How to Dynamically Change Anthropic API Key in Claude Code

03 Nov, 2025

There might cases in which you might not be able to set a static ANTHROPIC_API_KEY key and use Claude Code.

For example, your company might require you to rotate the key every 1 hour or you might need to load API key from some secret manager.

Claude Code has support for that using apiKeyHelper

What does apiKeyHelper setting does?

When apiKeyHelper setting is configured, it’ll run shell script and expect an API key as an output from it.

And that key will be used for X-Api-Key and Authorization: Bearer headers when making LLM request.

By default, it’ll be called after 5 minutes or when we recieve HTTP 401 response.

It also means that you can change the API key without even restarting the Claude Code.

First you’ll need a shell script where you can perform some operation and then return the API key.

In our case, we’ll be creating this file at ~/.claude/anthropic_key_helper.sh

# Add your custom logic to fetch the ANTHROPIC_API_KEY
echo "sk-........."

Then make that file executable

chmod +x ~/.claude/anthropic_key_helper.sh

Now just include that file in Claude Config ~/.claude/settings.json

{
  "apiKeyHelper": "~/.claude/anthropic_key_helper.sh"
}

You can control the behaviour by setting CLAUDE_CODE_API_KEY_HELPER_TTL_MS (default 5min)

For example:

# Refresh every 30 minutes
export CLAUDE_CODE_API_KEY_HELPER_TTL_MS=1800000