apple

Apple Sign In Emulator

Sign in with Apple emulation with authorization code flow, PKCE support, RS256 ID tokens, and OIDC discovery.

Start

Local listeners bind to 127.0.0.1 by default. For access from containers or other machines, pass --host 0.0.0.0 to the CLI or hostname: '0.0.0.0' to createEmulator. Configure --base-url or baseUrl for advertised URLs reachable by those clients.

# Apple only
npx emulate --service apple

# Default port (when run alone)
# http://localhost:4000

Or programmatically:

import { createEmulator } from 'emulate'

const apple = await createEmulator({ service: 'apple', port: 4004 })
// apple.url === 'http://localhost:4004'

Pointing Your App at the Emulator

Environment Variable

APPLE_EMULATOR_URL=http://localhost:4004

OAuth URL Mapping

Real Apple URL	Emulator URL
https://appleid.apple.com/.well-known/openid-configuration	$APPLE_EMULATOR_URL/.well-known/openid-configuration
https://appleid.apple.com/auth/authorize	$APPLE_EMULATOR_URL/auth/authorize
https://appleid.apple.com/auth/token	$APPLE_EMULATOR_URL/auth/token
https://appleid.apple.com/auth/keys	$APPLE_EMULATOR_URL/auth/keys
https://appleid.apple.com/auth/revoke	$APPLE_EMULATOR_URL/auth/revoke

Auth.js / NextAuth.js

import Apple from '@auth/core/providers/apple'

Apple({
  clientId: process.env.APPLE_CLIENT_ID,
  clientSecret: process.env.APPLE_CLIENT_SECRET,
  authorization: {
    url: `${process.env.APPLE_EMULATOR_URL}/auth/authorize`,
    params: { scope: 'openid email name', response_mode: 'form_post' },
  },
  token: {
    url: `${process.env.APPLE_EMULATOR_URL}/auth/token`,
  },
  jwks_endpoint: `${process.env.APPLE_EMULATOR_URL}/auth/keys`,
})

Passport.js

import { Strategy as AppleStrategy } from 'passport-apple'

const APPLE_URL = process.env.APPLE_EMULATOR_URL ?? 'https://appleid.apple.com'

new AppleStrategy({
  clientID: process.env.APPLE_CLIENT_ID,
  teamID: process.env.APPLE_TEAM_ID,
  keyID: process.env.APPLE_KEY_ID,
  callbackURL: 'http://localhost:3000/api/auth/callback/apple',
  authorizationURL: `${APPLE_URL}/auth/authorize`,
  tokenURL: `${APPLE_URL}/auth/token`,
}, verifyCallback)

Seed Config

apple:
  users:
    - email: [email protected]
      name: Test User
      given_name: Test
      family_name: User
    - email: [email protected]
      name: Private User
      is_private_email: true
  oauth_clients:
    - client_id: com.example.app
      team_id: TEAM001
      name: My Apple App
      redirect_uris:
        - http://localhost:3000/api/auth/callback/apple

When no OAuth clients are configured, the emulator accepts any client_id. With clients configured, strict validation is enforced for client_id and redirect_uri.

Users with is_private_email: true get a generated @privaterelay.appleid.com email in the id_token instead of their real email.

API Endpoints

OIDC Discovery

curl http://localhost:4004/.well-known/openid-configuration

Returns the standard OIDC discovery document with all endpoints pointing to the emulator:

{
  "issuer": "http://localhost:4004",
  "authorization_endpoint": "http://localhost:4004/auth/authorize",
  "token_endpoint": "http://localhost:4004/auth/token",
  "jwks_uri": "http://localhost:4004/auth/keys",
  "revocation_endpoint": "http://localhost:4004/auth/revoke",
  "response_types_supported": ["code"],
  "subject_types_supported": ["pairwise"],
  "id_token_signing_alg_values_supported": ["RS256"],
  "scopes_supported": ["openid", "email", "name"],
  "token_endpoint_auth_methods_supported": ["client_secret_post"],
  "response_modes_supported": ["query", "fragment", "form_post"]
}

JWKS

curl http://localhost:4004/auth/keys

Returns an RSA public key (kid: emulate-apple-1) for verifying id_token signatures.

Authorization

# Browser flow: redirects to a user picker page
curl -v "http://localhost:4004/auth/authorize?\
client_id=com.example.app&\
redirect_uri=http://localhost:3000/api/auth/callback/apple&\
scope=openid+email+name&\
response_type=code&\
state=random-state&\
nonce=random-nonce&\
response_mode=form_post"

Query parameters:

Param	Description
client_id	OAuth client ID (Apple Services ID)
redirect_uri	Callback URL
scope	Space-separated scopes (openid email name)
state	Opaque state for CSRF protection
nonce	Nonce for ID token (optional)
response_mode	query (default), form_post, or fragment

The emulator renders an HTML page where you select a seeded user. After selection, it redirects (or auto-submits a form for form_post) to redirect_uri with code and state. On the first authorization per user/client pair, a user JSON blob is also included (matching Apple's real behavior).

Token Exchange

curl -X POST http://localhost:4004/auth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "code=<authorization_code>&\
client_id=com.example.app&\
client_secret=<client_secret>&\
grant_type=authorization_code"

Returns:

{
  "access_token": "apple_...",
  "refresh_token": "r_apple_...",
  "id_token": "<jwt>",
  "token_type": "Bearer",
  "expires_in": 3600
}

The id_token is an RS256 JWT containing sub, email, email_verified (string), is_private_email (string), real_user_status, auth_time, and optional nonce.

Refresh Token

curl -X POST http://localhost:4004/auth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "refresh_token=r_apple_...&\
client_id=com.example.app&\
grant_type=refresh_token"

Returns a new access_token and id_token. No new refresh_token is issued on refresh (matching Apple's behavior).

Token Revocation

curl -X POST http://localhost:4004/auth/revoke \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "token=apple_..."

Returns 200 OK. The token is removed from the emulator's token map.

Common Patterns

Full Authorization Code Flow

APPLE_URL="http://localhost:4004"
CLIENT_ID="com.example.app"
REDIRECT_URI="http://localhost:3000/api/auth/callback/apple"

# 1. Open in browser (user picks a seeded account)
#    $APPLE_URL/auth/authorize?client_id=$CLIENT_ID&redirect_uri=$REDIRECT_URI&scope=openid+email+name&response_type=code&state=abc&response_mode=form_post

# 2. After user selection, emulator posts to:
#    $REDIRECT_URI with code=<code>&state=abc (and user JSON on first auth)

# 3. Exchange code for tokens
curl -X POST $APPLE_URL/auth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "code=<code>&client_id=$CLIENT_ID&grant_type=authorization_code"

# 4. Decode the id_token JWT to get user info

Private Relay Email

When a user has is_private_email: true in the seed config, the id_token will contain a generated @privaterelay.appleid.com email instead of the user's real email. This matches Apple's Hide My Email behavior.

Custom emulators alongside built-ins

Use npx emulate init --custom inventory to scaffold a third-party API emulator and test. Register it in emulate.config.ts with defineConfig from emulate, alongside built-in entries such as { emulator: "apple" }. Run npx emulate start --watch to reload imports and inspect custom state at the printed /_emulate URL. Successful reloads reset the run to seed. Existing flat seed configs still work; --config selects an explicit file. For authoring and testing third-party API emulators, see https://emulate.dev/docs/custom-emulators.