next
Next.js Integration
The @emulators/adapter-next package embeds emulators directly into a Next.js App Router app, running them on the same origin. This is particularly useful for Vercel preview deployments where OAuth callback URLs change with every deployment.
Install
npm install @emulators/adapter-next @emulators/github @emulators/google
Only install the emulators you need. Each @emulators/* package is published independently, keeping serverless bundles small.
Route Handler
Create a catch-all route that serves emulator traffic:
// app/emulate/[...path]/route.ts
import { createEmulateHandler } from '@emulators/adapter-next'
More from vercel-labs/emulate
google
Emulated Google OAuth 2.0, OpenID Connect, Gmail, Calendar, and Drive for local development and testing. Use when the user needs to test Google sign-in locally, emulate OIDC discovery, handle Google token exchange, configure Google OAuth clients, work with Gmail messages/drafts/threads/labels, manage Calendar events, upload or list Drive files, or work with Google userinfo without hitting real Google APIs. Triggers include "Google OAuth", "emulate Google", "mock Google login", "test Google sign-in", "OIDC emulator", "Google OIDC", "Gmail API", "Google Calendar", "Google Drive", "local Google auth", or any task requiring a local Google API.
77emulate
Local drop-in API emulator for Vercel, GitHub, Google, Slack, Apple, Microsoft, and AWS. Use when the user needs to start emulated services, configure seed data, write tests against local APIs, set up CI without network access, or work with the emulate CLI or programmatic API. Triggers include "start the emulator", "emulate services", "mock API locally", "create emulator config", "test against local API", "npx emulate", or any task requiring local service emulation.
59resend
Emulated Resend email API for local development and testing. Use when the user needs to send emails locally, test transactional email flows, implement magic link or verification code auth, inspect sent emails, manage domains/contacts/API keys, or work with the Resend API without sending real emails. Triggers include "Resend API", "emulate Resend", "send email locally", "test email", "magic link", "verification email", "email inbox", "RESEND_BASE_URL", or any task requiring a local email API.
52github
Emulated GitHub REST API for local development and testing. Use when the user needs to interact with GitHub API endpoints locally, test GitHub integrations, emulate repos/issues/PRs, set up GitHub OAuth flows, configure GitHub Apps, test webhooks, or work with actions/checks without hitting the real GitHub API. Triggers include "GitHub API", "emulate GitHub", "mock GitHub", "test GitHub OAuth", "GitHub App JWT", "local GitHub", or any task requiring a local GitHub API.
36aws
Emulated AWS cloud services (S3, SQS, IAM, STS) for local development and testing. Use when the user needs to interact with AWS API endpoints locally, test S3 bucket and object operations, emulate SQS queues and messages, manage IAM users/roles/access keys, test STS assume role, or work without hitting real AWS APIs. Triggers include "AWS emulator", "emulate AWS", "mock S3", "local SQS", "test IAM", "emulate S3", "AWS locally", "STS assume role", or any task requiring local AWS service emulation.
31stripe
Emulated Stripe API for local development and testing. Use when the user needs to process payments locally, test checkout flows, create customers, manage products and prices, handle payment intents, work with webhooks, or use the Stripe SDK without hitting real Stripe servers. Triggers include "Stripe API", "emulate Stripe", "test payments locally", "checkout flow", "payment intent", "Stripe webhook", "Stripe SDK", "STRIPE_API_KEY", or any task requiring a local Stripe API.
30