androjack-mcp

v1.6.4

Published

7 days ago

MCP server that validates AI-generated Android code against official SDK documentation.

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vikas9793

mcp android ai-tools developer-tools llm ai-validation kotlin jetpack-compose android-sdk

🤖 AndroJack — The Jack of All Android Trades

AndroJack Banner

🎬 Discover AndroJack

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

🚀 One-Click Install

VS Code distribution: AndroJack MCP is also live on the VS Code Marketplace as AndroJack MCP for VS Code. The VS Code badge above always reflects the currently published Marketplace version.

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

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

🔥 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.

⚡ 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:

Every one of these compiles. Most run without errors. The bugs surface later in CI flakiness, UI regressions, or Play Store review failures — and the developer has no idea the AI was confidently wrong.

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.

🧩 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)

⚠️ Honest Activation Model — Two Levels

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

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.

🪲 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

These are the bugs AndroJack was designed to prevent. The rule engine fires on these:

// ❌ 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 — And Why

[!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.

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

🎯 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.

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

✨ What AndroJack Covers — 21 Tools

🚀 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 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 IDE

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

🧩 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/.
Use config/claude_desktop_config.json for Claude Desktop.
Use config/cursor_mcp.json for Cursor.
Use config/vscode_mcp.json for VS Code / GitHub Copilot.
Use config/windsurf_mcp.json for Windsurf.
Use config/jetbrains_mcp.json for Android Studio / IntelliJ.
Use config/kiro_mcp.json for AWS Kiro.
Use config/antigravity_mcp.json for Google Antigravity.
Every example keeps AndroJack local by default and runs the published package via npx -y [email protected].

📍 The Ecosystem: AndroJack vs. Other MCPs

🔒 Security & Privacy

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 are annotated readOnlyHint: true.
Zero credentials: No API keys or tokens required for documentation fetching.
Security policy: Disclosure process and supported versions live in SECURITY.md.

📋 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 create 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.

👥 Authorship & Ownership

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

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