grok-build-upstream-mirror/crates/codegen/xai-grok-pager/docs/user-guide/02-authentication.md

# Authentication

Grok supports several authentication methods, including interactive browser login, enterprise single sign-on (SSO), and headless CI/CD runners.

---

## Browser Login (Default)

On first launch, Grok opens your browser to authenticate with grok.com:

```bash
grok
```

Grok stores credentials in `~/.grok/auth.json` and reuses them across sessions. Grok refreshes access tokens automatically in the background. When a token can't be refreshed, Grok prompts you to sign in again. Credentials without a server-provided expiry fall back to a 30-day lifetime.

### Re-authenticate

To switch accounts or resolve an authentication problem, run:

```bash
grok login
```

Running `grok login` starts the sign-in flow again, replacing your cached session. By default, it opens your browser and signs in through SpaceXAI OAuth at `auth.x.ai`. Pass a flag to select a different flow:

| Flag | Description |
|------|-------------|
| `--oauth` | Sign in through SpaceXAI OAuth at `auth.x.ai`. This is the default, so the flag is optional. |
| `--device-auth` (alias `--device-code`) | Sign in with the device-code flow for headless or remote environments. |

To sign out, run `grok logout`. It takes no flags and clears your cached credentials.

---

## API Key

For CI/CD, automation, or environments without browser access, use an API key from [console.x.ai](https://console.x.ai):

```bash
export XAI_API_KEY="xai-..."
grok
```

Grok uses the API key as a fallback when no session token is active. If you have already signed in interactively, the stored session token takes precedence. To fall back to the API key, run `grok logout` or delete `~/.grok/auth.json`.

---

## OIDC (Customer SSO)

Authenticate developers through your own Identity Provider (IdP) -- such as Okta, Azure AD, or Auth0 -- instead of grok.com.

### 1. Register a public client in your IdP

- Grant type: Authorization Code with PKCE (Proof Key for Code Exchange)
- Redirect URI: `http://127.0.0.1/callback` -- a loopback address. Grok binds a random port at sign-in time, and most IdPs treat the loopback redirect as port-agnostic per [RFC 8252](https://tools.ietf.org/html/rfc8252).
- No client secret. PKCE replaces it.

### 2. Configure the CLI

Via config file:

```toml
# ~/.grok/config.toml
[grok_com_config.oidc]
issuer = "https://acme.okta.com"
client_id = "0oa1b2c3d4e5f6g7h8i9"
```

Or via environment variables:

```bash
export GROK_OIDC_ISSUER="https://acme.okta.com"
export GROK_OIDC_CLIENT_ID="0oa1b2c3d4e5f6g7h8i9"
```

You can also override the API endpoint to point at your own proxy:

```bash
export GROK_CLI_CHAT_PROXY_BASE_URL="https://grok-proxy.acme.com/v1"
```

### 3. Run `grok`

The CLI discovers endpoints via `{issuer}/.well-known/openid-configuration`, opens the IdP login page, and stores tokens in `~/.grok/auth.json`. Tokens auto-refresh silently via the stored `refresh_token`.

### Optional fields

| Field | Default | Notes |
|-------|---------|-------|
| `scopes` | `["openid", "profile", "email", "offline_access", "api:access"]` | `offline_access` enables silent token refresh |
| `audience` | None | Required by some IdPs (e.g., Auth0) |

---

## External Auth Provider

When browser-based login isn't possible -- for example, on sandboxed VMs, CI runners, or air-gapped networks -- delegate authentication to an external binary or script.

