Authentication

Proxy authentication is how ColdProxy verifies that a request is allowed to use your plan. ColdProxy supports two methods: User:Pass (HTTP Basic or SOCKS5 auth) and IP Authentication (IP whitelisting). You can enable either method alone, or run both simultaneously on the same plan. This page shows how to configure each method and how to fix the common 407 Proxy Authentication Required error. For background on the two approaches, see IP whitelisting vs username/password.

#Method 1 — User:Pass

Include a username and password with every request. The gateway uses HTTP Basic auth for HTTP/HTTPS connections and SOCKS5 auth for SOCKS5 connections. This is the most portable method and the only one that supports per-request username tags for geo and session control.

cURL

curl -x "http://USERNAME:PASSWORD@gw-2312.coldproxy.com:30000" \
  "https://api.vipv6proxy.com/api/checker/my-ip"

Python (requests)

import requests

proxy = "http://USERNAME:PASSWORD@gw-2312.coldproxy.com:30000"
proxies = {"http": proxy, "https": proxy}

print(requests.get("https://api.vipv6proxy.com/api/checker/my-ip", proxies=proxies, timeout=30).json())

#Method 2 — IP Authentication (IP whitelisting)

Authorize the source IPs of the machines that will use the proxy: a server fleet, a scraper host, an office network. Requests from whitelisted IPs pass without any credentials in the connection string.

• Whitelist up to 50 addresses on every plan. The plan API returns your service's limit in the max_ip_auth field of info.
• The client area provides proxies in IP:PORT form when IP Authentication is active (for example 203.0.113.10:30000). Authentication is by your source IP, so the gateway hostname (gw-{service-id}.coldproxy.com) works the same way once your IP is whitelisted; use whichever form fits your tooling.
• Use My IP to find the public IP of each machine you want to whitelist.

cURL (IP:PORT form, no credentials)

# Replace 203.0.113.10:30000 with the IP:PORT from your client area
curl -x "http://203.0.113.10:30000" \
  "https://api.vipv6proxy.com/api/checker/my-ip"

Python (requests)

import requests

# Replace 203.0.113.10:30000 with the IP:PORT from your client area
proxy = "http://203.0.113.10:30000"
proxies = {"http": proxy, "https": proxy}

print(requests.get("https://api.vipv6proxy.com/api/checker/my-ip", proxies=proxies, timeout=30).json())

Manage your authorized IP list from the client area, or programmatically through the plan API (add one IP, delete one IP, list IPs, or replace the full list).

#Using both methods at once

User:Pass and IP Authentication can be active simultaneously on the same plan. A common pattern is IP Authentication for a fixed fleet of servers whose IPs are stable, combined with User:Pass for ad-hoc machines or for requests that need per-request geo and session tags.

#Fixing the 407 Proxy Authentication Required error

A 407 Proxy Authentication Required response means the gateway received your request but did not accept valid credentials. Common causes and fixes:

• Wrong or missing credentials (User:Pass). Confirm the username and password match exactly what the client area shows. A rotated password invalidates the old one immediately, so update every client after rotating.
• Credentials not sent at all. Some libraries need the credentials in the proxy URL (http://USERNAME:PASSWORD@gw-2312.coldproxy.com:30000); others need a separate auth option. Check that your client is actually attaching them.
• Source IP not whitelisted (IP Authentication). If you rely on IP whitelisting, the machine's current public IP must be on the authorized list. Use My IP to check the IP your traffic is leaving from, then add it in the client area.

#Ports per plan

Each plan can be provisioned with 1 to 5,000 unique ports within the 30000–34999 range. The 5,000 figure is the configurable ceiling, not a default. Each authentication method has its own port range on your service; the plan API's info action returns both (user_ports and ip_auth_ports).

#Next steps

• Protocols — HTTP, HTTPS, and SOCKS5 on the same gateway.
• Username Tag Scheme — per-request geo and session control (User:Pass only).
• Ports & SuperPorts — geo and session control without username tags, for IP-authenticated traffic.
• IP whitelisting vs username/password — a deeper comparison of the two auth models.
• Glossary: IP Whitelisting