React Native AI Debugger

An MCP (Model Context Protocol) server for AI-powered React Native debugging. Enables AI assistants like Claude to capture logs, execute code, inspect state, and control navigation in your React Native app.

Features

Runtime Interaction

• Console Log Capture - Capture console.log, warn, error, info, debug with filtering and search
• React Component Inspection - Inspect component tree, props, state/hooks, and layout styles at runtime
• Network Request Tracking - Monitor HTTP requests/responses with headers, timing, and body content
• JavaScript Execution - Run code directly in your app (REPL-style) and inspect results
• Global State Debugging - Discover and inspect Apollo Client, Redux stores, Expo Router, and custom globals
• Bundle Error Detection - Get Metro bundler errors and compilation issues with file locations
• Debug Web Dashboard - Browser-based UI for real-time log and network monitoring

Device Control

• iOS Simulator - Screenshots, app management, URL handling, boot/terminate (via simctl)
• Android Devices - Screenshots, app install/launch, package management (via ADB)
• UI Automation - Tap, swipe, long press, text input, and key events on both platforms
• Accessibility Inspection - Query UI hierarchy to find elements by text, label, or resource ID
• Element-Based Interaction - Tap/wait for elements by text without screenshots (faster, cheaper)
• OCR Text Extraction - Extract visible text with tap-ready coordinates (works on any screen content)

Under the Hood

• Auto-Discovery - Scans Metro on ports 8081, 8082, 19000-19002 automatically
• Smart Device Selection - Prioritizes Bridgeless > Hermes > standard React Native targets
• Auto-Reconnection - Exponential backoff (up to 8 attempts) when connection drops
• Efficient Buffering - Circular buffers: 500 logs, 200 network requests
• Platform Support - Expo SDK 54+ (Bridgeless) and React Native 0.70+ (Hermes)

Requirements

• Node.js 18+
• React Native app running with Metro bundler
• Optional for iOS UI automation: Facebook IDB - brew install idb-companion
• Optional for enhanced OCR: Python 3.10+ with EasyOCR (see OCR Setup)

Claude Code Setup

No installation required - Claude Code uses npx to run the latest version automatically.

Global (all projects)

claude mcp add rn-debugger --scope user -- npx react-native-ai-debugger

Project-specific

claude mcp add rn-debugger --scope project -- npx react-native-ai-debugger

Manual Configuration

Add to ~/.claude.json (user scope) or .mcp.json (project scope):

{ "mcpServers": { "rn-debugger": { "type": "stdio", "command": "npx", "args": ["react-native-ai-debugger"] } } }

Restart Claude Code after adding the configuration.

VS Code Copilot Setup

Requires VS Code 1.102+ with Copilot (docs).

Via Command Palette: Cmd+Shift+P → "MCP: Add Server"

Manual config - add to .vscode/mcp.json:

{ "servers": { "rn-debugger": { "type": "stdio", "command": "npx", "args": ["-y", "react-native-ai-debugger"] } } }

Cursor Setup

Docs

Via Command Palette: Cmd+Shift+P → "View: Open MCP Settings"

Manual config - add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{ "mcpServers": { "rn-debugger": { "command": "npx", "args": ["-y", "react-native-ai-debugger"] } } }

Available Tools

Connection & Logs

Tool	Description
scan_metro	Scan for Metro servers and auto-connect. Call this first to start debugging
connect_metro	Connect to a specific Metro port (use when you know the exact port)
get_apps	List connected apps. Run scan_metro first if none connected
get_connection_status	Get detailed connection health, uptime, and recent disconnects
ensure_connection	Verify/establish connection with health checks
get_logs	Retrieve console logs (filtering, truncation, summary, TONL format)
search_logs	Search logs for specific text (truncation, TONL format)
clear_logs	Clear the log buffer

Network Tracking

Tool	Description
get_network_requests	Retrieve network requests (filtering, summary, TONL format)
search_network	Search requests by URL pattern (TONL format)
get_request_details	Get full details of a request (headers, body with truncation)
get_network_stats	Get statistics: counts by method, status code, domain
clear_network	Clear the network request buffer

