Clerk React Patterns Agent Skill

React SPA auth patterns with @clerk/react for Vite/CRA - ClerkProvider setup, useAuth/useUser/useClerk hooks, React Router protected routes, custom sign-in route, custom sign-in form React.'

5k tokens

context cost

the whole folder, loaded on every use

files

ships runnable scripts

copies elsewhere

how many repositories repackaged it

stars on the repo

on the repository, not the skill itself

Install

one command, takes just this skill from the repository

npx skills add https://github.com/clerk/skills --skill clerk-react-patterns

What comes with it

15 700 bytes besides the instruction

evals/evals.json

references/custom-flows.md

references/hooks.md

references/protected-routes.md

references/router-integration.md

templates/react-basic-auth/index.html

templates/react-basic-auth/package.json

templates/react-basic-auth/src/App.tsx

templates/react-basic-auth/src/main.tsx

templates/react-basic-auth/tsconfig.json

templates/react-basic-auth/vite.config.ts

What it tells the agent to use

found in the instruction text

WebFetch fetches pages from the network

The instruction itself

11 sections, as written by the author

React SPA Patterns

> This skill covers @clerk/react for Vite/CRA SPAs. For Next.js use clerk-nextjs-patterns. For TanStack Start use clerk-tanstack-patterns.

What Do You Need?

| Task | Reference |

|------|-----------|

| useAuth / useUser / useClerk hooks | references/hooks.md |

| Protected routes with React Router | references/protected-routes.md |

| Custom sign-in / sign-up forms | references/custom-flows.md |

| React Router v6/v7 integration | references/router-integration.md |

References

| Reference | Description |

|-----------|-------------|

| references/hooks.md | useAuth, isLoaded guard |

| references/protected-routes.md | ProtectedRoute pattern |

| references/custom-flows.md | useSignIn, useSignUp flows |

| references/router-integration.md | React Router v6/v7 setup |

Setup

npm install @clerk/react

.env:

VITE_CLERK_PUBLISHABLE_KEY=pk_...

src/main.tsx:

import { StrictMode } from 'react'
import { createRoot } from 'react-dom/client'
import { ClerkProvider } from '@clerk/react'
import App from './App.tsx'

const PUBLISHABLE_KEY = import.meta.env.VITE_CLERK_PUBLISHABLE_KEY

createRoot(document.getElementById('root')!).render(
  <StrictMode>
    <ClerkProvider publishableKey={PUBLISHABLE_KEY}>
      <App />
    </ClerkProvider>
  </StrictMode>,
)

Mental Model

@clerk/react is client-only — there is no server-side auth(). All auth state comes from hooks.

isLoaded must be true before trusting isSignedIn — always guard on isLoaded
useClerk() gives access to signOut, openSignIn, openUserProfile and other methods
getToken() from useAuth() fetches the session JWT for API calls

Minimal Pattern

import { useAuth } from '@clerk/react'

export function Dashboard() {
  const { isLoaded, isSignedIn, userId } = useAuth()

  if (!isLoaded) return <div>Loading...</div>
  if (!isSignedIn) return <div>Please sign in</div>

  return <div>Hello {userId}</div>
}

Protected Route (React Router v6/v7)

import { Navigate, Outlet } from 'react-router-dom'
import { useAuth } from '@clerk/react'

export function ProtectedRoute() {
  const { isLoaded, isSignedIn } = useAuth()

  if (!isLoaded) return <div>Loading...</div>
  if (!isSignedIn) return <Navigate to="/sign-in" replace />

  return <Outlet />
}

<Routes>
  <Route element={<ProtectedRoute />}>
    <Route path="/dashboard" element={<Dashboard />} />
    <Route path="/settings" element={<Settings />} />
  </Route>
  <Route path="/sign-in" element={<SignIn />} />
</Routes>

Token for API Calls

import { useAuth } from '@clerk/react'

export function DataFetcher() {
  const { getToken } = useAuth()

  async function fetchData() {
    const token = await getToken()
    if (!token) return

    const res = await fetch('/api/data', {
      headers: { Authorization: `Bearer ${token}` },
    })
    return res.json()
  }

  return <button onClick={fetchData}>Load</button>
}

Common Pitfalls

| Symptom | Cause | Fix |

|---------|-------|-----|

| isSignedIn is undefined | isLoaded is still false | Always check isLoaded first |

| ClerkProvider missing | Provider not at root | Wrap <App> in main.tsx |

| Env var undefined | Wrong Vite prefix | Use VITE_CLERK_PUBLISHABLE_KEY, access via import.meta.env |

| Token is null | User not signed in | Null-check getToken() result |

| Sign-in component shows blank | No publishableKey on provider | Pass publishableKey explicitly |

Docs

React SDK

Other skills for the same job

different authors, same section of the catalogue

MCP Builder

by anthropics

vendor ×13

Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).

Automatically creates user-facing changelogs from git commits by analyzing commit history, categorizing changes, and transforming technical commits into clear, customer-friendly release notes. Turns hours of manual changelog writing into minutes of automated generation.

774 tokens

Finishing A Development Branch

by ZhanlinCui

×7

Use when implementation is complete, all tests pass, and you need to decide how to integrate the work - guides completion of development work by presenting structured options for merge, PR, or cleanup

Vercel React Native Skills

by vercel-labs

vendor ×6

React Native and Expo best practices for building performant mobile apps. Use when building React Native components, optimizing list performance, implementing animations, or working with native modules. Triggers on tasks involving React Native, Expo, mobile performance, or native platform APIs.

39k tokens

Vercel React Best Practices

by ratacat

×5

React and Next.js performance optimization guidelines from Vercel Engineering. This skill should be used when writing, reviewing, or refactoring React/Next.js code to ensure optimal performance patterns. Triggers on tasks involving React components, Next.js pages, data fetching, bundle optimization, or performance improvements.

Next.js best practices - file conventions, RSC boundaries, data patterns, async APIs, metadata, error handling, route handlers, image/font optimization, bundling

Use when starting feature work that needs isolation from current workspace or before executing implementation plans - creates isolated git worktrees with smart directory selection and safety verification

1k tokens

How to use it

Copy the folder

Take clerk/clerk-react-patterns from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference npm. Without those the skill loads but fails at the first command.