Karpathy Joins Anthropic

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Simplify Command Becomes /code-review

The /simplify command has been renamed to /code-review and rebuilt to report correctness bugs at a chosen effort level, for example /code-review high. Pass --comment to post findings as inline comments on a GitHub PR. The previous cleanup-and-fix behavior is gone, so if you scripted against /simplify, you'll need to adjust.

Worth Knowing

Usage Breakdown Now Shows What Is Driving Your Limits

/usage now itemizes your consumption by skills, subagents, plugins, and per-MCP-server cost. If you've been hitting caps and guessing at the cause, this gives you a direct attribution.

/model Now Changes Only the Current Session

/model now applies your choice to the current session only. Press d in the picker to set a default for new sessions. Resumed sessions also keep their original model instead of inheriting another session's selection.

Background Sessions Now Appear in /resume

Sessions started with claude --bg or from agent view now show up alongside interactive ones in /resume, marked with bg. Subagent completion notifications also include elapsed duration so you can see how long a job actually ran.

Scriptable Agent Listings and Better Trace Parenting

claude agents --json emits live sessions as JSON for status bars, tmux-resurrect, and session pickers. OTEL claude_code.tool spans now carry agent_id and parent_agent_id, and background subagent spans nest correctly under the dispatching Agent tool span.

GFM Task Lists Render and Pinned Sessions Survive Updates

Markdown output now renders - [ ] and - [x] as real checkboxes instead of plain bullets. Pinned background sessions (Ctrl+T in claude agents) stay alive when idle, restart in place to apply Claude Code updates, and are only shed under memory pressure after non-pinned sessions.

Under the Hood

Several Permission Bypasses Closed

Built-in PowerShell cd functions (cd.., cd\, X:) no longer change the working directory undetected, bare variable assignments in Bash are no longer auto-approved, and the sandbox write allowlist in git worktrees now scopes to .git instead of the entire main repo root. PowerShell prefix and wildcard allow rules also now match native executables as intended.

Startup No Longer Hangs Up to 75s on Network Issues

Side-channel API calls now time out after 15s, so captive portals, firewalls, and VPN hiccups no longer freeze startup for over a minute. Terminal output now self-heals after missed resize events instead of requiring Ctrl+L, and SDK/headless MCP startup is up to 2s faster with slow servers.

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