Claude Code 2.1.305 fixes a 2.1.304 tool-search regression and adds a Linux sandbox setting

Claude Code v2.1.305, released October 20, 2026, per its release notes:

• Regression fix: every request failing on Vertex, Bedrock and other providers when the endpoint or a gateway rejects tool search, a 2.1.304 regression. Claude Code now retries without it.
• New: sandbox.allowNestedUserNamespaces, so sandboxed commands on Linux can create user namespaces (Chromium, rootless podman). The notes say this lets them get around the sandbox's file protections. Also CLAUDE_CODE_RETRY_WATCHDOG_USAGE_LIMIT_RECHECK_MS, so unattended retry mode notices a usage limit that was lifted before its reset.
• Behaviour changes: allowedMcpServers no longer filters managed-mcp.json stdio servers that use ${VAR} only in env, so one your allowlist left out now loads on upgrade (use deniedMcpServers to keep it off). The /artifacts delete confirmation now takes 1/Enter to keep, 2 to delete, and Esc to cancel; y and n no longer answer it.
• Fixes include: new worktrees in a bare repository starting from local HEAD instead of the default branch; /effort and /autocompact not applying when the model name differed by case or a [1m] tag; Workflow resume re-running completed agents; self-hosted runner regressions since 2.1.296 and 2.1.300; and several Code Review, Claude Tag and Remote Control issues.
• Improved: /usage warnings are now one-line fixes naming their source, applied with f.