@emulators/core

HTTP server, in-memory store, plugin interface, and middleware for emulate service plugins.

Part of emulate — local drop-in replacement services for CI and no-network sandboxes.

Install

npm install @emulators/core

Overview

The core provides the shared infrastructure that every @emulators/* service plugin builds on:

• Store — a generic in-memory store with typed Collection<T> instances supporting CRUD, indexing, filtering, and pagination
• Server — Hono-based HTTP server with automatic port management
• Middleware — bearer token auth, error handling, CORS
• UI — shared authorization/consent page rendering with bundled fonts
• Persistence — pluggable save/load adapters for state durability

Persistence

File persistence

For local development, use the built-in file adapter:

import { filePersistence } from '@emulators/core'

persistence: filePersistence('.emulate/state.json')

Custom adapter

Any object with load and save methods works:

const kvAdapter = {
  async load() { return await kv.get('emulate-state') },
  async save(data: string) { await kv.set('emulate-state', data) },
}

The persistence adapter is called on cold start (load) and after every mutating request (save). Saves are serialized via an internal queue to prevent race conditions.

Links

• Full documentation
• GitHub