Grok (Sign in with Grok) AI chat fails with HTTP 426, outdated client version #667

What happens
After signing in with Grok (SuperGrok subscription) in Settings, AI chat with Grok as the model doesn't work. SuperCmd's requests come back with HTTP 426 (Upgrade Required).

Environment

• SuperCmd 1.0.9 (Homebrew cask, latest available)
• macOS 27.2, Apple silicon (M4 MacBook Pro)
• Grok provider via "Sign In with Grok" (OAuth to cli-chat-proxy.grok.com)
• Sign-in itself succeeds

Likely cause
xAI's cli-chat-proxy.grok.com now enforces a minimum Grok client version via the
x-grok-client-version header and returns 426 ("Your Grok CLI version ... is outdated")
when the value is missing or too old. The current minimum reported by others is 1.0.13.
The official Grok CLI is currently 1.0.62.

Other apps hit the same issue and fixed it by sending a current version in that header:

• fix(xai): Grok subscription inference fails with HTTP 426 on every request openclaw/openclaw#113663
• xAI vision requests fail 426 on cli-chat-proxy: missing x-grok-client-version header (min 1.0.13 enforced) openclaw/openclaw#165654
• [Bug]: Built-in Grok CLI provider is unavailable CherryHQ/cherry-studio#21259

Suggested fix
Send an up-to-date x-grok-client-version (and x-grok-client-mode: cli) on all requests
to cli-chat-proxy.grok.com. Ideally don't hardcode it: read ~/.grok/version.json when the
Grok CLI is installed, or fetch it remotely, since xAI raises the minimum over time.