Claude Code · Source-level changelog

Version 0.2.43

Package @anthropic-ai/claude-code Diff v0.2.42 → v0.2.43
7
Features & Changes
0
Bug Fixes
3
In Development
0
Env Vars / Flags

Changes

# Claude Code v0.2.43 Changelog

Overview

2 items

This release focuses on internal optimizations and introduces a new domain checking capability for web fetching. The terminal rendering system has been significantly refactored for better performance.

Domain Fetch Verification #

New

A new function tP3 has been added that checks whether a domain can be fetched before attempting web operations:

async function tP3(domain) {
  try {
    let response = await fetch(
      `https://claude.ai/api/web/domain_info?domain=${encodeURIComponent(domain)}`
    );
    if (response.ok) return (await response.json()).can_fetch === true;
    return false;
  } catch (error) {
    return (logError(error), true);
  }
}

This appears to be a pre-flight check for the WebFetch tool, allowing Claude Code to verify domain accessibility before attempting to fetch content.

Terminal Rendering Refactoring #

New

The terminal rendering system underwent significant optimization:

  1. Removed OSC 133 Terminal Integration: The shell integration sequences (OSC 133) that were used for marking prompts and command boundaries have been completely removed. This includes:
  • Prompt start/end markers (\x1B]133;A\x07, \x1B]133;B\x07)
  • Command markers (\x1B]133;C\x07, \x1B]133;D\x07)
  • Bracketed paste mode sequences (\x1B[?2026h, \x1B[?2026l)
  1. Simplified Render Buffer Class: The yy class (now uy) has been streamlined:
  • Removed startOscPrompt and endOscPrompt parameters
  • Simplified constructor to only take width and height
  • More efficient output generation using map/join instead of manual string concatenation
  1. Cleaner Output Handling: The main renderer class (Nngn) now:
  • No longer tracks or strips OSC sequences from output
  • Simplified terminal clearing logic
  • More direct output writing without intermediate processing

Import Changes

2 items
  • Stream Import Modified: Changed from default import to named import for better tree-shaking:
  // Before: import b$4 from "stream";
  // After: import { Readable as v$4 } from "stream";
  • Process Import Updated: Changed to named import:
  // Before: import Hh2 from "node:process";
  // After: import { cwd as ww0 } from "node:process";

Performance Improvements

  1. Reduced String Operations: The removal of regex-based OSC sequence stripping (t59 regex) eliminates unnecessary string processing on every render.
  1. Simplified Render Pipeline: The output generation is now more direct, reducing the number of intermediate transformations.
  1. Memory Efficiency: Removed several string constants and helper functions that were used for OSC sequence handling.

Technical Details

3 items
  • Structural Similarity: 99.8% - indicating this is primarily an optimization release
  • Declaration Changes: +3 additions, -12 deletions, 3 modifications
  • Affected Components: Terminal rendering, web fetching, import optimization

Impact for Users

3 items

This update should be transparent to end users with the following potential improvements:

  • Slightly faster terminal rendering, especially for output-heavy operations
  • More reliable web fetching with pre-flight domain checks
  • Reduced memory footprint due to code removal

The removal of OSC 133 sequences suggests Claude Code is moving away from shell-specific integrations in favor of a more universal approach to terminal handling.