phoenix-patterns

Included with Lifetime

$97 forever

Use when applying Phoenix Framework best practices including context design, controller patterns, and application architecture. Use when building Phoenix applications.

Design

What this skill does


# Phoenix Patterns

Master Phoenix Framework patterns to build well-structured, maintainable web applications in Elixir.

## Context Design

Contexts are dedicated modules that expose and group related functionality:

```elixir
defmodule MyApp.Accounts do
  @moduledoc """
  The Accounts context handles user management and authentication.
  """

  alias MyApp.Repo
  alias MyApp.Accounts.User

  def list_users do
    Repo.all(User)
  end

  def get_user!(id), do: Repo.get!(User, id)

  def get_user_by_email(email) do
    Repo.get_by(User, email: email)
  end

  def create_user(attrs \\ %{}) do
    %User{}
    |> User.changeset(attrs)
    |> Repo.insert()
  end

  def update_user(%User{} = user, attrs) do
    user
    |> User.changeset(attrs)
    |> Repo.update()
  end

  def delete_user(%User{} = user) do
    Repo.delete(user)
  end

  def change_user(%User{} = user, attrs \\ %{}) do
    User.changeset(user, attrs)
  end
end
```

## Controller Patterns

```elixir
defmodule MyAppWeb.UserController do
  use MyAppWeb, :controller

  alias MyApp.Accounts
  alias MyApp.Accounts.User

  action_fallback MyAppWeb.FallbackController

  def index(conn, _params) do
    users = Accounts.list_users()
    render(conn, :index, users: users)
  end

  def create(conn, %{"user" => user_params}) do
    with {:ok, %User{} = user} <- Accounts.create_user(user_params) do
      conn
      |> put_status(:created)
      |> put_resp_header("location", ~p"/api/users/#{user}")
      |> render(:show, user: user)
    end
  end

  def show(conn, %{"id" => id}) do
    user = Accounts.get_user!(id)
    render(conn, :show, user: user)
  end

  def update(conn, %{"id" => id, "user" => user_params}) do
    user = Accounts.get_user!(id)

    with {:ok, %User{} = user} <- Accounts.update_user(user, user_params) do
      render(conn, :show, user: user)
    end
  end

  def delete(conn, %{"id" => id}) do
    user = Accounts.get_user!(id)

    with {:ok, %User{}} <- Accounts.delete_user(user) do
      send_resp(conn, :no_content, "")
    end
  end
end
```

## Fallback Controller

```elixir
defmodule MyAppWeb.FallbackController do
  use MyAppWeb, :controller

  def call(conn, {:error, :not_found}) do
    conn
    |> put_status(:not_found)
    |> put_view(json: MyAppWeb.ErrorJSON)
    |> render(:"404")
  end

  def call(conn, {:error, %Ecto.Changeset{} = changeset}) do
    conn
    |> put_status(:unprocessable_entity)
    |> put_view(json: MyAppWeb.ChangesetJSON)
    |> render(:error, changeset: changeset)
  end

  def call(conn, {:error, :unauthorized}) do
    conn
    |> put_status(:unauthorized)
    |> put_view(json: MyAppWeb.ErrorJSON)
    |> render(:"401")
  end
end
```

## Plug Pipelines

```elixir
defmodule MyAppWeb.Router do
  use MyAppWeb, :router

  pipeline :browser do
    plug :accepts, ["html"]
    plug :fetch_session
    plug :fetch_live_flash
    plug :put_root_layout, html: {MyAppWeb.Layouts, :root}
    plug :protect_from_forgery
    plug :put_secure_browser_headers
  end

  pipeline :api do
    plug :accepts, ["json"]
    plug MyAppWeb.Plugs.Authenticate
  end

  pipeline :admin do
    plug MyAppWeb.Plugs.RequireAdmin
  end

  scope "/", MyAppWeb do
    pipe_through :browser
    get "/", PageController, :home
  end

  scope "/api", MyAppWeb do
    pipe_through :api

    resources "/users", UserController, except: [:new, :edit]

    scope "/admin" do
      pipe_through :admin
      resources "/settings", Admin.SettingsController
    end
  end
end
```

## Custom Plugs

```elixir
defmodule MyAppWeb.Plugs.Authenticate do
  import Plug.Conn

  def init(opts), do: opts

  def call(conn, _opts) do
    with ["Bearer " <> token] <- get_req_header(conn, "authorization"),
         {:ok, user} <- MyApp.Accounts.verify_token(token) do
      assign(conn, :current_user, user)
    else
      _ ->
        conn
        |> put_status(:unauthorized)
        |> Phoenix.Controller.put_view(json: MyAppWeb.ErrorJSON)
        |> Phoenix.Controller.render(:"401")
        |> halt()
    end
  end
end
```

## When to Use This Skill

Use phoenix-patterns when you need to:

- Structure Phoenix application architecture
- Design context boundaries
- Implement REST API controllers
- Create custom authentication/authorization
- Build reusable plug pipelines

## Best Practices

- Keep controllers thin, contexts fat
- Use action_fallback for error handling
- Group related functionality in contexts
- Use plugs for cross-cutting concerns
- Follow RESTful conventions in routing
- Separate API and browser pipelines

