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Matins
Thursday 7 May — v2.1.132
30 changes / 4 actionable / 2 deep dives
Claude Code

TL;DR

  • CLAUDE_CODE_SESSION_ID is now set in every Bash tool subprocess. If you have hooks or scripts that need the current session ID, it's available as an env var without extra plumbing.
  • New CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 keeps conversations in native scrollback. Set this if you prefer your terminal's own scroll buffer over the fullscreen alternate-screen renderer.
  • Pasting text that starts with / no longer vanishes. A bug was silently swallowing pasted content or triggering a spurious unknown-command error when the first character was a slash.
  • MCP memory leak fixed: a noisy stdio server could push RSS past 10GB. If you run MCP servers that emit non-protocol data on stdout, upgrade before your next long session. (more below)

New in 2.1.132, 2.1.131

2.1.132 (May 7, 2026)

  • Added CLAUDE_CODE_SESSION_ID environment variable to the Bash tool subprocess environment, matching the session_id passed to hooks
  • Added CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 env var to opt out of the fullscreen alternate-screen renderer and keep the conversation in the terminal's native scrollback
  • Added a "Pasting..." footer hint while a Ctrl+V image paste is being read from the clipboard
  • Fixed external SIGINT (e.g. IDE stop button, kill -INT) not running graceful shutdown. Terminal modes are now restored and the --resume hint is printed instead of an abrupt exit
  • Fixed an uncaught exception when the terminal is closed or SSH disconnects mid-session under the native build
  • Fixed --resume failing with no low surrogate in string when a tool error truncation split an emoji; pre-corrupted sessions are sanitized on load
  • Fixed --permission-mode flag being ignored when resuming a plan-mode session with -p --continue/--resume, and plan mode not being re-applied after ExitPlanMode within the same session
  • Fixed fullscreen mode showing a blank screen after laptop sleep/wake or Ctrl+Z/fg until the next keystroke or stream output
  • Fixed cursor landing mid-grapheme on Ctrl+E/A/K/U/arrow keys when an Indic conjunct or ZWJ emoji wraps across lines
  • Fixed vim operators corrupting text containing decomposed (NFD) accented characters
  • Fixed pasting text starting with / silently swallowing the input or triggering an unknown-command reply
  • Fixed pasting dumping stray escape sequences into the prompt when focus events or mouse-tracking reports interleave with the bracketed paste
  • Fixed mouse wheel scrolling being too fast in Cursor and VS Code 1.92-1.104 due to an upstream xterm.js bug
  • Fixed scroll-wheel handling in JetBrains IDE 2025.2 terminals (spurious arrow keys, wrong-direction events, runaway acceleration)
  • Fixed /usage Ctrl+S hanging when copying the stats screenshot to the clipboard on Linux/X11
  • Fixed /terminal-setup showing a contradictory error in Windows Terminal. Shift+Enter is natively supported there
  • Fixed /effort picker not reflecting the CLAUDE_CODE_EFFORT_LEVEL env var override
  • Fixed /status showing the wrong default model for some users
  • Fixed slash command autocomplete popup being capped at ~3-5 visible commands instead of scaling with terminal height
  • Fixed statusline context_window token counts reflecting cumulative session totals instead of current context usage
  • Fixed Alt+T (thinking toggle) not working on macOS terminals without "Option as Meta" enabled (iTerm2, Terminal.app defaults)
  • Fixed dead keyboard input on Windows after re-opening a background session from claude agents
  • Fixed unbounded memory growth (10GB+ RSS) when a stdio MCP server writes non-protocol data to stdout
  • Fixed MCP servers that connect but fail tools/list silently showing 0 tools. They now retry once and show "connected, tools fetch failed" in /mcp
  • Fixed unauthorized claude.ai MCP connectors showing as "failed" instead of "needs auth", and headless -p mode retrying non-transient 4xx connection failures
  • Improved visual consistency in slash command dialogs and /login, /upgrade, /extra-usage dialog spacing
  • Updated the /tui fullscreen startup banner to describe additional renderer benefits (lower memory usage, mouse support, auto-copy on select)
  • Fixed Bedrock and Vertex 400 errors when ENABLE_PROMPT_CACHING_1H is set

2.1.131 (May 7, 2026)

  • Fixed VS Code extension failing to activate on Windows due to a hardcoded build path in the bundled SDK (createRequire polyfill bug)
  • Fixed Mantle endpoint authentication failing with missing x-api-key header

Notes

The MCP memory leak is the highest-priority fix in this release. Any stdio MCP server that writes non-JSON-RPC output to stdout (debug logs, startup banners, crash traces) was causing Claude Code to buffer that data indefinitely. On long sessions with chatty servers, RSS could exceed 10GB. 2.1.128 added /mcp tool-count visibility that would have surfaced servers behaving oddly, but the underlying leak was not addressed until now. If you noticed sluggishness or OOM kills after hours of use with custom MCP servers, this is why.

Statusline context_window was reporting wrong numbers since it was introduced. The token counts reflected cumulative session totals (every message ever sent) rather than the current context window contents. If you built automations around the statusline JSON (compaction triggers, context budgets), the values you were reading were inflated. They now reflect actual current usage.