ln-770-crosscutting-setup

SKILL.md

Paths: File paths (references/, ../ln-*) are relative to this skill directory.

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)

Host Skill Invocation: Skill(skill: "...", args: "...") is mandatory delegation.

Claude: call the Skill tool exactly as shown.

Codex: if no Skill tool exists, locate the named skill in available skills, read its SKILL.md, treat args as $ARGUMENTS, execute that skill workflow, then return here with its result/artifact.

Do not inline worker logic or mark the worker complete without executing the target skill.

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

Optional reference: load references/meta_analysis_protocol.md only when the user asks for post-run meta-analysis or protocol-formatted run reflection.

Skill type: execution-orchestrator. When requested, run after all phases complete. Output to chat using the execution-orchestrator format.

Version: 2.0.0
Last Updated: 2026-01-10