AndroJack — The Jack of All Android Trades

An MCP server that equips your AI coding assistant with live, verified Android knowledge — so it builds from official sources, not from memory.

Also works with: Windsurf · VS Code Copilot · Google Antigravity · JetBrains AI — see Manual Config below ↓

VS Code distribution: Also live on the VS Code Marketplace as AndroJack MCP for VS Code.

PM / APM docs: Product strategy, JTBD, personas, roadmap, user stories, competitive analysis, and GTM materials live under product-management/README.md.

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Table of Contents

• The Crisis That Created This Tool
• What Actually Breaks In Practice
• What AndroJack Does
• Honest Activation Model
• What Can Still Break — Even at Level 3
• Defence-in-Depth
• The Killer Argument
• The 21 Tools
• Quick Start
• Manual Config
• Ecosystem Comparison
• Security & Privacy
• Changelog

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🔥 The Crisis That Created This Tool

In 2025, the Stack Overflow Developer Survey asked 49,000 developers about their experience with AI coding tools. The results should alarm every Android engineer:

• 84% of developers now use AI coding tools — up from 76% the year before.
• Trust in AI accuracy collapsed from 40% to just 29% in a single year.
• 35% of all Stack Overflow visits in 2025 are now triggered by developers debugging and fixing AI-generated code.

The gap between usage and trust is not a coincidence. It is the product of a structural problem: AI models predict tokens, not APIs. They were trained on a snapshot of the world and have no mechanism to know what changed at API 30, what shipped at Google I/O 2025, or what Google Play now rejects at review time.

For Android developers, this failure mode is uniquely dangerous. Android has the fastest-moving ecosystem in mobile development — a new Compose BOM every month, Navigation 3 going stable after seven years of Nav2, Android 16 rewriting the rules on screen orientation locking — and most AI tools have training data that is six months to two years stale by the time you use them.

The result is not just bad code. It is confidently bad code.

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⚡ What Actually Breaks In Practice — Documented Evidence

These are not hypothetical risks. They are documented failure modes from real developer projects.

The Navigation 3 Hallucination (January 2026)

A published case study from Atomic Robot documented a live Navigation 2 → Navigation 3 migration using both Gemini and Claude — with internet access enabled on both. The conclusion, verbatim:

"LLMs still hallucinate versions. Even with internet access, both agents wanted to use an outdated release candidate instead of the stable 1.0.0 release."

Navigation 3 went stable in November 2025 after seven years of the same library. It is a complete architectural rethink: back stacks are now plain Kotlin lists, the monolithic nav graph is gone, and NavDisplay replaces NavController. Google's own migration guide is so aware that AI tools get this wrong that it now contains special "AI Agent:" annotations — instructions embedded directly in the official docs for AI tools to follow. An AI tool that generates Nav2 code for a new Compose project in 2026 is not making a small mistake. It is creating an architectural incoherence that requires a full rewrite to fix.

The Compose Deprecation Treadmill

Jetpack Compose ships a new BOM every month. Since most models' training cutoffs, these APIs changed:

API	Status	What goes wrong
ContextualFlowRow / ContextualFlowColumn	Deprecated in Compose 1.8	AI still generates them — compile warning today, removal tomorrow
TestCoroutineDispatcher	Removed from coroutines-test 1.8+	AI still generates it — non-deterministic test failures in CI
FlowRow overflow parameter	Deprecated in 1.8	Subtle behavioral regression at runtime, silent in most linting setups
AnchoredDraggableState.confirmValueChange	Deprecated	Incorrect drag behavior at anchor boundaries
Navigation 2 in new projects	Superseded by Nav3 stable Nov 2025	Architectural dead-end that requires a rewrite to fix

Every one of these compiles. Most run without errors. The bugs surface later in CI flakiness, UI regressions, or Play Store review failures.

The Android 16 / API 36 Mandate (August 2026 deadline)

Android 16 made a platform-level change affecting every published app: on devices ≥600dp — tablets, foldables, ChromeOS — apps can no longer lock screen orientation or restrict resizability. Google Play requires API 36 targeting by August 2026.

An AI tool generating android:screenOrientation="portrait" or android:resizeableActivity="false" today is generating code that will trigger App Compatibility warnings in Play Console, fail large-screen quality checks, and get apps demoted in Play Store search results.

