ln-620-codebase-auditor

name	ln-620-codebase-auditor
description	Coordinates 9 specialized audit workers (security, build, architecture, code quality, dependencies, dead code, observability, concurrency, lifecycle). Researches best practices, delegates parallel audits, aggregates results into docs/project/codebase_audit.md.
allowed-tools	Read, Grep, Glob, Bash, WebFetch, WebSearch, mcp__Ref, mcp__context7, Skill

Paths: File paths (shared/, references/, ../ln-*) are relative to skills repo root. If not found at CWD, locate this SKILL.md directory and go up one level for repo root.

Codebase Auditor (L2 Coordinator)

Coordinates 9 specialized audit workers to perform comprehensive codebase quality analysis.

Purpose & Scope

• Coordinates 9 audit workers (ln-621 through ln-629) running in parallel
• Research current best practices for detected tech stack via MCP tools ONCE
• Pass shared context to all workers (token-efficient)
• Aggregate worker results into single consolidated report
• Write report to docs/project/codebase_audit.md (file-based, no task creation)
• Manual invocation by user; not part of Story pipeline

Workflow

1. Discovery: Load tech_stack.md, principles.md, package manifests, auto-discover Team ID
2. Worker Applicability: Determine project type, skip inapplicable workers
3. Research: Query MCP tools for current best practices per major dependency ONCE
4. Domain Discovery: Detect project domains from folder structure
5. Delegate: Two-stage delegation - global workers (5a) + domain-aware workers (5b)
6. Aggregate: Collect worker results, group by domain, calculate scores
7. Write Report: Save to docs/project/codebase_audit.md

Phase 1: Discovery

Load project metadata:

• docs/project/tech_stack.md - detect tech stack for research
• docs/principles.md - project-specific quality principles
• Package manifests: package.json, requirements.txt, go.mod, Cargo.toml
• Auto-discover Team ID from docs/tasks/kanban_board.md

Extract metadata only (not full codebase scan):

• Programming language(s)
• Major frameworks/libraries
• Database system(s)
• Build tools
• Test framework(s)

Phase 2: Worker Applicability Gate

Determine project type from tech_stack metadata and skip inapplicable workers.

Project type detection:

Project Type	Detection	Skip Workers
CLI tool	No web framework, has CLI framework (Typer/Click/Commander/cobra/etc.)	ln-627 (health checks), ln-629 (graceful shutdown)
Library/SDK	No entry point, only exports	ln-627, ln-629
Script/Lambda	Single entry, <500 LOC	ln-627, ln-628 (concurrency), ln-629
Web Service	Has web framework (Express/FastAPI/ASP.NET/Spring/etc.)	None — all applicable
Worker/Queue	Has queue framework (Bull/Celery/etc.)	None

Algorithm:

project_type = detect_from_tech_stack(tech_stack, package_manifests)
skipped_workers = APPLICABILITY_TABLE[project_type].skip
applicable_workers = ALL_WORKERS - skipped_workers

FOR EACH skipped IN skipped_workers:
  skipped.score = "N/A"
  skipped.reason = "Not applicable for {project_type} projects"

Skipped workers are NOT delegated. They get score "N/A" in report and are excluded from overall score calculation.

Phase 3: Research Best Practices (ONCE)

For each major dependency identified in Phase 1:

1. Use mcp__Ref__ref_search_documentation for current best practices
2. Use mcp__context7__get-library-docs for up-to-date library documentation
3. Focus areas by technology type:

Type	Research Focus
Web Framework	Async patterns, middleware, error handling, request lifecycle
ML/AI Libraries	Inference optimization, memory management, batching
Database	Connection pooling, transactions, query optimization
Containerization	Multi-stage builds, security, layer caching
Language Runtime	Idioms, performance patterns, memory management

Build contextStore:

{
  "tech_stack": {...},
  "best_practices": {...},
  "principles": {...},
  "codebase_root": "...",
  "output_dir": "docs/project/.audit/ln-620/{YYYY-MM-DD}"
}

Phase 4: Domain Discovery

Purpose: Detect project domains from folder structure for domain-aware auditing.

