Accounts

Ninebrains never handles your logins. You install claude and codex and log in to them yourself. Ninebrains starts the CLIs, and only ever asks them whether they are logged in.

One config directory per account

Both CLIs keep everything for an account in one directory:

CLI	Variable	Default
Claude Code	CLAUDE_CONFIG_DIR	~/.claude
Codex	CODEX_HOME	~/.codex

Logins are scoped per directory. A fresh, empty directory reports “not logged in” even when your default directory is logged in. Settings, workspace trust, hooks and transcripts are per directory too.

To add a second Claude Code account:

mkdir -p ~/.claude-work
CLAUDE_CONFIG_DIR=~/.claude-work claude auth login
CLAUDE_CONFIG_DIR=~/.claude-work claude auth status --json

The same for Codex:

mkdir -p ~/.codex-work
CODEX_HOME=~/.codex-work codex login
CODEX_HOME=~/.codex-work codex login status

Two things differ between directories that people often miss:

• Workspace trust. Claude Code asks whether you trust a folder once per config directory.
• MCP servers added in Settings are written to the default directory only.

Status-light hooks follow the variable, so they install into each account’s directory automatically.

Choosing an account for a lane

In this build, lanes launch with the CLI’s default directory.

CLAUDE_CONFIG_DIR and CODEX_HOME are on the environment allowlist that lanes inherit. If you start Ninebrains from a terminal where one of them is set, every lane uses that account. On macOS, an app opened from the Dock or Finder does not see variables set in your shell.

Planned: a per-lane account picker, and a usage meter per account. Moving a lane to another account will relaunch its CLI with a different directory. The app will not copy or move your login.

What Ninebrains never does

• It never reads .credentials.json, ~/.codex/auth.json or the provider entries in your OS keychain.
• It never copies, moves, symlinks or writes a config directory.
• It never runs a login for you. Status comes from claude auth status and codex login status.

This follows Anthropic’s rule that third-party apps must not offer Claude.ai login or its usage limits on the user’s behalf. Ninebrains stays a launcher for the CLIs you already use.

A logged-out account can look like success

A logged-out claude -p run can end with subtype: "success" while is_error is true and the text says “Not logged in”. Ninebrains decides success from is_error and the exit code, not the subtype. If a run does nothing, check the account with claude auth status --json.