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. If

shared/

is missing, fetch files via WebFetch from

https://raw.githubusercontent.com/levnikolaevich/claude-code-skills/master/skills/{path}

.

Code Quality Checker

Type: L3 Worker Category: 5XX Quality

Analyzes Done implementation tasks with quantitative Code Quality Score based on metrics, MCP Ref validation, and issue penalties.

Inputs

storyId

Resolution: Story Resolution Chain. Status filter: In Progress, To Review

MANDATORY READ: Load

shared/references/mcp_tool_preferences.md

shared/references/mcp_integration_patterns.md

hex-graph

Purpose & Scope

• Load Story and Done implementation tasks (exclude test tasks)
• Calculate Code Quality Score using metrics and issue penalties
• MCP Ref validation: Verify optimality, best practices, and performance via external sources
• Check for DRY/KISS/YAGNI violations, architecture boundary breaks, security issues
• Produce quantitative verdict with structured issue list; never edits Linear or kanban

Code Metrics

Code Quality Score

Formula:

Code Quality Score = 100 - metric_penalties - issue_penalties

Issue penalties by severity:

Score interpretation:

Issue Prefixes

OPT- subcategories:

ARCH- subcategories:

PERF- subcategories:

MNT- subcategories:

When to Use

• All implementation tasks in Story status = Done
• Before tech debt cleanup and inline agent review

Workflow (concise)

MANDATORY READ: Load

shared/references/input_resolution_pattern.md

1. Resolve storyId: Run Story Resolution Chain per guide (status filter: [In Progress, To Review]).

2. Load Story (full) and Done implementation tasks (full descriptions) via Linear; skip tasks with label "tests".

3. Collect changed files (

   changed_files[]

   ): MANDATORY READ: Load

   shared/references/git_scope_detection.md

   • IF invoked by ln-510: use

     changed_files[]

     from coordinator context → proceed to Enrich step in guide
   • IF invoked standalone: run full algorithm from guide

4. Two-Layer Detection (MANDATORY): MANDATORY READ: Load

   shared/references/two_layer_detection.md

   All threshold-based findings require Layer 2 context analysis. Layer 1 finding without Layer 2 = NOT a valid finding. Before reporting any metric violation, ask: "Is this violation intentional or justified by design?" See Exception column in metrics below.

5. Calculate code metrics:

   • Cyclomatic Complexity per function (target ≤10; Exception: enum/switch dispatch, state machines, parser grammars → downgrade to LOW)
   • Function size (target ≤50 lines; Exception: orchestrator functions with sequential delegation)
   • File size (target ≤500 lines; Exception: config/schema/migration files, generated code)
   • Nesting depth (target ≤3)
   • Parameter count (target ≤4; Exception: builder/options patterns)

6. MCP Ref Validation (MANDATORY for code changes — SKIP if

   --skip-mcp-ref

   flag passed): MANDATORY READ: Load

   shared/references/research_tool_fallback.md

   Fast-track mode: When invoked with

   --skip-mcp-ref

   , skip this entire step (no OPT-, BP-, PERF- checks). Proceed directly to step 6 (static analysis). This reduces cost from ~5000 to ~800 tokens while preserving metrics + static analysis coverage.

   Level 1 — OPTIMALITY (OPT-):

   • Extract goal from task (e.g., "user authentication", "caching", "API rate limiting")
   • Research alternatives:

     ref_search_documentation("{goal} approaches comparison {tech_stack} 2026")

   • Compare chosen approach vs alternatives for project context
   • Flag suboptimal choices as OPT- issues

   Level 2 — BEST PRACTICES (BP-):

   • Research:

     ref_search_documentation("{chosen_approach} best practices {tech_stack} 2026")

   • For libraries:

     query-docs(library_id, "best practices implementation patterns")

   • Flag deviations from recommended patterns as BP- issues

   Level 3 — PERFORMANCE (PERF-):

   • PERF-ALG: Analyze algorithm complexity (detect O(n²)+, research optimal via MCP Ref)
   • PERF-CFG: Check library configs (connection pooling, batch sizes, timeouts) via

     query-docs

   • PERF-PTN: Research pattern pitfalls:

     ref_search_documentation("{pattern} performance bottlenecks")

   • PERF-DB: Check for N+1, missing indexes via

     query-docs(orm_library_id, "query optimization")

   Triggers for MCP Ref validation:

   • New dependency added (package.json/requirements.txt changed)
   • New pattern/library used
   • API/database changes
   • Loops/recursion in critical paths
   • ORM queries added

7. Analyze code for static issues (assign prefixes): MANDATORY READ: Load

   shared/references/clean_code_checklist.md

   ,

   shared/references/destructive_operation_safety.md

   • For large code files, use

     outline(file_path)

     before targeted reads.
   • SEC-: hardcoded creds, unvalidated input, SQL injection, race conditions
   • SEC-DESTR-: unguarded destructive operations — use code-level guards table from destructive_operation_safety.md (loaded above). Check all 5 guard categories (DB, FS, MIG, ENV, FORCE).
   • MNT-: DRY violations (MNT-DRY-: duplicate logic), dead code (MNT-DC-: per checklist), complex conditionals, poor naming
   • MNT-DRY- cross-story hotspot scan: Grep for common pattern signatures (error handlers:

     catch.*Error|handleError

     , validators:

     validate|isValid

     , config access:

     getSettings|getConfig

     ) across ALL

     src/

     files (count mode). If any pattern appears in 5+ files, sample 3 files (Read 50 lines each) and check structural similarity. If >80% similar → MNT-DRY-CROSS (medium, -10 points):

     Pattern X duplicated in N files — extract to shared module.