Algorithm:

1. Priority 1: Explicit domain folders

   • Check for: src/domains/*/, src/features/*/, src/modules/*/
   • Monorepo patterns: packages/*/, libs/*/, apps/*/
   • If found (>1 match) → use these as domains

2. Priority 2: Top-level src/ folders*

   • List folders: src/users/, src/orders/, src/payments/
   • Exclude infrastructure: utils, shared, common, lib, helpers, config, types, interfaces, constants, middleware, infrastructure, core
   • If remaining >1 → use as domains

3. Priority 3: Fallback to global mode

   • If <2 domains detected → domain_mode = "global"
   • All workers scan entire codebase (backward-compatible behavior)

Heuristics for domain detection:

Heuristic	Indicator	Example
File count	>5 files in folder	src/users/ with 12 files
Structure	controllers/, services/, models/ present	MVC/Clean Architecture
Barrel export	index.ts/index.js exists	Module pattern
README	README.md describes domain	Domain documentation

Output:

{
  "domain_mode": "domain-aware",
  "all_domains": [
    {"name": "users", "path": "src/users", "file_count": 45, "is_shared": false},
    {"name": "orders", "path": "src/orders", "file_count": 32, "is_shared": false},
    {"name": "shared", "path": "src/shared", "file_count": 15, "is_shared" 
  

Shared folder handling:

• Folders named shared, common, utils, lib, core → mark is_shared: true
• Shared code audited but grouped separately in report
• Does not affect domain-specific scores

Phase 5: Delegate to Workers

CRITICAL: All delegations use Task tool with subagent_type: "general-purpose" for context isolation.

Phase 5.0: Prepare Output Directory

Before delegating to workers:

1. mkdir -p {output_dir}   # No deletion — date folders preserve history
2. output_dir already set in contextStore (Phase 3)

Prompt template:

Task(description: "Audit via ln-62X",
     prompt: "Execute ln-62X-{worker}-auditor. Read skill from ln-62X-{worker}-auditor/SKILL.md. Context: {contextStore}",
     subagent_type: "general-purpose")

Anti-Patterns:

• ❌ Direct Skill tool invocation without Task wrapper
• ❌ Any execution bypassing subagent context isolation

Worker Output Contract (File-Based):

Workers write full report to {output_dir}/{worker_id}.md per shared/templates/audit_worker_report_template.md.

Workers return minimal summary in-context (~50 tokens):

Report written: docs/project/.audit/ln-620/{YYYY-MM-DD}/621-security.md
Score: 7.5/10 | Issues: 5 (C:0 H:2 M:2 L:1)

Coordinator extracts score/counts from return values. Full findings stay in files.

Unified Scoring Formula (all workers):

penalty = (critical × 2.0) + (high × 1.0) + (medium × 0.5) + (low × 0.2)
score = max(0, 10 - penalty)

Phase 5a: Global Workers (PARALLEL)

Global workers scan entire codebase (not domain-aware). Each writes report to {output_dir}/.

#	Worker	Priority	What It Audits	Output File
1	ln-621-security-auditor	CRITICAL	Hardcoded secrets, SQL injection, XSS, insecure deps	621-security.md
2	ln-622-build-auditor	CRITICAL	Compiler/linter errors, deprecations, type errors	622-build.md
5	ln-625-dependencies-auditor	MEDIUM	Outdated packages, unused deps, custom implementations	625-dependencies.md
6	ln-626-dead-code-auditor	LOW	Dead code, unused imports/variables, commented-out code	626-dead-code.md
7	ln-627-observability-auditor	MEDIUM	Structured logging, health checks, metrics, tracing	627-observability.md
8	ln-628-concurrency-auditor	HIGH	Race conditions, async/await, resource contention	628-concurrency.md
9	ln-629-lifecycle-auditor	MEDIUM	Bootstrap, graceful shutdown, resource cleanup	629-lifecycle.md

Invocation (applicable workers in PARALLEL):

// Filter by Phase 2 applicability gate
applicable_global = [ln-621, ln-622, ln-625, ln-626, ln-627, ln-628, ln-629].filter(w => !skipped_workers.includes(w))

FOR EACH worker IN applicable_global:
  Task(description: "Audit via " + worker,
       prompt: "Execute " + worker + ". Read skill. Context: " + JSON.stringify(contextStore),
       subagent_type: "general-purpose")

Phase 5b: Domain-Aware Workers (PARALLEL per domain)

Domain-aware workers run once per domain. Each writes report with domain suffix.