App Inspection & Execution

Tool	Description
execute_in_app	Execute JavaScript code in the connected app and return the result
list_debug_globals	Discover available debug objects (Apollo, Redux, Expo Router, etc.)
inspect_global	Inspect a global object to see its properties and callable methods
reload_app	Reload the app (auto-connects if needed). Use sparingly - Fast Refresh handles most changes
get_debug_server	Get the debug HTTP server URL for browser-based viewing
restart_http_server	Restart the debug HTTP server

Bundle Tools

Tool	Description
get_bundle_status	Get Metro bundler status and build state
get_bundle_errors	Get compilation errors with file locations
clear_bundle_errors	Clear the bundle error buffer

React Component Inspection

Recommended Workflow: Use get_component_tree(focusedOnly=true, structureOnly=true) for a token-efficient overview of just the active screen (~1-3KB), then drill down with inspect_component or find_components.

Tool	Description
get_component_tree	Start here with focusedOnly=true, structureOnly=true for active screen overview
inspect_component	Drill-down tool: Inspect specific component's props, state/hooks, children
find_components	Targeted search: Find components by pattern with optional layout info
get_screen_layout	Full layout data - use sparingly, can be large for complex screens

Element Inspector (Coordinate-Based)

Inspect React components at specific screen coordinates - like React Native's built-in Element Inspector, but programmatically.

Tool	Description
get_inspector_selection	Main tool: Get React component at coordinates. Auto-enables inspector and taps if x/y provided
toggle_element_inspector	Manually toggle the Element Inspector overlay on/off
inspect_at_point	Inspect React component at (x,y) coordinates

Quick Inspection (Recommended):

# Single call - auto-enables inspector, taps, returns component info
get_inspector_selection(x=210, y=400)

Returns:

Element: FastImageView
Path: App > RootNavigation > ... > PlayerModal > FastImage > FastImageView
Frame: (62.3, 130.0) 295.67x295.67
Style: { borderRadius: 15, overflow: "hidden" }

Manual Flow (for more control):

# 1. Enable the inspector overlay
toggle_element_inspector()

# 2. Tap to select element (iOS)
ios_tap(x=210, y=400)

# 3. Read the selection
get_inspector_selection()

# 4. Disable overlay when done
toggle_element_inspector()

Token Efficiency: Returns ~0.2-0.5KB vs 15-25KB for full component tree. Works on all React Native versions including Fabric/New Architecture.

Android (ADB)

Tool	Description
list_android_devices	List connected Android devices and emulators via ADB
android_screenshot	Take a screenshot from an Android device/emulator
android_install_app	Install an APK on an Android device/emulator
android_launch_app	Launch an app by package name
android_list_packages	List installed packages (with optional filter)
android_tap	Tap at specific coordinates on screen
android_long_press	Long press at specific coordinates
android_swipe	Swipe from one point to another
android_input_text	Type text at current focus point
android_key_event	Send key events (HOME, BACK, ENTER, etc.)
android_get_screen_size	Get device screen resolution
android_describe_all	Get full UI accessibility tree via uiautomator
android_describe_point	Get UI element info at specific coordinates
android_tap_element	Tap element by text/contentDesc/resourceId
android_find_element	Find element by text/contentDesc/resourceId (no screenshot)
android_wait_for_element	Wait for element to appear (useful for screen transitions)

iOS (Simulator)

Tool	Description
list_ios_simulators	List available iOS simulators
ios_screenshot	Take a screenshot from an iOS simulator
ios_install_app	Install an app bundle (.app) on a simulator
ios_launch_app	Launch an app by bundle ID
ios_open_url	Open a URL (deep links or web URLs)
ios_terminate_app	Terminate a running app
ios_boot_simulator	Boot a simulator by UDID
ios_tap	Tap at coordinates (requires IDB)
ios_tap_element	Tap element by accessibility label (requires IDB)
ios_swipe	Swipe gesture (requires IDB)
ios_input_text	Type text into active field (requires IDB)
ios_button	Press hardware button: HOME, LOCK, SIRI (requires IDB)
ios_key_event	Send key event by keycode (requires IDB)
ios_key_sequence	Send sequence of key events (requires IDB)
ios_describe_all	Get full accessibility tree (requires IDB)
ios_describe_point	Get element at point (requires IDB)
ios_find_element	Find element by label/value (requires IDB, no screenshot)
ios_wait_for_element	Wait for element to appear (requires IDB)

OCR (Cross-Platform)

Tool	Description
ocr_screenshot	Extract all visible text with tap-ready coordinates (works on iOS/Android)

