Explore - Internal Codebase Exploration

Meta-skill for exploring an internal codebase at varying depths. READ-ONLY workflow - no code changes.

Usage

/explore <depth> [options]

Question Flow (No Arguments)

If the user types just /explore with no or partial arguments, guide them through this question flow. Use AskUserQuestion for each phase.

Phase 0: Workflow Selection

question: "How would you like to explore?"

header: "Explore"

options:

  - label: "Help me choose (Recommended)"

    description: "I'll ask questions to pick the right exploration depth"

  - label: "Quick - fast overview"

    description: "Chain: tldr tree → tldr structure (~1 min)"

  - label: "Deep - comprehensive analysis"

    description: "Chain: onboard → tldr → research → document (~5 min)"

  - label: "Architecture - layers & dependencies"

    description: "Chain: tldr arch → call graph → layer mapping (~3 min)"

Mapping:

• "Help me choose" → Continue to Phase 1-4 questions

• "Quick" → Set depth=quick, skip to Phase 2 (scope)

• "Deep" → Set depth=deep, skip to Phase 2 (scope)

• "Architecture" → Set depth=architecture, skip to Phase 2 (scope)

If Answer is Unclear (via "Other"):

question: "I want to understand how deep you want to explore. Did you mean..."

header: "Clarify"

options:

  - label: "Help me choose"

    description: "Not sure - guide me through questions"

  - label: "Quick - fast overview"

    description: "Just want to see what's here"

  - label: "Deep - comprehensive analysis"

    description: "Need thorough understanding"

  - label: "Neither - let me explain differently"

    description: "I'll describe what I need"

Phase 1: Exploration Goal

question: "What are you trying to understand?"

header: "Goal"

options:

  - label: "Get oriented in the codebase"

    description: "Quick overview of structure"

  - label: "Understand how something works"

    description: "Deep dive into specific area"

  - label: "Map the architecture"

    description: "Layers, dependencies, patterns"

  - label: "Find where something is"

    description: "Locate specific code/functionality"

Mapping:

• "Get oriented" → quick depth

• "Understand how" → deep depth

• "Map architecture" → architecture depth

• "Find where" → quick with --focus

Phase 2: Scope

question: "What area should I focus on?"

header: "Focus"

options:

  - label: "Entire codebase"

    description: "Explore everything"

  - label: "Specific directory or module"

    description: "I'll specify the path"

  - label: "Specific concept/feature"

    description: "e.g., 'authentication', 'API routes'"

If "Specific directory" or "Specific concept" → ask follow-up for the path/keyword.

Phase 3: Output Format

question: "What should I produce?"

header: "Output"

options:

  - label: "Just tell me what you find"

    description: "Interactive summary in chat"

  - label: "Create a documentation file"

    description: "Write to thoughts/shared/docs/"

  - label: "Create handoff for implementation"

    description: "Prepare context for coding agent"

Mapping:

• "Documentation file" → --output doc

• "Handoff for implementation" → --output handoff

Phase 4: Entry Point (Architecture only)

If architecture depth selected:

question: "Where should I start the analysis?"

header: "Entry point"

options:

  - label: "Auto-detect (main, cli, app)"

    description: "Find common entry points"

  - label: "Specific function/file"

    description: "I'll specify the entry point"

Summary Before Execution

Based on your answers, I'll run:

**Depth:** deep

**Focus:** "authentication"

**Output:** handoff

**Path:** src/

Proceed? [Yes / Adjust settings]

Depths

Depth

Time

What it does

quick

~1 min

tldr-explorer only - fast structure overview

deep

~5 min

onboard + tldr-explorer + research-codebase + write doc

architecture

~3 min

tldr arch + call graph + layer mapping + circular dep detection

Options

Option

Description

Example

--focus "area"

Focus on specific area

--focus "auth", --focus "api"

--output handoff

Create handoff for next agent

--output handoff

--output doc

Create documentation file

--output doc

--entry "func"

Start from specific entry point

--entry "main", --entry "process_request"

Examples

# Quick structure overview

/explore quick

# Deep exploration focused on auth

/explore deep --focus "auth" --output doc

# Architecture analysis from specific entry

/explore architecture --entry "cli" --output handoff

# Quick focused exploration

/explore quick --focus "hooks"

Workflow Details

Quick Depth

Fast structure overview using tldr-explorer. Best for:

• Initial orientation

• Quick questions about structure

• Finding where things are

Steps:

• Run tldr tree for file structure

• Run tldr structure for codemaps

• If --focus provided, run tldr search for targeted results

• Return summary

Commands:

# 1. File tree

tldr tree ${PATH:-src/} --ext .py

# 2. Code structure

tldr structure ${PATH:-src/} --lang python

# 3. Focused search (if --focus provided)

tldr search "${FOCUS}" ${PATH:-src/}

Deep Depth

Comprehensive exploration with documentation output. Best for:

• First time in a codebase

• Preparing for major work

• Creating reference documentation

Steps:

• Check if onboarded (look for .claude/cache/tldr/), if not run onboard

• Run tldr-explorer for structure

• Spawn research-codebase agent for patterns

• Write findings to doc or handoff

Subprocess:

# 1. Onboard check

if [ ! -f .claude/cache/tldr/arch.json ]; then

    # Spawn onboard agent

fi

# 2. Structure analysis

tldr structure src/ --lang python

tldr calls src/

# 3. Research patterns (via scout agent)

Task: research-codebase → "Document existing patterns in ${FOCUS:-codebase}"

