Constant CLAUDE_CODE_OAUTH_TOKEN_ENV 

pub const CLAUDE_CODE_OAUTH_TOKEN_ENV: &str = "CLAUDE_CODE_OAUTH_TOKEN";

The variable the flat token key is stamped onto for an Anthropic account (minted by claude setup-token). Its presence makes the account token-mode: the token is the account’s only credential. The value is trimmed once where it enters forge’s config, so every reader sees the same credential.