Claude Code: 9 Features, 40 Fixes Boost Performance & DX

Claude Code's dual release adds deferred permissions, PowerShell hardening, headless defer for CI, plus fixes for memory leaks, 1GB+ files, Windows quirks, and stability—run 'Claude update' to deploy.

Permissions and Hooks for Controlled Automation

Pre-tool use hooks now return 'defer' to pause headless sessions until manual resume, enabling CI pipelines to halt at tool calls and resume via flag. Permission denied hooks trigger post-automode blocks, logging denied commands in the permissions recent tab for instant retries. These changes give precise control over tool execution without halting workflows.

Performance Fixes Eliminate Bottlenecks

Key optimizations fix a memory leak from large JSON inputs cached as keys, out-of-memory crashes on files over 1GB, quadratic SSE transport for large frames (now linear time), mid-session tool schema prompt cache misses, and auto-compact trash loops that stop after three failed cycles. Headless resume no longer hangs on oversized inputs, and structured output schema cache bugs (causing high failure rates) are resolved, ensuring reliable scaling for big projects.

Platform Hardening and Voice Stability

Windows sees PowerShell checks hardened against trailing ampersands, bypasses, error action break, debugger hangs, and archive extraction races; edit/write stops double CRLF endings or stripping markdown breaks; Shift+Enter inserts lines in Terminal Preview. Voice mode fixes push-to-talk modifier combos, Windows web socket errors, and macOS Apple Silicon mic permissions. Text handling preserves CJK/emoji in prompt history past 4KB boundaries and fixes Devanagari truncation.

DX Polish and Fun Additions

Edit works on bash-viewed files (cat/sed) without red calls; at-mention typeahead prioritizes source files over MCP resources, including subagents. Stability covers LSP zombie auto-restarts post-crash, macOS Claude CL ID blanks, no duplicate collapsed search batches in parallel tools, accurate rate limit errors with hints, and 9 UI rendering fixes. New /powerup command launches interactive lessons; /buddy hatches a coding companion creature. Totals: 9 features, ~40 fixes, 14 improvements—update via 'Claude update'.

Video description
Claude Code v2.1.89-90 ships 9 new features, 41 bug fixes, and 14 improvements — including deferred hook permissions, memory leak fixes, SSE linear-time optimization, PowerShell security hardening, and /powerup interactive lessons. Full breakdown of every change. ---- Build AI Agents from scratch with the Dynamous AI Agent Mastery course — go from zero to deploying production-ready AI agents. Over 72 lessons across 12 modules. Use code DIYSMART for 10% off: https://www.dynamous.ai/ai-agent-mastery ---- Chapters 0:00 9 Features, 41 Fixes, 14 Improvements — Hooks & Auto Mode 0:27 Memory Leak, OOM Crash, SSE Quadratic Fix (Performance) 0:54 WatchNext 0:59 CRLF Double Fix, PowerShell Hardening (Windows) 1:23 Defer Decision, MCP Non-Blocking, --resume Fixes (Headless & SDK) 1:45 Push-to-Talk, WebSocket, macOS Mic, CJK/Devanagari (Voice & Input) 2:04 Edit After Bash, @-Mention Typeahead, /powerup, /buddy (DX) 2:28 LSP Auto-Restart, Deep Links, Rate Limit Clarity (Stability) 2:49 claude update — Subscribe & Comment Key Changes in This Release: - Deferred permissions: PreToolUse hooks can return "defer" to pause headless sessions, with new PermissionDenied hook for auto mode retry - Performance overhaul: Memory leak from JSON cache keys fixed, OOM crash on 1GB+ files resolved, SSE transport now linear instead of quadratic - Windows hardening: CRLF doubling fixed, PowerShell permission checks hardened against trailing & bypass, ErrorAction Break hang, archive TOCTOU - Headless mode: MCP_CONNECTION_NONBLOCKING skips connection wait in pipe mode, --resume no longer hangs on oversized inputs - New commands: /powerup delivers interactive feature lessons, /buddy hatches an April 1st creature companion Release Notes (v2.1.89): https://github.com/anthropics/claude-code/releases/tag/v2.1.89 Release Notes (v2.1.90): https://github.com/anthropics/claude-code/releases/tag/v2.1.90 Claude Code on GitHub (75K+ stars): https://github.com/anthropics/claude-code Update now: claude update Which fix were you waiting for the most? Drop it in the comments. #ClaudeCode #Claude #Anthropic #CodingAgent #AIAgent #DevTools #AIAssistant #Programming #CodingTools #ClaudeCodeUpdate #PermissionHooks #PowerShell #HeadlessMode #VoiceMode #DeveloperExperience #AITools #CodeAssistant #TerminalTools #SSE #MemoryLeak

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