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: testuser@icloud.com
name: Test User
given_name: Test
family_name: User
- email: private@example.com
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.