ObjectBox C / C++ Database
This is the ObjectBox documentation for our C and C++ APIs. We strive to provide you with the easiest and fastest solution to store and retrieve data.
Are you ready use ObjectBox? These two pages will get you up to speed:

Latest Versions (Changelogs)

V0.15.1 (2021-01-26)

  • Fix non-unique indexes triggering unique constraint violations in corner cases (requires at least two unique constraints in an entity and a specific order; introduced in 0.15.0)
  • Admin UI now supports multiple sessions to the same host using different ports (session ID via HTTP request)
  • Minor performance improvements with hashed indexes


  • Performance improvements for compression and decompression

V0.15.0 (2021-12-09)

  • New "Flex" data type that can contain data of various types like integers, floating points, strings, lists and maps
  • New query conditions for Flex lists to find a specific element
  • New query conditions for Flex maps to find elements with a specific key or key/value pair
  • New unique on-conflict strategy: replace conflicting objects (OBXPropertyFlags_UNIQUE_ON_CONFLICT_REPLACE)
  • New functions to attach to existing stores using only the file path (in the same process)
  • New APIs for ObjectBox Admin, the web based UI (formerly known as Object Browser): obx_admin_*
  • Minor performance improvements for indexed access
  • Major performance improvements for tree/GraphQL queries
  • ARM binaries are now built for minimal size reducing the library size significantly
  • New "no_reader_thread_locals" store option
  • Enable debug logging (requires a special build)
  • API: Type for query offsets and limits was changed from uint64_t to size_t
  • API: rarely used obx_txn_mark_success() was removed; use obx_txn_success()
  • API: feature checks consolidated to only use obx_has_feature()
  • Many internal improvements
  • Core version 3.0.1-2021-12-09


  • New API for embedded server mode: obx_sync_server_* (implementation available on request)

Earlier Versions

The changelogs of earlier versions are available as part of the GitHub releases.
Provides native dynamic/shared library (.so/.dylib/.dll)
  • Provides C & C++ headers (objectbox.h & objectbox.hpp)

ObjectBox Generator

Check the ObjectBox Generator releases for details.
Last modified 32m ago