API keys let programs (trading bots, portfolio trackers) work with your account without your password.

Open Account → API Keys and click + (Create API key) next to the title.
In Account choose Main account or one of your sub-accounts: the key will work on behalf of that account.
Enter a Name so you can recognise the key later. The keys of one account need different names (letter case and spaces at the ends do not count); the name of a revoked key can be used again. Otherwise you see "This account already has an API key with this name."
Choose the Permissions. Give only what the program needs: API key permissions and IP whitelist.
In IP Whitelist enter the IP addresses the program will connect from, one per line. Leave it empty to allow any IP (not recommended).
Confirm with the code from your email and, if two-factor authentication is on, the code from your authenticator app.
Copy and save the API Secret. It is shown only once. If you lose it, revoke the key and create a new one.

The list in Account → API Keys shows each key in full; the copy button next to it copies the key (not the secret). You get a notification and an email about every new or changed key. To change the name, permissions or the IP whitelist, click Edit in the key's row (confirmation codes are needed again). To switch a key off for good, click Revoke: a revoked key cannot be turned back on.

Where to read how to use the key: Where is the API documentation?

Stay safe: Strade support never asks for your password, 2FA codes, seed phrase or API secret. Never share your API secret, and revoke a key at once if it may have leaked.

How do I create an API key?