DeviceCheck

Elixir client for the Apple DeviceCheck API.

It supports the server-side DeviceCheck endpoints for:

• validating a device token from DCDevice
• querying the two Apple-hosted fraud bits
• updating one or both bits

Installation

Add to your mix.exs:

defp deps do
  [
    {:device_check, "~> 0.1.0"}
  ]
end

Configuration

config :device_check,
  team_id: System.get_env("APPLE_TEAM_ID"),
  key_id: System.get_env("DEVICE_CHECK_KEY_ID"),
  private_key_path: System.get_env("DEVICE_CHECK_PRIVATE_KEY_PATH"),
  development: true

Supported options:

• team_id - Apple Developer Team ID
• key_id - DeviceCheck key ID
• private_key - inline .p8 contents
• private_key_path - path to the .p8 file
• development - true for api.development.devicecheck.apple.com
• token_ttl_seconds - defaults to 3600

Quick Start

# Generate the JWT used for DeviceCheck requests
{:ok, token} = DeviceCheck.token()

# Validate a device token from the client app
{:ok, _} = DeviceCheck.validate_token(device_token)

# Query current bit state
{:ok, result} = DeviceCheck.query_bits(device_token)

# Update one or both bits
{:ok, _} = DeviceCheck.update_bits(device_token, bit0: true, bit1: false)

Request Metadata

The client automatically generates:

• transaction_id
• timestamp in milliseconds

You can override them when needed:

DeviceCheck.validate_token(device_token,
  transaction_id: "123e4567-e89b-12d3-a456-426614174000",
  timestamp: 1_700_000_000_000
)

Live Testing

Run the included smoke test:

cd device_check
elixir test_live.exs

To exercise Apple’s live endpoints, set a real device token in .env:

export DEVICE_CHECK_TEST_DEVICE_TOKEN="base64-token-from-dcdevice"

Notes

• query_bits/2 returns {:ok, :bit_state_not_found} when Apple has no stored bit state yet.
• update_bits/2 requires at least one of bit0 or bit1.
• Device tokens come from the client app via DCDevice, not from this library.

License

MIT