Node.js backend for lexbor

Backend for lexbor.com:

• Fuzzers Manager — web UI for managing fuzz testing processes: start/stop fuzzers, monitor logs, track crashes. See https://lexbor.com/fuzzers/
• Amalgamation Generator — public API and web UI for building single-file lexbor distributions from selected modules and versions. See https://lexbor.com/generate/amalgamation

Environment

Required:

Variable	Description
LEXBOR_SECRET	Session secret key
LEXBOR_ADMIN	Admin username
LEXBOR_ADMIN_PASS	Admin password

Optional:

Variable	Default	Description
LEXBOR_DIR	../lexbor	Path to the lexbor repository clone
LEXBOR_REPO_URL	https://github.com/lexbor/lexbor.git	Git repo URL; used to auto-clone if LEXBOR_DIR doesn't exist

Dependencies

• Node.js
• Perl (for single.pl amalgamation generator)
• Git (lexbor repo clone at LEXBOR_DIR)

Amalgamation API

Public API for generating lexbor amalgamation files (single-file builds).

GET /generate/amalgamation

https://lexbor.com/generate/amalgamation

HTML page with a form for selecting version, modules, filename, and extension.

GET /api/amalgamation/modules

https://lexbor.com/api/amalgamation/modules?version=latest

Returns available modules for a given version.

Parameters:

Parameter	Required	Description
version	yes	latest, master, or a tag (e.g. v2.7.0)

Response:

{
  "modules": ["core", "css", "dom", "encoding", ...],
  "version": "v2.7.0"
}

GET /api/amalgamation

https://lexbor.com/api/amalgamation?version=latest&modules=core,dom&ext=h

Generates and downloads an amalgamation file.

Parameters:

Parameter	Required	Default	Description
version	yes		latest, master, or a tag (e.g. v2.7.0)
modules	yes		Comma-separated module names (e.g. core,dom,html)
ext	no	h	File extension: h or c
filename	no	auto	Custom filename (alphanumeric, _, -)

Filename rules:

• All modules selected: lexbor-<version>.<ext>
• Custom filename: <filename>-<version>.<ext>
• Subset of modules: <module1>_<module2>-<version>.<ext>
• For master, version includes commit hash: master_a1b2c3

Examples:

# Latest release, all modules
curl -OJ "https://lexbor.com/api/amalgamation?version=latest&modules=core,css,dom,encoding,engine,html,ns,punycode,selectors,style,tag,unicode,url,utils"

# Specific version, selected modules
curl -OJ "https://lexbor.com/api/amalgamation?version=v2.7.0&modules=core,dom,html&ext=h"

# Custom filename
curl -OJ "https://lexbor.com/api/amalgamation?version=latest&modules=core,dom&filename=my_lexbor&ext=c"

# Master branch
curl -OJ "https://lexbor.com/api/amalgamation?version=master&modules=core"

Errors:

Code	Description
400	Missing parameters, unknown version, invalid module for the version, bad extension
500	Generation failure

Results are cached. Tag versions are cached permanently. Master is cached by commit hash (6 chars).

Deployment

1. Install dependencies

sudo apt update
sudo apt install -y nginx git curl perl nodejs npm

2. Clone and setup

git clone https://github.com/lexbor/fuzzers-manager lexbor-backend
cd lexbor-backend
npm install

The lexbor repository will be auto-cloned on first start from LEXBOR_REPO_URL if it doesn't exist at LEXBOR_DIR.

3. Configure environment

Create /var/www/lexbor-backend/.env or set variables in PM2 ecosystem file:

export LEXBOR_SECRET="your-secret-key"
export LEXBOR_ADMIN="admin"
export LEXBOR_ADMIN_PASS="your-password"
export LEXBOR_DIR="/var/www/lexbor"
export LEXBOR_REPO_URL="https://github.com/lexbor/lexbor.git"

4. Start with PM2

sudo npm install -g pm2

LEXBOR_SECRET="your-secret-key" \
LEXBOR_ADMIN="admin" \
LEXBOR_ADMIN_PASS="your-password" \
LEXBOR_DIR="/var/www/lexbor" \
pm2 start server.js --name "lexbor-backend"
pm2 startup
pm2 save

Or use an ecosystem file ecosystem.config.js:

module.exports = {
    apps: [{
        name: 'lexbor-backend',
        script: 'server.js',
        env: {
            LEXBOR_SECRET: 'your-secret-key',
            LEXBOR_ADMIN: 'admin',
            LEXBOR_ADMIN_PASS: 'your-password',
            LEXBOR_DIR: '/var/www/lexbor',
            LEXBOR_REPO_URL: 'https://github.com/lexbor/lexbor.git'
        }
    }]
};

pm2 start ecosystem.config.js
pm2 save

5. Configure Nginx

Add to your nginx server block:

location ~ ^/(socket.io|admin|fuzzers|login|logout|generate|api) {
    proxy_pass http://localhost:3000;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_read_timeout 120s;
}

sudo nginx -t
sudo systemctl reload nginx

6. Verify

# HTML page
curl -s https://lexbor.com/generate/amalgamation | head -5

# API: list modules
curl -s https://lexbor.com/api/amalgamation/modules?version=latest

# API: download file
curl -OJ "https://lexbor.com/api/amalgamation?version=latest&modules=core,dom&ext=h"

Maintenance

• Logs: pm2 logs lexbor-backend
• Restart: pm2 restart lexbor-backend
• Update: git pull && npm install && pm2 restart lexbor-backend
• Cache: lexbor repo is auto-updated every 5 minutes (git fetch --tags). Amalgamation results are cached in .amalgamation_cache/.

COPYRIGHT AND LICENSE

Lexbor.

Copyright 2018-2026 Alexander Borisov