Fix Codegen and Add MCPCode Generation

[MelbourneDeveloper]

TLDR;

New code generator that creates MCP server tools from OpenAPI specs, plus comprehensive NucliaDB sample implementation demonstrating the full workflow from OpenAPI → RestClient.Net extensions → MCP tools.

Summary

This PR adds RestClient.Net.McpGenerator, a code generator that transforms OpenAPI specifications into Model Context Protocol (MCP) server tools. The generator builds on top of the existing OpenAPI → RestClient.Net extension methods, creating type-safe MCP tools that expose REST APIs to Claude and other LLM tools. Includes a complete reference implementation using the NucliaDB API with tests, demo, and working MCP server.

Details

New Components (36 new files, 64 total changed)

MCP Generator (RestClient.Net.McpGenerator)

• McpToolGenerator.cs - Generates MCP tool classes wrapping RestClient.Net extensions
• McpServerGenerator.cs - Orchestrates OpenAPI → MCP tool code generation
• CLI tool for command-line generation

NucliaDB Sample Suite (Samples/NucliaDbClient*)

• Generated client code from NucliaDB OpenAPI spec (~5,800 LOC)
• Comprehensive integration tests with Docker-based NucliaDB instance
• Demo console application showing usage patterns
• Working MCP server implementation with setup documentation

Core Library Enhancements

• Added OPTIONS HTTP method support (CreateOptions delegates)
• Enhanced test coverage for all HTTP methods including cancellation scenarios

Infrastructure

• CI/CD: Added Docker verification and container cleanup to PR builds
• Test ordering: Priority-based test execution for integration tests
• Code quality: Relaxed StyleCop ordering rules, promoted EXHAUSTION001 to error

Key Features

• Generates type-safe MCP tools with proper parameter descriptions
• Integrates with IHttpClientFactory pattern (no socket exhaustion)
• Functional composition using Result types for error handling
• Full end-to-end example: OpenAPI → Extensions → MCP Tools → Working Server

[Copilot]

Pull Request Overview

Introduces a new MCP code generator and NucliaDB sample, plus expands the OpenAPI generator and core HTTP support.

• Adds RestClient.Net.McpGenerator and CLI to generate MCP tools from OpenAPI and a full NucliaDB sample suite.
• Enhances core RestClient.Net with HEAD and OPTIONS support and refactors OpenAPI generator to a new API surface.
• Updates CI to enforce formatting, run tests, and Docker cleanup.

Reviewed Changes

Copilot reviewed 59 out of 66 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
RestClient.Net/HttpClientExtensions.cs	Adds HeadAsync and OptionsAsync HTTP methods.
RestClient.Net/HttpClientFactoryExtensions.cs	Adds CreateHead and CreateOptions factory delegates.
RestClient.Net.OpenApiGenerator/*	Significant refactor to parsing and generation APIs and packaging.
RestClient.Net.McpGenerator/*	New MCP tool/server generator and CLI.
Samples/NucliaDbClient/*	New sample with docker-compose, setup scripts, demo, tests, and MCP server.
Samples/RestClient.OpenApiGenerator.Sample.*	Updates to Async methods and records usage.
.github/workflows/pr-build.yml	CI changes: tool restore, formatting check, Docker verify/cleanup, mutation testing.
.config/dotnet-tools.json	Adds csharpier tool.

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[Copilot]

Pull Request Overview

Copilot reviewed 58 out of 65 changed files in this pull request and generated 11 comments.

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[Copilot]

Pull Request Overview

Copilot reviewed 58 out of 65 changed files in this pull request and generated 13 comments.

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