The business impact is not theoretical: Foldable users spend 14× more on apps than phone-only users. Tablet + phone users spend 9× more. FlipaClip saw 54% growth in tablet users within four months of going adaptive.

The KMP Silent Failure

Kotlin Multiplatform went mainstream in 2025 — over 900 new KMP libraries published, Room added KMP support, companies now hire specifically for KMP skills. When a developer on a KMP project asks an AI tool to add database support, the AI generates Android-only Room code. It compiles. It runs perfectly on Android. The iOS build fails. The developer spends hours debugging before realizing the root cause: their AI tool does not know KMP exists.

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🧩 What AndroJack Does

AndroJack is a documentation-grounded Android engineering MCP server. It gives your AI coding assistant 21 specialized tools that fetch live, verified answers from official Android and Kotlin sources — instead of predicting from stale training data.

It does not make the AI smarter. It makes the AI accountable to evidence.

Think of it as a pre-build linter for LLMs. While other tools retrieve documentation, AndroJack acts as a strict architectural gatekeeper.

Without AndroJack:  You ask → AI predicts from stale weights → Code (possibly wrong)

With AndroJack:     You ask → AI calls tool → Tool fetches official source live
                             → AI reads verified answer → Code (grounded)

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⚠️ Honest Activation Model — Two Levels

Important

This is the most important thing to understand before you install AndroJack.

Level	What's Active	What the AI Does
Level 1 — Tools only	21 tools registered in IDE	AI may call the right tool. Depends on the IDE and the AI's judgment.
Level 2 — Tools + Grounding Gate	21 tools + mandatory pre-generation rulebook	AI must call the correct tool for every decision before writing code.
Level 3 — Full loop-back	Level 2 + android_code_validator	AI validates every code block against 24 rules. Errors must be fixed before the user sees the code.

Level 1 is passive. The tools are available but the AI decides when to use them. An AI building a Compose screen may call architecture_reference but skip material3_expressive — and ship M3E violations silently.

Level 2 is active. The androjack_grounding_gate system prompt maps every task type to the correct tool. Building Compose UI? The AI is mandated to call material3_expressive first. Adding a dependency? It must call gradle_dependency_checker. No exceptions.

Level 3 is the loop-back. android_code_validator runs on every code block the AI generates before returning it to the user. 24 rules covering removed APIs, deprecated patterns, and Android 16 compliance. Verdict FAIL means the AI must fix and re-validate — the user never sees the broken code.

→ For full grounding, always activate Level 2 + Level 3. See Getting the Full Guarantee below.

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🪲 What Can Still Break — Even at Level 3

Important

AndroJack is a documentation-grounding and API-validation tool. It is not a Compose layout engine, a design system enforcer, or a runtime renderer. Level 3 catches removed APIs and deprecated patterns. It cannot catch every class of Android bug. This is not a limitation of AndroJack — it is a fundamental property of static text analysis applied to a visual, runtime-rendered UI framework.

The following bugs were encountered in a real Android app built with AndroJack at Level 2 (v1.4.0). They are documented here honestly so you know exactly what to watch for — and where to reach for different tools.

✅ What Level 3 Catches

// ❌ REMOVED — android_code_validator fires: REMOVED_ASYNCTASK class MyTask : AsyncTask<Void, Void, String>()

// ❌ REMOVED — fires: REMOVED_TEST_COROUTINE_DISPATCHER val dispatcher = TestCoroutineDispatcher()

// ❌ DEPRECATED — fires: DEPRECATED_CONTEXTUAL_FLOW_ROW ContextualFlowRow { Text("hello") }

// ❌ LEAK — fires: GLOBALSCOPE_LAUNCH GlobalScope.launch { fetchData() }

⚠️ What Level 3 Cannot Catch

Warning

The following bugs were found in a real project. They are valid, API-current Compose code that violates design system constraints, accessibility minimums, or architectural boundaries. Static text scanning cannot detect them.

Bug PH-UI-001 — Segmented button text truncation

// Compiles and runs. Level 3 sees no violation. // The bug: Text inside MultiChoiceSegmentedButtonRow truncates because a // fixed height modifier prevents the Roboto Flex variable font from expanding. MultiChoiceSegmentedButtonRow { SegmentedButton(/* fixed height modifier */) { Text("Light") } }

[!NOTE] This is an absence bug. The correct modifier is missing — no wrong one is present. Use visual testing or runtime inspection.

