elixir

elixir is a skill for Claude Code, Codex from j4flmao/agent-skills. It costs 79 tokens per session (5,033 once invoked), scanned A, original, MIT.

A guide for building Elixir applications with Phoenix, LiveView, Ecto, and OTP. Elixir is a programming language for concurrent systems; OTP provides patterns for supervising processes and handling failures.

In plain words
What is it for?
Use it to create Phoenix projects, contexts, LiveViews, Ecto schemas, supervision trees, GenServers, PubSub messaging, and deployment configurations.
Why use it?
It helps organize concurrent, fault-tolerant applications into clear domain boundaries and supervision structures. It also gives consistent patterns for web interfaces, state, and database access.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/j4flmao/agent-skills/elixir
Any agent
npx skills add j4flmao/agent-skills --skill elixir
Clone the repo
git clone --depth 1 https://github.com/j4flmao/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for elixir

README.md
[![agentmods](https://agentmods.dev/badge/skills/j4flmao/agent-skills/elixir.svg)](https://agentmods.dev/skills/j4flmao/agent-skills/elixir)
Your own site
<a href="https://agentmods.dev/skills/j4flmao/agent-skills/elixir"><img src="https://agentmods.dev/badge/skills/j4flmao/agent-skills/elixir.svg" alt="Measured on agentmods" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,033 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00079 $0.05033
Opus 5 $0.00039 $0.02516
Sonnet 5 $0.00016 $0.01007
Haiku 4.5 $0.00008 $0.00503

Measured 5d ago against content hash 03aaa696220b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

elixir scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/backend/elixir/SKILL.md · 614 lines

How it starts

The opening of the file, as written. The whole thing — 614 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Elixir

Purpose

Build fault-tolerant, concurrent applications with Elixir/OTP — Phoenix web layer, LiveView interactivity, Ecto persistence, supervision trees, process architecture.

Agent Protocol

Trigger

User request includes: Elixir, Phoenix, Phoenix LiveView, OTP, BEAM, Elixir macros, Ecto, mix, phx.gen, Supervisor, GenServer, Phoenix channels, Phoenix PubSub, Elixir processes, iex.

Input Context

  • Framework (Phoenix, Phoenix LiveView, bare Elixir)
  • Persistence (Ecto with PostgreSQL, Ecto with SQLite, ETS)
  • State management (GenServer, Agent, ETS, Phoenix PubSub)
  • Deployment (Elixir releases, Docker, Gigalixir, Fly.io)

Output Artifact

Phoenix project structure, OTP supervision tree, Ecto schema, LiveView module, router config.

Response Format

Produce artifact directly. No preamble, no postamble, no explanations. No filler, no hedging, no transitions. Strip articles a/an/the where unambiguous. Compress output — why use many token when few do trick.

Completion Criteria

  • Phoenix project generated with mix phx.new
  • Contexts separated by domain boundary
  • Ecto schemas with proper associations
  • LiveView with state management and event handling
  • Supervision tree with appropriate restart strategy

Max Response Length

4096 tokens

Workflow

Step 1: Phoenix Project Setup

# Install Phoenix
mix archive.install hex phx_new

# Create new Phoenix app
mix phx.new my_app --database postgres
mix phx.new my_app --database sqlite3  # Alternative

# Setup database
mix ecto.create
mix ecto.migrate

# Start server
mix phx.server
my_app/
  lib/
    my_app/
      application.ex         # OTP application start
      repo.ex                # Ecto Repo
      accounts/              # Context: accounts
        user.ex              # Ecto schema
        user_notifier.ex     # Boundary call
        user_token.ex
        accounts.ex           # Context module (public API)
      catalog/               # Context: catalog
        product.ex
        category.ex
        catalog.ex
      store/                 # Context: orders
        order.ex
        line_item.ex
        store.ex
      web/
        endpoint.ex           # Phoenix endpoint
        router.ex             # Router
        controllers/          # Controllers (non-LiveView)
          user_session_controller.ex
        live/                 # LiveViews
          product_live/
            index.ex
            show.ex
          cart_live/
            index.ex
        components/           # Shared components
          layout.ex           # App layout
          navbar.ex
          product_card.ex
        templates/            # Templates (non-LiveView)
          layout/
      mailer.ex               # Mailer (Swoosh/Bamboo)
    my_app.ex                 # Module aliases
  priv/
    repo/
      migrations/
        20250101000000_create_users.exs
  config/
    config.exs
    dev.exs
    prod.exs
    runtime.exs
  mix.exs

Read the full file on GitHub · 614 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 614 lines · 79 tokens per session scan A 03aaa696220b

Subscribe to this mod's changes

elixir is a skill published in the GitHub repository j4flmao/agent-skills (20 stars, last pushed today), licensed MIT. It adds 79 tokens to every session and 5,033 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

elixir-expert

Expert-level Elixir, Phoenix, OTP, and concurrent systems. Use when the user mentions Phoenix, OTP, Erlang, concurrent, or functional, or when the task involves Elixir Fundamentals or Phoenix Framework.

personamanagmentlayer/pcl · 47 tokens

elixir-cyclic-deps

Detects and removes cyclic compile-time dependencies in Elixir codebases using mix xref, with minimal code changes. Use when the user explicitly asks to check for cycles, remove cyclic dependencies, or fix xref cycle failures. Requires Elixir 1.19 or higher for accurate results.

matteing/opal · 65 tokens

codegen-sync

Verifies TypeScript codegen is in sync with Elixir protocol definitions. Use this skill after modifying Elixir structs, protocol messages, or RPC types in lib/opal/ to regenerate and verify the TypeScript client SDK types.

matteing/opal · 50 tokens

elixir-thinking

This skill should be used when the user asks to "implement a feature in Elixir", "refactor this module", "should I use a GenServer here?", "how should I structure this?", "use the pipe operator", "add error handling", "make this concurrent", or mentions protocols, behaviours, pattern matching, with statements…

georgeguimaraes/claude-code-elixir · 91 tokens

elixir-iron-review

Review a diff or the working tree against the Emisar Iron Laws (IL-1…IL-20) — the mechanical Credo checks plus the judgment checks a static analyzer can't do. Use when reviewing portal/ Elixir before a PR, after a refactor, or to double-check context/query/changeset/LiveView changes. Reports law · file:line · fix.

AndrewDryga/emisar · 83 tokens

elixir-new-context

Scaffold a new Emisar domain context — context + authorizer + schema + query + changeset + migration + tests, wired into the permission union. Use when adding a new resource/table/domain concept to portal/apps/emisar, or starting a feature that needs its own context.

AndrewDryga/emisar · 61 tokens