Authentication and IP whitelisting
Everything authenticates by login and password. Residential lists can additionally trust your server addresses without credentials.
Credentials
The default and the one that works from anywhere. With HTTP the credentials travel in a Proxy-Authorization header; with SOCKS5 they are part of the protocol handshake, which is why SOCKS clients ask for them separately from the URL.
A rejection returns 407, which comes from us. A 401 comes from the destination. Telling them apart saves most of the time people spend debugging the wrong system.
Whitelisting
Residential lists accept a set of addresses that may connect without credentials. This exists mainly for tools that cannot send proxy authentication at all, Selenium being the standard example.
Whitelist servers rather than laptops. A home connection changes address regularly and the failure looks like a proxy fault rather than an expired whitelist entry.
Managing the list
GET /api/v1/user/residential/whitelist
POST /api/v1/user/residential/whitelist
# Keep credentials working as well: if the whitelist is your only
# path and the server address changes, you lose access entirely.Which product supports what
Residential supports both credentials and whitelisting. ISP, datacenter, IPv6 and mobile authenticate by credentials only.
On a shared or cloud host, remember the address may not be exclusively yours. Anyone who can send traffic from a whitelisted address inherits your access, so prefer credentials on anything multi-tenant.
Which tools need which
Most clients handle proxy credentials without complaint. A short list does not, and knowing which is which saves an afternoon.
Selenium is the notable case: neither Chrome nor Firefox accepts proxy credentials through the standard capability, so either selenium-wire handles it or you whitelist the machine instead.
Credential support by tool
requests, httpx, curl, Scrapy credentials in the URL, fine
Playwright username and password fields
Puppeteer page.authenticate, per page
Selenium no native support: selenium-wire,
a generated extension, or whitelisting
Antidetect browsers credential fields in the profile form