Skill v1.0.1

version: "1.0.1" name: r8-analyzer description: Analyzes Android build files and R8 keep rules to identify redundancies, broad package-wide rules, and rules that subsume library consumer keep rules. Use when developers want to optimize their app's size, remove redundant or overly broad keep rules, or troubleshoot Proguard configurations. license: Complete terms in LICENSE.txt metadata: author: Google LLC last-updated: '2026-08-06' keywords:

• R8
• proguard
• keep rules
• app size
• optimization

Step 1. Setup and configuration check

• Inspect build.gradle, build.gradle.kts, and gradle.properties.
• Use references/CONFIGURATION.md to identify missing optimizations.
• AGP : If version is lower than 9.0, suggest migration to 9.0 for build-time performance improvement.
• Full Mode : Verify android.enableR8.fullMode=false is removed from gradle.properties.

Step 2. Analysis path selection

• Inspect build.gradle, build.gradle.kts, gradle.properties, libs.versions.toml, and the top-level settings.gradle or settings.gradle.kts to get the AGP and R8 versions. An explicit com.android.tools:r8 version in the settings file overrides the version embedded in AGP.

• If AGP \>= 9.3.0 : Proceed to Path A (Standalone Task).

• If AGP \< 9.3.0 and R8 \>= 9.3.7-dev : Proceed to Path B (Quantitative).

• If none of the conditions are met, proceed to Path C (Heuristic).

Path A: Standalone Gradle task (AGP \>= 9.3.0)

• Step 1: Run standalone task : Run ./gradlew :app:analyzeReleaseR8Config to evaluate the R8 configuration. You MUST wait for this command to finish before proceeding.
• Step 2: Analyze : Read the generated HTML report at app/build/reports/r8/r8-config-analyzer-release.html for scores and rule impact metrics.

Path B: Quantitative data generation (R8 \>= 9.3.7-dev and AGP \< 9.3.0)

• Step 1: Generate report : Run mkdir -p "$PWD/tmp/r8analysis" && ./gradlew assembleRelease -Dcom.android.tools.r8.dumpkeepradiushtmltodirectory="$PWD/tmp/r8analysis". You MUST wait for this command to finish before proceeding.
• Step 2: Analyze : Read the generated HTML report in tmp/r8analysis/ for scores and rule impact metrics.

Path C: Heuristic evaluation and recommendation (R8 \< 9.3.7-dev)

(Use ONLY if quantitative data generation is not possible)

• Step 1: Manual evaluation : Inspect proguard-rules.pro.
• Step 2: Library check : Compare rules against references/REDUNDANT-RULES.md. Suggest Remove for bundled rules.
• Step 3: Custom rule check : Use references/KEEP-RULES-IMPACT-HIERARCHY.md and references/REFLECTION-GUIDE.md to prioritize and evaluate. Suggest Refine for broad rules (for example, package-wide).
• Step 4: Validation : Suggest Macrobenchmark tests using UI Automator for any proposed changes. Proceed to Step 3.

Step 3. Report generation

• Format : Follow references/REPORT_FORMAT.md strictly.
• Input: Extract metrics (Scores, Impacts, Example Classes) from the generated HTML report if using Path A or Path B, or from manual findings if using Path C.
• Output : Output ONLY the raw Markdown report in the chat. Do NOT output conversational filler (for example, "Here is your report..."). Do NOT provide recommendations, next steps, or any other text outside of the sections defined in references/REPORT_FORMAT.md Do NOT mention the path used for analysis of the configuration

Constraints

• Strict output limit: The final output MUST strictly be the Markdown report and nothing else.
• No code changes: Research and suggest only; Do not modify files.
• No redundancy: Do not explain R8 benefits or reference skill internal files in the report.
• Focus: Omit sections (for example, Subsumed Rules, Configuration) if no issues or items are found.