How to set a custom base URL for Claude Code

What you need before you start

Four things: a working Claude Code install, Node 18 or newer, an active gateway plan and one API key. The key is created once and works for every tool on this site.

• A QuickRouter account with an active plan - Claude Code needs an authenticated endpoint, there is no anonymous tier.
• An API key from the console: open token management, add a token and copy the value once. The full key is only shown at creation time.
• Node.js 18+ and the Claude Code CLI. Install it with npm install -g @anthropic-ai/claude-code.
• A shell you can restart, so the new environment variables are picked up.

Set the two environment variables

Export ANTHROPIC_BASE_URL with the host root and ANTHROPIC_AUTH_TOKEN with your key. Claude Code treats the Anthropic base URL as a host, not as an OpenAI-style path, so adding /v1 produces a 404 instead of a connection.

1. 01

   Open a terminal and export the variables

   Run both lines in the shell you start Claude Code from. Use the host root, without /v1.

   export ANTHROPIC_BASE_URL="https://api.quickrouter.homes"
   export ANTHROPIC_AUTH_TOKEN="sk-qr-your-key"

2. 02

   Optionally pin the model

   Without a model variable Claude Code uses its own default model name. Pin the gateway model you want to pay for, so the request cannot silently fall back to a name your key does not cover.

   export ANTHROPIC_MODEL="claude-sonnet-4-5"

3. 03

   Make it permanent if it works

   Add the same lines to ~/.zshrc or ~/.bashrc after you have verified them. Store the key in your secret manager rather than in a dotfile you sync to a public repo.

4. 04

   Restart Claude Code

   Environment variables are read at process start, so an already-running session keeps the old endpoint until you reopen it.

   claude "summarise this repository"

Verify the request reaches the gateway

Send one prompt, then open the usage view in the console. A request that appears there with a token count and a status code came through the gateway; a response that arrives with no console entry came from somewhere else.

• In the console, open the usage view and look for a row with the model name you pinned and a timestamp from seconds ago.
• Run the built-in /status command inside Claude Code to confirm which endpoint and model the session is using.
• If you see the row and the answer, the wiring is done. Roll the key into your other machines the same way.

Errors you are most likely to hit

Nearly every Claude Code connection problem is one of three things: the wrong variable name, a /v1 suffix on the Anthropic base URL, or a model name the gateway does not serve.

Which Claude model should Claude Code use?

Sonnet is the usual default for day-to-day coding, Haiku is the cheapest option for sub-agents and small edits, and Opus is reserved for the hardest reasoning steps because its output price is fifteen times Sonnet’s.