Identity and devices

OpenCDP mobile SDKs use three different identifiers. Confusing them is the most common cause of “push not received” during testing.

Person ID (`identifier`)

What it is: The user ID you pass to identify(). This is how OpenCDP knows who the person is.

Where to use it:

Console Test push notification → Test by User ID
Server sendPush({ identifiers: { id: '...' } })
In-app sync (query param person_id in API calls)

Rules:

Must not be an email address
Must be consistent across identify, push targeting, and campaigns

Example:

await OpenCDPSDK.instance.identify(
  identifier: 'user_123',
  properties: {
    'email': '[email protected]',
    'plan': 'pro',
  },
);

How to find it during testing:

Enter it on the example app config screen before initializing
Read it from the example app status panel (Flutter / React Native)
With debug: true, look for person_id= in SDK log URLs

Device ID (`deviceId`)

What it is: A stable ID for the physical device, generated by the SDK and sent in the registerDevice API body. It is not the same as the person ID or the FCM/APNs token.

How it is generated (mobile SDKs):

MD5("{device_model}-{manufacturer}-{identifier}")

Where identifier is the current person ID if identified, otherwise an anonymous device identifier stored locally.

Where it is used:

POST /v1/persons/registerDevice payload field deviceId
Server-side registerDevice when registering tokens manually

How to inspect it:

Enable debug: true and trace the registerDevice network request body
It is not shown in example app UIs by default

You typically do not need the device ID to send a push from the console — use the person ID instead.

Push token (FCM / APNs)

What it is: The platform push registration token from Firebase (Android) or Apple (iOS). Required for the OS to deliver notifications to the device.

Where to use it:

Pass to registerDeviceToken(fcmToken: ...) or registerDeviceToken(apnToken: ...)
Console Test push notification → Enter Device Token (direct device test, bypasses user lookup)

How to obtain it:

Platform	Source
Android	`FirebaseMessaging.getInstance().token` or `onNewToken` in your `FirebaseMessagingService`
iOS	`application(_:didRegisterForRemoteNotificationsWithDeviceToken:)` in AppDelegate
Flutter	Firebase Messaging / turnkey `setupPushNotifications`
React Native	Firebase Messaging or Expo notifications — then call `registerDeviceToken`

Quick reference

ID	Purpose	Console test field	Example value
Person ID	Who receives the message	User ID	`user_123`
Device ID	Device record in CDP	— (automatic)	`a1b2c3...` (MD5 hash)
FCM/APNs token	OS delivery	Device Token	Long platform string

Register device flow

When you call registerDeviceToken, the SDK sends:

{
  "identifier": "user_123",
  "deviceId": "<sdk-generated-md5>",
  "platform": "android",
  "fcmToken": "<token>",
  "apnToken": null,
  "model": "Pixel 8",
  "osVersion": "14",
  "appVersion": "1.0.0"
}

Both person ID and push token must be registered before push delivery works reliably.

Person ID (identifier)​

Device ID (deviceId)​

Push token (FCM / APNs)​

Quick reference​

Register device flow​

Related​

Person ID (`identifier`)

Device ID (`deviceId`)

Push token (FCM / APNs)

Quick reference

Register device flow

Related