Signing in agents

Each agent signs in to its own service, inside the sandbox, and the login is kept in the project. There is no separate login command: after you connect, VS Code or the app offers the agent’s sign-in when the project is not signed in yet. You can also choose Sign in… on a worker or sandbox any time.

Agent	Sign in with
Claude Code	a Claude subscription or Anthropic Console account (a terminal in the sign-in dialog runs claude auth login), or an API key
Codex	ChatGPT (a device code: a link and a code to enter), or an OpenAI API key
DeepSeek Harness	a DeepSeek API key, or any OpenAI-compatible endpoint with its key
OpenCode	a terminal runs opencode auth login: a ChatGPT subscription, or a key for OpenAI, Anthropic, OpenRouter, OpenCode Zen and others

Terminal sign-ins run in a terminal in the dialog; links it prints become buttons, and codes it asks for get a field. The sandbox needs to reach the agent’s service, which a network-isolated sandbox always may.

API keys in config.yaml

Instead of signing in each project, give an agent an API key in config.yaml, from one of three places:

agents:
  claude:
    api_key_env: ANTHROPIC_API_KEY        # an environment variable on this computer
  codex:
    api_key_file: ~/.secrets/openai-key   # a file on this computer
  dsh:
    api_key: sk-…                          # or the key itself

• With api_key written in the file, config.yaml must not be readable by other users (chmod 600); code flower refuses it otherwise.
• The key is written into the agent’s own settings in the project. A subscription login already there is kept.
• OpenCode does not take a key from config.yaml, since a key alone does not say which provider it is for: sign in in the sandbox instead.

Where logins are kept

In the project’s folder, in each agent’s own files (e.g. harness/claude for Claude Code). Signing in once per project is enough for every later sandbox of that project, including batch tasks. The agents never see your API keys as environment variables.

To sign a project out, delete that agent’s folder in the project (e.g. harness/claude) while no sandbox of the project runs.