Claude Code — Development skill for Claude Code

Claude Code Source - Buildable Research Fork

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A **buildable, modifiable, and runnable** version of the Claude Code source.

Based on the Claude Code source snapshot publicly exposed on 2026-03-31 via an npm source map leak. The original snapshot contained only raw TypeScript source with no build configuration — it could not be compiled or run. This fork reconstructs the full build system and fixes all missing components to make it functional.

**[Quick Start](#quick-start)** | **[Architecture](#architecture-overview)** | **[Feature Flags](#feature-flags)** | **[Extension Guide](#extension-points-no-source-modification-needed)**

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Quick Start

Prerequisites

• Bun >= 1.3.x
• Valid Anthropic authentication (OAuth via claude login or ANTHROPIC_API_KEY)

Install & Run

git clone https://github.com/beita6969/claude-code.git
cd claude-code

# Install dependencies (auto-creates bun:bundle polyfill via postinstall)
bun install

# Run directly
bun src/main.tsx -p "your prompt here" --output-format text

Build (Optional)

# Compile to single bundle (~20MB)
bun build src/main.tsx --outdir=dist --target=bun

Run Modes

# Headless print mode (no TTY needed)
bun src/main.tsx -p "your prompt here" --output-format text

# JSON output
bun src/main.tsx -p "your prompt here" --output-format json

# Interactive REPL mode (needs TTY)
bun src/main.tsx

**Note**: If `ANTHROPIC_API_KEY` is set in your environment, it must be valid. To use OAuth instead, unset it:

unset ANTHROPIC_API_KEY

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What Changed vs. the Original Snapshot

The original snapshot shipped **no `package.json`, no `tsconfig.json`, no lockfile, and no build scripts**. Over 100 internal/feature-gated modules were also missing from the source map.

Build System (Reconstructed)

File	Purpose
package.json	60+ npm dependencies reverse-engineered from ~1,900 source files
tsconfig.json	TypeScript config (ESNext + JSX + Bun bundler resolution)
bunfig.toml	Bun runtime configuration
scripts/postinstall.sh	Auto-creates bun:bundle runtime polyfill after bun install
.gitignore	Excludes node_modules/, dist/, lockfiles

Stub Modules (Created)

The original so