Authenticate and choose a model
You have just installed Zi and nothing is configured yet. Zi can start without configured credentials; no model is selected until a configured provider is available or you provide a runtime override.
Log in first, then pick a model.
Login in the terminal
/loginThe login flow asks for a provider and authentication method. API-key entry is hidden in the composer and never shown in the transcript. OAuth providers can show device codes, URLs, prompts, and progress through the same input surface.
Stored credentials go in:
$HOME/.zi/agent/auth.jsonZi also supports provider-native environment variables such as ANTHROPIC_API_KEY and OPENAI_API_KEY through Pi AI.
Logout
/logoutLogout removes stored credentials for the selected provider. It does not remove environment variables or external provider configuration.
Pick a model
/model
/model provider/model-id
/model model-id/model lists models from configured providers. It shows the last known catalog immediately, then refreshes configured provider catalogs in the background.
Refreshed catalogs are retained in $HOME/.zi/agent/models-store.json; packaged models remain available when refresh fails or Zi is offline.
A fully qualified provider/model-id selects directly when it matches. A bare model ID selects directly only when it is unambiguous. The selected provider and model are persisted together so Zi does not combine a project model with the wrong global provider.
One-process credentials
For CI, local scripts, or one-off experiments:
zi --model provider/model-id --api-key "$KEY" "summarize this repo"The key is applied in memory to the selected provider only. It is never written to settings, credentials, events, diagnostics, or session journals. Like any command-line secret, it may still be visible in shell history or process listings.
First-run behavior
If Zi can infer one configured default, it selects it. Otherwise interactive mode opens with an explicit unselected model and asks you to authenticate or choose a model before provider work starts.
Headless modes require enough configuration to run. Missing-model and authentication diagnostics go to stderr, not stdout.
See CLI for the flags that override a single run and Settings for the defaults Zi keeps between runs.