How to Use Claude Code With an API Gateway

TL;DR

Claude Code talks to any server that speaks the Anthropic Messages API. Set ANTHROPIC_BASE_URL to the gateway root, set ANTHROPIC_AUTH_TOKEN to your gateway key, and set ANTHROPIC_MODEL to a model the gateway offers. No plugin or code change is needed.

Why run Claude Code through a gateway?

Claude Code sends every request to one base URL, so that URL decides where your traffic goes. Pointing it at a gateway gives you a few things that a single vendor key does not:

• One key for several models. You can try another model by changing an environment variable.
• Failover. If one upstream fails before it starts answering, the gateway can send the request to another one.
• Usage in one place. Requests, tokens and cost are recorded per key, which helps when a team shares a budget.

Step 1: Create an API key

Sign in to the console and create a key under API Keys. Give each machine or teammate its own key, so that usage stays readable and one key can be revoked without touching the others.

Step 2: Set the environment variables

On Linux or macOS:

export ANTHROPIC_BASE_URL=https://ai.cloudtay.comexport ANTHROPIC_AUTH_TOKEN=your_api_keyexport ANTHROPIC_MODEL=your_model

On Windows PowerShell:

$env:ANTHROPIC_BASE_URL="https://ai.cloudtay.com"$env:ANTHROPIC_AUTH_TOKEN="your_api_key"$env:ANTHROPIC_MODEL="your_model"

Use the root address. Claude Code adds /v1/messages by itself, so do not append /v1 or /anthropic.

Pick a model name from the pricing page. To use one model for everything, including the background tasks Claude Code runs on a smaller model, also set the tier overrides:

export ANTHROPIC_DEFAULT_OPUS_MODEL=your_modelexport ANTHROPIC_DEFAULT_SONNET_MODEL=your_modelexport ANTHROPIC_DEFAULT_HAIKU_MODEL=your_model

Step 3: Start Claude Code

cd /path/to/my-projectclaude

Send a short prompt, then open the usage page in the console. The request should appear there with the model you chose. If it does, the setup is working.

Step 4: Make it permanent

Environment variables only last for the current shell. To keep the setup, put the same values under env in ~/.claude/settings.json:

{    "env": {        "ANTHROPIC_BASE_URL": "https://ai.cloudtay.com",        "ANTHROPIC_AUTH_TOKEN": "your_api_key",        "ANTHROPIC_MODEL": "your_model"    }}

The Claude Code guide covers the remaining options.

How do you fix common Claude Code gateway errors?

Frequently asked questions

Do I need an Anthropic account to use Claude Code with a gateway?

No. Claude Code only needs a server that speaks the Anthropic Messages API and a token that server accepts.

Can Claude Code use non-Claude models?

Yes, when the gateway translates the Anthropic Messages format to the protocol of the upstream model. Tool calling is what Claude Code depends on most, so test a real coding task with any model you plan to keep.

What is the difference between ANTHROPIC_API_KEY and ANTHROPIC_AUTH_TOKEN?

ANTHROPIC_API_KEY is sent in the x-api-key header, and ANTHROPIC_AUTH_TOKEN is sent as an Authorization: Bearer header. Gateways usually document the one they expect. Use ANTHROPIC_AUTH_TOKEN here.

Next steps

• Read the Base URL FAQ if your client uses a different field name.
• Compare models and prices on the pricing page.