---
title: "Claude Code v2.1.236 Release: Adds Default Model Variable and Fixes Multiple Stability Issues"
source: "Claude Code：GitHub Releases（RSS）"
source_tier: "t1_5"
url: "https://github.com/anthropics/claude-code/releases/tag/v2.1.236"
permalink: "https://feed.astralor.com/items/itm_2f87387c7d5ec25020a4aa83"
published: "2026-08-19T20:02:05.000Z"
score: 75
channel: "ai"
tags: ["Claude Code","Sandbox","Environment Variable","Auto Mode"]
---

# Claude Code v2.1.236 Release: Adds Default Model Variable and Fixes Multiple Stability Issues

## AI commentary

> While this update is mostly about fixes, ANTHROPIC_DEFAULT_MODEL and notify_when_idle are genuinely useful new capabilities, especially for people running automated tasks with Claude Code. The tighter sandbox rules also remind us that protecting sensitive files like .env is becoming more important. After upgrading, I recommend first checking whether your automation scripts are affected.

## At a glance

Claude Code released v2.1.236. A new ANTHROPIC_DEFAULT_MODEL environment variable sets the default model for new sessions, while a /model pick still overrides it and persists across restarts. SendMessage now supports notify_when_idle, allowing another session to send a one-shot notice when it next goes idle without polling. On macOS sandbox, wildcard read-deny rules take precedence inside allowed read regions, cover directory contents, and cannot be bypassed by renaming. The release also fixes issues with clipboard, fullscreen rendering, tmux titles, and improves auto mode classification and startup performance.

## Key points

- Added ANTHROPIC_DEFAULT_MODEL environment variable to configure the default model for new sessions; /model picks persist across restarts.
- SendMessage now has notify_when_idle for one-shot cross-session idle notices without polling.
- macOS sandbox wildcard read-deny rules now take precedence inside allowed read regions, cover directory contents, and cannot be bypassed by renaming.
- Fixed numerous stability issues including clipboard, fullscreen rendering, SendMessage, tmux titles, and improved auto mode and startup performance.

## Full text

What's changed Added ANTHROPIC_DEFAULT_MODEL environment variable: sets the model new sessions start on, while a /model pick still overrides it and persists across restarts (unlike ANTHROPIC_MODEL) Added notify_when_idle to cross-session SendMessage: ask another Claude Code session on this machine to send one notice when it next goes idle — opt-in, one-shot, no polling (macOS and Linux) Sandbox: on macOS, wildcard read-deny rules (e.g. **/.env) now take precedence inside allowed read regions, cover matched directories' contents, and can't be bypassed by renaming the denied file Fixed clipboard copy, background housekeeping, background sessions, and local MCP logs breaking after the directory a session had switched into was removed (since 2.1.229) Fixed the fullscreen renderer failing permanently after a single failed start: it now falls back to the classic renderer instead of exiting on every subsequent launch Fixed the /model picker rendering taller than the terminal: it now shows only as many models as fit the window, with the rest reachable by scrolling Fixed SendMessage calls being rejected when a malformed closing tag left the message text inside the summary field Fixed unhandled promise rejections when a subprocess fails to start, for example powershell.exe on WSL with Windows interop disabled (regression in 2.1.234) Fixed fullscreen mode sometimes not showing a newly sent message until the next update after the terminal was resized Fixed a blank band that could remain above the prompt after clearing a multi-line prompt, and panes not repainting after resizing the terminal away and back, in fullscreen mode Fixed the managed-settings approval prompt sometimes not appearing at startup while still capturing the first keypress as approval Fixed terminal tab titles jumping in tmux (iTerm tmux integration): the title is now written only when its text changes instead of animating every 960ms Fixed an unclear error when the cloud environments list came back empty or malformed Fixed the Fable 5 first-time usage-credits prompt auto-selecting the fallback model after 60 seconds with no answer when using Remote Control Fixed spinner tips never appearing, with a repeated background error, when the cached guest-pass reward in ~/.claude.json was malformed Fixed skills hot-reload in SDK/VS Code sessions raising an error on every skills change after the session's working directory was deleted (2.1.229+) Fixed self-hosted runner sessions released on idle, retire, or startup timeout occasionally resuming on another runner before the post-session hook had finished Fixed the Clawd mascot's eyes and feet rendering unevenly in iTerm2 at some font sizes Fixed occasional runaway session recaps: recap text (automatic and /recap) is now capped at 400 characters, cut at a word boundary Improved startup performance: the session counter is now written in the background Improved auto mode: Monitor allow rules are now set aside while auto mode is active, so Monitor commands are reviewed the same way Bash commands are Improved auto mode on Bedrock, Vertex AI, and Foundry, and when telemetry is disabled: the classifier now uses the same defaults as on the Claude API, including severity-scored classification Improved auto mode: the git status check can no longer be fooled by a repo's status.showUntrackedFiles=no setting into reporting a clean tree Changed the /model picker to highlight only the newest model's name, so the highlight marks the new release rather than an arbitrary subset of the list /goal: an idle session whose goal is parked behind long-running background work now checks in automatically after 30 minutes (then 1h, 2h) instead of waiting for you to return /usage now shows the usage-credits spend row for Team and Enterprise members, and shows a capped row at 0% before anything is spent SIGTERM in print/SDK mode no longer records an interrupted turn or synthetic tool denials before exiting; running commands are still terminated and the process still exits with code 143 Pressing Enter on a slash-command typo or a command unavailable in this session now reports it instead of running the closest fuzzy match; prefixes and aliases still run Remote Control now marks a session offline within seconds when the CLI exits or its terminal closes SendMessage now refuses further messages to a session up front once a rapid burst would exceed what that session's inbox accepts, instead of reporting them sent while they were dropped Aligned the session title chip on the prompt border with the footer's right edge Right-aligned footer items (goal indicator, session state, background agent status) and truncated notices now share a consistent right margin with the rest of the prompt area [VSCode] Added screen reader support for the transcript: live announcements for replies, permission requests, errors, and status changes, plus per-turn heading navigation

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