Authentication

deer uses your Claude credentials to power agents. No separate account or API key is required if you already have Claude Code installed and logged in.

Credential resolution

Credentials are resolved in priority order. The first match wins:

Priority	Source	Type
1	CLAUDE_CODE_OAUTH_TOKEN env var	Subscription
2	~/.claude/agent-oauth-token file	Subscription
3	macOS Keychain (Claude Code's stored credentials)	Subscription
4	~/.claude.json -- claudeAiOauth.accessToken	Subscription
5	~/.config/claude/config.json	Subscription
6	~/.claude/.credentials.json	Subscription
7	ANTHROPIC_API_KEY env var	API key

Subscription vs API key

• Subscription (OAuth) is always preferred over an API key. If both are available, the subscription is used.
• If you have Claude Code installed and logged in on macOS, deer picks up your subscription automatically -- no extra setup needed.
• API key mode works but is billed separately from your Claude subscription.

How credentials are used

Credentials never enter the sandbox. The host-side auth proxy injects them into API requests transparently.

Inside the sandbox, Claude Code sees ANTHROPIC_BASE_URL=http://api.anthropic.com (plain HTTP, no token). Requests flow through the SRT proxy to the host-side auth proxy, which adds the real credentials before forwarding to Anthropic's servers over HTTPS.

See Network & Auth Proxy for the full request flow diagram.

GitHub authentication

deer uses the GitHub CLI for all GitHub operations (PR creation, issue lookup, git push/pull):

gh auth token

This token is also proxied through the auth proxy -- the sandbox never sees it directly.

To set up GitHub authentication:

gh auth login

Token expiry

OAuth tokens are checked for expiry at startup by inspecting the JWT exp claim. If the token is expired, deer shows a warning.

To refresh an expired token:

claude /login

This re-authenticates with Anthropic and stores a fresh token that deer will pick up on the next launch.