Add a custom model option

Use ANTHROPIC_CUSTOM_MODEL_OPTION to add a single custom entry to the /model picker without replacing the built-in aliases. This is useful for testing model IDs that Claude Code does not list by default. For LLM gateway deployments, Claude Code can populate the picker from the gateway's /v1/models endpoint when CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1 is set, so this variable is needed only when discovery is disabled or does not return the model you want. See gateway model discovery.

To list several models instead, in your own order and under labels you choose, set modelPicker. Its entry says which rows the picker keeps when that lineup replaces the built-in one.

This example sets all three variables to make a gateway-routed Opus deployment selectable. Claude Code reads environment variables at startup, so run the exports before launching claude, or restart an existing session to pick them up:

export ANTHROPIC_CUSTOM_MODEL_OPTION="my-gateway/claude-opus-5"
export ANTHROPIC_CUSTOM_MODEL_OPTION_NAME="Opus via Gateway"
export ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION="Custom deployment routed through the internal LLM gateway"

ANTHROPIC_CUSTOM_MODEL_OPTION_NAME and ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION are optional:

• If you omit the name, the entry shows the model's name when Claude Code recognizes the ID, and the model ID otherwise.