Claude Code v2.1.197 to v2.1.198 Major Updates - The Arrival of Claude Sonnet 5 and the Resumption of Claude Fable 5!
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This is Ishikawa from the Cloud Business Division. Here is a summary of the Claude Code updates for v2.1.197 ~ v2.1.198 (2026/06/30 ~ 2026/07/01).
Update Summary
This covers 2 versions (v2.1.197 ~ v2.1.198, 2026/06/30 ~ 2026/07/01), with a total of 33 changes included in the official CHANGELOG. The highlights are the new model Claude Sonnet 5 becoming the default and Claude in Chrome reaching General Availability (GA), along with numerous improvements and fixes related to background agents. As related news from the same period, Claude Fable 5 has resumed with promotional access available for a limited time (until 2026/07/07), making it available for use again (details below).
Notable Updates
- New Feature: Claude Sonnet 5 has been introduced and becomes the default model for Claude Code. It natively supports a 1 million token context window (v2.1.197)
- New Feature: Claude in Chrome (Chrome browser operation feature) has reached General Availability (GA) (v2.1.198)
- New Feature: Background agents launched from
claude agentsnow automatically commit, push, and open a draft PR upon completing code work in a worktree, instead of stopping for confirmation (v2.1.198) - Bug Fix: An issue where brief network interruptions during a response would abort the turn has been fixed, and temporary errors are now automatically retried (v2.1.198)
- Bug Fix: An issue where an expired STS token when using AWS would cause users to get stuck at "Please run /login" has been fixed (v2.1.198)
Target Versions and Period
| Version | Release Date |
|---|---|
| v2.1.197 | 2026/06/30 |
| v2.1.198 | 2026/07/01 |
New Features
Claude Sonnet 5 Becomes the Default Model (v2.1.197)
Claude Sonnet 5 has been announced and becomes the default model for Claude Code. It natively supports a 1 million token context window, and will be offered at a promotional price (input $2 / output $10 per 1 million tokens) through August 31. Updating to v2.1.197 or later is required to use it.
Claude in Chrome Reaches General Availability (GA) (v2.1.198)
Claude in Chrome has reached General Availability. Working in conjunction with the Claude in Chrome extension, this feature allows Claude Code to operate the Chrome browser to perform web app testing, debugging using console logs, form input automation, data extraction from pages, and more.
Other New Features (v2.1.198)
- Background agent notifications have been added to
claude agents. Sessions waiting for input or sessions that have completed will fireNotificationhooks (agent_needs_input/agent_completed), allowing them to be connected to desktop notifications and similar alerts via hooks - A
/datavizskill for chart and dashboard design guidance has been added. It comes with an executable color palette validator - Claude Platform on AWS (
anthropicAws) has been added as an upstream provider for Gateway. It will also now proceed to the next failover candidate upon receiving a model-not-found response. This is a change for environments using Claude Code via Gateway
Related News: Claude Fable 5 Available Again
Separate from the CHANGELOG for the target versions, the official X account announced "Fable 5 is back," and promotional access to Claude Fable 5 has resumed.
It is available for a limited time as part of subscription plans at no additional cost.
- The period is 2026/07/01 ~ 2026/07/07 23:59:59 (Pacific Time)
- Eligible plans are Pro, Max, Team, and premium seats on seat-based Enterprise plans (when enabled by the organization)
- During the period, Claude Fable 5 can be used at no additional cost for up to 50% of the weekly usage limit. After reaching the limit, you can continue using usage credits or switch to another model to continue within the remaining limit
- v2.1.170 or later is required to use it in Claude Code
- API usage is not eligible; usage via the Claude API is billed separately at standard rates
Note that after the period ends, it will no longer be included in your plan's weekly usage limit, and you can continue using it through usage credits. Please refer to the support article below for details.