Usage

1. Start your React Native app:
   npm start

or

expo start 2. In Claude Code, scan for Metro:

Use scan_metro to find and connect to Metro  

3. Get logs:

Use get_logs to see recent console output  

get_logs Tool Reference

The get_logs tool has multiple parameters for controlling output size and format. Here's the complete reference:

Parameter	Type	Default	Description
maxLogs	number	50	Maximum number of logs to return
level	string	"all"	Filter by level: all, log, warn, error, info, debug
startFromText	string	-	Start from the last log containing this text
maxMessageLength	number	500	Max chars per message (0 = unlimited)
verbose	boolean	false	Disable all truncation, return full messages
format	string	"text"	Output format: text or tonl (30-50% smaller)
summary	boolean	false	Return counts + last 5 messages only

Recommended Usage Patterns

# Quick overview (always start here)
get_logs with summary=true

# Recent errors only
get_logs with level="error" maxLogs=20

# Logs since last app reload
get_logs with startFromText="Running app" maxLogs=100

# Full messages for debugging specific issues
get_logs with maxLogs=10 verbose=true

# Token-efficient format for large outputs
get_logs with format="tonl" maxLogs=100

# Compact overview with shorter messages
get_logs with maxMessageLength=200 maxLogs=50

Filtering Logs

get_logs with maxLogs=20 and level="error"

Available levels: all, log, warn, error, info, debug

Start from Specific Line

get_logs with startFromText="iOS Bundled" and maxLogs=100

This finds the last (most recent) line containing the text and returns logs from that point forward. Useful for getting logs since the last app reload.

Search Logs

search_logs with text="error" and maxResults=20

Case-insensitive search across all log messages.

Token-Optimized Output

The tools include several options to reduce token usage when working with AI assistants.

Summary Mode (Recommended First Step)

Always start with summary=true - it gives you the full picture in ~10-20 tokens instead of potentially thousands:

get_logs with summary=true

Returns:

• Total count - How many logs are in the buffer
• Breakdown by level - See if there are errors/warnings at a glance
• Last 5 messages - Most recent activity (truncated to 100 chars each)

Example output:

Total: 847 logs

By Level:
  LOG: 612
  WARN: 180
  ERROR: 55

Last 5 messages:
  14:32:45 [LOG] User clicked button...
  14:32:46 [WARN] Slow query detected...
  14:32:47 [ERROR] Network request failed...

Why Summary First?

Approach	Tokens	Use Case
summary=true	~20-50	Quick health check, see if errors exist
level="error"	~100-500	Investigate specific errors
maxLogs=50 (default)	~500-2000	General debugging
verbose=true	~2000-10000+	Deep dive into specific data

Recommended workflow:

1. summary=true → See the big picture
2. level="error" or level="warn" → Focus on problems
3. startFromText="..." → Get logs since specific event
4. verbose=true with low maxLogs → Full details when needed

Message Truncation

Long log messages are truncated by default (500 chars). Adjust as needed:

# Shorter for overview
get_logs with maxMessageLength=200

# Full messages (use with lower maxLogs)
get_logs with maxLogs=10 verbose=true

# Unlimited
get_logs with maxMessageLength=0

TONL Format

Use TONL (Token-Optimized Notation Language) for ~30-50% smaller output:

get_logs with format="tonl"

Output:

[Format: TONL - compact token-optimized format. Fields in header, values in rows.]
{logs:[{time:"14:32:45",level:"LOG",msg:"App started"},{time:"14:32:46",level:"WARN",msg:"Slow query"}]}

TONL is also available for search_logs, get_network_requests, and search_network.

Network Tracking

View Recent Requests

get_network_requests with maxRequests=20

Filter by Method

get_network_requests with method="POST"

Filter by Status Code

Useful for debugging auth issues:

get_network_requests with status=401

Search by URL

search_network with urlPattern="api/auth"

Get Full Request Details

After finding a request ID from get_network_requests:

get_request_details with requestId="123.45"

Shows full headers, request body, response headers, and timing.

Request body is truncated by default (500 chars). For full body:

get_request_details with requestId="123.45" verbose=true

Summary Mode (Recommended First Step)

Get statistics overview before fetching full requests:

get_network_requests with summary=true

This returns the same output as get_network_stats - counts by method, status, and domain.