### How It Works

```
+--------------+     sh -c     +------------------------+
|     Grok     |-------------->|  your auth binary      |
|              |               |                        |
|  reads       |<-- stdout ----|  prints token          |
|  auth.json   |               |                        |
|              |   (stderr)    |  prints status/URLs    |--> surfaced to user
+--------------+               +------------------------+
```

1. Grok runs your command via `sh -c "<command>"`
2. Your binary runs whatever auth flow it needs (SSO, device code, certificate exchange)
3. **stderr** carries human-readable output, such as login URLs and status messages. Grok reads stderr and surfaces it to the user; in the TUI, it turns the first `https://` URL into a clickable sign-in link.
4. **stdout** is captured by Grok and saved as the access token
5. Exit 0 = success; exit non-zero = Grok falls back to interactive login

### The stdout / stderr Contract

| Stream | What to print | Who sees it |
|--------|---------------|-------------|
| **stdout** | The token -- nothing else | Grok (parsed and stored in auth.json) |
| **stderr** | Login URLs, status messages, errors | The user (Grok reads stderr and shows the sign-in URL as a clickable link in the TUI) |

**Do not print anything to stdout except the token.** No progress messages, no debug output. Grok reads stdout, trims surrounding whitespace, and parses the result as a token.

### stdout Token Format

**Bare string** -- just the raw token:

```
eyJhbGciOiJSUzI1NiIs...
```

**JSON** -- with optional refresh token, expiry, and issuer:

```json
{"access_token": "eyJhbGciOi...", "refresh_token": "ref-tok", "expires_in": 3600, "issuer": "https://idp.example.com"}
```

Use JSON if your tokens expire and you want Grok to automatically re-run the binary before expiry.

JSON fields:

| Field | Required | Meaning |
|-------|----------|---------|
| `access_token` | yes | Bearer token Grok sends to the xAI API |
| `refresh_token` | no | Stored for reference. Grok refreshes by re-running your binary, not with an OAuth refresh grant |
| `expires_in` | no | Token lifetime in seconds; enables proactive refresh before expiry |
| `issuer` | no | Identifies the token's issuer |

### Configuration

Via config file:

```toml
# ~/.grok/config.toml
[auth]
auth_provider_command = "/usr/local/bin/my-auth-provider"
auth_provider_label = "Acme Corp"   # optional -- customizes the TUI login button
auth_token_ttl = 3600               # optional -- token lifetime in seconds
```

Or via environment variables:

```bash
export GROK_AUTH_PROVIDER_COMMAND="/usr/local/bin/my-auth-provider"
export GROK_AUTH_PROVIDER_LABEL="Acme Corp"
export GROK_AUTH_TOKEN_TTL=3600
```

### Token Refresh

When Grok needs to refresh an expired token, it re-runs your binary with `GROK_AUTH_EXPIRED=1` set in the environment. Each run fully replaces the stored credential, so emit the same JSON fields (such as `issuer`) on every invocation, including refreshes. Your binary can use this to take a faster silent-refresh path:

```bash
#!/bin/sh
if [ "$GROK_AUTH_EXPIRED" = "1" ]; then
    echo "Refreshing token..." >&2
    TOKEN=$(my-company-auth --refresh --silent)
else
    echo "Authenticating via Acme Corp SSO..." >&2
    TOKEN=$(my-company-auth --login --interactive)
fi

if [ -z "$TOKEN" ]; then
    echo "Authentication failed" >&2
    exit 1
fi

echo "{\"access_token\": \"$TOKEN\", \"expires_in\": 3600}"
```

### Environment Variables

| Variable | Description |
|----------|-------------|
| `GROK_AUTH_PROVIDER_COMMAND` | Path to your auth binary |
| `GROK_AUTH_PROVIDER_LABEL` | Display name on the TUI login screen (e.g., "Acme Corp") |
| `GROK_AUTH_TOKEN_TTL` | Token lifetime in seconds (for bare-string tokens without `expires_in`) |
| `GROK_AUTH_EXPIRED` | Set to `1` by Grok when re-running the binary for token refresh |
| `GROK_AUTH_EARLY_INVALIDATION_SECS` | Seconds before expiry to proactively refresh (default: 300) |

---

## Device Code Flow

For headless environments (SSH sessions, Docker containers, remote VMs) where no browser is available locally:

```bash
grok login --device-auth    # or: grok login --device-code
```

This prints a URL and code to the terminal. Open the URL on any device, enter the code, and complete authentication. Grok polls until the login is confirmed.