Bug PH-UI-003 — Disabled button contrast failure

// Correct Material 3 API. Level 3 sees no violation. // The bug: disabled state colours fail WCAG AA 4.5:1 contrast against surface. Button(enabled = false, onClick = {}) { Text("INITIALIZE VAULT") }

[!NOTE] This is a runtime visual property bug. Use paparazzi screenshot tests or Google's Accessibility Scanner.

Bug PH-AR-004 — Raw stack trace rendered to end user

// A missing try/catch produces no pattern match. class VaultViewModel : ViewModel() { fun initializeVault() { viewModelScope.launch { val result = repository.initialize() // Missing try/catch _uiState.value = UiState.Success(result) } } }

[!WARNING]UDF architecture violations require Detekt with custom rules or unit tests verifying exception mapping.

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🗂️ Defence-in-Depth: The Right Tool for Each Bug Class

Bug Class	Real Example	Right Tool
Removed / deprecated API	AsyncTask, TestCoroutineDispatcher	✅ AndroJack Level 3
Android 16 violations	screenOrientation, resizeableActivity=false	✅ AndroJack Level 3
Architecture (flagged root)	GlobalScope leaking to UI	✅ AndroJack Level 3
Absent modifier / missing constraint	PH-UI-009 (innerPadding)	🔧 Android Lint / IDE inspector
Runtime contrast / colour failures	PH-UI-003 (WCAG)	🔧 paparazzi + Accessibility Scanner
Touch target violations	PH-UX-008	🔧 Accessibility Scanner
Architecture boundary (missing catch)	PH-AR-004 (stack trace to UI)	🔧 Detekt + ViewModel unit tests

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🎯 The Killer Argument

"Can your agents.md file tell me the Gradle version that shipped last Tuesday?"

No markdown file can. No rules in .cursorrules can. No SKILL.md can.

✅ Only a live tool call can.

That's the job AndroJack exists to do — and nothing else in the current ecosystem does it for Android specifically.

What you need	agents.md / SKILL.md	AndroJack MCP
Format output a specific way	✅ Perfect	Works too
Follow team conventions	✅ Perfect	Works too
Latest Gradle version right now	❌ Guesses from memory	✅ Fetches live
Is AsyncTask removed?	❌ May be wrong	✅ Verified against SDK
Android 16 Play Store rules	❌ Unknown	✅ Official source

Prompt engineering controls how the AI responds. MCP controls what the AI knows.

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✨ What AndroJack Covers — 21 Tools

#	Tool	What It Does	What Breaks Without It
1	🔍 search	Live search across official Android/Kotlin docs	AI reasons from memory — possibly wrong today
2	⚠️ component	Deprecated/removed check on 40+ APIs	Compiles fine, breaks at runtime/review
3	📐 architecture	Guides for 40+ topics — MVVM, Nav3, MVI...	AI gives 2022 advice; misses Nav3
4	🐛 debugger	Parses stacktraces → searches Issue Tracker	AI hallucinates fixes for known bugs
5	📦 gradle	Live lookup from Google Maven + BOM resolution	Stale Compose BOM, KAPT instead of KSP
6	📊 api-level	API 21–36 table, minSdk warnings	API 26+ calls in minSdk 21 apps
7	🎯 kotlin	10 patterns — coroutines, MVI, Compose state	GlobalScope.launch, runBlocking in UI
8	🎨 m3e	Material 3 Expressive components & Motion	M2 MaterialTheme in M3E app
9	🔐 permissions	40+ permissions rules & contracts	deprecated requestPermissions()
10	🧪 testing	Unit/Compose UI testing official patterns	Thread.sleep() in tests; missing Hilt
11	🏗️ build	R8, libs.versions.toml, signing, AAB	implementation instead of ksp
12	📱 large-screen	WindowSizeClass, Adaptive Scaffolds	Phone-only layouts on foldables
13	🚀 scalability	Paging 3, WorkManager, modularization	Naive loadAll(); unstable keys in lists
14	🧭 nav3	Nav3 (Nov 2025) — Scenes, migration	AI generates Nav2 dead-ends
15	✅ compliance	API 36 / Android 16 / 16 KB page size	Apps fail Play Store August 2026 mandate
16	🌐 kmp	Room KMP, Ktor, source sets	Android-only code in KMP projects
17	🤖 ondevice-ai	AICore, ML Kit Gen AI, Gemini Nano	Cloud-only AI when offline is required
18	📋 policy	Play Store age-gating, health, data safety	Apps rejected for unknown policy changes
19	🥽 xr	Android XR SDK, SpatialPanel, Orbiter	Works as 2D panel, misses spatial value
20	⌚ wear	Tiles, Health, M3 Expressive for Wear OS	Handheld patterns on round displays
21	🛡️ validator	Level 3 loop-back validation gate	AI ships broken code without checking

