MCP Server Status Monitor - Statuslines

Features

• Real-time connected server count
• Active tools aggregation across all servers
• Server name display with truncation
• Color-coded connection status
• Performance-optimized JSON parsing
• Graceful fallback when MCP unavailable
• Tool category breakdown (database, filesystem, API, etc.)
• Server health monitoring with error detection

Use Cases

• Monitoring MCP server connectivity during development
• Tracking available tools across connected servers
• Debugging MCP connection issues
• Verifying server plugin installations
• Multi-server workflows requiring tool availability awareness
• Troubleshooting MCP integration problems with real-time status

Requirements

• Claude Code CLI installed and configured with MCP support
• Bash shell available (bash 4.0+ recommended for associative arrays and string manipulation)
• jq command-line JSON processor (jq 1.6+ recommended for safe extraction with // defaults)
• base64 command (usually pre-installed, required for base64 encoding/decoding of server data)
• Terminal with ANSI color code support (256-color mode recommended for color-coded connection status)
• MCP servers configured in ~/.mcp.json or via Claude Code MCP configuration (statusline reads from Claude Code context)

Configuration

{
  "statusLine": {
    "type": "command",
    "command": "$CLAUDE_PROJECT_DIR/.claude/statuslines/mcp-server-status-monitor.sh",
    "refreshInterval": 2000
  }
}

Examples

Enhanced MCP Server Status Monitor with Health Checks

Extended version checking individual server health and connection status

#!/usr/bin/env bash

# Enhanced MCP Server Status Monitor with Health Checks

input=$(cat)

mcp_servers=$(echo "$input" | jq -r '.mcp.servers // []' 2>/dev/null || echo "[]")
server_count=$(echo "$mcp_servers" | jq 'length' 2>/dev/null || echo "0")

active_tools=0
healthy_servers=0
unhealthy_servers=0

if [ "$server_count" -gt 0 ]; then
  for server in $(echo "$mcp_servers" | jq -r '.[] | @base64'); do
    decoded=$(echo "$server" | base64 -d 2>/dev/null || echo "{}")
    tools=$(echo "$decoded" | jq '.tools | length // 0' 2>/dev/null || echo "0")
    status=$(echo "$decoded" | jq -r '.status // "unknown"' 2>/dev/null || echo "unknown")

    active_tools=$((active_tools + tools))

    if [ "$status" = "connected" ] || [ "$status" = "healthy" ]; then
      healthy_servers=$((healthy_servers + 1))
    else
      unhealthy_servers=$((unhealthy_servers + 1))
    fi
  done
fi

# Color based on server health
if [ "$unhealthy_servers" -gt 0 ]; then
  color="\033[33m"  # Yellow - some servers unhealthy
  icon="⚠️"
elif [ "$server_count" -gt 0 ]; then
  color="\033[32m"  # Green - all servers healthy
  icon="🔌"
else
  color="\033[90m"  # Gray - no servers
  icon="⚫"
fi

server_names=$(echo "$mcp_servers" | jq -r '.[].name // empty' 2>/dev/null | tr '\n' ',' | sed 's/,$//')
if [ -n "$server_names" ] && [ ${#server_names} -gt 30 ]; then
  server_names="${server_names:0:27}..."
fi

RESET="\033[0m"

if [ "$server_count" -gt 0 ]; then
  health_info=""
  if [ "$unhealthy_servers" -gt 0 ]; then
    health_info=" (${unhealthy_servers} unhealthy)"
  fi

  if [ -n "$server_names" ]; then
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers${health_info} │ ${active_tools} tools │ ${server_names}"
  else
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers${health_info} │ ${active_tools} tools"
  fi
else
  echo -e "${icon} MCP ${color}disconnected${RESET}"
fi

MCP Server Status Monitor with Tool Categories

Version grouping tools by category for better organization

#!/usr/bin/env bash

# MCP Server Status Monitor with Tool Categories

input=$(cat)

mcp_servers=$(echo "$input" | jq -r '.mcp.servers // []' 2>/dev/null || echo "[]")
server_count=$(echo "$mcp_servers" | jq 'length' 2>/dev/null || echo "0")

active_tools=0
declare -A tool_categories

if [ "$server_count" -gt 0 ]; then
  for server in $(echo "$mcp_servers" | jq -r '.[] | @base64'); do
    decoded=$(echo "$server" | base64 -d 2>/dev/null || echo "{}")
    tools=$(echo "$decoded" | jq '.tools | length // 0' 2>/dev/null || echo "0")
    server_name=$(echo "$decoded" | jq -r '.name // "unknown"' 2>/dev/null || echo "unknown")

    active_tools=$((active_tools + tools))

