Skip to main content

Call verification banner

Call verification is the Revolut-style anti-impersonation flow. When your app is in the foreground and an active call is in progress, the SDK queries Relavoi to confirm the call is a legitimate masked call for this user. You then display a banner accordingly.

How it works​

  1. The SDK registers a TelephonyManager listener on init
  2. When the OS reports an off-hook state, the SDK records a flag
  3. When the user opens your app while the flag is active, call Relavoi.verification.verify(userPhone)
  4. The SDK hashes the phone with the tenant salt and hits GET /v1/sessions/verify
  5. You receive a VerificationResult indicating verified or not, with optional context text

Basic usage​

VerificationResult is a plain data class — not a sealed hierarchy. Read the verified boolean and use the bannerText helper for a ready-to-display label.

import com.relavoi.sdk.Relavoi
import com.relavoi.sdk.session.VerificationResult

class HomeFragment : Fragment() {
  override fun onResume() {
    super.onResume()
    if (Relavoi.verification.isCallActive()) {
      viewLifecycleOwner.lifecycleScope.launch {
        val result = Relavoi.verification.verify(userPhone = "+2348087654321")
        showBanner(result)
      }
    }
  }

  private fun showBanner(result: VerificationResult) {
    if (result.verified) {
      banner.setBackgroundColor(Color.GREEN)
      // bannerText falls back to "Verified call" when no context string is present.
      banner.text = result.bannerText ?: "Verified call"
    } else {
      banner.setBackgroundColor(Color.RED)
      banner.text = "Warning: this call is not verified"
    }
  }
}

The fields available on VerificationResult are verified: Boolean, context: String?, sessionId: String?, proxyNumber: String?, and expiresAt: String?, plus the derived bannerText: String?.

:::note About context The backend does not currently populate the context string, so bannerText returns the generic "Verified call" for verified results today. Do not hard-code a brand name from the result. :::

Re-checking on resume​

CallVerificationManager does not expose a call-state observer. Poll isCallActive() at natural UI moments — typically onResume() — and call verify() when a call is in progress, as shown above. The SDK installs its own TelephonyManager call-state observer internally at initialize() time to keep isCallActive() current.

Permission notes​

READ_PHONE_STATE is required for the SDK to detect call state. See Permissions for the runtime-request snippet. If permission is denied:

  • Relavoi.verification.isCallActive() can never become true, so verification never auto-fires
  • Use Relavoi.verification.hasPhoneStatePermission(context) to check the grant and prompt the user
if (!Relavoi.verification.hasPhoneStatePermission(requireContext())) {
  // Route the user through the runtime permission request.
}

:::tip UX guidance Show the green banner only after verify() returns Verified — never assume the call is legitimate just because one is in progress. The red banner has even more value than the green one: customers learn to trust the warning. :::