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} .

ln-770-crosscutting-setup

Type: L2 Domain Coordinator Category: 7XX Project Bootstrap Parent: ln-700-project-bootstrap

Coordinates cross-cutting concerns configuration for .NET and Python projects.

Overview

Aspect Details

Input Project root directory

Output Configured logging, error handling, CORS, health checks, API docs

Workers ln-771 to ln-775

Stacks .NET (ASP.NET Core), Python (FastAPI)

Phase 1: Detect Project Stack

Determine the technology stack by scanning project files.

Detection Rules:

File Pattern Stack Framework

*.csproj

.NET ASP.NET Core

pyproject.toml or requirements.txt

• FastAPI Python FastAPI

Actions:

• Glob for *.csproj files

• If not found, Glob for pyproject.toml or requirements.txt

• If Python, check for FastAPI in dependencies

• Store detected stack in Context Store

Context Store Initial:

{ "STACK": ".NET" | "Python", "FRAMEWORK": "ASP.NET Core" | "FastAPI", "PROJECT_ROOT": "/path/to/project", "FRAMEWORK_VERSION": "8.0" | "0.109.0" }

Phase 2: Check Existing Configuration

Scan for already configured cross-cutting concerns.

Detection Patterns:

Concern .NET Pattern Python Pattern

Logging Serilog in *.csproj, UseSerilog in Program.cs structlog in requirements, logging config

Error Handling GlobalExceptionMiddleware , UseExceptionHandler

@app.exception_handler , exception_handlers.py

CORS AddCors , UseCors

CORSMiddleware

Health Checks AddHealthChecks , MapHealthChecks

/health routes

API Docs AddSwaggerGen , UseSwagger

FastAPI auto-generates

Actions:

• Grep for each pattern

• Mark configured concerns as skip: true

• Update Context Store with findings

Context Store Updated:

{ "concerns": { "logging": { "configured": false }, "errorHandling": { "configured": false }, "cors": { "configured": true, "skip": true }, "healthChecks": { "configured": false }, "apiDocs": { "configured": false } } }

Phase 3: Invoke Workers (Conditional)

Delegate to workers only for unconfigured concerns.

Worker Invocation Order:

Order Worker Condition Skill Call

1 ln-771-logging-configurator logging.configured == false

/skill ln-771-logging-configurator

2 ln-772-error-handler-setup errorHandling.configured == false

/skill ln-772-error-handler-setup

3 ln-773-cors-configurator cors.configured == false

/skill ln-773-cors-configurator

4 ln-774-healthcheck-setup healthChecks.configured == false

/skill ln-774-healthcheck-setup

5 ln-775-api-docs-generator apiDocs.configured == false

/skill ln-775-api-docs-generator

Invocations (conditional — skip if concern already configured):

Skill(skill: "ln-771-logging-configurator", args: "{STACK} {FRAMEWORK}") Skill(skill: "ln-772-error-handler-setup", args: "{STACK} {FRAMEWORK}") Skill(skill: "ln-773-cors-configurator", args: "{STACK} {FRAMEWORK}") Skill(skill: "ln-774-healthcheck-setup", args: "{STACK} {FRAMEWORK}") Skill(skill: "ln-775-api-docs-generator", args: "{STACK} {FRAMEWORK}")

Pass Context Store to each worker.

Worker Response Format:

{ "status": "success" | "skipped" | "error", "files_created": ["path/to/file.cs"], "packages_added": ["Serilog.AspNetCore"], "message": "Configured structured logging with Serilog" }

Phase 4: Generate Aggregation File

Create a single entry point for all cross-cutting services.

.NET: Extensions/ServiceExtensions.cs

Generate based on configured workers:

// Structure only - actual code generated via MCP ref public static class ServiceExtensions { public static IServiceCollection AddCrosscuttingServices( this IServiceCollection services, IConfiguration configuration) { // Calls added based on configured workers: // services.AddLogging(configuration); // if ln-771 ran // services.AddCorsPolicy(configuration); // if ln-773 ran // services.AddHealthChecks(); // if ln-774 ran // services.AddSwaggerServices(); // if ln-775 ran return services; } }

Python: middleware/init.py

Generate based on configured workers:

Structure only - actual code generated via MCP ref

def configure_middleware(app): # Middleware added based on configured workers: # configure_logging(app) # if ln-771 ran # configure_error_handlers(app) # if ln-772 ran # configure_cors(app) # if ln-773 ran # configure_health_routes(app) # if ln-774 ran pass

Phase 5: Summary Report

Display summary of all configured concerns.