    # Categorize by server name prefix
    if [[ "$server_name" == *"filesystem"* ]] || [[ "$server_name" == *"file"* ]]; then
      tool_categories["filesystem"]=1
    elif [[ "$server_name" == *"git"* ]]; then
      tool_categories["git"]=1
    elif [[ "$server_name" == *"database"* ]] || [[ "$server_name" == *"db"* ]]; then
      tool_categories["database"]=1
    fi
  done
fi

if [ "$server_count" -gt 0 ]; then
  color="\033[32m"
  icon="🔌"
else
  color="\033[90m"
  icon="⚫"
fi

categories_list=""
for category in "${!tool_categories[@]}"; do
  if [ -z "$categories_list" ]; then
    categories_list="$category"
  else
    categories_list="$categories_list,$category"
  fi
done

server_names=$(echo "$mcp_servers" | jq -r '.[].name // empty' 2>/dev/null | tr '\n' ',' | sed 's/,$//')
if [ -n "$server_names" ] && [ ${#server_names} -gt 30 ]; then
  server_names="${server_names:0:27}..."
fi

RESET="\033[0m"

if [ "$server_count" -gt 0 ]; then
  if [ -n "$categories_list" ]; then
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers │ ${active_tools} tools │ ${categories_list}"
  elif [ -n "$server_names" ]; then
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers │ ${active_tools} tools │ ${server_names}"
  else
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers │ ${active_tools} tools"
  fi
else
  echo -e "${icon} MCP ${color}disconnected${RESET}"
fi

MCP Server Status Monitor Installation Example

Complete setup script with MCP configuration verification

#!/bin/bash
# Installation script for MCP Server Status Monitor

# Check for jq (required for JSON parsing)
if ! command -v jq &> /dev/null; then
    echo "Installing jq for JSON parsing..."
    if [[ "$OSTYPE" == "darwin"* ]]; then
        brew install jq
    elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
        sudo apt-get install -y jq || sudo yum install -y jq
    else
        echo "Please install jq manually: https://stedolan.github.io/jq/"
    fi
fi

# Check for base64 (usually available, but verify)
if ! command -v base64 &> /dev/null; then
    echo "Warning: base64 command not found. Script may not work correctly."
    echo "Install base64: macOS (usually pre-installed), Linux (coreutils package)"
fi

# Check MCP configuration
if [ -f ~/.mcp.json ]; then
    echo "MCP configuration found: ~/.mcp.json"
    echo "Verifying configuration..."
    if jq empty ~/.mcp.json 2>/dev/null; then
        echo "MCP configuration is valid JSON"
    else
        echo "Warning: MCP configuration may be invalid JSON"
    fi
else
    echo "Note: MCP configuration not found at ~/.mcp.json"
    echo "MCP servers can be configured in ~/.mcp.json or via 'claude mcp add' command"
fi

# Test Unicode characters
if echo -e '🔌 ⚫ ⚠️' &> /dev/null; then
    echo "Unicode characters supported"
else
    echo "Warning: Unicode characters may not be supported in your terminal"
fi

mkdir -p .claude/statuslines

cat > .claude/statuslines/mcp-server-status-monitor.sh << 'SCRIPT_EOF'
#!/usr/bin/env bash

# MCP Server Status Monitor
# Shows connected MCP servers and active tools

read -r input

mcp_servers=$(echo "$input" | jq -r '.mcp.servers // []' 2>/dev/null || echo "[]")
server_count=$(echo "$mcp_servers" | jq 'length' 2>/dev/null || echo "0")

active_tools=0
if [ "$server_count" -gt 0 ]; then
  for server in $(echo "$mcp_servers" | jq -r '.[] | @base64'); do
    decoded=$(echo "$server" | base64 -d 2>/dev/null || echo "{}")
    tools=$(echo "$decoded" | jq '.tools | length // 0' 2>/dev/null || echo "0")
    active_tools=$((active_tools + tools))
  done
fi

if [ "$server_count" -gt 0 ]; then
  color="\033[32m"
  icon="🔌"
else
  color="\033[90m"
  icon="⚫"
fi

server_names=$(echo "$mcp_servers" | jq -r '.[].name // empty' 2>/dev/null | tr '\n' ',' | sed 's/,$//')
if [ -n "$server_names" ] && [ ${#server_names} -gt 30 ]; then
  server_names="${server_names:0:27}..."
fi