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🚀 Quick Start — Zero Install Required

Option 1 — Interactive CLI (v1.6.4) ✨ Recommended

npx -y [email protected] install

Launches a full animated terminal wizard with auto-detection for VS Code, Cursor, Claude, Windsurf, JetBrains, Kiro, and Antigravity.

Option 2 — Targeted Installs

Preview detected IDEs and config paths

npx -y [email protected] install --list

Auto-detect all

npx -y [email protected] install --auto

Install to a specific IDE

npx -y [email protected] install --ide=cursor npx -y [email protected] install --ide=claude npx -y [email protected] install --ide=vscode npx -y [email protected] install --ide=windsurf npx -y [email protected] install --ide=jetbrains npx -y [email protected] install --ide=kiro npx -y [email protected] install --ide=antigravity

Option 3 — Test Without an IDE

npx -y @modelcontextprotocol/inspector npx -y [email protected]

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🧩 Manual Config / Copy / Paste

If you prefer to wire the server manually, or want to inspect the exact JSON before writing anything:

• Run npx -y [email protected] install --list to preview detected IDEs and target config paths.
• Ready-to-paste examples live in config/.

IDE / Client	Config file
Claude Desktop	config/claude_desktop_config.json
Cursor	config/cursor_mcp.json
VS Code / GitHub Copilot	config/vscode_mcp.json
Windsurf	config/windsurf_mcp.json
Android Studio / IntelliJ	config/jetbrains_mcp.json
AWS Kiro	config/kiro_mcp.json
Google Antigravity	config/antigravity_mcp.json

Every example keeps AndroJack local by default and runs the published package via npx -y [email protected].

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📍 The Ecosystem: AndroJack vs. Other MCPs

Feature	Google Developer Knowledge MCP	AndroJack MCP
Identity	The Librarian (Information)	The Gatekeeper (Enforcement)
Mechanism	Context Retrieval	Context Enforcement
Scope	Generalist — Firebase, Cloud, Maps	Android engineering specialist
Tools	3 retrieval tools	21 specialized tools
Setup	Google Cloud project + API key required	npx [email protected] — zero auth
Enforcement	Passive — AI decides when to retrieve	Active — mandating calls by task type

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🔒 Security & Privacy

Property	Implementation
Domain allowlist	Requests only to Google/Android/Kotlin official domains
HTTPS only	Outbound documentation fetches refuse non-HTTPS URLs, cap body size, and redact query strings in retry logs
Local by default	serve binds to loopback only unless you explicitly pass --allow-remote
HTTP hardening	Streamable HTTP validates Origin and Host headers and caps request bodies and active sessions
Transparent agent	User-Agent: AndroJack-MCP/1.6.4
Read-only	All 21 tools annotated readOnlyHint: true
Zero credentials	No API keys or tokens required for documentation fetching
Security policy	Disclosure process and supported versions in SECURITY.md

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📋 Changelog

v1.6.4 — CLI Routing Fixes and Local Transport Hardening

• Fix: npx androjack-mcp install, install --auto, install --ide=..., help, and --version now route correctly instead of falling through to the stdio server.
• Fix: install --auto no longer over-detects IDEs from parent directories and creates configs in a clean workspace.
• Fix: HTTP serve mode now fails closed on non-loopback binds unless --allow-remote is explicit.
• Security: Streamable HTTP now validates Origin and Host headers and enforces request body and session limits.
• Security: Outbound fetches now enforce HTTPS, cap response size, and redact sensitive URL parts from retry logs.

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👥 Authorship & Ownership

Vikas Sahani — Product Lead ([email protected])
Claude AI — AI Engineering Lead

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MIT License © 2026 Vikas Sahani | SECURITY.md

Built because 35% of Stack Overflow visits in 2025 are developers debugging AI-generated code.
AndroJack exists so none of those visits are yours.