> ## Documentation Index
> Fetch the complete documentation index at: https://setup.despia.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Identity

> Tie attribution and events to your own user IDs, pass hashed email and phone for audience matching, and read the AppsFlyer device ID.

Identity commands connect AppsFlyer's device-level attribution to your own user model. Everything here is forwarded to the native SDK. Email and phone are SHA256-hashed on the device before transmission, so raw PII never leaves the app.

## Installation

<Tabs>
  <Tab title="Bundle">
    <CodeGroup>
      ```bash npm theme={null}
      npm install despia-native
      ```

      ```bash pnpm theme={null}
      pnpm add despia-native
      ```

      ```bash yarn theme={null}
      yarn add despia-native
      ```
    </CodeGroup>

    ```javascript theme={null}
    import despia from 'despia-native';
    ```
  </Tab>

  <Tab title="CDN">
    <CodeGroup>
      ```html UMD theme={null}
      <script src="https://cdn.jsdelivr.net/npm/despia-native/index.min.js"></script>
      ```

      ```html ESM theme={null}
      <script type="module">
          import despia from 'https://cdn.jsdelivr.net/npm/despia-native/+esm'
      </script>
      ```
    </CodeGroup>
  </Tab>
</Tabs>

***

## set\_user\_id

Call as soon as the user signs up or logs in. All subsequent events carry your internal user ID across AppsFlyer, Meta, and TikTok reporting, and raw-data exports become joinable with your own database.

```javascript theme={null}
const userId = "user_123"
despia("appsflyer://set_user_id?customer_user_id=" + encodeURIComponent(userId))
```

<ParamField path="customer_user_id" type="string" required>
  Your internal, stable user identifier. Avoid emails or anything that changes.
</ParamField>

***

## set\_email

Passes the user's email for audience matching. The value is normalized and SHA256-hashed natively before it is sent.

```javascript theme={null}
const email = "user@example.com"
despia("appsflyer://set_email?email=" + encodeURIComponent(email))
```

<Info>
  Lowercase and trim the email in your web layer before sending. Hashes only match across systems when the input is normalized identically everywhere.
</Info>

***

## set\_phone

Passes the user's phone number, SHA256-hashed natively and attached to the user's event data as `phone_hash`.

```javascript theme={null}
const phone = "+15550001234"
despia("appsflyer://set_phone?phone=" + encodeURIComponent(phone))
```

<Info>
  Send phone numbers in E.164 format (`+<country code><number>`, no spaces or dashes) so hashes are consistent.
</Info>

***

## get\_uid

Reads the AppsFlyer device ID. It is already injected on every page load as `despia.appsFlyerUID`. Use the await pattern when you need a guaranteed-fresh value inline:

```javascript theme={null}
const data = await despia("appsflyer://get_uid", ["appsFlyerUID"])
const uid = data.appsFlyerUID
// e.g. store next to the user record for server-to-server events
await fetch("/api/users/me/af-uid", { method: "POST", body: uid })
```

***

## Recommended order

<Steps>
  <Step title="Consent first">
    Forward the user's cookie-banner choice with [set\_consent](/analytics/appsflyer/consent) before identifying or logging anything.
  </Step>

  <Step title="Identify at signup or login">
    `set_user_id`, then `set_email` and `set_phone` if you have them.
  </Step>

  <Step title="Log events">
    Everything from here on is tied to the user. See [Events](/analytics/appsflyer/events).
  </Step>
</Steps>

***

## Resources

<CardGroup cols={2}>
  <Card title="NPM Package" icon="npm" href="https://www.npmjs.com/package/despia-native">
    despia-native
  </Card>

  <Card title="Support" icon="envelope" href="mailto:support@despia.com">
    [support@despia.com](mailto:support@despia.com)
  </Card>
</CardGroup>