Hacker News — 2026-07-12#

Top Story#

What xAI’s Grok Build CLI Actually Sends to xAI A meticulous reverse-engineering teardown reveals that xAI’s official Grok Build CLI secretly uploads entire user repositories—including unredacted .env files—to a Google Cloud storage bucket. The multi-gigabyte background uploads occur regardless of what files the agent actually reads, and explicitly turning off the “Improve the model” setting does not stop the exfiltration.

Front Page Highlights#

Claude Code sends 33k tokens before reading the prompt; OpenCode sends 7k A proxy-based token audit reveals how much context overhead popular AI coding harnesses are silently burning. Claude Code proved exceptionally hungry and cache-inefficient, frequently rewriting tens of thousands of prompt-cache tokens mid-session and resulting in massive hidden costs compared to the much leaner OpenCode.