r8-analyzer

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha ba2d4bc1b905 · 31 Oct 2026Report an issue or request a re-scan

• Publisherandroid GitHub organizationOwner of the repository this skill is read from
• Source folderandroid/skills/performance/r8-analyzerThe exact folder we audited
• LicenceApache-2.0As the repository states it
• Commit pinned for this verdictba2d4bc1b905A new audit runs when the source changes
• Repository statusNot archivedLast push 1 day ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Analyzes Android build files and R8 keep rules to identify redundancies,

---
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
  this skill when developers want to optimize their Android app's size, remove redundant
  or overly broad keep rules, or troubleshoot ProGuard configurations. Don't use for
  general Gradle build errors, Compose UI performance, or runtime CPU profiling.
license: Complete terms in LICENSE.txt
metadata:
  author: Google LLC
  last-updated: '2026-10-24'
  keywords:
  - R8
  - proguard
  - keep rules
  - app size
  - optimization
  - shrinking
  - minification
  - obfuscation
---

## Step 1. Setup and configuration check

- Inspect `build.gradle`, `build.gradle.kts`, and `gradle.properties`.
- Use [references/CONFIGURATION.md](references/CONFIGURATION.md) to identify missing optimizations.
- **AGP** : If the version is lower than 9.3, suggest migration to 9.3 for the simplified [`optimization {}` DSL](references/android/topic/performance/app-optimization/enable-app-optimization.md) and the Configuration Analyzer task.
- **Full mode** : Verify `android.enableR8.fullMode=false` is removed from the `gradle.properties` file.

## Step 2. Analysis path selection

- Inspect `build.gradle`, `build.gradle.kts`, `settings.gradle`, `settings.gradle.kts`, `gradle.properties`, and `libs.versions.toml` to get the AGP and R8 versions. An R8 version pinned in `settings.gradle(.kts)` replaces the R8 bundled with AGP.
- Find the app module (usually `app`) and a build variant with R8 enabled (usually `release`). The following commands use them as `<module>` and `<Variant>`, for example `:app:minifyReleaseWithR8`.
- The helper scripts are in this skill's `scripts/` directory. In the following
  commands, `<skill_dir>` is this skill's directory. Run every command from the
  project root.

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

- **If AGP \< 9.3.0** : Proceed to **Path B (Quantitative)**.

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

- **Step 1: Check requirements** : Python and the `protobuf` package 6.33.4 or later are mandatory (used by [`scripts/keep_radius_pb2.py`](scripts/keep_radius_pb2.py)). Install it with `pip install "protobuf>=6.33.4"`; versions lower than 6.33.4 fail on import with a `VersionError` or `ImportError`.
- **Step 2: Run standalone task on R8-enabled build** : For the module and variant you found during path selection, run `./gradlew :<module>:analyze<Variant>R8Config` (for example, `./gradlew :app:analyzeReleaseR8Config`). It generates the report in `<module>/build/reports/r8/` (for example, `app/build/reports/r8/r8-config-analyzer-release.pb`). You must wait for this command to finish before proceeding.
- **Step 3: Convert to JSON** : You must explicitly run the conversion script [`scripts/convert_pb_to_json.py`](scripts/convert_pb_to_json.py) as `python3 <skill_dir>/scripts/convert_pb_to_json.py` with arguments `<module>/build/reports/r8` and `tmp/keepradius/keepruleradius.json`. Wait for this command to finish.
- **Step 4: Analyze** : You must explicitly run the analysis script [`scripts/analyze.py`](scripts/analyze.py) by executing `python3 <skill_dir>/scripts/analyze.py tmp/keepradius/keepruleradius.json`. This outputs `tmp/keepradius/analysis_result.txt`. Wait for this command to finish.

### Path B: Invoke R8 release build (AGP \< 9.3.0)

- **Step 1: Check requirements** : Python and the `protobuf` package 6.33.4 or later are mandatory: `pip install "protobuf>=6.33.4"`.
- **Step 2: Generate and analyze** : You must run the shell commands described in [references/FULL_BUILD_CONFIG_ANALYZER.md](references/FULL_BUILD_CONFIG_ANALYZER.md) to temporarily update the R8 version in `settings.gradle(.kts)` to 9.4.34 or later (so R8 generates the report), generate the proto report in `tmp/r8analysis/`, convert it to `tmp/r8analysis/keepruleradius.json`, analyze the result, and revert the temporary `settings.gradle(.kts)` change.
- **Step 3: Analyze** : Verify that the analysis outputs `tmp/r8analysis/analysis_result.txt` for scores and rule impact metrics.

## Step 3. Report generation

- **Format** : Follow [references/REPORT_FORMAT.md](references/REPORT_FORMAT.md) strictly.
- **Redundant rules** : Check keep rules against [references/INSPECT-RULES.md](references/INSPECT-RULES.md). If a keep rule matches a pattern in [references/INSPECT-RULES.md](references/INSPECT-RULES.md), include the guidance and remediation from that reference alongside the impact metrics.
- **Input** : Extract metrics (Scores, Impacts, Example Classes, rule origins) directly from the generated file `tmp/keepradius/analysis_result.txt` if using Path A, or `tmp/r8analysis/analysis_result.txt` if using Path B.
- **Output** : Short progress updates are fine while Gradle runs; the final message is the report only. 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](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 project files. Create files only under `tmp/` (analysis output, the settings backup, and any scratch scripts), and never write the report to a file. The one exception is the temporary R8 `classpath` in `settings.gradle(.kts)` that Path B needs when the project doesn't already pin R8 9.4.34 or later: ask the user first when running interactively, and revert it after the analysis (see [references/FULL_BUILD_CONFIG_ANALYZER.md](references/FULL_BUILD_CONFIG_ANALYZER.md)). If that change is needed but the user says no, or asks you not to edit build files, report rule-level and 

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/android/skills
git -C skills checkout ba2d4bc1b905

Works in

1. 2026-10-31
   ✓SAFE B 89 / 100

   first audit · source ba2d4bc1b905

Questions about r8-analyzer

• github.com/android/skills/tree/main/performance/r8-analyzer — the audited source at commit ba2d4bc1b905 and every finding aboveObserved · 31 Oct 2026

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