Agent Skill · Android
r8-analyzer
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.
Skill body
Step 1. Setup and configuration check
- Inspect
build.gradle,build.gradle.kts, andgradle.properties. - Use references/CONFIGURATION.md to identify missing optimizations.
- AGP : If < 9.0, suggest migration to 9.0 for build time improvement performance
- Full Mode : Verify
android.enableR8.fullMode=falseis removed from gradle.properties.
Step 2. Analysis path selection
-
Inspect
build.gradle,build.gradle.kts, andgradle.propertiesandlibs.versions.tomlto get the R8 version -
If R8 >= 9.3.7-dev : Proceed to Path A (Quantitative).
-
If R8 < 9.3.7-dev : Proceed to Path B (Heuristic).
Path A: Quantitative data generation (R8 >= 9.3.7-dev)
- Check requirements : Python and
protobufpackage are mandatory. - Generate and analyze : You MUST run the shell commands described in references/CONFIGURATION-ANALYZER.md to generate the proto file using R8 configuration analyzer, convert it to json and analyze the result.
- Report : Rely entirely on the generated file
analysis.txtfor scores and rule impact metrics. Proceed to Step 3.
Path B: Heuristic evaluation and recommendation (R8 < 9.3.7-dev)
(Use ONLY if quantitative data generation is not possible)
- Manual evaluation : Inspect
proguard-rules.pro. - Library check : Compare rules against references/REDUNDANT-RULES.md. Suggest Remove for bundled rules.
- 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).
- 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) directly from generated file analysis.txt if using Path A, or from manual findings if using Path B.
- 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.
Skill frontmatter
license: Complete terms in LICENSE.txt
metadata: {"author"=>"Google LLC", "last-updated"=>"2026-05-19", "keywords"=>["R8", "proguard", "keep rules", "app size", "optimization"]}