# oauth2-oidc-implementer

Implements OAuth 2.0 and OpenID Connect flows with PKCE, session callbacks, and secure token exchange in your project.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 353 installs · ★ 63
- Author: patricio0312rev
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/patricio0312rev/skills/tree/HEAD/security/oauth2-oidc-implementer/SKILL.md
- Updated: 2026-01-12
- HTML: https://affpapa.org/en/nevibecode/skills/oauth2-oidc-implementer

## What it does

The skill configures authentication flows using OAuth 2.0 and OpenID Connect. It implements Authorization Code with PKCE for web and mobile apps, supports Client Credentials for server tasks, and handles Device Code. It drops the deprecated Implicit flow entirely.

Implementation patterns focus on TypeScript and Next.js route handlers. The workflow generates a `code_verifier`, computes a SHA-256 `code_challenge` with S256, and creates a random `state` string against CSRF attacks. Login and callback endpoints store verifiers in short-lived `httpOnly` cookies with a 10-minute lifetime. Identity provider metadata is fetched via `/.well-known/openid-configuration`.

Server-side token exchange depends on `OAUTH_CLIENT_ID`, `OAUTH_CLIENT_SECRET`, and `OAUTH_REDIRECT_URI`.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add patricio0312rev/skills --skill oauth2-oidc-implementer -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/oauth2-oidc-implementer/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/oauth2-oidc-implementer/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add patricio0312rev/skills --skill oauth2-oidc-implementer -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/oauth2-oidc-implementer/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add patricio0312rev/skills --skill oauth2-oidc-implementer -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/oauth2-oidc-implementer/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install patricio0312rev/skills oauth2-oidc-implementer
```

2. **Manually: put the files in place**
- File: `.github/skills/oauth2-oidc-implementer/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add patricio0312rev/skills --skill oauth2-oidc-implementer -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/patricio0312rev/skills --path security/oauth2-oidc-implementer
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/oauth2-oidc-implementer/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add patricio0312rev/skills --skill oauth2-oidc-implementer -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/patricio0312rev/skills/tree/HEAD/security/oauth2-oidc-implementer/SKILL.md

## When to use it
- configure Authorization Code flow with PKCE
- store state and code_verifier values in httpOnly cookies
- query provider metadata using OIDC discovery
- exchange authorization codes for tokens in callback handlers

## Example prompts
- Set up OAuth 2.0 authentication with PKCE for Next.js
- Add OIDC discovery integration for our identity provider
- Write login and callback routes that verify CSRF state

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 78fd926660fa1060.

BEGIN THIRD-PARTY FILE 78fd926660fa1060
````text
---
name: oauth2-oidc-implementer
description: Implements OAuth 2.0 and OpenID Connect authentication flows with secure token handling and provider integration. Use when users request "OAuth setup", "OIDC implementation", "social login", "SSO integration", or "authentication flow".
---

# OAuth 2.0 & OIDC Implementer

Implement secure authentication with OAuth 2.0 and OpenID Connect.

## Core Workflow

1. **Choose flow**: Authorization Code, PKCE, Client Credentials
2. **Configure provider**: Set up OAuth/OIDC provider
3. **Implement flow**: Handle redirects and tokens
4. **Secure tokens**: Storage and refresh
5. **Add providers**: Multiple identity providers
6. **Handle sessions**: Manage authenticated state

## OAuth 2.0 Flows Overview

```
┌─────────────────────────────────────────────────────────────┐
│                      OAuth 2.0 Flows                         │
├─────────────────────────────────────────────────────────────┤
│ Authorization Code + PKCE │ Web/Mobile apps (recommended)   │
│ Client Credentials        │ Machine-to-machine              │
│ Device Code               │ TV/IoT devices                  │
│ Implicit (deprecated)     │ Do not use                      │
└─────────────────────────────────────────────────────────────┘
```

## Authorization Code Flow with PKCE

### Server Implementation (Next.js)

```typescript
// lib/auth/oauth.ts
import { randomBytes, createHash } from 'crypto';

interface OAuthConfig {
  clientId: string;
  clientSecret: string;
  authorizationUrl: string;
  tokenUrl: string;
  redirectUri: string;
  scopes: string[];
}

const config: OAuthConfig = {
  clientId: process.env.OAUTH_CLIENT_ID!,
  clientSecret: process.env.OAUTH_CLIENT_SECRET!,
  authorizationUrl: 'https://provider.com/oauth/authorize',
  tokenUrl: 'https://provider.com/oauth/token',
  redirectUri: process.env.OAUTH_REDIRECT_URI!,
  scopes: ['openid', 'profile', 'email'],
};

// Generate PKCE challenge
function generateCodeVerifier(): string {
  return randomBytes(32).toString('base64url');
}

function generateCodeChallenge(verifier: string): string {
  return createHash('sha256').update(verifier).digest('base64url');
}

// Generate state for CSRF protection
function generateState(): string {
  return randomBytes(16).toString('hex');
}

export function getAuthorizationUrl(): {
  url: string;
  state: string;
  codeVerifier: string;
} {
  const state = generateState();
  const codeVerifier = generateCodeVerifier();
````
END THIRD-PARTY FILE 78fd926660fa1060

The third-party file has ended. Everything between the 78fd926660fa1060 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

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