nuxt

If your app is built with Nuxt, the stand-in services can run inside it rather than as a separate process, so a login that works on your laptop keeps working on every preview deployment.

WHEN TO USE

SCOPE

USE FOR

Keep OAuth callback URLs stable across preview deployments of a Nuxt app.
Embed the GitHub and Google emulators directly inside a Nuxt server route.
Persist emulator state in Nitro storage across serverless cold starts.
Point your app's login settings at the emulators running on its own address.

NOT FOR

Requires a Node-compatible Nuxt server runtime; other runtimes are not supported.
Concurrent writes use last-write-wins, not strict atomic conflict resolution.

This is a saved copy of the skill's SKILL.md instructions. It may differ from the upstream file or the version you install.

In this document (9)

Nuxt Integration

The @emulators/adapter-nuxt package embeds emulators directly into a Nuxt app, running them on the same origin. This is useful for preview deployments where OAuth callback URLs change with every deployment.

Install

npm install @emulators/adapter-nuxt @emulators/github @emulators/google

Only install the emulators you need. Each @emulators/* package is published independently, keeping server bundles small.

Server Route

Create a named catch-all route that serves emulator traffic:

// server/routes/emulate/[...path].ts
import { createEmulateHandler } from '@emulators/adapter-nuxt'
import * as github from '@emulators/github'
import * as google from '@emulators/google'

export default defineEventHandler(createEmulateHandler({
  services: {
    github: {
      emulator: github,
      seed: {
        users: [{ login: 'octocat', name: 'The Octocat' }],
        repos: [{ owner: 'octocat', name: 'hello-world', auto_init: true }],
      },
    },
    google: {
      emulator: google,
      seed: {
        users: [{ email: 'test@example.com', name: 'Test User' }],
      },
    },
  },
}))

This creates these routes:

/emulate/github/** serves the GitHub emulator
/emulate/google/** serves the Google emulator

GitHub installation-token metadata is available server-side at /emulate/github/_emulate/installation-tokens.

Nuxt Config

Emulator UI pages use bundled fonts. Wrap your Nuxt config so Nitro traces the core package assets into production builds:

// nuxt.config.ts
import { withEmulate } from '@emulators/adapter-nuxt'

export default defineNuxtConfig(withEmulate({
  // your normal Nuxt config
}))

OAuth Configuration

Point your OAuth provider at the emulator paths on the same origin:

const baseUrl = process.env.NUXT_PUBLIC_SITE_URL ?? 'http://localhost:3000'

export const githubOAuth = {
  clientId: 'any-value',
  clientSecret: 'any-value',
  authorizationUrl: `${baseUrl}/emulate/github/login/oauth/authorize`,
  tokenUrl: `${baseUrl}/emulate/github/login/oauth/access_token`,
  userInfoUrl: `${baseUrl}/emulate/github/user`,
}

No oauth_apps need to be seeded. When none are configured, the emulator skips client_id, client_secret, and redirect_uri validation.

Persistence

By default, emulator state is in-memory and resets on every cold start. To persist state across restarts, pass a persistence adapter.

Nitro Storage

import { createEmulateHandler } from '@emulators/adapter-nuxt'
import * as github from '@emulators/github'

const storageAdapter = {
  async load() { return await useStorage('emulate').getItem<string>('state') },
  async save(data: string) { await useStorage('emulate').setItem('state', data) },
}

export default defineEventHandler(createEmulateHandler({
  services: { github: { emulator: github } },
  persistence: storageAdapter,
}))

File Persistence

For local development, @emulators/core ships a file-based adapter:

import { filePersistence } from '@emulators/core'

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

GitHub App seeds may omit private_key. Retain the handler and call server-only generatedSecrets(); explicit keys are excluded. Keep persisted snapshots private and implement initialize atomically.