Improvements
- Background agents automatically create draft PRs: Background agents launched from
claude agentsnow automatically proceed to commit, push, and open a draft PR upon completing code work in a worktree, rather than stopping for confirmation (v2.1.198) - Explore agent model inheritance: The built-in Explore agent now inherits the model from the main session (up to opus as the maximum) instead of being fixed to haiku (v2.1.198)
- Extended thinking setting inheritance: Sub-agents and context compaction now inherit the session's extended thinking settings, improving the output quality of delegated tasks (v2.1.198)
- Focus mode improvements: Sub-agents launched during a turn are now shown in the activity summary, and completed background notifications are collapsed into a single count (v2.1.198)
- Improved display during API retries: From the second attempt onward, the reason for the error is displayed, and a link to the status page is shown when the API is overloaded (v2.1.198)
- Handling of instructions to sub-agents: Sub-agents now treat messages from the agent that launched them as ordinary task instructions. However, messages from agents will still not be treated as user approvals (v2.1.198)
/loginin theclaude agentsview: A sign-in dialog now opens instead of displaying "unavailable" (v2.1.198)- Improved syntax highlighting accuracy: Upgrading to highlight.js 11 has improved the display accuracy of code blocks, diffs, and file previews (v2.1.198)
- Shortcut display when connected via SSH: When connecting via SSH from a Mac, keyboard shortcut hints are now displayed as opt/cmd instead of alt/super (v2.1.198)
Fixes (Major)
Here is a selection of fixes primarily related to stability and usability. All items apply to v2.1.198.
- Fixed turn interruption caused by brief network outages: An issue where brief network interruptions occurring mid-response would abort the turn has been fixed. Temporary errors such as ECONNRESET are now automatically retried with backoff
- Fixed STS token expiry when using AWS: An issue where an expired STS token in Claude Platform on AWS and Mantle sessions would cause users to get stuck at "Please run /login" has been fixed.
awsAuthRefreshis now executed automatically - Fixed "Running" display getting stuck in the task panel: An issue where background tasks in the Web, Desktop, and VS Code task panels would remain stuck as "Running" after completion or after session resumption has been fixed
- Fixed agent team behavior on stop: Teammates that stopped due to an API error now report "failed" to the lead, and sending a message to an unresponsive teammate will now immediately trigger a retry
- Fixed excessive background classification requests: An issue where sandboxed processes repeatedly accessing the same network host would generate excessive background classification requests has been fixed
- Fixed missing updates in the
/diffpanel: An issue where the/diffpanel would not update when switching branches or committing outside of a session has been fixed - Fixed silent failure when combining
claude --bgand--print: An issue where a non-attachable session would be silently created has been fixed, and conflicting flag combinations are now rejected upfront - Fixed conditional rules not being loaded via symlinks: An issue where conditional rules in
.claude/rules/were not loaded when accessing a target file via a symlink path has been fixed - Fixed auto-approval at the start of plan mode: An issue where read-only tool calls were not automatically approved when starting a session in plan mode has been fixed
- In addition, numerous minor bugs have been fixed related to fullscreen mode display (Markdown tables, URL selection, Cmd+click in Warp), macOS background agents (local network connections, reconnection display),
claude attachkey operations,/desktopand/branchbehavior, workflow progress view, and more
Breaking Changes / Deprecations
- The
/agentswizard has been removed (v2.1.198): To create and manage sub-agents going forward, either ask Claude directly (e.g., "Create a sub-agent that does ○○") or directly edit the definition files in the.claude/agents/directory
Closing
v2.1.197 ~ v2.1.198 brings updates that broaden the scope of automation and daily stability, including Claude Sonnet 5 becoming the default, Claude in Chrome reaching GA, automatic draft PR creation by background agents, and automatic retries on brief network interruptions. Updating to v2.1.197 or later is required to use Claude Sonnet 5. Also, users who were using the /agents wizard will be affected by its removal, so please confirm your migration to the alternative approach. If any changes catch your interest, try updating and checking them out.
References
