Environment Variables - agent-code Documentation

API Configuration

Variable	Description
`AGENT_CODE_API_KEY`	API key (highest priority, works with any provider)
`ANTHROPIC_API_KEY`	Anthropic API key (auto-selects Anthropic provider)
`OPENAI_API_KEY`	OpenAI API key (auto-selects OpenAI provider)
`AGENT_CODE_API_BASE_URL`	API endpoint URL override
`AGENT_CODE_MODEL`	Model name override
`AGENT_CODE_AUTH_MODE`	`api_key` or `codex_chatgpt`
`AGENT_CODE_CODEX_HOME`	Codex home for `codex_chatgpt` auth
`CODEX_HOME`	Fallback Codex home used by Codex and `codex_chatgpt` auth

Behavior

Variable	Description
`EDITOR`	Determines REPL editing mode (`vi` if contains "vi", else emacs)
`SHELL`	Reported in the system prompt environment section

Resolution order

API key is resolved from the first available:

--api-key CLI flag
Config file (api.api_key)
AGENT_CODE_API_KEY env var
ANTHROPIC_API_KEY env var
OPENAI_API_KEY env var

Base URL auto-detection:

If only OPENAI_API_KEY is set → defaults to https://api.openai.com/v1
Otherwise → defaults to https://api.anthropic.com/v1

This can always be overridden with --api-base-url or the config file.

For ChatGPT subscription auth, run codex login and set AGENT_CODE_AUTH_MODE=codex_chatgpt or pass --auth-mode codex_chatgpt. This reuses Codex's auth.json and defaults OpenAI traffic to the Codex ChatGPT backend instead of requiring OPENAI_API_KEY.