v2.0.21 Claude Code Release Notes

Oct 18, 2025

Claude's Analysisby Sonnet 4.6

Haiku 4.5 debuts as a Pro/Max model option; plan mode now asks more questions before acting, and MCP gains structuredContent support in tool responses.

Changes

Total Changes (vs Average)

0.3×

Version Type

Patch

Release Focus

Features

Day Since Prior Release

Release # This Month

#14 of 20

Bug Fix Ratio

20%

Post-Release Edits

—

Change Category

Ecosystem Impact

MCP has appeared in 3 of the last 10 releases, with this version adding structuredContent support — part of a steady protocol alignment track through the v2.0.x series as MCP matures toward richer data interchange.

Key Themes

1Model Expansion: Haiku 4.5 for Pro/Max|2Proactive Clarification Before Acting|2MCP Alignment and Queue Reliability

May Help If You've Noticed

You're on Pro or Max but Haiku 4.5 doesn't appear as a model option in your settings

Added3 changes

•Support MCP structuredContent field in tool responses
•Added an interactive question tool
•Added Haiku 4.5 as a model option for Pro users

Fixed1 change

•Fixed an issue where queued commands don't have access to previous messages' output

Other1 change

•Claude will now ask you questions more often in plan mode

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v2.0.21 Claude Code Release Notes

Oct 18, 2025

Claude's Analysisby Sonnet 4.6

Full Analysis

Haiku 4.5 debuts as a Pro/Max model option; plan mode now asks more questions before acting, and MCP gains structuredContent support in tool responses.

Changes

Total Changes (vs Average)

0.3×

Version Type

Patch

Release Focus

Features

Day Since Prior Release

Release # This Month

#14 of 20

Bug Fix Ratio

20%

Post-Release Edits

—

Change Category

Ecosystem Impact

Key Themes

1Model Expansion: Haiku 4.5 for Pro/Max|2Proactive Clarification Before Acting|2MCP Alignment and Queue Reliability

May Help If You've Noticed

You're on Pro or Max but Haiku 4.5 doesn't appear as a model option in your settings

Added3 changes

•Support MCP structuredContent field in tool responses
•Added an interactive question tool
•Added Haiku 4.5 as a model option for Pro users

Fixed1 change

•Fixed an issue where queued commands don't have access to previous messages' output

Other1 change

•Claude will now ask you questions more often in plan mode

v2.0.21 Claude Code Release Notes

Changes in Claude Code v2.0.21

Added3 changes

Fixed1 change

Other1 change

v2.0.21 Claude Code Release Notes

Changes in Claude Code v2.0.21

Added3 changes

Fixed1 change

Other1 change