Developer Preview 1 was the first Android 8.1 build, released on 25 October 2017. It already had final APIs: Google called API level 27 “already finalized” and opened Google Play to apps compiled against or targeting it that day.
| Release date | 25 October 2017 |
| Build | OPP5.170921.005 |
| Devices | Pixel 2, Pixel 2 XL, Pixel, Pixel XL, Pixel C, Nexus 5X and Nexus 6P, through the Android Beta Program; the Android Emulator |
| Google Play services | 11.5.76 |
| Platform stability | Yes, from this build: API level 27 was final |
Google’s post listed four API areas: the Android Go memory optimizations and
the low-RAM hardware feature constants, the Neural Networks API in the NDK,
Autofill changes such as setAutofillOptions() for spinners, and the
SharedMemory API. The release notes add a Wear change shipped alongside it:
the AmbientMode headless fragment, so a Wear app no longer has to extend
WearableActivity to stay visible in ambient mode. Google recommended
Android Studio 3.0 and Support Library 27.0.0 to build against API 27.
Known issues in Developer Preview 1
- Pixel 2 factory images. A bootloader configuration issue stopped this build from being flashed onto a Pixel 2; Google told owners to enrol in the Android Beta Program instead.
- Neural Networks API.
ANeuralNetworksModel_identifyInputsAndOutputs()could not be resolved in this build. Developer Preview 2 fixed it. - Pixel Visual Core. Pixel 2 owners could not try it yet. Android Police reported on 1 November that the “Camera HAL HDR+” developer option only appeared on debug builds, and that Google had updated its notes to say testing would start with Developer Preview 2.