Android API Diff

Android API Diff

Use the android-api-diff CLI as the only tool interface. Keep its default JSON output so results remain machine-readable.

Route the request

• Run generate when the user wants Java hidden-API access code. It performs the version query internally, so never call query first.
• Run query when the user wants signatures, version ranges, availability, missing reasons, or source metadata.
• Run resolve when the user only needs the matching frameworks/base file and target kind.
• Run source when the user wants the complete content of a known source path at an exact Android release tag. If only an API name is known, run resolve first and use its source.path.
• Run preload only when the user explicitly asks to preload several APIs.

Always quote API names because constructors and member references can contain shell-sensitive characters.

android-api-diff resolve "ContentObserver()"
android-api-diff source android-17.0.0_r1 core/java/android/accessibilityservice/AccessibilityButtonController.java
android-api-diff query "IActivityManager.getTasks" --min-sdk 28
android-api-diff generate "ActivityThread.currentApplication" --min-sdk 28
android-api-diff preload "ContentObserver()" "IActivityManager.getTasks" --min-sdk 28

Omit --min-sdk unless the user provides a minimum Android API level. The CLI then uses its built-in default.

Interpret results

Treat exit code 0 together with top-level ok: true as success. Read the operation result from the top-level result field.

For query, describe range endpoints as the first or last tag checked in the current snapshot. A last-checked endpoint is not a promise that no later revision exists.

For member queries, treat result.overloads as the source of truth. Each item has a stable overloadId, its latest checked signature and member, and independent ranges. A range with missingReason: "overload-not-found" means the member name exists in that source revision but that specific parameter signature does not. Use top-level result.ranges[].overloadIds only when describing which overloads were available together.

On a nonzero exit code, read the structured JSON error from stderr and report its error.code and error.message. Do not add an automatic retry: the CLI network layer already retries transient fetches.

Handle a missing CLI

If android-api-diff is not installed, stop and tell the user to run:

npm install --global android-api-diff@latest
android-api-diff skill install

Run the Skill command from the root of the current Git or Gradle project so it remains project-scoped. Do not implement or simulate version checks. The package manager owns CLI update detection and upgrades.