Configuration details of SaaS

This document describes the IP configuration, hostnames, and usage limits that govern the interactions with app.humansignal.com (app.heartex.com).

Mail configuration

app.humansignal.com (app.heartex.com) sends emails from the humansignal.com domain by using SendGrid, and has its own dedicated IP addresses:

• 208.117.59.219

app.humansignal.eu sends emails from the humansignal.eu domain by using SendGrid, and has its own dedicated IP address in EU region:

• 159.183.231.189

IP Ranges

app.humansignal.com (app.heartex.com)

Inbound Traffic IP Addresses

• 34.199.69.93
• 52.22.82.31
• 3.233.209.176

Outbound Connections IP Addresses

Used for Import/Export, ML backends, and Prompts

• 3.219.3.197
• 34.237.73.3
• 44.216.17.242

app.humansignal.eu

Inbound Traffic IP Addresses

• 3.79.91.185
• 63.176.196.34
• 18.153.87.16

Outbound Connections IP Addresses

Used for Import/Export, ML backends, and Prompts

• 52.59.18.15
• 18.194.85.62
• 54.93.122.250

Hostname list

For setting up allow-lists in local HTTP(S) proxies, or other web-blocking software on user-end computers, add the following hostnames:

• app.humansignal.com
• app.humansignal.eu

Please note that our documentation and company pages, served via https://app.humansignal.com/docs/api and https://humansignal.com/ respectively, load certain page content directly from commonly used public CDN hostnames.

Usage Limits

Label Studio imposes rate limits on a per-Access Token basis. If a request exceeds the rate limit, a response with a 429 status code is returned. Clients are advised to pause and retry after a short delay in such instances.

Path	Rate limit
/api/projects/*/import	1 request / 1 second
/api/tasks/*/annotations	5 request / 1 second
/api	Limits are set per user within an organization. The default limit is: 15 requests / 1 second per user

Other Operational Limits

Setting	Default Limit
Maximum import file size	200 MB
Timeout for page load	90 seconds