# Claude Code v2.0.31 > Claude Code v2.0.31, released 31 Oct 2025 (2025-10-31). 12 entries read out of the shipped bundle. Unofficial, and not affiliated with Anthropic. Web version: https://changelogs.core-directive.com/v/2.0.31 Version 2.0.31 introduces startup performance profiling capabilities, significantly enhances sed command security validation, and adds support for the latest web-search API. Additionally, internal improvements to diff rendering and telemetry tracking provide better visibility into Claude Code's operations. ## Changes ### Startup Performance Profiling **What:** Optional profiling system to measure Claude Code's startup performance and memory usage across initialization phases. **How to use:** `# Enable startup profiling CLAUDE_CODE_PROFILE_STARTUP=1 claude # The profiling report will automatically display after startup showing: # - Time elapsed at each checkpoint (absolute and delta) # - Memory usage (RSS and heap) at each checkpoint # - Total startup time` **Details:** - Tracks 30+ checkpoints throughout the startup sequence - Records both timing (via Node.js `perf_hooks`) and memory metrics - Zero overhead when disabled (default) - Useful for diagnosing slow startup issues or investigating performance regressions - **Evidence**: `o5()` at line 3881, `RB9()` at line 3891, `B80()` at line 3919, profiler initialization in `aqA` at line 3926 ### File Operation Telemetry **What:** Privacy-preserving telemetry that tracks file operations (read, write, edit) using hashed identifiers. **How it works:** - File paths are hashed (SHA256, first 16 characters) for anonymization - File content is hashed (SHA256) to detect duplicate operations - Operation type and tool name are recorded - Data sent via existing telemetry infrastructure **Details:** - Automatically enabled when telemetry is active - Only metadata is recorded - actual file paths and content remain private - Helps Anthropic understand common file operation patterns - **Evidence**: `sM()` function at line 249864, hash functions `Nd8()` at line 249858 and `Ld8()` at line 249861 ### Web Search API Update **What:** Support for the new `web-search-2025-03-05` beta API. **Details:** - Automatically enabled for Vertex AI platform with Claude 4.x models - Provides access to updated web search capabilities - Part of Anthropic's beta features system - **Evidence**: `ErB = "web-search-2025-03-05"` at line 203723, `AT8()` function at line 203732 ### Enhanced Sed Command Validation **What:** Significantly improved security validation for sed commands to prevent dangerous operations while allowing safe read-only usage. **How it works:** The validation now uses a comprehensive whitelist approach with multiple layers: - **Pre-parsing flag detection** - Blocks dangerous flag combinations like `-ew`, `-we` before parsing - **Whitelist validation** - Only allows two safe patterns: - Print-only operations with `-n` flag (e.g., `sed -n '1,10p' file.txt`) - Simple substitutions with safe flags (e.g., `sed 's/old/new/' file.txt`) - **Comprehensive blacklist** - Blocks 15+ dangerous patterns including: - Write commands (`w`, `W`) - Execute commands (`e`, `E`) - Non-ASCII characters and escape sequences - Command chaining with semicolons in certain contexts - Braces, negation operators, and other advanced features **Details:** - Builds upon existing sed validation from v2.0.30 (function `hoB` at line 209135) - Adds four new validation helpers: `Aj8()` at line 209202, `Bj8()` at line 209245, `Qj8()` at line 209254, `Zj8()` at line 209384 - New validation function `JtB()` at line 209288 replaces `hoB` - Dangerous flag combination detection in `Gj8()` at line 209345 - Prevents file modification and command execution while allowing safe text processing - **Evidence**: Comparison of `hoB()` at line 209135 in v2.0.30 vs `JtB()` at line 209288 in v2.0.31 ### Diff Rendering Simplification **What:** Streamlined diff patch rendering with cleaner code and fewer configuration options. **Changes:** - Removed `skipUnchanged` and `hideLineNumbers` parameters from diff rendering - Eliminated conditional dimmed color variants (`diffAddedWordDimmed`, `diffRemovedWordDimmed`) - Simplified component interface from 7 parameters to 5 - Removed `hidden` parameter from line number component calls **Details:** - Function signature changed from `hB6(A, B, Q, I, G, Z, Y)` to `$Q6(A, B, Q, I, G)` - More consistent visual rendering across different diff contexts - **Evidence**: `hB6()` at line 288996 in v2.0.30 vs `$Q6()` at line 289176 in v2.0.31; word diff function `fB6()` at line 288906 in v2.0.30 vs `wQ6()` at line 289088 in v2.0.31 ### Settings Loading Profiling **What:** Added profiling checkpoints around settings initialization. **Details:** - Tracks time spent loading settings from various sources - Helps identify slow configuration loading - **Evidence**: `o5("eagerLoadSettings_start")` at line 485096, `o5("eagerLoadSettings_end")` at line 485107 in function `Bo5()` at line 485095 ### CLI Argument Parsing Instrumentation **What:** Added profiling checkpoints before and after CLI argument parsing. **Details:** - Helps identify overhead from command-line option processing - Part of the overall startup profiling infrastructure - **Evidence**: `o5("cli_before_main_import")` at line 486806, `o5("cli_after_main_import")` at line 486808 in function `Wo5()` at line 486798 ### Redirect Operator Quoting **What:** Fixed shell command quoting logic to correctly handle file descriptor redirects. **Details:** - File descriptor redirects like `2>` or `2>>` are no longer incorrectly quoted - Prevents errors when redirecting stderr or other file descriptors - **Evidence**: Function `ET8()` at line 204583 adds check for `\d+>>?` pattern, replacing `bR8()` at line 204525 in v2.0.30 ### Hook Removal Edge Case **What:** Fixed settings cleanup when removing the last hook from a configuration source. **Details:** - Ensures `hooks` object is properly removed when empty - Prevents empty configuration objects from persisting - **Evidence**: Function `rV2()` at line 414417 adds proper cleanup logic at lines 414433-414435, improving upon `qV2()` at line 414128 in v2.0.30 ### Import Organization **What:** Consolidated and reorganized various module imports. **Changes:** - Replaced `import Ae from "stream"` with `import { PassThrough as Lr5 } from "stream"` at line 482338 - Replaced `import e51 from "node:child_process"` with `import { execSync as U6Q, spawn as Qd8 } from "node:child_process"` at line 249174 - Added `import { cwd as hR0 } from "node:process"` at line 70725 - Added `import { homedir as br5 } from "node:os"` at line 484007 - Added `import { createHash as pB6, randomBytes as lB6 } from "crypto"` at line 286520 - Removed redundant `import BP9 from "node:os"` and `import il2 from "node:process"` **Details:** - More explicit imports improve tree-shaking and code clarity - Reduces namespace pollution from default imports ### Color Diff Module Loading **What:** Updated native color diff module loading with better error handling. **Details:** - Added async function `GVQ()` at line 289328 for loading the Rust-based ColorDiff module - Improved fallback behavior when native module unavailable - Better logging for debugging color diff issues - **Evidence**: Function `GVQ()` at line 289328, initialization in `uy1` at line 289318 ### Component Refactoring **What:** Various minor component and utility function additions. **Details:** - Added `BVQ` component at line 289014 for diff patch rendering - Added utility functions: `Vc()` at line 446305, `Qp5()` at line 460873, `xM2()` at line 429780 - Added helper functions for tool management: `Gu2()` at line 456056, `Ve1()` at line 456053, `Iu2()` at line 456048 **Note:** This changelog focuses on user-visible changes and significant internal improvements. Version 2.0.31 includes additional internal refactoring and code organization improvements not detailed here.