Local Lens CLI

Universal CLI tool to capture server logs from any backend framework and forward them to Local Lens.

Features

• Framework-agnostic: Works with any backend (Rails, Express, Django, FastAPI, Laravel, etc.)
• Zero configuration: No setup required, just wrap your server command
• Real-time forwarding: Logs appear immediately in Local Lens MCP tools
• Process management: Graceful start/stop with proper signal handling

Installation

Install globally via npm:

npm install -g @local-lens/cli

Or build locally with Local Lens:

npm run build:all

Usage

Basic Usage

Wrap any server command with local-lens capture:

# Rails server
local-lens capture "rails server"

# Express/Node.js
local-lens capture "npm start"

# Django
local-lens capture "python manage.py runserver"

# FastAPI
local-lens capture "uvicorn main:app --reload"

# Any command with arguments
local-lens capture "rails server" "-p" "4000"

Options

# Custom process name for logs
local-lens capture "rails server" --name "my-api"

# Custom Local Lens server URL
local-lens capture "npm start" --server "http://localhost:27497"

# Silent mode (suppress Local Lens output)
local-lens capture "rails server" --silent

Status Check

Check if Local Lens server is running:

local-lens status

Examples

Rails Development

# Start Rails server with log capture
local-lens capture "rails server" --name "rails-api"

Your Rails logs (including ActiveRecord queries) will now appear in Local Lens with source: backend-console.

Express Development

# Start Express server with log capture
local-lens capture "npm run dev" --name "express-server"

Django Development

# Start Django server with log capture
local-lens capture "python manage.py runserver" --name "django-api"

Integration with Local Lens

Once your server is running with Local Lens CLI, you can query the logs using MCP tools:

// Get all backend console logs
get_console_logs({ source: "backend-console" })

// Search for specific logs from your process
search_logs({ query: "error", source: "backend-console", backendProcess: "rails-api" })

// Get logs from a specific process
get_console_logs({ backendProcess: "express-server" })

How It Works

1. Process Wrapping: CLI spawns your server process and captures stdout/stderr
2. Log Formatting: Formats logs according to Local Lens schema with metadata
3. Real-time Forwarding: Sends logs to Local Lens server via HTTP API
4. Source Tagging: Tags all logs with source: "backend-console" for filtering

Process Management

• Graceful Shutdown: Ctrl+C properly terminates the wrapped process
• Signal Forwarding: SIGTERM and SIGINT are forwarded to your server
• Exit Codes: Preserves original process exit codes
• Error Handling: Captures and reports process startup errors

This allows you to capture server logs from any backend framework without modifying your application code.