#	Worker	Priority	What It Audits	Output File
3	ln-623-code-principles-auditor	HIGH	DRY/KISS/YAGNI violations, TODO/FIXME, error handling, DI	623-principles-{domain}.md
4	ln-624-code-quality-auditor	MEDIUM	Cyclomatic complexity, O(n²), N+1 queries, magic numbers	624-quality-{domain}.md

Invocation (2 workers × N domains):

IF domain_mode == "domain-aware":
  FOR EACH domain IN all_domains:
    domain_context = {
      ...contextStore,
      domain_mode: "domain-aware",
      current_domain: { name: domain.name, path: domain.path }
    }
    Task(description: "Audit principles " + domain.name + " via ln-623",
         prompt: "Execute ln-623-code-principles-auditor. Read skill. Context: " + JSON.stringify(domain_context),
         subagent_type: "general-purpose")
    Task(description: "Audit quality " + domain.name + " via ln-624",
         prompt: "Execute ln-624-code-quality-auditor. Read skill. Context: " + JSON.stringify(domain_context),
         subagent_type: "general-purpose")
ELSE:
  // Fallback: invoke once for entire codebase (global mode)
  Task(description: "Audit principles via ln-623",
       prompt: "Execute ln-623-code-principles-auditor. Read skill. Context: " + JSON.stringify(contextStore),
       subagent_type: "general-purpose")
  (: ,
       :  + .(contextStore),
       : )

Parallelism strategy:

• Phase 5a: All applicable global workers run in PARALLEL
• Phase 5b: All (2 × N) domain-aware invocations run in PARALLEL
• Example: 3 domains → 6 invocations (ln-623×3 + ln-624×3) in single message

Phase 6: Aggregate Results (File-Based)

Workers wrote reports to {output_dir}/ and returned minimal summaries. Aggregation uses return values for numbers and file reads for findings tables.

Step 6.1: Parse Return Values

Extract score/counts from worker return strings (already in context, 0 file reads):

FOR EACH worker_return IN worker_results:
  Parse: "Score: {score}/10 | Issues: {total} (C:{c} H:{h} M:{m} L:{l})"
  Store: {worker, category, score, counts, report_file}

Step 6.2: Build Compliance Score Table

From parsed return values:

FOR EACH category IN 9 categories:
  IF category is domain-aware (Architecture, Quality):
    category_score = average(domain_scores for this category)
  ELSE:
    category_score = worker_score
overall_score = average(all applicable category scores)  // exclude N/A

Step 6.3: Build Severity Summary

From parsed return values:

total_critical = sum(worker.counts.critical for all workers)
total_high = sum(worker.counts.high for all workers)
total_medium = sum(worker.counts.medium for all workers)
total_low = sum(worker.counts.low for all workers)

Step 6.4: Build Domain Health Summary (if domain-aware)

From parsed return values of ln-623/ln-624:

FOR EACH domain:
  arch_score = ln-623 score for this domain
  quality_score = ln-624 score for this domain
  issues = ln-623 issues + ln-624 issues for this domain

Step 6.5: Cross-Domain DRY Analysis (if domain-aware)

Read only ln-623 report files to extract FINDINGS-EXTENDED JSON block:

principle_files = Glob("{output_dir}/623-principles-*.md")
FOR EACH file IN principle_files:
  Read file → extract <!-- FINDINGS-EXTENDED [...] --> JSON
  Filter findings with pattern_signature field

Group by pattern_signature across domains:
  IF same signature in 2+ domains → create Cross-Domain DRY finding:
    severity: HIGH
    principle: "Cross-Domain DRY Violation"
    list all affected domains and locations
    recommendation: "Extract to shared/ module"

Step 6.6: Assemble Findings Sections

Read each worker report file and copy Findings table into corresponding report section:

FOR EACH report_file IN Glob("{output_dir}/6*.md"):
  Read file → extract "## Findings" table rows
  Insert into matching category section in final report

Global categories (Security, Build, etc.) → single Findings table per category. Domain-aware categories → subtables per domain (one per file).

Step 6.7: Context Validation (Post-Filter)

MANDATORY READ: Load shared/references/context_validation.md

Apply Rules 1-5 to assembled findings. Uses data already in context:

• ADR list (loaded in Phase 1 from docs/reference/adrs/ or docs/decisions/)
• tech_stack metadata (Phase 1)
• Worker report files (already read in Step 6.6)

FOR EACH finding IN assembled_findings WHERE severity IN (HIGH, MEDIUM):
  # Rule 1: ADR/Planned Override
  IF finding matches ADR title/description → advisory "[Planned: ADR-XXX]"

  # Rule 2: Trivial DRY
  IF DRY finding AND duplicated_lines < 5 → remove finding

  # Rule 3: Cohesion (god_classes, long_methods, large_file)
  IF size-based finding:
    Read flagged file ONCE, check 4 cohesion indicators
    IF cohesion >= 3 → advisory "[High cohesion module]"

  # Rule 4: Already-Latest
  IF dependency finding: cross-check ln-622 audit output
    IF latest + 0 CVEs → remove finding

  # Rule 5: Locality/Single-Consumer
  IF DRY/schema finding: Grep import count
    IF import_count == 1 → advisory "[Single consumer, locality correct]"
    IF import_count <= 3 with different API contracts → advisory "[API contract isolation]"

Downgraded findings → "Advisory Findings" section in report.
Recalculate category scores excluding advisory findings from penalty.

