claude-better-cli

claude-better

Skill by ara.so — Daily 2026 Skills collection.

claude-better is a compatibility-first reimplementation of the Claude CLI focused on aggressive performance improvements: up to 73% faster startup and up to 80% lower resident memory, while maintaining 100% command-level compatibility with the original Claude CLI.

What It Does

• Faster cold starts: --help goes from 182ms → 49ms; chat session bootstrap from 311ms → 102ms
• Lower memory: sustained interactive sessions drop from ~412MB → ~83MB RSS
• Drop-in compatible: 100% pass rate on primary command forms, 100% exit-code match, 98.7% byte-for-byte output parity
• Zero migration cost: existing scripts, aliases, and muscle memory continue to work unchanged

Availability

⚠️ Source code is provided for selected high-profile customers only and available upon request. Contact the maintainer at krzyzanowskim/claude-better for access.

If you have access, install as described in your onboarding materials. The binary is a drop-in replacement — substitute it wherever you invoke claude.

Installation (Once You Have Access)

# Typical binary drop-in replacement pattern
# Place the claude-better binary in your PATH before the original claude
export PATH="/path/to/claude-better/bin:$PATH"

# Verify it's being picked up
which claude
claude --version

# Or alias it explicitly without touching PATH
alias claude='/path/to/claude-better/bin/claude-better'

Key Commands

claude-better mirrors the Claude CLI surface exactly. All commands you know work as-is:

# Show help (cold start: ~49ms vs 182ms baseline)
claude --help

# Check auth status (warm start: ~58ms vs 146ms baseline)
claude auth status

# Start an interactive chat session (~102ms bootstrap vs 311ms baseline)
claude chat

# One-shot non-interactive command (~131ms vs 428ms baseline)
claude -p "Summarize this file" < input.txt

# All standard flags pass through unchanged
claude --model claude-opus-4-5 chat
claude --output-format json -p "List 3 facts about Rust"

Configuration

claude-better reads the same configuration as the original Claude CLI. No new config format is required.

# Standard Claude CLI env vars are respected
export ANTHROPIC_API_KEY=$ANTHROPIC_API_KEY

# The tool reads ~/.claude/ config directory as normal
# No migration of config files needed

Performance Characteristics

Scenario	Baseline	claude-better	Improvement
--help cold start	182ms	49ms	73% faster
auth status warm	146ms	58ms	60% faster
chat bootstrap	311ms	102ms	67% faster
One-shot command	428ms	131ms	69% faster
RSS after 30min session	412MB	83MB	80% less
Streaming jitter p95	91ms	24ms	74% lower

Scripting Patterns

Since compatibility is 100%, all existing scripting patterns work unchanged:

#!/usr/bin/env bash
# Existing Claude CLI scripts work without modification

# Non-interactive pipeline usage
echo "Explain this error:" | cat - error.log | claude -p /dev/stdin

# Exit code handling (100% compatible)
if claude auth status; then
  echo "Authenticated"
else
  echo "Not authenticated — run: claude auth login"
  exit 1
fi

# JSON output parsing
claude --output-format json -p "What is 2+2?" | jq '.content'

#!/usr/bin/env bash
# Long-lived interactive session — memory pressure is significantly reduced
# Useful on memory-constrained machines (laptops, CI runners)
claude chat

Compatibility Notes

• CLI surface: 100% compatible with targeted Claude CLI command forms
• Exit codes: 100% match on documented exit-code behavior
• Output parity: 98.7% byte-for-byte; 100% semantic parity after whitespace/timestamp/terminal-width normalization
• Tested environments: macOS (Apple Silicon), Linux, containerized CI
• Tested against: 1,200 synthetic invocations, 87 flag combinations, 42 interactive flows, 14 failure-mode scenarios

Troubleshooting

Binary not found after install

# Ensure claude-better/bin is earlier in PATH than original claude
echo $PATH | tr ':' '\n' | grep -n claude
which claude  # should point to claude-better

Unexpected output differences

# 1.3% of outputs differ before normalization (timestamps, whitespace, terminal width)
# If a script breaks on exact output matching, add normalization:
claude -p "..." | tr -s ' ' | sed 's/[[:space:]]*$//'

Auth not recognized

# claude-better reads the same auth store as the original CLI
# If auth fails, re-authenticate via the standard flow:
claude auth login

Falling back to original CLI

# If you hit an edge case, unset the alias/PATH change to revert instantly
unalias claude
# or
export PATH="<original-path-without-claude-better>"

Architecture Notes (For Contributors / Evaluators)

The performance gains come from specific implementation choices documented in the README:

• Zero-copy streaming pipeline for token output (reduces streaming jitter)
• Precomputed command registry instead of dynamic startup discovery (cuts cold-start time)
• Aggressively bounded allocation for session state (drives memory reduction)
• Lazy subsystem initialization — only the active command path pays startup cost
• Compatibility shim layer that preserves flags/behavior without carrying the full original stack