Output Format:

Cross-cutting Setup Complete

Stack: .NET (ASP.NET Core 8.0)

Configured: ✓ Logging (Serilog) - Extensions/LoggingExtensions.cs ✓ Error Handling - Middleware/GlobalExceptionMiddleware.cs ✓ CORS - Extensions/CorsExtensions.cs ✓ Health Checks - Extensions/HealthCheckExtensions.cs ✓ API Docs (Swagger) - Extensions/SwaggerExtensions.cs

Skipped (already configured):

• None

Entry Point: Extensions/ServiceExtensions.cs Add to Program.cs: builder.Services.AddCrosscuttingServices(builder.Configuration);

Packages to Install: dotnet add package Serilog.AspNetCore dotnet add package Swashbuckle.AspNetCore

Workers

Worker Purpose Stacks

ln-771-logging-configurator Structured logging .NET (Serilog), Python (structlog)

ln-772-error-handler-setup Global exception middleware .NET, Python

ln-773-cors-configurator CORS policy configuration .NET, Python

ln-774-healthcheck-setup /health endpoints .NET, Python

ln-775-api-docs-generator Swagger/OpenAPI .NET (Swashbuckle), Python (FastAPI built-in)

Context Store Interface

Workers receive and return via Context Store:

Input to Workers:

{ "STACK": ".NET", "FRAMEWORK": "ASP.NET Core", "FRAMEWORK_VERSION": "8.0", "PROJECT_ROOT": "/path/to/project", "ENVIRONMENT": "Development" }

Output from Workers:

{ "status": "success", "files_created": [], "packages_added": [], "registration_code": "services.AddLogging(configuration);" }

Idempotency

This skill is idempotent:

• Phase 2 detects existing configuration

• Workers skip if already configured

• Aggregation file preserves existing entries

Critical Rules

• Skip already configured concerns — Phase 2 detection must gate worker invocation (set skip: true )

• Pass Context Store to every worker — workers depend on STACK , FRAMEWORK , PROJECT_ROOT

• Generate aggregation file only for workers that ran — do not add registration calls for skipped concerns

• Support only .NET and Python — detect via *.csproj or pyproject.toml /requirements.txt

• FastAPI

• Idempotent execution — re-running must not duplicate configs or break existing setup

TodoWrite format (mandatory):

• Detect project stack (in_progress)
• Check existing configuration (pending)
• Invoke ln-771-logging-configurator (pending)
• Invoke ln-772-error-handler-setup (pending)
• Invoke ln-773-cors-configurator (pending)
• Invoke ln-774-healthcheck-setup (pending)
• Invoke ln-775-api-docs-generator (pending)
• Generate aggregation file (pending)
• Summary report (pending)

Worker Invocation (MANDATORY)

Phase Worker Context

3 ln-771-logging-configurator Shared (Skill tool) — structured logging setup

3 ln-772-error-handler-setup Shared (Skill tool) — global exception middleware

3 ln-773-cors-configurator Shared (Skill tool) — CORS policy configuration

3 ln-774-healthcheck-setup Shared (Skill tool) — /health endpoints

3 ln-775-api-docs-generator Shared (Skill tool) — Swagger/OpenAPI docs

All workers: Invoke via Skill tool — workers see coordinator context.

Definition of Done

• Project stack detected and stored in Context Store

• Existing configurations detected (Phase 2 complete)

• All unconfigured concerns delegated to workers (ln-771 through ln-775)

• Aggregation entry point generated (ServiceExtensions.cs or middleware/init.py )

• Summary report displayed with configured/skipped concerns and package install commands

Reference Files

• Worker skills: ln-771-logging-configurator/SKILL.md through ln-775-api-docs-generator/SKILL.md

• references/logging_patterns.md — structured logging patterns per stack (passed to ln-771)

• references/error_handling_patterns.md — global exception handling patterns (passed to ln-772)

• references/cors_configuration.md — CORS dev/prod policies per stack (passed to ln-773)

Phase 6: Meta-Analysis

MANDATORY READ: Load shared/references/meta_analysis_protocol.md

Skill type: execution-orchestrator . Run after all phases complete. Output to chat using the execution-orchestrator format.

Version: 2.0.0 Last Updated: 2026-01-10