Bot signals · Web crawler

What is Checkly?

Checkly monitoring

Checkly is a monitoring platform for developers. Its API and browser checks test the sites and APIs its customers set up, and Checkly is in the user agent unless the customer sets a custom one.

risk.is_crawler

Check an IP

Is this IP really Checkly?

Free. The same answer as risk.is_crawler in the lookup API.

01 · Profile

Checkly at a glance.

What to look for in your logs, and what the lookup API returns for its addresses.

Type
Web crawler
User agent
Checkly
API flag
risk.is_crawler

A user agent alone never sets a flag. Anyone can claim to be Checkly; the flag follows the address the request comes from.

02 · In the response

What a match looks like.

A lookup of a Checkly address sets risk.is_crawler. The flags come with geolocation and network data in the same response, for API keys on every paid plan.

The response says which kind of bot an address belongs to, not which operator. A request that claims to be Checkly while risk.is_crawler is false should not be trusted as Checkly.

GET /api/lookup/{ip}?key=YOUR_API_KEY
{
  // … location and network fields …
  "risk": {
    "is_ai": false,
    "is_crawler": true,
    "is_scanner": false
  }
}

03 · Control

Allow or block Checkly.

Your options

  • robots.txt works only for crawlers that choose to follow it. Check the operator’s documentation for the token it reads.
  • Firewall, WAF or CDN. Many offer bot rules you can allow or deny by category. Use them to enforce what robots.txt only asks for.
  • In your app. Look up the client address and allow or deny on risk.is_crawler, alongside the user agent.
  • Never on the user agent alone. Blocking the name stops only honest clients; allowing it lets anyone in who borrows it.

04 · Questions

About Checkly.

What is Checkly?

Checkly is a monitoring platform for developers. Its API and browser checks test the sites and APIs its customers set up, and Checkly is in the user agent unless the customer sets a custom one.

How do I block Checkly?

Deny it at your firewall, WAF or CDN, or look up each client address and deny requests where risk.is_crawler is true. Do not rely on the user agent alone.

Can I trust a request that says it is Checkly?

Not on the user agent alone: any client can send “Checkly” in its user agent. A user agent alone never sets a flag. Check the address with the free bot checker or the lookup API.

Which risk flag does Checkly set?

Its addresses set risk.is_crawler in the lookup response. The risk flags come with every paid plan.

Recognise Checkly on every request.

is_ai, is_crawler and is_scanner in every lookup, on every paid plan, from 9,00 € a month (VAT included).