← Claude Code changelog

Claude Code 2.1.172

This release significantly expands agent capabilities with nested sub-agents, allowing up to five levels of delegation for intricate tasks. Users will benefit from crucial fixes addressing 1M context sessions getting stuck, accurate model selection and availableModels restrictions, and reliable background agent operations. Performance improvements include reduced idle CPU usage and faster browser tool loading, alongside various user experience refinements for the agent panel, Bedrock region detection, and plugin marketplace. This update enhances stability, performance, and flexibility for all users.

Added

  • Added a search bar when browsing a marketplace's plugins in `/plugin`
  • Added `model` attribute to the `claude_code.lines_of_code.count` OTEL metric

Improved

  • Improved performance in long conversations by removing redundant message normalization and avoiding full message-history transforms when streaming tool-use state is unchanged
  • Improved Claude in Chrome tool loading: browser tools now load in a single batched call instead of one per tool
  • Improved the non-interactive Usage Policy refusal message to suggest starting a new session or changing your model

Changed

  • Sub-agents can now spawn their own sub-agents (up to 5 levels deep)
  • Amazon Bedrock now reads the AWS region from `~/.aws` config files when `AWS_REGION` isn't set, matching AWS SDK precedence; `/status` shows where the region came from
  • Disable mouse tracking on Windows consoles that don't fully support it
  • Reduced idle CPU usage: `/goal` status chip no longer re-renders the terminal at 5 Hz while idle, and fewer UI re-renders while subagents run in parallel
  • `/code-review` now keeps the `ultra` option visible when you're not signed in to claude.ai, with an explanation that the cloud review requires a claude.ai account
  • Shortened the Remote Control footer indicator to "/rc active" and hid it on narrow terminals
  • Stopped promoting `/loop` in remote sessions, where pending loops don't keep the container alive

Fixed

  • Fixed sessions using 1M context without usage credits getting permanently stuck — the session now automatically compacts back under the standard context limit
  • Fixed a repeating "an image in the conversation could not be processed and was removed" error when the conversation contained multiple images
  • Fixed the agents view keeping a session under Working with a busy spinner for up to 30 seconds after the worker replied
  • Fixed background agents potentially reading another directory's project settings (`.mcp.json` approvals, trust) when dispatched onto a pre-warmed worker
  • Fixed background-session attach failing with EAUTH for sessions started on an older version after the daemon auto-updated
  • Fixed a background sub-agent staying stuck as "active" in the agent panel after a nested agent it spawned was stopped
  • Fixed `/model` suggestions in the `claude agents` dispatch input rendering with a misleading slash prefix and showing models disabled for your org
  • Fixed `availableModels` restrictions not being applied to subagent model overrides, the agent dispatch model picker, and the advisor model
  • Fixed `availableModels` allowlists hiding the `/model` picker's Opus and Sonnet 1M rows when entries use version-specific IDs like `claude-opus-4-8`
  • Fixed the `/model` picker on Bedrock offering models the provider doesn't serve — selecting one silently switched the session model and lit the selection marker on multiple rows
  • Fixed model IDs getting a doubled 1M-context suffix (e.g. `[1M][1m]`) when `ANTHROPIC_DEFAULT_OPUS_MODEL` already includes one
  • Fixed `opusplan` model setting not shipping with 1M context in plan mode for entitled users; the `opusplan[1m]` workaround now also correctly switches to Opus in plan mode
  • Fixed `WebFetch(domain:*.example.com)` wildcard domain rules never matching subdomains in allow, deny, and ask position, and file permission rules with mid-pattern wildcards (e.g. `Read(secrets-*/config.json)`) being rejected at startup
  • Fixed up-arrow prompt history showing the main agent's prompts while a subagent's chat tab is open
  • Fixed memory recall not finding mounted team memory stores (`CLAUDE_MEMORY_STORES`) in remote sessions
  • Fixed workflow validation rejecting scripts whose prompt strings or comments merely mention `Date.now()`/`Math.random()`
  • Fixed the `/plugin` marketplace list losing its cursor after backing out of a long plugin list, and Esc from the plugin browser returning to the wrong tab
  • Fixed PowerShell tool calls rendering as raw JSON instead of a proper command display and permission dialog, and stripped ANSI escape codes from displayed shell output