A router for the Claude API, also known as a gateway or proxy, is a service between your application and the Claude models. It accepts a request in the format you already use, forwards it and returns the response. The word is confusing because it brings to mind the networking box at home or in the office. Here it means a software intermediary that handles HTTP requests. Below we cover what a gateway does in practice, how it differs from calling Anthropic directly, and what to check before you switch.
What a Claude API router does in practice
Technically it is a reverse proxy with extra logic. Your application sends a request to the gateway's address the same way it would send it straight to Anthropic: the same JSON, often the same SDK. The gateway accepts the request, adds its own credentials for talking to the model provider and returns the response in the format your code expects.
Besides forwarding, gateways usually take on several jobs at once:
- One entry point. A single key and a single address replace separate settings for every model provider.
- Its own billing. You pay the gateway, not the provider directly, so the available payment methods and the billing currency change.
- Routing between models (not every gateway). Some gateways switch between several models or providers by rule: price, availability, type of task. It is a separate feature and never a requirement.
- Limits and observability (not every gateway). Per-key limits, token usage logs, filtering by IP or by client.
No gateway does everything on this list. A gateway built around a single model provider may get by with the first two items, and that is not a flaw: the narrower the job, the fewer layers sit between your request and the model.
A router versus direct access to the Anthropic API
With direct access your code calls api.anthropic.com using a key from the Anthropic console. Nobody stands between you and Anthropic's servers except ordinary network infrastructure.
A gateway adds one more node to that chain, and several things change at once:
- Account. You sign up and pay through the gateway, not through Anthropic. For some users that is the whole reason to pick one: an Anthropic account is hard to open because of the region or the payment method.
- Key and address. Every gateway has its own key format and its own base URL, not
api.anthropic.com. - An extra network hop. The request passes through one more server, so in theory some latency is added. For most tasks the difference does not matter. If your application is sensitive to latency (voice assistants, interactive agents), measure it on your own load instead of trusting promises.
- Who answers for uptime. When Anthropic has an outage, you see it directly. When the gateway has one, you see it even if the models are running normally. The reverse can happen too: a resilient gateway can smooth over some provider-side overload with its own request retries.
A gateway is not better or worse than the direct API on its own. These are different trade-offs, and the choice depends on what matters more for your task: a direct line to one provider, or easy signup and payment.
What to check before choosing a gateway
Who can read your requests
A gateway can technically see the content of requests and responses, otherwise it could not forward and process them. That is no argument against gateways as a class, but it is a reason to read the privacy policy of the specific service: what is logged, how long it is kept, whether it is shared with third parties. If you work with sensitive data, check this before connecting, not after.
How fully the gateway reproduces the API format
"Anthropic API compatible" can mean different things, from full support for streaming, tool calls, vision and prompt caching down to plain text messages and nothing else. Test your own scenario with every feature your application uses. A simple text request from the documentation proves little.
How prices work
A gateway's per-token rates usually differ from Anthropic's direct prices because they include a markup for infrastructure and service. Check whether each model has its own price listed, and whether there are hidden minimums or fees for simply using the service on top of the token cost.
What happens in an outage
Ask yourself what happens to your application if the gateway goes down for an hour. A gateway for a single model provider adds one point of failure on top of the provider's own. Look at the uptime history if the service publishes one, and at how quickly support answers. You cannot verify either in advance except through reviews and your own experience after connecting.
codexkey as one option
codexkey is a gateway for Claude models. It does not carry a catalogue of fifty providers, and it is aimed squarely at this use case. The request format is compatible with the Anthropic SDK, so moving from the direct API usually comes down to replacing base_url and the key.
import anthropic
client = anthropic.Anthropic(
api_key="sk_cdx_YOUR_KEY",
base_url="https://api.codexkey.online",
)
message = client.messages.create(
model="claude-sonnet-5",
max_tokens=1024,
messages=[{"role": "user", "content": "Hello"}],
)
You can sign up with a login and password or through Google, GitHub or Telegram, with no email confirmation. Payment works with a Russian card, SBP (the Russian Faster Payments System) or cryptocurrency, and the balance can be topped up from 1 dollar. For the current list of models and the rate for each, see the models and pricing pages. Prices change, and quoting figures here would mean promising something that goes stale before you finish reading.
How to choose a gateway for your task
Boiled down to an order of work, the sections above give you this:
- Decide what matters more: full compatibility with every Anthropic API feature, or convenient payment and signup.
- Read the data-handling policy of the specific service if you work with sensitive information.
- Run a real scenario, including streaming and tool calls if your application uses them.
- Compare prices for the models you actually need, and do not stop at the cheapest one in the lineup.
- Work out what happens to your application when the gateway is unavailable, and whether you have a fallback plan.
FAQ
Is a Claude API router the same thing as a regular network router?
No. In the Claude API context a router is a software service at the HTTP request level that forwards calls to the models. It has nothing to do with home or office networking hardware. Only the word is shared.
Does a gateway have to switch between different models?
No. Some gateways do route requests between several models or providers by rule, but that is a separate feature, not a trait of every gateway. A gateway built around one provider can do without it.
Does using a gateway violate Anthropic's terms?
Anthropic's terms of use govern your relationship with Anthropic itself. If you reach the models through a third-party gateway and have no Anthropic account of your own, those account-level terms do not apply to you: the agreement is between you and the gateway operator.
Does a gateway add latency to every request?
Technically yes, because the request passes through an extra server. How noticeable that is depends on the gateway's infrastructure and on your task. For most text scenarios the difference does not matter, while latency-sensitive applications should measure it on a real load.
Can I use a gateway with existing code without rewriting it?
In most cases yes, if the gateway is compatible with the Anthropic or OpenAI SDK format. You change the base_url and key values, and the rest of the code, including streaming handling and tool calls, stays as it was. Check compatibility against the specific features your application uses.
How does a gateway differ from a Claude Pro or Max subscription?
A Claude Pro or Max subscription gives you access through the claude.ai web interface and apps for a fixed monthly price, with no direct API access. A gateway gives programmatic access to the API with pay-as-you-go billing, and it suits embedding in your own code rather than chatting in a browser.