Claude API Proxy: The Complete 2026 Guide

TL;DR — A Claude API proxy is a service that sits between your tools (Claude Code, Cursor, Codex) and the Anthropic API. It exposes an Anthropic-compatible endpoint, so any Claude-native client keeps working unchanged, while the proxy adds value on top: reachability from restricted regions, unified billing, key/rate-limit pooling, and automatic failover. You can self-host one (LiteLLM, one-api) or use a managed proxy like CCSub. This guide covers what a Claude API proxy is, when you need one, the trade-offs, and a 5-minute setup.

What is a Claude API proxy?

A Claude API proxy is a gateway that speaks the Anthropic Messages API (/v1/messages) on the front, forwards your requests upstream, and returns the response — usually streamed — back to your client. Because it is protocol-compatible, tools that already target Claude don't need code changes; you only change two things:

• the base URL (point it at the proxy instead of api.anthropic.com), and
• the API key (the proxy's key instead of your Anthropic key).

That's the whole trick. Claude Code, Cursor's "custom model" mode, Codex CLI, Cline, Roo Code, and most Anthropic SDKs all accept a custom base URL, which is exactly what makes a Claude API proxy a drop-in layer rather than a rewrite.

Why use a Claude API proxy?

A raw Anthropic key works fine if you're in a supported country, have a foreign card, and only run one project. A proxy earns its keep the moment any of those stop being true:

1. Region access. In mainland China and some other regions, reaching api.anthropic.com directly is unreliable and paying Anthropic needs a foreign card. A proxy hosted on a reachable endpoint (and that accepts local payment — WeChat, Alipay, USDT) removes both blockers.
2. Unified billing & cost control. One balance, one dashboard, per-key spend limits, and usage logs across every tool and teammate — instead of juggling separate Anthropic invoices.
3. Rate-limit & key pooling. A proxy can spread traffic across a pool of upstream capacity, so a single project's burst (say, Claude Code firing many parallel sub-agents) doesn't hit a per-key ceiling.
4. Automatic failover. If one upstream is slow or rate-limited, a good proxy transparently retries on another, so your claude command doesn't just hang.
5. One endpoint, many models. Route Claude, GPT, and Gemini-family requests through the same Anthropic-compatible (or OpenAI-compatible) gateway, and switch models by name without re-plumbing your setup.

Self-hosted vs managed Claude API proxy

There are two ways to get a Claude API proxy. Neither is strictly "better" — it depends on how much you want to operate yourself.

| | Self-hosted (LiteLLM / one-api / new-api) | Managed proxy (e.g. CCSub) | |---|---|---| | Setup time | Hours to days (server, TLS, keys, upgrades) | Minutes | | Upstream capacity | You supply your own Anthropic/other keys | Provided + pooled | | Region reachability | You must host on a reachable node yourself | Handled for you | | Local payment (CN) | You still need a foreign card for upstream | WeChat / Alipay / USDT | | Maintenance | Yours (uptime, failover, patching) | Yours is zero | | Control / privacy | Full — runs on your infra | Trust the provider | | Best for | Teams that already have keys + ops capacity | Individuals & teams who want to start now |

If you already hold Anthropic keys and want maximum control, self-hosting LiteLLM is a solid, open-source route. If you want a working claude command in five minutes — especially from a region where the direct API is a pain — a managed proxy is the pragmatic choice.

How to set up a Claude API proxy (5 minutes)

The steps below use CCSub, an Anthropic-compatible (and OpenAI-compatible) managed proxy built for Claude Code, Cursor, and Codex. The same pattern — change base URL + key — applies to any proxy.

1. Create an account and top up

Register at ccsub.net/register, verify your email, then open Billing / Subscription and add balance. Pay-as-you-go balance is billed at ¥1 = $1 USD and never expires; there's also a monthly plan with a daily quota if you're a heavy user. Local payment methods (WeChat Pay, Alipay, USDT) are supported — no foreign card required.

2. Create an API key

Open API Keys → Create Key, choose a group (the Starter group at 0.7× is a good default for new users), and copy the sk--prefixed key. Treat it like a password.

3. Point Claude Code at the proxy

Set two environment variables:

export ANTHROPIC_BASE_URL=https://www.ccsub.net/api
export ANTHROPIC_AUTH_TOKEN=sk-your-key-here

Add them to ~/.zshrc or ~/.bashrc (macOS/Linux) or your System Environment Variables (Windows) so they persist.

4. Verify

claude "write a hello world HTTP server in Go"

A streamed answer means your Claude API proxy is live. That's it — Claude Code now routes through the proxy, with the same model names (claude-sonnet-4-6, etc.) you'd use against Anthropic directly.

Using the same proxy with Cursor and Codex

• Cursor — Settings → Models → add a custom Anthropic base URL https://www.ccsub.net/api and paste your key.
• Codex CLI — set the base URL to https://www.ccsub.net/v1 (Codex appends /responses itself) and use your key as the API key.

One key, one balance, three tools.

Choosing a Claude API proxy: what to check

Not all proxies are equal. Before you commit real traffic, verify:

• Compatibility — does it implement the full Anthropic Messages API, including streaming and tool use? (Claude Code relies heavily on both.)
• Reachability & latency — test from your network. A proxy that's fast for someone else may route poorly for you.
• Failover — does it retry on another upstream when one is down, or just error out?
• Transparent billing — per-token pricing, usage logs, and per-key limits you can actually see.
• Payment & support — local payment options and a real support channel matter when something breaks mid-session.

FAQ

Is a Claude API proxy the same as a VPN? No. A VPN tunnels all your traffic at the network layer. A Claude API proxy operates at the application layer — it only handles your Claude/LLM API calls and gives you a stable, Anthropic-compatible endpoint plus billing and failover. Many people in restricted regions use a proxy specifically so they don't need a VPN for coding.

Will my existing Claude Code setup keep working? Yes. That's the point of an Anthropic-compatible proxy — you change only the base URL and key. Model names, streaming, and tool calls behave the same.

Can one proxy serve Claude, GPT, and Gemini? A multi-model proxy exposes both Anthropic-compatible and OpenAI-compatible endpoints, so you can address different model families by name through one gateway and one balance. CCSub works this way.

How much does it cost? Self-hosting is free software but you pay your own upstream bills and ops time. A managed proxy adds a margin on top of usage; with CCSub, pay-as-you-go balance is ¥1 = $1 and never expires, so you only pay for tokens you actually use.

Conclusion

A Claude API proxy is the simplest way to get a stable, billable, region-friendly Claude endpoint without rewriting your tooling. Self-host with LiteLLM if you want full control and already have keys; use a managed proxy like CCSub if you want a working claude command in five minutes with local payment and built-in failover. Either way, the setup is the same two-line change — base URL and key — and every Claude-native tool you already use keeps working.

Ready to try it? Create a CCSub account, grab a key, and point Claude Code at it in under five minutes.