# 4. Write output

→ thoughts/shared/research/YYYY-MM-DD-explore-{focus}.md

→ OR thoughts/shared/handoffs/{session}/explore-{focus}.yaml

Architecture Depth

Architecture-focused analysis with layer detection. Best for:

• Understanding system boundaries

• Preparing for refactoring

• Identifying coupling issues

Steps:

• Run tldr arch for layer detection

• Run tldr calls for cross-file call graph

• Analyze entry/middle/leaf layers

• Detect circular dependencies

• Map architectural boundaries

Commands:

# 1. Architecture detection

tldr arch ${PATH:-src/}

# Returns: entry_layer, middle_layer, leaf_layer, circular_deps

# 2. Call graph

tldr calls ${PATH:-src/}

# Returns: edges, nodes

# 3. Impact analysis from entry point (if --entry provided)

tldr impact ${ENTRY} ${PATH:-src/} --depth 3

Output Structure:

layers:

  entry: [routes.py, cli.py, main.py]  # Controllers/handlers

  middle: [services.py, auth.py]        # Business logic

  leaf: [utils.py, helpers.py]          # Utilities

call_graph:

  total_edges: 142

  hot_paths: [process_request → validate → authorize]

circular_deps:

  - [module_a, module_b]  # A imports B, B imports A

boundaries:

  - name: API layer

    files: [src/api/*]

    calls_to: [src/services/*]

Output Formats

--output doc

Creates: thoughts/shared/research/YYYY-MM-DD-explore-{focus}.md

---

date: {ISO timestamp}

type: exploration

depth: {quick|deep|architecture}

focus: {focus area or "full"}

commit: {git hash}

---

# Codebase Exploration: {focus}

## Summary

{High-level findings}

## Structure

{File tree / codemaps}

## Architecture

{Layer analysis - for architecture depth}

## Key Components

{Important files and their roles}

## Patterns Found

{Existing patterns - for deep depth}

## References

- `path/to/file.py:line` - Description

--output handoff

Creates: thoughts/shared/handoffs/{session}/explore-{focus}.yaml

---

type: exploration

ts: {ISO timestamp}

depth: {quick|deep|architecture}

focus: {focus area}

commit: {git hash}

---

summary: {One-line summary of findings}

structure:

  entry_points: [{main.py}, {cli.py}]

  key_modules: [{auth.py}, {routes.py}]

  test_coverage: [{tests/}]

architecture:

  layers:

    entry: [{files}]

    middle: [{files}]

    leaf: [{files}]

  circular_deps: [{pairs}]

findings:

  - {key finding with file:line}

next_steps:

  - {Recommended action based on exploration}

refs:

  - path: {file.py}

    role: {what it does}

Integration with /build

The explore skill is designed to feed into /build brownfield:

# Step 1: Explore to understand

/explore architecture --output handoff

# Step 2: Build with context from exploration

/build brownfield --from-handoff thoughts/shared/handoffs/session/explore-full.yaml

Implementation

When user invokes /explore <depth> [options]:

Parse Arguments

depth = args[0]  # quick | deep | architecture

focus = extract_option(args, "--focus")

output = extract_option(args, "--output")  # handoff | doc

entry = extract_option(args, "--entry")

Execute Based on Depth

Quick:

# Just tldr commands, no agents

tldr tree ${src_dir} --ext .py

tldr structure ${src_dir} --lang python

if [ -n "$focus" ]; then

    tldr search "$focus" ${src_dir}

fi

Deep:

# 1. Check/run onboard

if [ ! -f .claude/cache/tldr/meta.json ]; then

    # Spawn onboard agent via Task tool

fi

# 2. Structure

tldr structure src/ --lang python

# 3. Research (spawn scout agent)

# Task tool with subagent_type: "scout"

# Prompt: "Research patterns in ${focus:-codebase}"

# 4. Write output

# → doc or handoff based on --output

Architecture:

# 1. Arch detection

arch_output=$(tldr arch ${src_dir})

# 2. Call graph

calls_output=$(tldr calls ${src_dir})

# 3. Impact from entry (if provided)

if [ -n "$entry" ]; then

    impact_output=$(tldr impact $entry ${src_dir} --depth 3)

fi

# 4. Synthesize and write output

Key Principles

• READ-ONLY - This skill never modifies code

• Uses scout, not Explore - Per project rules, scout (Sonnet) over Explore (Haiku)

• Token-efficient - Uses tldr commands (95% savings over raw reads)

• Outputs to shared locations - thoughts/shared/research/ or handoff directory

• Entry point to /build - Exploration handoffs feed into brownfield builds

Related Skills

Skill

When to Use

tldr-explorer

Direct tldr commands (used internally by explore)

tldr-code

Specific analysis commands (cfg, dfg, slice)

onboard

First-time project setup (used by deep depth)

research-codebase

Pattern documentation (used by deep depth)

create_handoff

Handoff format (used by --output handoff)

Troubleshooting

tldr not found:

# Check if installed

which tldr

# Install if missing

uv tool install llm-tldr

# or: pip install llm-tldr

No Python files found:

# Check language, adjust --lang

tldr structure src/ --lang typescript  # or go, rust

Empty architecture output:

# May need to specify src directory

tldr arch ./  # Current directory

tldr arch src/  # Explicit src