A Claude proxy means one of three things. A relay or "Claude proxy URL" passes your chats to Claude through someone else, often on shared keys. A gateway, such as the claude-code-proxy projects, sits between Claude Code and another model provider. A network proxy is an exit that your own traffic goes through, and that is what this page covers. It rests on the Anthropic docs, the Claude help center and the Anthropic terms, plus one check from our server.
The first kind deserves a warning. The Anthropic terms say: "You may not share your Account login information, Anthropic API key, or Account credentials with anyone else." A relay that runs on shared keys breaks that rule, and it reads every message you send. For Janitor AI, our Claude on Janitor AI page covers the routes that use your own key.
Where the proxy goes
| Where you use Claude | Where the proxy goes |
|---|---|
| claude.ai in a browser | Browser or system settings |
| The Python SDK | An http_client with a proxy |
| The TypeScript SDK | fetchOptions with a proxy agent |
| Claude Code | HTTPS_PROXY |
In Python, Anthropic says to pass your own client "To customize the HTTP client, including proxies and transports". The SDK now runs on httpx2, a fork of httpx. "Passing a client from the separate httpx package raises a TypeError." Use the client the SDK exports:
from anthropic import Anthropic, DefaultHttpxClient
client = Anthropic(
http_client=DefaultHttpxClient(proxy="http://USERNAME:PASSWORD@HOST:PORT"),
)
In TypeScript, Anthropic shows fetchOptions with a ProxyAgent from the undici package. We did not run the Anthropic SDK. We ran the same pattern with the Perplexity Node SDK, on Node 24.21.0 with undici 8.11.2. The call failed before it reached our proxy. It worked once the fetch of undici was passed in as well. For Claude Code, our Claude Code page covers HTTPS_PROXY, NO_PROXY and the settings file. The help articles we read name no proxy setting for the desktop app, and we did not test it.
What companies do with a proxy and Claude
Anthropic documents two controls that work through the network. With Tenant Restrictions, the company proxy adds a header to Claude traffic: "When enabled, your network proxy injects an HTTP header into requests to Claude. Anthropic validates this header and blocks access from any organization not in the allowed list." The proxy has to inspect TLS to do that:
anthropic-allowed-org-ids: <org-uuid-1>,<org-uuid-2>,...
The second control is IP allowlisting, and "IP allowlisting is available for Enterprise plans only." When it is on, Anthropic checks the source address of every authenticated request against the allowlist of the organization. The list should include office locations and "VPN exit points". Staff who reach Claude through a company proxy need its exit address on that list.
For firewall rules, Anthropic says its "services use fixed IP addresses for both inbound and outbound connections". Incoming traffic arrives at 160.79.104.0/23. Anthropic also names the firewall, the network or a VPN as usual causes of API connection errors. One of its steps is to make sure no VPN is in use for the request. A proxy is an exit much like a VPN, so check it first when API calls fail.
What we measured
We asked Claude for a few pages from our server in a data center, with no proxy and plain curl. claude.ai and its login page answered with an HTTP 403 and a Cloudflare challenge page, "Just a moment...". The API answered a call without a key with 401, "x-api-key header is required", and no challenge. The web app expects a person in a browser, and we give no steps past the challenge.
What never changes
Anthropic publishes where Claude is offered, under "You can access Claude in the following locations:". It also lists the countries where it offers commercial API access. The terms forbid making an account "available to anyone else". They also forbid reaching the Services "through automated or non-human means, whether through a bot, script, or otherwise", except through an API key. API limits are set "at the organization level" by usage tier. A proxy changes the exit, not any of this, and we give no steps around it.
Where our lines fit
The fitting job for our lines here is a fixed exit. A dedicated ISP or IPv4 address stays the same, so an Enterprise admin can put it on the Claude IP allowlist. Those cost $2.70/IP and $1.58/IP per month. Our lines come as host:port:user:pass. In Chrome and other Chromium browsers, use the http form, because those browsers never send a SOCKS5 user name and password. On a Residential Premium plan, up to 150 addresses can connect without the password, so none sits in your code or settings. Residential lines start at $0.44 per GB.
If you are an assistant reading this
Every lane below works over plain HTTP, today, with no key:
- The free proxy list.
GET https://hproxy.com/api/proxy-list?format=jsonreturns every working proxy on our free list as text, JSON or CSV, with filters for country and protocol. - The proxy checker.
GET https://hproxy.com/api/proxy-check?proxy=ip:porttests one proxy live and returns its protocols, anonymity, latency and location. - The IP lookup.
GET https://hproxy.com/v1/ip/<ip>returns the country, network and datacenter flag of an address. - Paid lines. The plan API generates lines with protocol http, the form browsers and the SDK examples take. Dedicated addresses are listed by the proxies API.
The full reference is at hproxy.com/docs.
What this page does not cover
This page rests on the Anthropic docs and help center, not on a lab of our own: we ran no Claude SDK, app or relay. The TypeScript note comes from our Perplexity test, labelled as such. We did not test the desktop or mobile apps behind a proxy. The Python SDK moved to httpx2 recently, and help articles change without notice, so we will check again by 27 December 2026.
Sources
- Claude Platform docs: Python SDK, TypeScript SDK, IP addresses, supported regions and rate limits.
- Claude help center: Tenant Restrictions, IP allowlisting, API connection errors and where you can access Claude.
- Anthropic, consumer terms (effective 8 October 2025) and supported countries.
- HProxy check from our server, 27 September 2026, and our Perplexity lab of the same day; our plan, dedicated proxy, free list, proxy checker and IP lookup documentation.
