---
name: elixir
description: "Use when implementing Elixir/Phoenix contexts, OTP processes, Ecto data access, LiveView, or error handling."
---

# Elixir

## When to invoke

Use when implementing Elixir/Phoenix contexts, OTP processes, Ecto data access, LiveView, or error handling. Preserve the repository's established stack and conventions.

## Inputs and evidence

Inspect Elixir/OTP/Phoenix versions, process/supervision design, public return contracts, Ecto constraints, and existing UI/auth choices. Identify installed versions, affected callers,
existing tests, and the user's requested behavior before editing.

## Workflow

1. Define expected failures and process/state ownership before changing functions or supervision.
2. Implement idiomatic pattern matching, context APIs, validated data, and bounded asynchronous work.
3. Run formatter and ExUnit plus relevant transaction/concurrency/LiveView checks, including recovery behavior.

Load [implementation guidance](references/implementation.md) only for the selected
feature, API, or verification concern; follow its primary links for version details.

## Outputs and handoff

Report the changed behavior, affected files, checks and their actual outcomes,
and remaining limitations. Include relevant configuration or migration steps.

## Completion evidence

Verify the requested behavior at its public boundary, including a meaningful
failure case. Separate static review from executed tests and runtime acceptance.

## Must not

Do not change the stack, dependencies, or architecture merely to match examples.
Do not expose credentials or private data. External writes, deployments, paid
operations, and destructive changes require authority from the user's request.

---

Adapted from Mindrally/skills and modified by Andrew Cox (2026), under Apache-2.0. See [package notices](../../NOTICE.md).