiomatic Elixir code with BEAM-aware patterns. ## Iron Laws — Never Violate These 1. **NO PROCESS WITHOUT A RUNTIME REASON** — Processes model concurrency, state, isolation—NOT code structure 2. **MESSAGES ARE COPIED** — Keep messages small (except binaries >64 bytes) 3. **GUARDS USE `and`/`or`/`not`** — Never use short-circuit operators in guards (guards require boolean operands) 4. **CHANGESETS FOR EXTERNAL DATA** — Use `cast/4` for user input, `change/2` for internal 5. **RESCUE ONLY FOR EXTERNAL CODE** — Never use rescue for control flow 6. **NO DYNAMIC ATOM CREATION** — `String.to_atom(user_input)` causes memory leak (atoms aren't GC'd) 7. **@external_resource FOR COMPILE-TIME FILES** — Modules reading files at compile time MUST declare `@external_resource` 8. **SUPERVISE ALL LONG-LIVED PROCESSES** — Never bare `GenServer.start_link`/`Agent.start_link` in production. Use supervision trees 9. **WRAP THIRD-PARTY LIBRARY APIs** — Always facade external deps behind a project-owned module. Enables swapping without touching callers 10. **MIX TASKS START ONLY WHAT THEY NEED** — `Mix.Task.run("app.config")` + `Application.ensure_all_started/1`, n
- Iron Laws — Never Violate These
- BEAM Architecture (Why Elixir Works This Way)
- Core Principles
- Quick Decision Trees
- Control Flow
- Error Handling
- OTP
- Quick Patterns
- Common Pitfalls
- References
What does the elixir-idioms skill do?
OTP/BEAM patterns and Elixir idioms — GenServer, Supervisor, Task, Registry, pattern matching, with chains, pipes. Use when designing processes or debugging BEAM issues.
How do I install it?
Run `npx skills add oliver-kriska/claude-elixir-phoenix --skill elixir-idioms --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From oliver-kriska/claude-elixir-phoenix, a repository with 515 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.