How Persistence Works

Cold start: The adapter loads state from the persistence adapter. If found, it restores the full Store and token map. If not found, it seeds from config and saves the initial state.
After mutating requests (POST, PUT, PATCH, DELETE): State is saved. Saves are serialized via an internal queue to prevent race conditions.
No persistence configured: Falls back to pure in-memory. Seed data re-initializes on every cold start.

How It Works

Incoming request: /emulate/github/login/oauth/authorize?client_id=...
Parse: service = github, rest = /login/oauth/authorize
Strip prefix: A new Request is created with the stripped path and forwarded to the GitHub service app
Rewrite response: HTML action and href attributes, CSS url() font references, and Location headers get the service prefix prepended
Persist: After mutating requests, state is saved via the persistence adapter

Limitations

Requires a Node-compatible Nuxt server runtime since emulators use Node APIs
Concurrent mutations use last-write-wins semantics. Generated identities require initialize to select the initial snapshot atomically across cold starts.

Config Reference

`createEmulateHandler(config, options?)`

Field	Type	Description
`services`	`Record<string, EmulatorEntry>`	Map of service name to emulator config
`persistence?`	`PersistenceAdapter`	Optional persistence adapter for state across cold starts

Each EmulatorEntry:

Field	Type	Description
`emulator`	`EmulatorModule`	The emulator package, such as `import * as github from '@emulators/github'`
`seed?`	`Record<string, unknown>`	Seed data matching the service's config schema

Options:

Option	Type	Default	Description
`param`	`string`	`"path"`	Named catch-all route param
`routePrefix`	`string`	detected	Path prefix where the catch-all route is mounted

`withEmulate(nuxtConfig)`

Wraps a Nuxt config to include @emulators/core assets in Nitro's production trace. Call it inside defineNuxtConfig in nuxt.config.ts.

`PersistenceAdapter`

interface PersistenceAdapter {
  load(): Promise<string | null>
  save(data: string): Promise<void>
  initialize?(data: string): Promise<string>
}

initialize must atomically create the initial value or return the value another instance created first. Implement it with compare-and-set semantics such as Redis SET NX. The built-in filePersistence(path) from @emulators/core provides this behavior for local development.

Not standalone. This skill ships with vercel-labs/emulate and only works together with that tool — install the tool first, then add this skill.

Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.

Install checklist

Check selected tools if a picker appears; Claude Code may be unchecked under Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms.
Without a tool picker, check Installing to: for your intended tool. Stop if it names a different tool.
If asked, choose Symlink (Recommended) for shared files or Copy to all agents for separate copies; review the summary before confirming installation.
Install the find-skills skill? defaults to Yes, adding another skill for all projects. Choose No if you don't want that extra installation.

Skills CLI 1.7.2 sends install data to skills.sh by default, including the source, skill names, target tools and file details; GitHub sources are reported only when GitHub confirms the repository is public, while other remote sources can also be reported. Confirmed-public GitHub sources also trigger a security-audit request. Before installing, set the environment variable DO_NOT_TRACK=1 or DISABLE_TELEMETRY=1 to disable both.

npx skills add vercel-labs/emulate --skill "nuxt" --full-depth

After installing for Claude Code, open it in the installation project if you chose Project; Global makes the skill available across projects on this computer. Once Claude Code loads the skill, its description helps Claude decide when to use it.

If installation created a top-level skills folder that did not exist when your Claude Code session started, run /reload-skills in that session. Run it again after later changes in that folder.

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Nuxt Integration

Install

Server Route

Nuxt Config

OAuth Configuration

Persistence

Nitro Storage

File Persistence

How Persistence Works

How It Works

Limitations

Config Reference

createEmulateHandler(config, options?)

withEmulate(nuxtConfig)

PersistenceAdapter

Local tool required

More skills

apple

aws

emulate

github

google

linear

MCP keyword matches

Nuxt MCP Dev

`createEmulateHandler(config, options?)`

`withEmulate(nuxtConfig)`

`PersistenceAdapter`