The Claude Code Changelog

Claude Code 2.1.309 and 2.1.310 tighten sandbox and permission boundaries, including fixes for Windows hooks that could fail open. Learn how to check your version, test a blocking hook and an Edit deny rule, and diagnose Ubuntu sandbox startup issues with /sandbox.

Claude Code 2.1.310 enables the Monitor tool on Amazon Bedrock, Google Vertex, and Microsoft Foundry—even with telemetry or nonessential traffic disabled. Learn how to replace sleep-and-check loops with event-driven monitoring, configure permissions, and avoid leaving background monitors running.The episode also covers gateway retry behavior, a compaction fix, clearer symlink permission prompts, Linux sandbox guidance, and custom Enterprise roles for cloud sessions and Remote Control.

Claude Code 2.1.309 adds a workspace-trust check to claude ultrareview. Learn how to handle the prompt, update scripts and CI with the correctly ordered --trust-workspace flag or the environment variable, and weigh the security and billing caveats. We also cover smaller updates to dangerous-command handling, sed -i, large nested CLAUDE.md files, sandboxed Bash startup files, and VS Code diagnostics.Show Notesclaude-code/CHANGELOG.md at main - GitHub: https://github.com/anthropics/claude-code/blob/main/CHANGELOG.md

Claude Code 2.1.307 adds the claude_code.safety_event OpenTelemetry event, letting teams track when permissions, safety checks, hooks, or the sandbox stop, prompt, or send back a tool call. Learn how to query the event for sandbox violations and recurring permission prompts, plus caveats about interpreting the counts. We also cover the release’s MCP retry and authentication fixes, checkout-hook timeouts, and pull-request review controls.

Claude Code 2.1.305 adds sandbox.allowNestedUserNamespaces for Linux and WSL2, enabling tools such as headless Chromium and rootless Podman to run inside the Bash sandbox. Learn how to enable it and why it weakens the sandbox’s file protections. The hosts also cover fixes and quality-of-life updates in 2.1.304–2.1.306, including gateway retries, /usage fixes, and retry-watchdog configuration.

Claude Code 2.1.304 expands /auto-mode-setup to more provider and gateway sessions, helping you draft trusted environment rules from project files and recent activity. Learn what the setup scans, how to review and verify its all-at-once settings changes, and why managed settings are safer for team-wide rules. Plus, a few useful fixes and quality-of-life updates from the release.

How Claude Code’s experimental /advisor pairs a lower-cost executor with a stronger model that can review the full session and offer guidance. Learn how to enable it, prompt for consultations, inspect advice, and check provider, model-pairing, and cost caveats. We also cover smaller improvements in versions 2.1.301–2.1.303.

Claude Projects is becoming a coordinator for parallel Claude Code cloud sessions: learn how to connect repositories, set project instructions, choose thread models and effort, and manage local-only work. We also cover practical limits and cost traps, including paused sandboxes, pull-request follow-up threads, and usage-limit resumption, plus smaller fixes in 2.1.301 and 2.1.302.

Claude Code 2.1.302 adds CLAUDE_CODE_AUTO_MODE_MODEL, letting users on proxy, Bedrock, or Vertex setups choose the model used by the client-side auto-mode classifier. The episode also covers a breaking default for headless sessions—explicitly set --permission-mode auto in CI—as well as server-side auto-mode compaction and smaller updates to subagents, idle compaction, hooks, image handling, and plugin startup.

Claude Code 2.1.301 adds CLAUDE_CODE_RETRY_WATCHDOG_MAX_USAGE_LIMIT_WAIT_MS, letting CI jobs fail quickly or switch to a fallback model instead of idling through a distant quota reset. Learn how to set it alongside the general retry wait cap, where to scope the watchdog variables, and what “per API request turn” means. Also covered: richer OpenTelemetry tool-decision events, safer worktree cleanup, clearer Grep and Glob errors, and several usability fixes.

Claude Code 2.1.300 adds step-aware workflow routing: mods can rewrite an agent’s prompt and choose its model, letting teams balance cost and capability across a workflow. We cover model fallbacks and allowlists, stricter hook validation, practical safeguards, and several smaller fixes—including clearer cache metrics and improved MCP tool search behavior.

Discover how Claude Code 2.1.299 introduces idle compaction to save you tokens and speed up your workflow after stepping away from the terminal. Lachlan and James break down the 54-minute cache window, configuration settings, and handy updates to hooks and file mentions.

Learn how to control costs and balance performance using the CLAUDE_CODE_WORKFLOW_SUBAGENT_MODEL environment variable introduced in Claude Code 2.1.296. We explore the orchestrator plus swarm pattern, how to configure model overrides without breaking interactive sessions, and other quality-of-life updates in this release.

Learn how to tame 529 overloaded errors in headless Claude Code runs using the newly released watchdog wait caps and retry delays. We break down the ideal CI environment configurations and highlight important quality-of-life fixes in versions 2.1.295 and 2.1.296.

We explore how the new allow_large parameter in Claude Code 2.1.296 handles oversized text files in a single pass while surprisingly cutting token costs. Plus, learn how to trigger it automatically and catch up on key fixes to encodings, PowerShell limits, and hook debugging.

Lachlan and James break down Claude Code 2.1.296, exploring how the new autoCompactWindow setting prevents worker subagents from bloating context windows and running up cache read costs. They also cover practical configuration tips, token limits, and new quality-of-life updates including cheaper Sonnet 5.5 cache reads.

Learn about Claude Code version 2.1.295 and the crucial new onFailure: "block" setting for command and HTTP hooks. We dive into how to prevent broken or missing guard scripts from failing open, plus key caveats to consider before updating your configuration.Show NotesReleases · anthropics/claude-code - GitHub: https://github.com/anthropics/claude-code/releases

Anthropic launched Claude Haiku 5.5 featuring adjustable effort dials, a 1M token context window, and significantly slashed pricing. Learn how to configure custom subagents in Claude Code to take advantage of these massive cost savings while dodging key caveats like token price cliffs and verification quirks.

James and Lachlan explore Claude Code 2.1.292, which introduces a dedicated effort parameter for subagents to dramatically slash token costs in multi-agent workflows. They also cover practical orchestration tips, CI-friendly retry configurations, and critical security patches for UNC paths.

Lachlan and James break down Claude Code versions 2.1.290 and 2.1.291, highlighting new hourly refills for WebSearch budgets and pagination support for truncated WebFetch pages. They also cover critical regression fixes and expanded permission prompts for Bash commands with wildcards.