Oxylabs proxy auth fails because you used the wrong username prefix

TL;DR

Keep two separate credential pairs, one per family, and never reuse the residential user on a datacenter host. If your Oxylabs proxy auth keeps failing with correct dashboard credentials, check the username prefix for the product family.

Steps

1. If your Oxylabs proxy auth keeps failing with correct dashboard credentials, check the username prefix for the product family. Residential/Mobile: host pr.oxylabs.io port 7777, username customer-USERNAME (literally prepend customer-). Datacenter/ISP/Dedicated: username user-USERNAME. Keep two separate credential pairs, one per family, and never reuse the residential user on a datacenter host. Geo and session params append to the username with hyphens, e.g. customer-USERNAME-cc-US-city-new_york-sessid-abc123:PASSWORD. Alternatively skip password auth entirely: whitelist your server IP in the Oxylabs dashboard and requests from that IP authenticate automatically.

When to use

You are seeing this: Residential/Mobile: host pr.oxylabs.io port 7777, username customer-USERNAME (literally prepend customer-). Use this skill when you run into "Oxylabs proxy auth fails because you used the wrong username prefix".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: Official docs (Oxylabs agent-skills proxy reference): documents a gotcha that trips agents when switching proxy products. Residential and Mobile proxies authenticate as customer-USERNAME:PASSWORD against pr.oxylabs.io:7777, while shared Datacenter, ISP, and Dedicated products authenticate as user-USERNAME:PASSWORD. The credentials are per product family (OXYRESUSERNAME vs OXYDCUSERNAME) and the prefix is not interchangeable; using customer- on a datacenter host (or vice versa) fails auth.

Verified resolution: If your Oxylabs proxy auth keeps failing with correct dashboard credentials, check the username prefix for the product family. Residential/Mobile: host pr.oxylabs.io port 7777, username customer-USERNAME (literally prepend customer-). Datacenter/ISP/Dedicated: username user-USERNAME. Keep two separate credential pairs, one per family, and never reuse the residential user on a datacenter host. Geo and session params append to the username with hyphens, e.g. customer-USERNAME-cc-US-city-new_york-sessid-abc123:PASSWORD. Alternatively skip password auth entirely: whitelist your server IP in the Oxylabs dashboard and requests from that IP authenticate automatically.

Source URL: https://github.com/oxylabs/agent-skills/blob/HEAD/skills/proxies/SKILL.md