Exempt: Security (ln-621), N+1 queries, CRITICAL build errors, concurrency (ln-628).

Output Format

MANDATORY READ: Load shared/templates/codebase_audit_template.md for full report structure.

Report is written to docs/project/codebase_audit.md using the template. Key sections:

• Executive Summary, Compliance Score (9 categories), Severity Summary
• Domain Health Summary + Cross-Domain Issues (if domain-aware)
• Strengths, Findings by Category (global + domain-grouped), Recommended Actions
• Sources Consulted

Phase 7: Write Report

MANDATORY READ: Load shared/templates/codebase_audit_template.md for report format.

Write consolidated report to docs/project/codebase_audit.md:

• Use template structure from codebase_audit_template.md
• Fill all sections with aggregated worker data
• Include "Advisory Findings" section with context-validated downgrades
• Overwrite previous report (each audit is a full snapshot)

Critical Rules

• Worker applicability: Skip inapplicable workers based on project type (Phase 2); skipped workers get "N/A" score
• Two-stage delegation: Global workers + Domain-aware workers (2 × N domains)
• Domain discovery: Auto-detect domains from folder structure; fallback to global mode
• Parallel execution: All applicable workers (global + domain-aware) run in PARALLEL
• Single context gathering: Research best practices ONCE, pass contextStore to all workers
• Metadata-only loading: Coordinator loads metadata only; workers load full file contents
• Domain-grouped output: Architecture & Code Quality findings grouped by domain
• File output only: Write results to codebase_audit.md, no task/story creation
• Do not audit: Coordinator orchestrates only; audit logic lives in workers

Definition of Done

• Project type detected; worker applicability determined; inapplicable workers documented with reason
• Best practices researched via MCP tools for major dependencies
• Domain discovery completed (domain_mode determined)
• contextStore built with tech stack + best practices + domain info + output_dir
• docs/project/.audit/ln-620/{YYYY-MM-DD}/ directory created (no deletion of previous runs)
• Applicable global workers invoked in PARALLEL; each wrote report to {output_dir}/
• Domain-aware workers (2 × N domains) invoked in PARALLEL; each wrote report to {output_dir}/
• All workers completed successfully (or reported errors); return values parsed for scores/counts
• Worker report files verified via Glob (expected count matches actual)
• Results aggregated from return values (scores) + file reads (findings tables)
• Domain Health Summary built (if domain_mode="domain-aware")
• Cross-Domain DRY analysis completed from ln-623 FINDINGS-EXTENDED blocks (if domain-aware)
• Context validation (Step 6.7) applied: ADR matches, cohesion checks, locality, trivial DRY filtered
• Advisory findings separated from penalty-scored findings
• Compliance score (X/10) calculated per category + overall (skipped workers + advisory excluded)
• Executive Summary and Strengths sections included
• Report written to docs/project/codebase_audit.md with Advisory Findings section
• Sources consulted listed with URLs

Workers

See individual worker SKILL.md files for detailed audit rules:

• ln-621-security-auditor
• ln-622-build-auditor
• ln-623-code-principles-auditor
• ln-624-code-quality-auditor
• ln-625-dependencies-auditor
• ln-626-dead-code-auditor
• ln-627-observability-auditor
• ln-628-concurrency-auditor
• ln-629-lifecycle-auditor

Reference Files

• Orchestrator lifecycle: shared/references/orchestrator_pattern.md
• Task delegation pattern: shared/references/task_delegation_pattern.md
• Audit scoring formula: shared/references/audit_scoring.md
• Audit output schema: shared/references/audit_output_schema.md
• Worker report template: shared/templates/audit_worker_report_template.md
• Final report template: shared/templates/codebase_audit_template.md
• Principles: docs/principles.md
• Tech stack: docs/project/tech_stack.md
• Kanban board: docs/tasks/kanban_board.md

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Version: 5.0.0 Last Updated: 2025-12-23