TONL Format

Use TONL for ~30-50% smaller output:

get_network_requests with format="tonl"

View Statistics

get_network_stats

Example output:

Total requests: 47
Completed: 45
Errors: 2
Avg duration: 234ms

By Method:
  GET: 32
  POST: 15

By Status:
  2xx: 43
  4xx: 2

By Domain:
  api.example.com: 40
  cdn.example.com: 7

Debug Web Dashboard

The MCP server includes a built-in web dashboard for viewing logs and network requests in your browser. This is useful for real-time monitoring without using MCP tools.

Getting the Dashboard URL

Use the get_debug_server tool to find the dashboard URL:

get_debug_server

The server automatically finds an available port starting from 3456. Each MCP instance gets its own port, so multiple Claude Code sessions can run simultaneously.

Available Pages

URL	Description
/	Dashboard with overview stats
/logs	Console logs with color-coded levels
/network	Network requests with expandable details
/apps	Connected React Native apps

Features

• Auto-refresh - Pages update automatically every 3 seconds
• Color-coded logs - Errors (red), warnings (yellow), info (blue), debug (gray)
• Expandable network requests - Click any request to see full details:
  • Request/response headers
  • Request body (with JSON formatting)
  • Timing information
  • Error details
• GraphQL support - Shows operation name and variables in compact view:

POST  200  https://api.example.com/graphql         1ms  ▶  
           GetMeetingsBasic (timeFilter: "Future", first: 20)  

• REST body preview - Shows JSON body preview for non-GraphQL requests

JSON API Endpoints

For programmatic access, JSON endpoints are also available:

URL	Description
/api/status	Server status and buffer sizes
/api/logs	All logs as JSON
/api/network	All network requests as JSON
/api/bundle-errors	Metro bundle errors as JSON
/api/apps	Connected apps as JSON

App Inspection

Discover Debug Globals

Find what debugging objects are available in your app:

list_debug_globals

Example output:

{ "Apollo Client": ["APOLLO_CLIENT"], "Redux": ["REDUX_STORE"], "Expo": ["EXPO_ROUTER"], "Reanimated": ["__reanimatedModuleProxy"] }

Inspect an Object

Before calling methods on an unfamiliar object, inspect it to see what's callable:

inspect_global with objectName="__EXPO_ROUTER__"

Example output:

{ "navigate": { "type": "function", "callable": true }, "push": { "type": "function", "callable": true }, "currentPath": { "type": "string", "callable": false, "value": "/" }, "routes": { "type": "array", "callable": false } }

Execute Code in App

Run JavaScript directly in the connected app:

execute_in_app with expression="__DEV__"
// Returns: true

execute_in_app with expression="__APOLLO_CLIENT__.cache.extract()"
// Returns: Full Apollo cache contents

execute_in_app with expression="__EXPO_ROUTER__.navigate('/settings')"
// Navigates the app to /settings

Async Code

For async operations, promises are awaited by default:

execute_in_app with expression="AsyncStorage.getItem('userToken')"

Set awaitPromise=false for synchronous execution only.

React Component Inspection

Inspect React components at runtime via the React DevTools hook. These tools let you debug component state, verify layouts, and understand app structure without adding console.logs.

Recommended Workflow (Token-Efficient)

Always use the 2-step approach:

1. Step 1: Get focused screen overview (~1-3KB)

get_component_tree with focusedOnly=true structureOnly=true  

2. Step 2: Drill down into specific components as needed

inspect_component with componentName="HomeScreen"  
# or  
find_components with pattern="Button" includeLayout=true  

This approach uses ~10-20x fewer tokens than getting full details upfront.

Token Consumption Comparison

Approach	Tokens	Use Case
focusedOnly=true, structureOnly=true	~1-3KB	Recommended - active screen structure only
structureOnly=true	~15-25KB	Full tree structure (includes navigation, overlays)
inspect_component	~1-2KB	Deep dive into specific component
find_components	~2-5KB	Targeted search with layout
get_screen_layout	~20-50KB+	Full layout (use sparingly)

Focused Screen Mode (focusedOnly)

The focusedOnly parameter dramatically reduces output by returning only the active screen subtree:

• Skips navigation wrappers - Providers, NavigationContainers, SafeAreaProviders
• Skips global overlays - BottomSheet, Modal, Toast, Snackbar components
• Returns just the focused screen - Components matching *Screen or *Page pattern

get_component_tree with focusedOnly=true structureOnly=true

Output:

