Phoenix Api Channels

This gets you up to speed on building JSON APIs and real-time features with Phoenix on the BEAM. It covers the full stack: controllers with plugs and versioned routes, Ecto contexts for data ownership, WebSocket Channels for chat and notifications, Presence for tracking who's online, and PubSub for fan-out broadcasts. The guide is opinionated about keeping controllers thin and letting contexts own business logic, which matches idiomatic Phoenix. You'll want this when you need both REST endpoints and WebSocket bidirectionality in the same app, or when you're adding collaborative features that need fault-tolerant concurrency. It includes auth patterns, testing helpers, and telemetry setup. The coverage is practical without rehashing basic Elixir syntax.

skills.sh installs: 348
GitHub stars: 79
last updated: Aug 21, 2026

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Install

$ npx -y skills add bobmatnyc/claude-mpm-skills --skill phoenix-api-channels --agent claude-code

Installs into .claude/skills of the current project.

Files

Phoenix APIs, Channels, and Presence (Elixir/BEAM)

Phoenix excels at REST/JSON APIs and WebSocket Channels with minimal boilerplate, leveraging the BEAM for fault tolerance, lightweight processes, and supervised PubSub/Presence.

Core pillars

Controllers for JSON APIs with plugs, pipelines, and versioning.
Contexts own data (Ecto schemas + queries) and expose a narrow API to controllers/channels.
Channels + PubSub for fan-out real-time updates; Presence for tracking users/devices.
Auth via plugs (session/cookie for browser, token/Bearer for APIs), with signed params.

Project Setup

mix phx.new my_api --no-html --no-live
cd my_api
mix deps.get
mix ecto.create
mix phx.server

Key files:

lib/my_api_web/endpoint.ex — plugs, sockets, instrumentation
lib/my_api_web/router.ex — pipelines, scopes, versioning, sockets
lib/my_api_web/controllers/* — REST/JSON controllers
lib/my_api/* — contexts + Ecto schemas (ownership of data logic)
lib/my_api_web/channels/* — Channel modules

Routing and Pipelines

Separate browser vs API pipelines; version APIs with scopes.

defmodule MyApiWeb.Router do
  use MyApiWeb, :router

SKILL.md on GitHub

Details

Repository: github.com/bobmatnyc/claude-mpm-skills
Category: Backend & APIs
First seen: Jun 3, 2026