At least require a secret/nonce in the url or similar?
Any page can fetch('http://localhost:4567/health').then(async(r)=>{console.log(await r.json())}), so any page can prompt inject my machine running with the coding agents permissions.
Especially sketchy with bypass permissions https://github.com/aidenybai/react-grab/blob/main/packages/provider-claude-code/src/client.ts#L30