Focused: HomeScreen

HomeScreen
  Header
    Logo
    SearchBar
  FlatList
    ListItem (×12)
  Footer

When to skip focusedOnly:

• Debugging navigation structure itself
• Investigating which screens are mounted
• Checking global overlay state

Inspecting Overlays (BottomSheet, Modal, Toast)

Since focusedOnly skips global overlays by design, use this workflow to debug them:

1. Find the overlay component:

find_components with pattern="BottomSheet|Modal|Toast"  

2. Inspect its state/props:

inspect_component with componentName="MyBottomSheet"  

This targeted approach uses ~2-4KB vs ~20KB+ for the full tree.

Step 1: Get Component Tree

View the React component hierarchy with minimal data:

# Focused screen only (recommended)
get_component_tree with focusedOnly=true structureOnly=true

# Full tree structure
get_component_tree with structureOnly=true

Output (ultra-compact):

HomeScreen Header FlatList Footer

This gives you the focused screen structure in just 1-3KB.

### Step 2a: Inspect Specific Component

After identifying a component in the structure, drill down:

inspect_component with componentName="HomeScreen"

Output:

{
  "component": "HomeScreen",
  "path": "... > Navigator > HomeScreen",
  "props": {
    "navigation": "[Object]",
    "route": { "name": "Home", "key": "home-xyz" }
  },
  "hooks": [
    { "hookIndex": 0, "value": false },
    { "hookIndex": 3, "value": 42 }
  ]
}

Options:

* `includeChildren=true` \- Include children tree
* `childrenDepth=2` \- How deep to show children (1=direct only, 2+=nested tree)
* `includeState=false` \- Skip hooks/state (faster)
* `index=1` \- Inspect 2nd instance if multiple exist

### Step 2b: Find Components by Pattern

Search for components and optionally get their layout:

find_components with pattern="Screen$" includeLayout=true

Output:

pattern: Screen$ found: 5 #found{component,path,depth,key,layout} HomeScreen|... > Navigator > HomeScreen|45|paddingHorizontal:16| SettingsScreen|... > Navigator > SettingsScreen|45|flex:1|

Options:

* `includeLayout=true` \- Include flex, padding, margin values
* `summary=true` \- Get counts only (e.g., "HomeScreen: 1")
* `maxResults=10` \- Limit number of results

### Full Layout (Use Sparingly)

For detailed layout of all visible components:

get_screen_layout

**Warning**: This returns \~20-50KB for complex screens. Use `find_components` with `includeLayout=true` instead for targeted queries.

### Use Cases

**Figma Alignment / Layout Verification**

Step 1: See focused screen structure

get_component_tree with focusedOnly=true structureOnly=true

Step 2: Get layout for specific components

find_components with pattern="Header|Footer|Button" includeLayout=true

**Debug State Changes**

Check hook values before action

inspect_component with componentName="LoginForm"

→ hookIndex 2: false (isLoading)

After user action, check again

inspect_component with componentName="LoginForm"

→ hookIndex 2: true (isLoading changed!)

**Debug Navigation Issues**

Find which screen is currently mounted (use full tree)

get_component_tree with structureOnly=true

or

find_components with pattern="Screen$"

Check if a screen rendered multiple times (memory leak)

find_components with pattern="HomeScreen" summary=true

**Debug Overlays (BottomSheet, Modal, Toast)**

Find and inspect overlay components

find_components with pattern="BottomSheet|Modal"

Get overlay props/state

inspect_component with componentName="PaywallModal"

**Understand Unfamiliar Codebase**

Quick focused screen overview

get_component_tree with focusedOnly=true structureOnly=true

Full app structure (navigation, providers)

get_component_tree with structureOnly=true

Find all button variants

find_components with pattern="Button"

Find all context providers

find_components with pattern="Provider$"

## Device Interaction

### Android (requires ADB)

List connected devices:

list_android_devices

Take a screenshot:

android_screenshot

Tap on screen (coordinates in pixels):

android_tap with x=540 y=960

Swipe gesture:

android_swipe with startX=540 startY=1500 endX=540 endY=500

Type text (tap input field first):

android_tap with x=540 y=400 android_input_text with text="hello@example.com"

Send key events:

android_key_event with key="BACK" android_key_event with key="HOME" android_key_event with key="ENTER"

### iOS Simulator (requires Xcode)

List available simulators:

list_ios_simulators

Boot a simulator:

ios_boot_simulator with udid="XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"

ios_screenshot

Launch an app:

ios_launch_app with bundleId="com.example.myapp"

Open a deep link:

ios_open_url with url="myapp://settings"

## Efficient UI Automation (No Screenshots)

For action triggering without layout debugging, use element-based tools instead of screenshots. This is **2-3x faster** and uses fewer tokens.

