SafeLine — Self-Hosted Web Application Firewall

What it is

SafeLine is a self-hosted Web Application Firewall by Chaitin Technology. Unlike traditional WAFs that rely on regex pattern matching, SafeLine uses semantic analysis to understand the intent of HTTP requests. This approach catches sophisticated attacks that rule-based systems miss while dramatically reducing false positives.

It targets DevOps engineers, security teams, and small-to-medium organizations that want WAF protection without paying for commercial cloud WAF services. SafeLine runs as a reverse proxy in front of your web applications.

How it saves time or tokens

Traditional regex-based WAFs require constant rule tuning to balance detection accuracy against false positives. SafeLine's semantic engine understands the structure of SQL, JavaScript, and shell commands, so it distinguishes between legitimate user input containing SQL-like syntax and actual injection attempts. This eliminates the hours spent writing and maintaining custom WAF rules.

One-line installation means you go from zero to protected in minutes rather than the hours or days required for configuring ModSecurity or AWS WAF rule sets.

How to use

1. Install SafeLine with the official one-liner:

bash -c "$(curl -fsSLk https://waf.chaitin.com/release/latest/setup.sh)"

1. Open the dashboard at https://your-ip:9443 and complete the setup wizard.

1. Configure upstream servers -- point SafeLine at your web application backends and it begins inspecting traffic immediately.

Example

After installation, SafeLine exposes a management API for automation:

# Check SafeLine status
curl -k https://localhost:9443/api/v1/health

# List protected sites
curl -k -H 'Authorization: Bearer YOUR_TOKEN' \
  https://localhost:9443/api/v1/sites

The dashboard provides real-time attack visualization, blocked request logs, and traffic analytics without additional tooling.

Related on TokRepo

• Security Tools -- Security scanners and vulnerability detection tools for your infrastructure
• Self-Hosted Tools -- Run security and monitoring tools on your own servers

Common pitfalls

• SafeLine acts as a reverse proxy, so your application sees SafeLine's IP rather than the client IP. Configure X-Forwarded-For header forwarding to preserve original client addresses.
• The default admin credentials should be changed immediately after installation. The setup wizard prompts for this, but scripted installations may skip it.
• Resource sizing matters: semantic analysis is more CPU-intensive than regex matching. For high-traffic sites (10K+ requests per second), allocate at least 4 CPU cores and 8GB RAM.