Claude Code 的回退模型和跨会话安全加固解决了生产环境中模型不可用和权限泄露的痛点，做自动化脚本和团队协作的开发者可以直接升级体验。
Anthropic 发布了 Claude Code v2.1.166，新增了回退模型配置功能，允许设置最多三个备用模型，在主模型过载或不可用时按序切换。同时，拒绝规则中的工具名称支持通配符（* 表示禁止所有工具），并强化了跨会话消息的安全性——来自其他 Claude 会话的 SendMessage 不再携带用户权限，接收方会拒绝转发的权限请求。此外，该版本修复了多个问题，包括图像处理错误、远程会话卡死、JetBrains IDE 终端闪烁、PowerShell 命令验证挂起等。
v2.1.166
What's changed Added fallbackModel setting to configure up to three fallback models tried in order when the primary model is overloaded or unavailable; --fallback-model now also applies to interactive sessions Added glob pattern support in deny rule tool-name position ( "*" denies all tools); allow rules reject non-MCP globs, and unknown tool names in deny rules warn at startup Hardened cross-session messaging: messages relayed via SendMessage from other Claude sessions no longer carry user authority — receivers refuse relayed permission requests, and auto mode blocks them MAX_THINKING_TOKENS=0 , --thinking disabled , and the per-model thinking toggle now disable thinking on models that think by default via the Claude API (3P providers unchanged) Claude Code now retries a turn once on the fallback model when the API rejects an unexpected non-retryable error; auth, rate-limit, request-size, and transport errors still surface immediately claude update now announces the target version before downloading instead of going silent claude agents : typing a URL into the list now filters to the session whose first prompt contained it Fixed a recurring "image could not be processed" error and extra token usage when an unprocessable image was sent in a session Fixed remote sessions becoming permanently stuck when a brief backend disruption occurred during worker registration at startup Fixed flickering in JetBrains IDE terminals (IntelliJ, PyCharm, WebStorm, etc.) on 2026.1+ by enabling synchronized output Fixed Shift+non-ASCII characters (e.g. Shift+ä → Ä) being dropped in terminals using the Kitty keyboard protocol (WezTerm, Ghostty, kitty) Fixed PowerShell command validation occasionally hanging far past its time budget on Windows when a killed process's children held its output pipes Fixed orphaned claude --bg-pty-host processes spinning at 100% CPU after the daemon dies while connected on macOS Fixed voice mode requiring /login to clear a stale auth check after toggling /voice Fixed managed settings with an invalid entry silently disabling enforcement of their remaining valid policies Fixed managed-settings allowedMcpServers / deniedMcpServers predicates not matching when they use ${VAR} references Fixed background agent sessions that entered a git worktree crash-looping with "No conversation found" when reopened from claude agents Fixed duplicated thinking text in the Ctrl+O transcript view while streaming Fixed /doctor showing a contradictory failed "Not inside a remote session" check when run inside a remote session Fixed the cursor sticking at the end of the first line when typing a multiline prompt in the claude agents dispatch and reply inputs Fixed blank lines appearing between background agent rows in the task list on terminals without Unicode support