### Android - Find and Tap by Text

Wait for screen to load

android_wait_for_element with text="Login"

Find element (returns tap coordinates)

android_find_element with textContains="submit"

Tap the element (use coordinates from find_element)

android_tap with x=540 y=960

Search options:

* `text` \- exact text match
* `textContains` \- partial text (case-insensitive)
* `contentDesc` \- accessibility content description
* `contentDescContains` \- partial content description
* `resourceId` \- resource ID (e.g., "button" or "com.app:id/button")

### iOS - Find and Tap by Label (requires IDB)

# Install IDB first
brew install idb-companion

Wait for element

ios_wait_for_element with label="Sign In"

Find element by partial label

ios_find_element with labelContains="welcome"

Search options:

* `label` \- exact accessibility label
* `labelContains` \- partial label (case-insensitive)
* `value` \- accessibility value
* `valueContains` \- partial value
* `type` \- element type (e.g., "Button", "TextField")

### Wait for Screen Transitions

Both platforms support waiting with timeout:

android_wait_for_element with text="Dashboard" timeoutMs=15000 pollIntervalMs=500 ios_wait_for_element with label="Home" timeoutMs=10000

### Recommended Workflow (Priority Order)

**Always try accessibility tools first, fall back to screenshots only when needed:**

1. **Wait for screen** → Use `wait_for_element` with expected text/label
2. **Find target** → Use `find_element` to get tap coordinates
3. **Tap** → Use `tap` with coordinates from step 2
4. **Fallback** → If element not in accessibility tree, use `screenshot`

Example: Tap "Submit" button after screen loads

android_wait_for_element with text="Submit" # Step 1: Wait android_find_element with text="Submit" # Step 2: Find (returns center coordinates) android_tap with x=540 y=1200 # Step 3: Tap (use returned coordinates)

**Why this order?**

* `find_element`: \~100-200 tokens, <100ms
* `screenshot`: \~400-500 tokens, 200-500ms

### When to Use Screenshots vs Element Tools

| Use Case                     | Recommended Tool          |
| ---------------------------- | ------------------------- |
| Trigger button taps          | find\_element \+ tap      |
| Wait for screen load         | wait\_for\_element        |
| Navigate through flow        | wait\_for\_element \+ tap |
| Debug layout issues          | screenshot                |
| Verify visual appearance     | screenshot                |
| Find elements without labels | screenshot                |

## OCR Text Extraction

The `ocr_screenshot` tool extracts all visible text from a screenshot with tap-ready coordinates. This is useful when accessibility labels are missing or when you need to find text that isn't exposed in the accessibility tree.

### Why OCR?

| Approach                           | Pros                                               | Cons                                             |
| ---------------------------------- | -------------------------------------------------- | ------------------------------------------------ |
| Accessibility tree (find\_element) | Fast, reliable, low token usage                    | Only finds elements with accessibility labels    |
| Screenshot + Vision                | Visual layout understanding                        | High token usage, slow                           |
| **OCR**                            | Works on ANY visible text, returns tap coordinates | Requires text to be visible, may miss small text |

### Usage

ocr_screenshot with platform="ios"

Returns all visible text with tap-ready coordinates:

{
  "platform": "ios",
  "engine": "easyocr",
  "processingTimeMs": 850,
  "elementCount": 24,
  "elements": [
    { "text": "Settings", "confidence": 98, "tapX": 195, "tapY": 52 },
    { "text": "Login", "confidence": 95, "tapX": 187, "tapY": 420 }
  ]
}

Then tap the element:

ios_tap with x=187 y=420

### OCR Engine

The tool uses EasyOCR (Python-based) for text recognition. It provides excellent accuracy on colored backgrounds and stylized text common in mobile UIs.

