Claude Code 2.1.94 & 2.1.96: Default Effort Goes High, Bedrock Gets Mantle, and 25+ Fixes Land in One Day

Two Claude Code releases dropped today within seven hours of each other. Version 2.1.94 is a substantial update — 25 CLI changes and 2 system prompt changes — while 2.1.96 is a targeted hotfix for a Bedrock auth regression introduced hours earlier. Here is everything that shipped.

What Changed in 2.1.94

Default Effort Level: Medium to High

The most impactful change for daily workflows: the default model effort level has been bumped from medium to high for API-key users, Bedrock/Vertex/Foundry users, Team users, and Enterprise users. This means deeper reasoning and more thorough results out of the box. You can still override via the /effort command, but the new baseline favors quality over speed.

Amazon Bedrock Powered by Mantle

Native support for Amazon Bedrock powered by Mantle is now available. Enable it with CLAUDE_CODE_USE_MANTLE=1. This expands Claude Code's reach for teams running inference through AWS infrastructure.

System Prompt: MEMORY.md and Agent Behavior

Two system prompt changes affect how Claude Code reasons:

• MEMORY.md is no longer ignored. Previously, the ignore-memory flag treated MEMORY.md as empty. Now entries from MEMORY.md are included in assistant responses, ensuring persistent context is actually used.
• Agents call tools first. New examples in the prompt encourage agents to invoke tools before planning, reducing idle reasoning steps and speeding up tool-driven actions.

Plugin System Improvements

• Plugin skills declared via "skills": ["./"] now use the skill's frontmatter name for the invocation name instead of the directory basename. This provides stable names across different install methods.
• Plugin skill hooks defined in YAML frontmatter are no longer silently ignored.
• Plugin hooks no longer fail with "No such file or directory" when CLAUDE_PLUGIN_ROOT is not set.
• ${CLAUDE_PLUGIN_ROOT} now correctly resolves to the installed cache directory for local-marketplace plugins on startup.

UI/UX Enhancements

• Compact Slacked #channel header with a clickable channel link for Slack MCP send-message tool calls.
• New keep-coding-instructions frontmatter field for plugin output styles.
• hookSpecificOutput.sessionTitle added to UserPromptSubmit hooks for setting session titles programmatically.

Bug Fixes — Core

• Rate-limit visibility: Agents no longer appear stuck after a 429 response with a long Retry-After header. The error surfaces immediately.
• macOS login: Console login no longer silently fails with "Not logged in" when the login keychain is locked or password is out of sync. The error is surfaced, and claude doctor now diagnoses the fix.
• Session resume: --resume now resumes sessions from other worktrees of the same repo directly instead of printing a cd command.
• CJK text corruption: Fixed multibyte text (CJK and other scripts) being corrupted with U+FFFD when chunk boundaries split a UTF-8 sequence in stream-json.
• SDK interruption: SDK/print mode now preserves partial assistant responses in conversation history when interrupted mid-stream.

Bug Fixes — Display and Input

• Fixed scrollback showing the same diff repeated and blank pages in long-running sessions.
• Fixed multiline user prompts indenting wrapped lines under the > caret instead of under the text.
• Fixed alt-screen rendering bug where content height changes mid-scroll could leave compounding ghost lines.
• Fixed Shift+Space inserting the literal word "space" instead of a space character in search inputs.
• Fixed hyperlinks opening two browser tabs when clicked inside tmux running in xterm.js-based terminals (VS Code, Hyper, Tabby).
• Fixed native terminal cursor not tracking the selected tab in dialogs, improving screen reader and magnifier support.

Bug Fixes — Cloud Platforms

• Fixed Bedrock invocation of Sonnet 3.5 v2 by switching to the us. inference profile ID.

VSCode Extension

• Reduced cold-open subprocess work when starting a session.
• Fixed dropdown menus selecting the wrong item when mouse was over the list while typing or using arrow keys.
• Added a warning banner when settings.json files fail to parse, so users know permission rules are not being applied.

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What Changed in 2.1.96

Released 6 hours and 54 minutes after 2.1.94, this is a single-fix hotfix:

• Fixed Bedrock 403 errors when using AWS_BEARER_TOKEN_BEDROCK or the CLAUDE_CODE_SKIP_BEDROCK_AUTH flag. The 2.1.94 release introduced a regression where Bedrock requests failed with 403 "Authorization header is missing". This restores correct authentication behavior.

The delta is minimal: +0.1 kB bundle size, +6 estimated lines of code, and a slight reduction in prompt tokens (-662, -0.1%).

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Upgrade

claude update

Verify with claude --version — you should see 2.1.96.

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