## Common Pitfalls

- Putting business logic in controllers
- Not using contexts for organization
- Creating overly large contexts
- Forgetting to handle errors properly
- Not using pipelines effectively
- Mixing concerns in single plugs

Files: 1

Size: 4.9 KB

Complexity: 13/100

Category: Design

Source: https://github.com/thebushidocollective/han/tree/main/plugins/frameworks/phoenix/skills/phoenix-patterns

Related in Design

contribute

Included

Local-only OSS contribution command center. Auto-refreshes the user's in-flight PR and issue state on invoke so conversations start with full context — no need to brief Claude on what's in flight. Helps the user find issues to contribute to on GitHub, builds per-repo dossiers of what each upstream expects (CLA, DCO, branch convention, AI policy, draft-first, review bots, issue templates), runs deterministic gates before any external action so AI-assisted contributions don't reach maintainers as slop. State is markdown-only: candidate files at ~/.contribute-system/candidates/, repo dossiers at ~/.contribute-system/research/, append-only event log at ~/.contribute-system/log.jsonl. No database, no cloud calls. Use when the user asks about their PRs / issues / contributions, wants to find new work to take on, claim an issue, build/refresh a repo's dossier, or draft a Design Issue or PR. Trigger with "/contribute", "what's my PR status", "find a contribution", "claim issue X", "draft a Design Issue for Y", "refresh dossier for Z".

Designscripts

architectural-analysis

Included

User-triggered deep architectural analysis of a codebase or scoped subtree across eight modes — information architecture, data flow, integration points, UI surfaces, interaction patterns, data model, control flow, and failure modes. This skill should be used when the user asks to "diagram this codebase," "map the architecture," "show the data flow," "give me an ERD," "trace control flow," "find the integration points," "verify the layout pattern," "audit the UX architecture," or any similar request whose primary deliverable is mermaid diagrams plus cited reports under docs/architecture/. Dispatches haiku/sonnet sub-agents in parallel for per-mode exploration, then verifies every citation mechanically before any node lands in a diagram. Not for one-off prose explanations of code (use code-explanation) or for high-level system design from scratch (use system-design).

Designscripts

mcp

Included

Model Context Protocol (MCP) server development and tool management. Languages: Python, TypeScript. Capabilities: build MCP servers, integrate external APIs, discover/execute MCP tools, manage multi-server configs, design agent-centric tools. Actions: create, build, integrate, discover, execute, configure MCP servers/tools. Keywords: MCP, Model Context Protocol, MCP server, MCP tool, stdio transport, SSE transport, tool discovery, resource provider, prompt template, external API integration, Gemini CLI MCP, Claude MCP, agent tools, tool execution, server config. Use when: building MCP servers, integrating external APIs as MCP tools, discovering available MCP tools, executing MCP capabilities, configuring multi-server setups, designing tools for AI agents.

Designscripts

react-native-skia

Included

Design, build, debug, and optimise high-polish animated graphics in React Native or Expo using @shopify/react-native-skia, Reanimated, and Gesture Handler. Use when the user wants canvas-driven UI, shaders, paths, rich text, image filters, sprite fields, Skottie, video frames, snapshots, web CanvasKit setup, or performance tuning for custom motion-heavy elements such as loaders, hero art, cards, charts, progress indicators, particle systems, or gesture-driven surfaces. Also use when the user asks for fluid, glow, glass, blob, parallax, 60fps/120fps, or GPU-friendly animated effects in React Native, even if they do not explicitly say "Skia". Do not use for ordinary form/layout work with standard views.

Designscripts

plaid

Included

Product Led AI Development — guides founders from idea to launched product. Six capabilities: Idea (discover a product idea), Validate (pressure-test the idea against fatal flaws, problem reality, competition, and 2-week MVP feasibility), Plan (vision intake + document generation), Design (translate image references into a design.md spec), Launch (go-to-market strategy), and Build (roadmap execution). Use when someone says "PLAID", "plaid idea", "help me find an idea", "product idea", "idea from my business", "idea from my expertise", "plaid validate", "validate my idea", "pressure-test", "is this idea good", "find fatal flaws", "validate the problem", "plan a product", "define my vision", "generate a PRD", "product strategy", "plaid design", "design from image", "translate image to design", "create design.md", "extract design tokens", "plaid launch", "go-to-market", "launch plan", "GTM strategy", "launch playbook", "plaid build", "build the app", "start building", or "execute the roadmap".

Designscripts

nextjs-framer-motion-animations

Included

Adds production-safe Motion for React or Framer Motion animations to Next.js apps, including reveal, hover and tap micro-interactions, whileInView, stagger, AnimatePresence, layout and layoutId transitions, reorder, scroll-linked UI, and lightweight route-content transitions. Use when the user asks to add, refactor, or debug Motion or Framer Motion in App Router or Pages Router codebases, especially around server/client boundaries, reduced motion, LazyMotion, bundle size, hydration, or route transitions. Avoid for GSAP-style timelines, WebGL or 3D scenes, heavy scroll storytelling, or CSS-only effects unless Motion is explicitly requested.

Designscripts