# Prp Codebase Question > Research codebase questions using parallel agents - documents what exists, not what should change. Use when the user asks how the codebase works, where something lives, or invokes $prp-codebase-question. - Skill: `wirasm/prp-codebase-question` (Agent Skill) - Install (CLI): `npx skillmds add wirasm/prp-codebase-question` - Raw SKILL.md: https://api.skillmd.com/api/skills/wirasm/prp-codebase-question/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Research & Search - Author: Wirasm (https://skillmd.com/u/wirasm) - Updated: 2026-09-10 - Page: https://skillmd.com/skills/wirasm/prp-codebase-question --- > **Arguments:** `$ARGUMENTS` (and `$1`, `$2`, ...) refer to the arguments given when this skill was invoked. Take them from the user's request; if absent, infer them from the conversation. # Codebase Research **Input**: $ARGUMENTS --- ## Your Mission Answer codebase questions thoroughly by spawning parallel specialized agents, synthesizing their findings, and producing a research document. **Core Philosophy**: Document what IS, not what SHOULD BE. You are a technical cartographer. **Golden Rule**: Every claim must have a `file:line` reference. No speculation, no suggestions, no critique. --- ## CRITICAL: Documentarian Only - **DO NOT** suggest improvements or changes - **DO NOT** perform root cause analysis unless explicitly asked - **DO NOT** propose future enhancements - **DO NOT** critique implementations or identify problems - **DO NOT** recommend refactoring or optimization - **ONLY** describe what exists, where it exists, how it works, and how components interact --- ## Phase 1: PARSE - Understand the Query ### 1.1 Read Mentioned Files If the user mentions specific files, read them FULLY first (no limit/offset) before any decomposition. ### 1.2 Classify the Query | Type | Indicators | Agent Focus | |------|-----------|-------------| | **Where** | "where is", "find", "locate" | `codebase-explorer` primary | | **How** | "how does", "trace", "flow" | `codebase-analyst` primary | | **What** | "what is", "explain", "describe" | Both agents in parallel | | **Pattern** | "how do we", "convention", "examples" | `codebase-explorer` primary | | **External** | "docs", "best practice", "API" | Add `web-researcher` | ### 1.3 Determine Scope - Identify specific components, patterns, or concepts to investigate - Note any `--web` flag for external research - Note any `--follow-up` flag for appending to existing research **PHASE_1_CHECKPOINT:** - [ ] Mentioned files read in full - [ ] Query type classified - [ ] Research scope identified - [ ] Flags parsed (--web, --follow-up) --- ## Phase 2: DECOMPOSE - Break into Research Areas ### 2.1 Create Research Plan Break the query into 2-5 composable research areas: ``` RESEARCH QUESTION: {user's question} AREAS: 1. {Area} → Agent: {which agent} 2. {Area} → Agent: {which agent} 3. {Area} → Agent: {which agent} ``` ### 2.2 Agent Selection | Agent | Use When | |-------|----------| | `codebase-explorer` | Finding WHERE code lives, locating files, extracting patterns, discovering conventions | | `codebase-analyst` | Understanding HOW code works, tracing data flow, mapping integration points | | `web-researcher` | Only when `--web` flag is set or user explicitly asks for external docs | **Strategy:** 1. Start with `codebase-explorer` to find what exists 2. Then use `codebase-analyst` on the most relevant findings to trace how they work 3. Run agents in parallel when they're searching for different areas **PHASE_2_CHECKPOINT:** - [ ] Query decomposed into 2-5 research areas - [ ] Agent assigned to each area - [ ] Parallel vs sequential execution planned --- ## Phase 3: EXPLORE - Spawn Parallel Agents ### 3.1 Launch Codebase Agents **Launch agents in parallel by spawning them as subagents in one step.** For each research area, use the appropriate agent: **`codebase-explorer`:** ``` Find all code relevant to: {research area} LOCATE: 1. {Specific files/components to find} 2. {Patterns or conventions to extract} 3. {Related test files and configuration} Categorize findings by purpose. Return ACTUAL code snippets with file:line references. Remember: Document what exists, no suggestions or improvements. ``` **`codebase-analyst`:** ``` Analyze the implementation of: {research area} TRACE: 1. {Data flow to trace} 2. {Integration points to document} 3. {Contracts between components} Document what exists with precise file:line references. No suggestions. ``` ### 3.2 Launch Web Research (if --web or explicitly requested) **`web-researcher`:** ``` Research external documentation for: {topic} FIND: 1. {Specific documentation needed} 2. {API references or patterns} Return findings with direct links and citations. ``` ### 3.3 Wait for All Agents **IMPORTANT**: Wait for ALL agents to complete before proceeding. **PHASE_3_CHECKPOINT:** - [ ] All agents launched (parallel where possible) - [ ] All agents completed - [ ] Results collected from each agent --- ## Phase 4: SYNTHESIZE - Merge Findings ### 4.1 Compile Results - Prioritize live codebase findings as primary source of truth - Connect findings across different components - Include specific `file:line` references throughout - Document patterns, connections, and architectural decisions as they exist ### 4.2 Answer the Question Map findings back to the user's original question: | Question Aspect | Finding | Evidence | |----------------|---------|----------| | {aspect 1} | {what was found} | `file.ts:123` | | {aspect 2} | {what was found} | `file.ts:456` | ### 4.3 Identify Gaps Note any areas that couldn't be fully documented: - {Area that needs further investigation} - {Question that remains open} **PHASE_4_CHECKPOINT:** - [ ] All agent results synthesized - [ ] Findings connected across components - [ ] Original question answered with evidence - [ ] Gaps identified --- ## Phase 5: DOCUMENT - Generate Research File ### 5.1 Gather Metadata ```bash date -u +"%Y-%m-%dT%H:%M:%SZ" git rev-parse --short HEAD git branch --show-current basename $(git rev-parse --show-toplevel) ``` ### 5.2 Create Research Directory ```bash # --- PRP store resolver (canonical; keep byte-identical across skills) --- # Adopt the store that already records this root; mint a key only when none does. _gd="$(git rev-parse --path-format=absolute --git-common-dir 2>/dev/null)" case "$_gd" in */.git) _root="${_gd%/.git}" ;; "") _root="$PWD" ;; *) _root="$_gd" ;; esac _root="$(cd "$_root" && pwd -P)" _name="$(basename "$_root" | tr '[:upper:]' '[:lower:]' | tr -cs 'a-z0-9' '-' | sed 's/^-*//;s/-*$//')" _home="${PRP_HOME:-$HOME/.prp}" _hit="$(grep -lsF "\"path\": \"$_root\"" "$_home"/*/project.json 2>/dev/null | head -1)" PRP_DIR="${_hit%/project.json}" [ -n "$PRP_DIR" ] || PRP_DIR="$_home/${_name:-project}-$(printf %s "$_root" | git hash-object --stdin | cut -c1-8)" mkdir -p "$PRP_DIR"; [ -f "$PRP_DIR/project.json" ] || printf '{"path": "%s", "name": "%s"}\n' "$_root" "${_name:-project}" > "$PRP_DIR/project.json" mkdir -p "$PRP_DIR/research" ``` ### 5.3 Determine Filename **If --follow-up**: Append to existing research file instead of creating new one. **If new research**: **Path**: `$PRP_DIR/research/{YYYY-MM-DD}-{kebab-case-topic}.md` Examples: - `2025-01-08-authentication-flow.md` - `2025-01-15-database-migration-patterns.md` ### 5.4 Write Research Document ```markdown --- date: {ISO timestamp with timezone} git_commit: {short hash} branch: {branch name} repository: {repo name} topic: "{User's Question/Topic}" tags: [research, codebase, {relevant-component-names}] status: complete last_updated: {YYYY-MM-DD} --- # Research: {User's Question/Topic} **Date**: {ISO timestamp} **Git Commit**: {short hash} **Branch**: {branch name} **Repository**: {repo name} ## Research Question {Original user query} ## Summary {High-level documentation of what was found, answering the question by describing what exists} ## Detailed Findings ### {Component/Area 1} - Description of what exists (`file.ts:123`) - How it connects to other components - Current implementation details ### {Component/Area 2} ... ## Code References | File | Lines | Description | |------|-------|-------------| | `path/to/file.ts` | 123-145 | {What's there} | | `another/file.ts` | 45-67 | {What's there} | ## Architecture Documentation {Current patterns, conventions, and design implementations found} ## Open Questions - {Areas that need further investigation} ``` ### 5.5 Add GitHub Permalinks (if applicable) ```bash # Check if on main or pushed git branch --show-current gh repo view --json owner,name -q '"\(.owner.login)/\(.name)"' ``` If on main/pushed, replace local file references with: `https://github.com/{owner}/{repo}/blob/{commit}/{file}#L{line}` ### 5.6 Handle Follow-ups If `--follow-up` flag and existing research file: 1. Read the existing research file 2. Update frontmatter: `last_updated` and add `last_updated_note` 3. Append new section: `## Follow-up Research {timestamp}` 4. Spawn new agents as needed 5. Save updated document **PHASE_5_CHECKPOINT:** - [ ] Metadata gathered - [ ] Research file created (or existing file updated for follow-up) - [ ] All sections filled with evidence-based content - [ ] GitHub permalinks added (if applicable) - [ ] No placeholder values remain --- ## Phase 6: OUTPUT - Present to User ```markdown ## Research Complete **Question**: {original question} **Document**: `{expanded absolute path to $PRP_DIR/research/{filename}.md}` ### Summary {2-3 sentence answer to the question} ### Key Findings - **{Finding 1}**: {brief} (`file.ts:123`) - **{Finding 2}**: {brief} (`file.ts:456`) - **{Finding 3}**: {brief} (`file.ts:789`) ### Architecture {1-2 sentence description of relevant architecture} ### Open Questions - {Any unanswered aspects} ### Follow-up To dig deeper: `$prp-codebase-question --follow-up {topic}` To include external docs: `$prp-codebase-question --web {topic}` ``` --- ## Usage Examples ```bash # Basic codebase question $prp-codebase-question how does authentication work # Include external documentation $prp-codebase-question --web how does the PRP runner execute commands # Follow up on previous research $prp-codebase-question --follow-up what error handling patterns exist in the runner # Locate and document a specific area $prp-codebase-question where are all the command templates and how are they structured ``` --- ## Critical Reminders 1. **Document, don't evaluate.** Describe what IS, never what SHOULD BE. 2. **Evidence required.** Every claim needs a `file:line` reference. 3. **Agents are parallel.** Launch multiple agents simultaneously when researching different areas. 4. **Wait for completion.** Never synthesize until ALL agents have returned. 5. **Read first.** If the user mentions files, read them fully before spawning agents. 6. **No placeholders.** Every field in the research document must have real values. 7. **Codebase is truth.** Live code always overrides documentation or assumptions. --- ## Success Criteria - **QUESTION_ANSWERED**: User's question addressed with concrete evidence - **AGENTS_USED**: Specialized agents spawned for each research area - **EVIDENCE_COMPLETE**: Every finding has `file:line` references - **DOCUMENT_CREATED**: Research file saved at `{expanded absolute path to $PRP_DIR/research/}` - **NO_OPINIONS**: Document describes what exists, not what should change - **PERMALINKS_ADDED**: GitHub links included when possible