Claude Code v0.2.42

# Claude Code v0.2.42 Changelog

A powerful new tool that allows executing multiple tools in a single request for improved performance:

• Tool Name: BatchTool (displayed as "Call" to users)
• Purpose: Run multiple independent tool operations at once to reduce context usage and latency
• Execution: Tools are executed in parallel when possible, otherwise serially
• Usage Example:

  claude> /call
  {
    "invocations": [
      {
        "tool_name": "Bash",
        "input": {
          "command": "git blame src/foo.ts"
        }
      },
      {
        "tool_name": "Glob", 
        "input": {
          "pattern": "**/*.ts"
        }
      },
      {
        "tool_name": "Grep",
        "input": {
          "pattern": "function",
          "include": "*.ts"
        }
      }
    ]
  }

• New Environment Variable: MCP_TIMEOUT
• Default: 5000ms (5 seconds)
• Usage: Set custom timeout for MCP server operations

  MCP_TIMEOUT=10000 claude  # Set 10 second timeout

• Benefit: Allows users to adjust timeout for slower MCP servers

• MCP server initialization no longer blocks the application from starting
• Improves startup time when MCP servers are slow to initialize
• Application becomes responsive immediately while MCP servers load in background

• New help display showing keyboard shortcuts when help is open
• Displays:
• ! for bash mode - Quick access to bash command mode
• / for commands - Access slash commands
• Platform-specific newline instructions:
• Mac with Karabiner: shift + ⏎ for newline
• Terminal supporting backslash: \⏎ for newline
• Default: Backslash (\) + Return (⏎) for newline

• Updated security requirement: URLs must be provided directly by the user (removed "in the current or a previous message" qualifier)
• Strengthens security by requiring explicit user-provided URLs

• Switched from native fetch to axios for better control
• Added proper redirect handling with maxRedirects: 0
• Improved error messages with HTTP status codes
• Better content length limiting with maxContentLength

• Added v0.2.41 release notes documenting:
• MCP server startup timeout configuration via MCP_TIMEOUT
• Non-blocking MCP server startup behavior

• Renamed internal functions and variables for consistency
• Improved stream handling using named imports
• Better error handling in HTTP requests
• Enhanced batch tool execution with proper progress tracking and error aggregation