RESET="\033[0m"

if [ "$server_count" -gt 0 ]; then
  if [ -n "$server_names" ]; then
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers │ ${active_tools} tools │ ${server_names}"
  else
    echo -e "${icon} MCP ${color}${server_count}${RESET} servers │ ${active_tools} tools"
  fi
else
  echo -e "${icon} MCP ${color}disconnected${RESET}"
fi
SCRIPT_EOF

chmod +x .claude/statuslines/mcp-server-status-monitor.sh

# Add to settings.json
if [ ! -f .claude/settings.json ]; then
    echo '{"statusLine":{"type":"command","command":"$CLAUDE_PROJECT_DIR/.claude/statuslines/mcp-server-status-monitor.sh","refreshInterval":2000}}' > .claude/settings.json
else
    jq '.statusLine = {"type":"command","command":"$CLAUDE_PROJECT_DIR/.claude/statuslines/mcp-server-status-monitor.sh","refreshInterval":2000}' .claude/settings.json > .claude/settings.json.tmp
    mv .claude/settings.json.tmp .claude/settings.json
fi

echo "MCP Server Status Monitor installed successfully!"
echo "Note: MCP server status requires Claude Code to expose MCP context in statusline JSON"
echo "Verify MCP servers: claude mcp list"
echo "Add MCP server: claude mcp add --transport stdio server-name command"

Troubleshooting

Statusline shows 'MCP disconnected' despite configured servers

Verify servers are actually connected: run 'claude mcp list' to check server status. Ensure servers are properly configured in ~/.mcp.json and restart Claude Code if needed. Check MCP context is available in statusline JSON: echo '$input' | jq .mcp. Verify Claude Code version supports MCP statusline API. Check server startup logs for errors.

Server count shows 0 but MCP servers are running in terminal

Check that MCP context data is accessible. Verify Claude Code version supports MCP statusline API. Run 'claude mcp get [server-name]' to verify individual server status. Check if MCP context is exposed in statusline JSON: echo '$input' | jq .mcp.servers. Ensure servers are registered with Claude Code, not just running externally. Restart Claude Code to refresh MCP connections.

Tool count incorrect or not updating

This indicates silent tool registration failure. Run '/mcp' in Claude Code to verify tool registration. Restart connected servers if tools remain unavailable despite connection. Check tool count calculation: for each server, verify tools array exists. Verify base64 decoding works: echo 'test' | base64 | base64 -d. Check jq parsing: echo '$input' | jq '.mcp.servers[0].tools | length'.

MCP server startup failures or connection timeouts

Launch with --mcp-debug flag. Check logs: ~/Library/Logs/Claude/mcp.log (macOS) or ~/.local/share/claude/mcp.log (Linux). Verify server.connect() is called and transport listener is active. Check server configuration in ~/.mcp.json. Verify server command is executable: which [server-command]. Test server manually: [server-command] --help.

JSON-RPC errors like 'Method not found' or invalid JSON

Server may not support prompts/list or resources/list, or writes non-JSON to stdout. Ensure JSON-RPC 2.0 compliance. Use MCP Inspector for interactive testing. Check server implementation follows MCP protocol. Verify server stdout/stderr separation. Check for error messages in server logs.

Server names not displaying or showing as empty

Verify server name extraction: echo '$input' | jq '.mcp.servers[].name'. Check server name field exists in MCP context. Verify jq parsing works: echo '$input' | jq '.mcp.servers | length'. Check string truncation logic if names are too long. Verify tr and sed commands work: echo 'test\ntest' | tr '\n' ',' | sed 's/,$//'.

Base64 decoding errors or script failures

Verify base64 command is available: which base64. Test base64 encoding/decoding: echo 'test' | base64 | base64 -d (should return 'test'). Check base64 -d flag syntax (may vary by OS). Verify jq @base64 encoding works: echo '[{"name":"test"}]' | jq -r '.[] | @base64'. Add error handling for base64 decode failures.

Statusline not updating or stuck at 'disconnected'

Check JSON input is being read: echo '$input' | jq .. Verify mcp.servers field exists: echo '$input' | jq .mcp.servers. Check jq is installed: which jq. Verify MCP context is available in Claude Code statusline JSON (may require Claude Code version with MCP support). Check refreshInterval in settings.json is set to 2000ms or lower. Restart Claude Code to refresh MCP connections.