---

name: claude-code-internals description: >- This skill should be used when the user asks to "explore claude code source", "find internal features", "investigate cli.js", "check beta headers", "discover hidden settings", or mentions "minified code analysis", "anthropic-beta headers", "context management internals". context: fork

Claude Code Internals Explorer

Analyze Claude Code's minified source to understand internal behavior and discover features.

Important Caveats

• Minified code: Variable names are obfuscated (e.g., UnB, cT0)
• Version-specific: Findings may change between versions
• Unofficial: Discovered features may be unsupported/unstable
• Token-intensive: Mitigated via subagent delegation (see Workflow Phase 0)

Quick Start

1. Delegate exploration to Explore subagent:

Task tool (subagent_type: Explore)
Prompt: "Run ${CLAUDE_PLUGIN_ROOT}/scripts/find_installation.sh,
        then search for [keyword] in cli.js. Report file paths and matching lines."

2. Analyze findings in main context (subagent returns summary)

3. Iterate with follow-up delegation if deeper investigation needed

Workflow

0. Delegate Context Gathering

Principle: Initial exploration consumes tokens in subagent context, preserving main context for analysis.

Call Task tool with:

• subagent_type: Explore
• prompt: Specify search target and expected output format

Example delegation:

Find Claude Code installation path using ${CLAUDE_PLUGIN_ROOT}/scripts/find_installation.sh.
Then search for patterns related to [feature] in cli.js.
Return: installation path, version, matching lines with context.

The subagent will:

1. Execute shell scripts and grep commands
2. Filter and summarize findings
3. Return structured results to main context

Main agent then performs interpretation and decision-making.

1. Locate Source

Run scripts/find_installation.sh to find:

• cli.js path (minified JavaScript source, ~9.9MB)
• Current version
• Binary location

Typical path: ~/.npm/_npx/*/node_modules/@anthropic-ai/claude-code/cli.js

2. Choose Investigation Type

Goal	Approach
Specific feature	Search for known keywords
New version changes	Compare with known-features.md, check release notes
Hidden settings	Search for setting patterns
Beta features	Search for beta headers

3. Search Strategies

For minified code, search string literals (not variable names).

Quick example:

grep -E "anthropic-beta|context-management" cli.js

See references/search-patterns.md for comprehensive patterns by category.

4. Analyze Findings

When you find relevant code:

1. Note line numbers with grep -n "pattern" cli.js
2. Extract surrounding context with sed -n 'LINE-10,LINE+10p' cli.js
3. Trace related code by searching for adjacent strings
4. Compare findings with references/known-features.md

5. Document Discoveries

Update references/known-features.md with:

• New features found
• Changed defaults/thresholds
• New beta headers
• Corrected information

Common Investigations

Task	Approach
Check feature enabled	grep -n "feature_name" cli.js -> examine conditional logic
Find default values	See references/search-patterns.md Settings section
Discover new commands	See references/search-patterns.md Commands section
Compare release notes	Search mentioned features -> compare with references/known-features.md

Resources

• scripts/find_installation.sh: Locate Claude Code installation
• references/search-patterns.md: Comprehensive grep patterns by category
• references/known-features.md: Baseline of known features for comparison

Resource Map

Resource	Path	Load When
Known features baseline	references/known-features.md	Comparing with new discoveries
Search pattern library	references/search-patterns.md	Investigating specific category
Installation finder	scripts/find_installation.sh	Starting investigation

Tips

1. Start narrow: Search specific terms before broad exploration
2. Use line numbers: -n flag helps locate code for context reading
3. Chain searches: Find one string, search nearby for related code
4. Save findings: Update known-features.md to track discoveries
5. Version awareness: Note version when documenting findings