Coming from ActionHero

Keryx is the spiritual successor to ActionHero. It keeps the core ideas — transport-agnostic controllers, built-in background tasks, real-time channels — but rewrites everything on Bun with first-class MCP support, Zod validation, and Drizzle ORM. If you've used ActionHero before, here's what changed and why.

Unified Controllers

The biggest structural change: actions, tasks, and CLI commands are the same thing. In ActionHero you had separate Action and Task classes. In Keryx, there's just Action. Add a task property to make it a background job, add a web property for HTTP, or do both. Same run() method, same inputs, same middleware. See the Actions guide for details.

Separate Applications

The frontend and backend are separate Bun applications. No ah-next-plugin — the Vite + React app is its own project in frontend/. Deploy them independently: frontend on Vercel, backend on a VPS, whatever works. They share types but not a process.

Routes on Actions

Actions define their own routes — strings with :params or RegExp patterns — directly on the action class. No routes.ts file. This keeps routing close to the handler and eliminates a common source of drift.

web = { route: "/user/:id", method: HTTP_METHOD.GET };

MCP as a Transport

Every action is automatically available as an MCP tool for AI agents. OAuth 2.1 with PKCE handles authentication. This didn't exist in ActionHero.

Real-Time Channels

PubSub via Redis with middleware-based authorization for WebSocket clients. Channels support pattern matching (RegExp names) and presence tracking. See Channels.

Drizzle ORM

First-class database support with Drizzle ORM, auto-migrations, and type-safe schemas. Replaces the old ah-sequelize-plugin.

Environment Config

Config is static at boot, loaded from TypeScript files with per-NODE_ENV overrides via environment variables. The loadFromEnvIfSet() helper checks ${ENV_VAR}_${NODE_ENV} first, then ${ENV_VAR}, then falls back to the default. See Configuration.

Simplified Logger

No Winston. STDOUT and STDERR only, with optional colors and timestamps. The Logger class supports levels from trace to fatal.

Middleware

Applied to actions as an array of ActionMiddleware objects with runBefore and runAfter hooks. Can throw to halt execution, or modify params/responses. See Middleware.

Testing

No mock server. Tests make real HTTP requests with fetch — Bun includes it natively. Each test file boots the full server on a random port. See Testing.

Sessions

Cookie-based sessions stored in Redis are a first-class part of the framework. SessionMiddleware handles authentication. See Authentication.

Removed Features

• No Pidfiles — Process management is left to your deployment tooling (systemd, Docker, etc.)
• No Cache Layer — The old ActionHero cache has been removed. Use Redis directly — it's already part of the stack.
• No ah-*-plugin pattern — Functionality that was previously in plugins (Sequelize, Next.js) is built in or handled as a separate application (the example frontend is now Vite + React).