   • MNT-DRY- preferred (hex-graph): If hex-graph indexed, use

     audit_workspace(path=scan_path, verbosity="full")

     . Each clone group with 2+ members in different files = MNT-DRY-CROSS. Use returned hotspot and clone context for priority. Fall back to Grep pattern scan above if hex-graph unavailable.
   • MNT-DC- cross-story unused export scan: For each file modified by Story, count

     export

     declarations. Then Grep across ALL

     src/

     for import references to those exports. Exports with 0 import references → MNT-DC-CROSS (medium, -10 points):

     {export} in {file} exported but never imported — remove or mark internal.

   • OPT-OSS- cross-reference ln-645 (static, fast-track safe): IF

     docs/project/.audit/ln-640/*/645-open-source-replacer*.md

     exists (glob across dates, take latest), check if any HIGH-confidence replacement matches files changed in current Story. IF match found → create OPT-OSS-{N} issue with module path, goal, recommended package, confidence, stars, license from ln-645 report. Severity: high if >200 LOC, medium otherwise. This check reads local files only — no MCP calls — runs even with

     --skip-mcp-ref

     .
   • ARCH-: layer violations, circular dependencies, guide non-compliance
   • ARCH-LB-: layer boundary violations (HTTP/DB/FS calls outside infrastructure layer)
   • ARCH-TX-: transaction boundary violations (commit() across multiple layers)
   • ARCH-DTO-: missing DTOs (4+ repeated params), entity leakage (ORM entities returned from API)
   • ARCH-DI-: direct instantiation in business logic (no DI container or mixed patterns)
   • ARCH-CEH-: centralized error handling absent or bypassed
   • ARCH-SES-: session ownership conflicts (DI + local session in same module)
   • ARCH-AI-SEB: side-effect breadth (3+ categories in one leaf function; orchestrator functions exempt — see Conflict Resolution in table above)
   • ARCH-AI-AH: architectural honesty (read-named function with hidden writes)
   • ARCH-AI-FO: flat orchestration (leaf service importing 3+ services; orchestrator imports exempt)
   • ARCH-EVENT-: event channel mismatch — Grep for

     NOTIFY|pg_notify|\.publish\(|\.emit\(

     (publishers) and

     LISTEN|\.subscribe\(|\.on\(

     (subscribers) in changed_files[]. Cross-reference channel name strings. <!-- Defense-in-depth: also checked by ln-652 Rule 6 -->
   • MNT-GOD-: god classes (>15 methods or >500 lines per class)
   • MNT-SIG-: method signature quality (boolean flags, unclear returns)
   • MNT-ERR-: error contract inconsistency (mixed raise/return patterns in same service)

8. Calculate Code Quality Score:

   • Start with 100
   • Subtract metric penalties (see Code Metrics table)
   • Subtract issue penalties (see Issue penalties table)

9. Output verdict with score and structured issues. MANDATORY READ: Load

   references/output_schema.md

   Format output per schema. Add Linear comment with findings.

Critical Rules

• Read guides mentioned in Story/Tasks before judging compliance.
• MCP Ref validation: For ANY architectural change, MUST verify via ref_search_documentation before judging.
• Context7 for libraries: When reviewing library usage, query-docs to verify correct patterns.
• Language preservation in comments (EN/RU).
• Do not create tasks or change statuses; caller decides next actions.

Runtime Summary Artifact

MANDATORY READ: Load

shared/references/quality_summary_contract.md

shared/references/quality_worker_runtime_contract.md

Runtime profile:

• family:

  quality-worker

• worker:

  ln-511

• summary kind:

  quality-worker

• payload fields used by coordinators:

  worker

  ,

  status

  ,

  verdict

  ,

  score

  ,

  issues

  ,

  warnings

Invocation rules:

• standalone: omit

  runId

  and

  summaryArtifactPath

• managed: pass both

  runId

  and exact

  summaryArtifactPath

• always write the validated summary before terminal outcome

Definition of Done

• Story and Done implementation tasks loaded (test tasks excluded)
• Code metrics calculated (Cyclomatic Complexity, function/file sizes)
• MCP Ref validation completed (OPT-, BP-, PERF- categories)
• ARCH- subcategories checked (LB, TX, DTO, DI, CEH, SES, EVENT); MNT- subcategories checked (DC, DRY, GOD, SIG, ERR)
• Issues identified with prefixes and severity, sources from MCP Ref/Context7
• Code Quality Score calculated
• Output formatted per

  references/output_schema.md

• Linear comment posted with findings

Reference Files

• Git scope detection:

  shared/references/git_scope_detection.md

• Code metrics:

  references/code_metrics.md

  (thresholds and penalties)
• Guides:

  docs/guides/

• Templates for context:

  shared/templates/task_template_implementation.md

• Clean code checklist:

  shared/references/clean_code_checklist.md

• Research tool fallback:

  shared/references/research_tool_fallback.md

Version: 5.1.0 Last Updated: 2026-03-15