StackPatch

Product Introduction

1. Definition: StackPatch is an open-source Command Line Interface (CLI) tool designed for the Next.js ecosystem. It programmatically integrates production-ready features like authentication, session management, and protected routes directly into an existing Next.js codebase.
2. Core Value Proposition: It eliminates the complexity, boilerplate code, and vendor lock-in associated with adding critical functionality like Google and GitHub authentication. Developers gain fully editable, self-hosted code instantly, accelerating development without SaaS dependencies or structural overhauls.

Main Features

1. Auto-detection:
   How it works: StackPatch scans the target Next.js project directory upon execution, identifying key elements like framework version (e.g., Next.js 16), directory structure (app/ vs pages/), existing files (layout.tsx), and dependencies. This analysis ensures safe, context-aware patching tailored to the specific project setup. Technologies used include filesystem parsing and dependency analysis.
2. Smart Code Injection:
   How it works: The CLI intelligently modifies only necessary files, respecting existing conventions and structure. For authentication, it injects an <AuthSessionProvider> into the root layout.tsx and generates specific files like app/api/auth/route.ts and providers.ts. It avoids overwriting custom logic and provides a file tree preview before applying changes.
3. Zero Configuration:
   How it works: StackPatch requires no manual configuration files (stackpatch.config.js). It leverages its auto-detection capabilities to apply pre-configured, opinionated patches (e.g., NextAuth.js setup with Google/GitHub) that work immediately post-installation (npx stackpatch add auth).
4. Fully Reversible:
   How it works: All modifications are tracked in a .stackpatch/manifest.json file. This allows developers to completely revert any patch (e.g., npx stackpatch reset) with a single command, restoring the project to its pre-patch state.

Problems Solved

1. Pain Point: Integrating production-grade authentication (OAuth providers, session handling, protected routes) into an existing Next.js app is time-consuming, involves significant boilerplate code, and risks structural inconsistencies.
2. Target Audience:
   • Full-stack Next.js Developers: Seeking rapid, maintainable feature integration.
   • Small Teams & Startups: Needing to ship secure features fast without dedicated DevOps.
   • Developers Avoiding SaaS Lock-in: Prioritizing ownership of auth logic and data.
   • Maintainers of Legacy Next.js Apps: Requiring incremental upgrades without full rewrites.
3. Use Cases:
   • Adding Google/GitHub login to a prototype for user testing within minutes.
   • Securing specific admin routes in an existing internal dashboard.
   • Modernizing an older Next.js pages app with App Router-compatible auth.
   • Avoiding monthly costs and complexity of managed auth services like Auth0 or Clerk.

Unique Advantages

1. Differentiation: Unlike SaaS auth platforms (Clerk, Supabase Auth, Auth0) or generic boilerplate generators, StackPatch injects minimal, editable code directly into the developer's repo. It offers the convenience of a managed service (zero config, quick start) with the control and ownership of self-hosted solutions like raw NextAuth.js – but without the manual setup burden.
2. Key Innovation: The combination of project-aware auto-detection and non-destructive, reversible patching is unique. This allows it to safely integrate complex features into highly customized or existing Next.js projects where traditional templates or SaaS wrappers would fail or require significant adaptation. The open-source, file-based approach ensures complete transparency and control.

Frequently Asked Questions (FAQ)

1. Is StackPatch reversible if I don't like the changes?
   Yes, StackPatch meticulously tracks all modifications in .stackpatch/manifest.json. Running npx stackpatch reset completely reverts the last applied patch, restoring your project.
2. Does StackPatch add external dependencies or require a paid service?
   No. StackPatch is fully open-source (MIT license) and generates self-contained, editable code within your Next.js project. It uses standard libraries like NextAuth.js but requires no external SaaS platform or paid subscription.
3. Can I customize the authentication code added by StackPatch?
   Absolutely. All generated code (e.g., route.ts, providers.ts, components) is placed directly in your project's file structure and is fully editable. StackPatch provides a foundation you own and can extend freely.
4. What Next.js versions and structures does StackPatch support?
   StackPatch auto-detects and supports both the legacy pages directory and the modern app directory (App Router) in Next.js. It explicitly identifies versions (e.g., Next.js 16) during its scan to ensure compatibility.
5. What features beyond authentication does StackPatch offer?
   While the initial focus is on authentication, StackPatch's architecture is designed for adding other "patches" like Redis integration, payments (Stripe), and more. The CLI's core functionality (auto-detection, safe patching, reversibility) applies to these future features.