This directory contains golden files for the APIs exposed by the platform at each API level. The covered APIs include those exposed directly to developers in the IDK/SDK and indirectly via prebuilts in the IDK/SDK. Additionally, any API that has compatibility checks, such as those used by host tools and for CTF test configuration, are covered. (See SDK categories for more information.)
There is a subdirectory for each API level in the Supported or Sunset phase plus NEXT. See Numerical subdirectory addition and removal.
For FIDL libraries, there is a golden <library_name.api_summary.json file for each API level. If a library is not supported at a specific API level, the corresponding file will be empty. This correlates with the presence of generated files (e.g., build rules and C header files) when targeting any Supported API level in the SDK, even when the API is not supported. For unstable FIDL libraries, the golden files for all API levels are empty.
For shared object libraries, there is a golden lib<library_name>.ifs file for each API level that represents the functions exposed by the library at that specific API level.
Source and static libraries are not yet covered by golden files.
No changes to the files in the numerical sub-directories are allowed as these represent part of the Fuchsia System Interface for that API level. The exceptions are the addition or removal of empty files when a library is added to or removed from, respectively, the SDK at NEXT.
Note: Currently, there are very rare occasions where exceptions are made due to limitations of the implementation of versioning mechanisms or, for example to remove APIs that were never implemented. Over time, this will no longer be relevant or allowed.
All changes to these directories should be explained in the commit message.
A very limited set of approvers in FROZEN_API_LEVEL_OWNERS enforce this policy.
NEXT API levelAll changes must go through API review. This is enforced by FROZEN_API_LEVEL_OWNERS.
When adding new files, the library API must have gone through API calibration unless it is unstable.
New numerical API level subdirectories are added when a new stable API level is created. Existing numerical API level sub-directories are removed when an API level is retired and ABI compatibility for the level is no longer required.