drawio-mcp-server: Instructions file for GitHub Copilot

GitHub Copilot Instructions for this Repository

Project Overview

This is a TypeScript MCP (Model Context Protocol) server for programmatic Draw.io diagram generation. It produces standard Draw.io XML directly — no browser extension or Draw.io instance required.

• Runtime: Deno ≥ 2.7
• Language: TypeScript (strict mode)
• Key dependencies: @modelcontextprotocol/sdk, hono (HTTP transport), zod (input validation), fuzzy-search, fast-xml-parser
• Deno standard libraries: @std/path, @std/cli, @std/assert, @std/testing, @std/encoding
• Test framework: Deno's built-in test runner (deno test) with V8 coverage

General

• Use the Draw.io MCP server for all diagram generation tasks.
• When asked to create diagrams such as flowcharts, decision trees, technical architecture diagrams, etc., always use the Draw.io MCP server and XML format.
• Content returned from the Draw.io MCP server will be in XML format. Take this content and create or update a .drawio file in the repository with that content.
• Store generated Markdown documents in docs/ and update any links accordingly.
• Prioritize speed, memory footprint, and maintainability in all implementations. The server should be efficient and responsive, even with large diagrams.
• Follow the coding conventions and project structure outlined below to ensure consistency and readability across the codebase.

Repository Structure

• src/ — Source code
• docs/ — Generated Markdown documentation
• src/index.ts — Entry point, server lifecycle (startup, shutdown, transport)
• src/tool_definitions.ts — Centralized tool metadata (names, descriptions, Zod input schemas, TOOL_NAMES constant)
• src/tool_registrations.ts — Loops over TOOL_DEFINITIONS to register all tools on the MCP server
• src/tools.ts — Tool handler implementations (the handlers object)
• src/tool_handler.ts — Factory that wires handlers to the MCP server
• src/diagram_model.ts — Core diagram model (cells, layers, pages, XML generation)
• src/config.ts — CLI/env configuration parsing (pure functions)
• src/utils.ts — Shared utilities (esmDirname, readRelativeFile — ESM path helpers)
• src/instructions.md — Server instructions sent to MCP clients during initialization
• src/shapes/ — Shape libraries (Azure icons, basic shapes)
• src/loggers/ — Logger implementations (console, MCP server)
• tests/ — Test files (*.test.ts)
• build/ — Compiled binary (git-ignored, generated by deno task compile)
• assets/azure-public-service-icons/ — Azure icon library XML