AI library

Source · release

Claude Code releases 2.1.305 and 2.1.306

Author
Anthropic
Published
20 October 2026
Added
21 October 2026
Original
https://github.com/anthropics/claude-code/releases/tag/v2.1.305

Summary

Claude Code 2.1.305 (2026-10-20) mostly fixes bugs, including a 2.1.304 regression that broke every request on Vertex, Bedrock, and gateways that reject tool search. It also adds a Linux sandbox setting for user namespaces, a one-key fix flow in /usage, and a change to how allowedMcpServers filters managed servers. 2.1.306 (2026-10-21) fixes two more issues in cloud sessions and in sessions with many MCP tools. Dates come from the GitHub release feed.

Key points

  • Sandbox user namespaces (Linux): set sandbox.allowNestedUserNamespaces: true so sandboxed commands can run Chromium or rootless podman. The changelog warns that this lets those commands get around the sandbox's file protections, so turn it on only where needed.
  • /usage fixes: each warning is now a one-line fix that names its source, and pressing f applies the fixes. The same fixes appear in VS Code and /doctor.
  • Unattended retries: CLAUDE_CODE_RETRY_WATCHDOG_USAGE_LIMIT_RECHECK_MS makes CLAUDE_CODE_RETRY_WATCHDOG mode notice when a usage limit is lifted before its reset time. This is useful for headless or cron runs.
  • Regression fix: requests on Vertex, Bedrock, and gateways that reject tool search (or that leave ToolSearch out of --tools) failed in 2.1.304. Claude Code now retries without tool search. Upgrade if you run through a gateway.
  • MCP: allowedMcpServers no longer filters managed-mcp.json stdio servers that use ${VAR} only in env, so a server your allowlist left out may now load after the upgrade. Use deniedMcpServers to keep it off. An SDK setMcpServers server is no longer replaced by a same-named server from your own settings. In 2.1.306, sessions with many MCP tools no longer see an API error replaced by "prompt is too long", which had also triggered an unneeded compaction.
  • Workflows: resuming a workflow serves completed pipeline() and parallel() agents from the run's journal instead of running them again.
  • Code Review: re-reviews no longer open with "LGTM" while earlier blocking findings are still open, and the newest commit is reviewed when several pushes land during a review.
  • VS Code: a "Running start-up hooks" spinner shows while SessionStart or Setup hooks run.

Why it matters

Anyone on Bedrock, Vertex, or a gateway should skip 2.1.304 and use 2.1.305 or later. Organizations with managed MCP allowlists should check whether the allowedMcpServers change lets a server load that they meant to block.