---
title: "Libraries"
canonical_url: https://developer.repebble.com/pebbleos/docs/libraries/
last_updated: 2026-10-21
sdk_version: 4.33.1
---
# Libraries

Source: https://developer.repebble.com/pebbleos/docs/libraries/

Generic support code shared by the firmware, the bootloader and host builds lives under `lib/`. It depends on no OS service, so it is also what the unit tests link against directly.

- **Utilities** : `lib/util`, included as `pbl/util/<module>.h`; see [the API reference](https://developer.repebble.com/pebbleos/apidoc/d4/d3a/group__util.html).

- **Shared definitions** : headers under `include/pebbleos/` describe data exchanged with the bootloader and host tooling, so their layout is fixed; see [the API reference](https://developer.repebble.com/pebbleos/apidoc/d8/d3e/group__pebbleos.html).

Generated from PebbleOS [3a7b71785](https://github.com/coredevices/pebbleos/commit/3a7b71785fd439666c4a8bc116f561140e8dec01). This page is maintained in the pebbleos repository: [docs/libraries/index.md](https://github.com/coredevices/pebbleos/blob/3a7b71785fd439666c4a8bc116f561140e8dec01/docs/libraries/index.md).