Update Log

2026-08-03

• Re-checked the official changelog, local CLI, and npm; v2.1.220 remains latest and next, and v2.1.212 remains stable.
• Found no command addition, removal, or rename after the August 1 update.
• Kept the current /branch, /fork, /subtask, /verify, and /code-review guidance and synchronized the verification date across both Claude handbooks.

2026-08-01

• Updated the release baseline to Claude Code v2.1.220 (latest/next) and v2.1.212 (stable) after checking npm, the local CLI, and the official v2.1.206–220 changelog.
• Added Opus 5 as the Anthropic API opus path with native 1M context, the current provider matrix, and the v2.1.219 minimum CLI requirement.
• Updated /fast to Opus 5 and Opus 4.8, noting the removal of Opus 4.7 support.
• Split /branch, /fork, and /subtask according to the v2.1.212 lifecycle change.
• Marked /verify and /code-review user-invoked only and documented /code-review background-subagent execution.
• Added current subagent limits, forked-skill defaults, sandbox isolation controls, hook, and headless MCP-error guidance.

2026-07-19

• Updated Fable 5 subscription access after the 2026-07-07 temporary allowance ended, separating Pro/Max/Team and seat-based Enterprise usage credits from API consumption billing.
• Added HTTP 200 stop_reason: "refusal" handling, nullable stop_details, Message Batches detection, and refusal-specific monitoring guidance.
• Documented server-side fallbacks, SDK refusal-fallback middleware, manual retry, and the distinction from Claude Code availability fallback settings.
• Added pre-output refusal billing, automatic versus manual fallback credit, and prompt-cache write-cost protection.
• Added Fable prompting guidance to avoid reasoning_extraction refusals caused by internal-reasoning extraction instructions.

2026-07-10

• Updated the English command baseline to Claude Code v2.1.205 after checking the official changelog and npm dist-tags (latest=2.1.205, stable=2.1.197; excluded next=2.1.206 because it has no public changelog entry yet).
• Added the advisory Dynamic workflow size setting and workflow.run_id/workflow.name OTel attributes from v2.1.202.
• Clarified that /review is the fast single-pass review and /code-review <level> <PR> is the multi-agent path.
• Updated /doctor as a full setup checkup with /checkup alias, and added v2.1.203–205 Agent View/background/MCP roots, headless hook streaming, Auto-mode transcript protection, unresolved rm -rf prompting, and --json-schema validation changes.

2026-07-04

• Updated the English command baseline to Claude Code v2.1.201 after checking the official changelog and npm dist-tags (latest=2.1.201, stable=2.1.185).
• Fable 5 redeployment: Fable 5 and Mythos 5 were released GA on 2026-06-09, suspended for all users on 2026-06-12 under US export controls (~19 days), then Fable 5 was restored globally across the Claude Platform, Claude.ai, Claude Code, and Cowork on 2026-07-01 with an improved safety classifier targeting the reported vulnerability-finding behavior. Mythos 5 (no safety classifiers) was redeployed only to restricted US critical-infrastructure organizations via Project Glasswing and is not selectable through /model.
• Added the Fable 5 plan-usage note to the /model guidance: for Pro/Max/Team/select Enterprise, Fable 5 is included up to 50% of weekly usage limits through 2026-07-07, after which it is billed via usage credits.
• Added the new /dataviz skill (v2.1.198) to the command catalog, and reflected v2.1.198 background-by-default subagents, v2.1.199 SSL/streaming/subagent fixes, v2.1.200 default permission mode "Manual", and v2.1.201 removal of the mid-conversation system role on Sonnet 5 sessions.

2026-07-01

• Updated the English command baseline to Claude Code v2.1.197 after checking the official changelog and npm dist-tags (latest=2.1.197, stable=2.1.185).
• Reflected Sonnet 5 as the current Anthropic API sonnet alias and added the v2.1.196 organization-default model note for /model governance.
• Updated verification and command summaries so the English edition matches the Korean handbook baseline.

2026-06-25

• Updated the English command baseline to Claude Code v2.1.190 after checking the official changelog and npm dist-tags (latest=2.1.190, stable=2.1.179).
• Added model-operation notes for model restrictions, Haiku main-model limits with subagent allowance, and stronger deprecated-model warnings.
• Added MCP-operation notes for claude mcp login/logout, CLAUDE_CODE_MCP_TOOL_IDLE_TIMEOUT, and misleading /mcp status fixes.
• Added sandbox and permission notes for sandbox.credentials, destructive-command sandbox auto-approval, Windows PowerShell sandbox fixes, Agent deny rules, and background permission prompts.
• Refreshed background/subagent guidance for the three-level nesting cap, nested-agent stability, and background-agent worktree/comment/commit edge cases.
• Added operating notes for Korean paste handling, non-interactive fallback reliability, output-schema determinism, and app/schema bug fixes.

2026-06-10

• Updated the English command baseline to Claude Code v2.1.170 and Claude Fable 5.
• Added current model guidance for /model fable, best, Fable fallback to Opus, and fallbackModel availability chains.
• Added /advisor Fable option and detailed /cd cwd-switch guidance from the recent changelog.
• Added claude --safe-mode troubleshooting guidance, including how it differs from --bare, plus bundled skill/workflow disable controls.
• Added the v2.1.170 transcript persistence fix and v2.1.169 self-hosted runner post-session hook to the operating notes.
• Kept Opus 4.8 as the default high-capability Opus path and left fast mode scoped to the documented Opus behavior.

2026-05-29

• Updated the English command baseline to Claude Code v2.1.154 and Claude Opus 4.8.
• Added current model guidance for /model, provider-specific aliases, Opus 4.8 high effort, and Opus 4.8 fast mode.
• Added current command coverage for /workflows, /goal, /background//bg, /usage-credits, /reload-skills, /run, /verify, /run-skill-generator, /code-review, and claude --bg --exec.
• Clarified that /simplify is now cleanup-only and correctness review belongs under /code-review.
• Updated Agent View/background-session guidance in automation and operations pages.

2026-05-06

• Added the English locale for Claude Code Command Master.
• Registered claude-code-command-master under the English content tree.
• Updated the Korean source to the v2.1.131-era command baseline at the same time.
• Covered recent command changes: /skills, /theme, /usage consolidation, /fast, /schedule, /autofix-pr, /web-setup, /desktop, and claude project purge.
• Documented the editorial decision to group English command pages by workflow instead of translating every Korean command detail page one-to-one.