You can also implement the device-code flow through an [External Auth Provider](#external-auth-provider) for full control.

---

## Automatic Credential Refresh

Grok automatically refreshes expired credentials:

- **Before expiry:** If your auth provider returned `expires_in` (JSON output) or you set `auth_token_ttl`, Grok re-runs the auth binary ~5 minutes before expiry.
- **On auth error:** If the server returns 401 Unauthorized, Grok refreshes the credentials and retries the request.
- **OIDC:** If a `refresh_token` is available, Grok silently refreshes via your IdP without re-opening the browser.

Tune the refresh buffer:

```bash
# Refresh 5 minutes before expiry (default)
export GROK_AUTH_EARLY_INVALIDATION_SECS=300

# Disable the proactive buffer: refresh at expiry or on a 401 (set to 0)
export GROK_AUTH_EARLY_INVALIDATION_SECS=0
```

---

## Hot Reload

Grok picks up changes to `~/.grok/auth.json` automatically. If you update credentials externally (for example, with a script that writes new tokens), Grok uses the new credentials on the next API call without a restart.

---

## Auth Precedence

Grok resolves credentials for each request in this order, highest to lowest:

1. **Per-model `api_key` or `env_key`** -- set under `[model.<name>]` in `config.toml`. Wins whenever present.
2. **Active session token** -- obtained through browser, OIDC/OAuth2, or external-provider login and stored in `~/.grok/auth.json`.
3. **`XAI_API_KEY`** -- fallback when no session token is active.

When more than one login flow is configured, Grok populates the session token from the first available source, highest to lowest:

1. **External auth provider** (`auth_provider_command`)
2. **Enterprise OIDC** -- when OIDC is configured, through `[grok_com_config.oidc]` in `config.toml` or the `GROK_OIDC_ISSUER` and `GROK_OIDC_CLIENT_ID` environment variables
3. **SpaceXAI OAuth2 browser login** -- the default

During a session, the active method handles all mid-session refreshes.

---

## Troubleshooting

### Debug logging

Set `RUST_LOG` to control the verbosity of the file log and headless stderr output. (The TUI's on-screen tracing pane uses a fixed filter and ignores `RUST_LOG`.) In the TUI, file logging defaults to `DEBUG`; in headless mode (`-p`), `RUST_LOG` defaults to `off` so only the answer is printed — set `RUST_LOG=error` (or broader) to see logs on stderr.

In the TUI, set `GROK_LOG_FILE` to an absolute path to write logs to that file:

```bash
GROK_LOG_FILE=/tmp/grok.log RUST_LOG=debug grok
tail -f /tmp/grok.log
```

`GROK_LOG_FILE` is treated as a literal file path. A relative value such as `1` writes a file named `1` in the current directory.

In headless mode, logs go to stderr. Redirect them to a file:

```bash
RUST_LOG=debug grok -p "hello" 2> /tmp/grok.log
```

### Common log messages

| Log message | What it means |
|-------------|---------------|
| `auth: running external auth provider` | Grok is running your binary |
| `auth: external auth provider returned fresh token` | Grok parsed and stored the token |
| `auth: external auth provider failed` | Binary exited non-zero or stdout was empty |
| `auth: external auth provider timed out (likely needs interactive auth), killing` | Binary did not exit before the timeout and was killed |
| `auth: failed to start external auth provider` | Command could not be spawned (binary not found) |

### Common fixes

- **"Authentication failed"** -- Run `grok logout` to clear cached credentials, then `grok login` to sign in again.
- **Token expires too quickly** -- Set `auth_token_ttl` or return `expires_in` in your auth provider's JSON output.
- **OIDC redirect fails** -- Ensure your IdP allows loopback redirect URIs (`http://127.0.0.1/callback`).
- **External auth provider not found** -- Check that the `auth_provider_command` path is correct and the binary is executable.