rcosteira79/android-source-search

Android Source Search

Overview

Two separate source trees, two access strategies. AOSP lives on android.googlesource.com (Gitiles); AndroidX lives on GitHub. cs.android.com blocks automated fetching — it's for human browsing only.

Preferred: android-source-explorer MCP

If mcp__android-sources__* tools are available, always prefer them over WebFetch/gh. They provide local source with sub-10ms lookups:

| Goal | MCP tool | |------|----------| | Find a class by name/pattern | mcp__android-sources__search_classes (glob, e.g. *ViewModel*) | | Read full class source | mcp__android-sources__lookup_class (by fully qualified name) | | Read a specific method | mcp__android-sources__lookup_method (class + method name) | | List members of a class | mcp__android-sources__list_class_members | | Get class hierarchy | mcp__android-sources__get_class_hierarchy | | Search text/regex across sources | mcp__android-sources__search_in_source | | List AndroidX artifact versions | mcp__android-sources__list_available_versions | | Go to definition (requires LSP) | mcp__android-sources__goto_definition | | Find references (requires LSP) | mcp__android-sources__find_references | | Get type info/hover (requires LSP) | mcp__android-sources__get_type_info |

If MCP tools are not available, fall back to the WebFetch/gh strategies below.

Fallback: WebFetch and gh CLI

Which Source?

| You need... | Source | Access method | |-------------|--------|---------------| | Framework internals (View, Activity, system services) | AOSP | WebFetch → Gitiles | | @hide APIs, internal constants, default attr values | AOSP | WebFetch → Gitiles | | AndroidX/Jetpack source (androidx.*) | AndroidX GitHub | WebFetch → raw.githubusercontent.com | | AndroidX samples (e.g. LookaheadScope, LazyColumn) | AndroidX GitHub | WebFetch → raw.githubusercontent.com | | Directory listings (when path is unknown) | AndroidX GitHub | gh api via Bash |

AOSP — Fetching via Gitiles

HTML view

https://android.googlesource.com/platform/frameworks/base/+/refs/heads/main/{path}

Raw text (base64-encoded, smaller payload)

https://android.googlesource.com/platform/frameworks/base/+/refs/heads/main/{path}?format=TEXT

Key repo structure

| Repo | Path | Contains | |------|------|----------| | platform/frameworks/base | core/java/android/ | View, Activity, Context, etc. | | platform/frameworks/base | services/core/java/ | System services (AMS, WMS, etc.) | | platform/frameworks/base | core/res/ | Default attrs, styles, drawables | | platform/libcore | ojluni/src/main/java/ | Java core libraries | | platform/development | samples/ | AOSP sample apps |

Path inference

android.view.ViewGroup → core/java/android/view/ViewGroup.java

AndroidX — Fetching via GitHub

File content (WebFetch)

https://raw.githubusercontent.com/androidx/androidx/androidx-main/{path}

Directory listing (Bash + gh CLI)

gh api repos/androidx/androidx/contents/{path} --jq '.[].name'

Key repo paths

| Library | Path prefix | |---------|-------------| | Compose UI | compose/ui/ui/src/commonMain/kotlin/androidx/compose/ui/ | | Compose UI samples | compose/ui/ui/samples/src/main/java/androidx/compose/ui/samples/ | | Compose Animation | compose/animation/animation/src/commonMain/kotlin/ | | Compose Animation samples | compose/animation/animation/samples/src/main/java/ | | Compose Foundation | compose/foundation/foundation/src/commonMain/kotlin/ | | Navigation | navigation/navigation-compose/src/main/java/ |

Example — fetch LookaheadScope samples

https://raw.githubusercontent.com/androidx/androidx/androidx-main/compose/ui/ui/samples/src/main/java/androidx/compose/ui/samples/LookaheadScopeSamples.kt

Search Strategy (path unknown)

1. Use cs.android.com as a human search UI to find the class/file path
2. For AOSP: fetch via Gitiles once path is known
3. For AndroidX: fetch via raw.githubusercontent.com or list via gh api

# Human search (not WebFetch — JS SPA)
https://cs.android.com/search?q=ClassName+methodName&ss=android
https://cs.android.com/search?q=ClassName&ss=androidx

Common Patterns

| Goal | What to look for | |------|-----------------| | Default attribute value | mGroupFlags \|= or field initializer | | @hide method signature | Full method with /** @hide */ Javadoc | | Delegation to system service | getService() or IActivityManager calls | | API level gating | Build.VERSION.SDK_INT >= Build.VERSION_CODES.X | | AndroidX sample for an API | {ClassName}Samples.kt in the samples/ subpath |

Common Mistakes

• Trusting training data line numbers — both trees change frequently. Always fetch current source.
• Using WebFetch on cs.android.com — JS SPA, results won't be in raw HTML.
• Using master branch on Gitiles — prefer refs/heads/main; use a tag like android-14.0.0_r74 for specific API levels.
• Using Gitiles for AndroidX — AndroidX is not in android.googlesource.com; use GitHub raw URLs.
• Using WebFetch on github.com — use raw.githubusercontent.com for file content, gh api for listings.