### Installing EasyOCR (Required for OCR)

# Install Python 3.10+ if not already installed
brew install python@3.11

# Install EasyOCR
pip3 install easyocr

First run will download models (\~100MB for English). Additional language models are downloaded automatically when configured.

### OCR Language Configuration

By default, OCR recognizes English text. To add more languages, set the `EASYOCR_LANGUAGES` environment variable. English is always included as a fallback.

# Add Spanish and French (English always included)
EASYOCR_LANGUAGES=es,fr

Add to your MCP configuration:

{
    "mcpServers": {
        "rn-debugger": {
            "command": "npx",
            "args": ["react-native-ai-debugger"],
            "env": {
                "EASYOCR_LANGUAGES": "es,fr"
            }
        }
    }
}

See EasyOCR supported languages for the full list of language codes.

### Recommended Workflow

1. **Try accessibility first** \- Use `find_element` / `wait_for_element` (faster, cheaper)
2. **Fall back to OCR** \- When element isn't in accessibility tree
3. **Use screenshot** \- For visual debugging or layout verification

Step 1: Try accessibility-based approach

android_find_element with text="Submit"

Step 2: If not found, use OCR

ocr_screenshot with platform="android"

Step 3: Tap using coordinates from OCR result

android_tap with x=540 y=1200

## Supported React Native Versions

| Version        | Runtime                 | Status     |
| -------------- | ----------------------- | ---------- |
| Expo SDK 54+   | React Native Bridgeless | ✓          |
| RN 0.70 - 0.76 | Hermes React Native     | ✓          |
| RN < 0.70      | JSC                     | Not tested |

## How It Works

1. Fetches device list from Metro's `/json` endpoint
2. Connects to the main JS runtime via CDP (Chrome DevTools Protocol) WebSocket
3. Enables `Runtime.enable` to receive `Runtime.consoleAPICalled` events
4. Enables `Network.enable` to receive network request/response events
5. Stores logs and network requests in circular buffers for retrieval

## Auto-Reconnection

The server automatically handles connection interruptions:

### Auto-Connect on Startup

When the MCP server starts, it automatically scans common Metro ports (8081, 8082, 19000-19002) and connects to any running Metro bundlers. No need to manually call `scan_metro` if Metro is already running.

### Reconnection on Disconnect

When the connection to Metro is lost (e.g., app restart, Metro restart, or network issues):

1. The server automatically attempts to reconnect
2. Uses exponential backoff: immediate, 500ms, 1s, 2s, 4s, 8s (up to 8 attempts)
3. Re-fetches device list to handle new WebSocket URLs
4. Preserves existing log and network buffers

### Connection Gap Warnings

If there was a recent disconnect, `get_logs` and `get_network_requests` will include a warning:

[WARNING] Connection was restored 5s ago. Some logs may have been missed during the 3s gap.

### Monitor Connection Health

Use `get_connection_status` to see detailed connection information:

=== Connection Status ===

--- React Native (Port 8081) --- Status: CONNECTED Connected since: 2:45:30 PM Uptime: 5m 23s Recent gaps: 1 - 2:43:15 PM (2s): Connection closed

## Troubleshooting

### No devices found

* Make sure the app is running on a simulator/device
* Check that Metro bundler is running (`npm start`)

### Wrong device connected

The server prioritizes devices in this order:

1. React Native Bridgeless (SDK 54+)
2. Hermes React Native
3. Any React Native (excluding Reanimated/Experimental)

### Logs not appearing

* Ensure the app is actively running (not just Metro)
* Try `clear_logs` then trigger some actions in the app
* Check `get_apps` to verify connection status

## Telemetry

This package collects anonymous usage telemetry to help improve the product. No personal information is collected.

### What is collected

| Data              | Purpose                                  |
| ----------------- | ---------------------------------------- |
| Tool names        | Which MCP tools are used most            |
| Success/failure   | Error rates for reliability improvements |
| Duration (ms)     | Performance monitoring                   |
| Session start/end | Retention analysis                       |
| Platform          | macOS/Linux/Windows distribution         |
| Server version    | Adoption of new versions                 |

**Not collected**: No file paths, code content, network data, or personally identifiable information.

### Opt-out

To disable telemetry, set the environment variable:

export RN_DEBUGGER_TELEMETRY=false

Or inline:

RN_DEBUGGER_TELEMETRY=false npx react-native-ai-debugger

## License

MIT