MSBuild Graph

CI NuGet License: MIT .NET Tests

Pre-build static analysis of MSBuild solutions for LLM-powered coding assistants. Analyze project dependencies, detect build issues, inspect shared imports, and compare configurations — all through natural language, before building.

No existing MCP server provides pre-build project graph analysis. This fills that gap.

What It Does

Ask your AI assistant natural questions about your .NET/C++ solution:

• "Show me the dependency graph for this solution" → Full DAG with topological sort
• "Are there any TFM mismatches?" → Finds net6.0 projects referencing net8.0 libraries
• "What does Directory.Build.props affect?" → Shows all projects importing each shared file
• "Compare Debug vs Release" → Property and package reference differences
• "Where does LangVersion come from?" → Traces to Directory.Build.props line 3

Tools

Tool	Description
analyze_solution	Parse .sln/.slnx/.slnf — projects, TFMs, output types, configurations
get_project_graph	Build the full dependency DAG with topological sort and graph metrics
find_shared_imports	Discover Directory.Build.props/.targets and other shared imports
detect_build_issues	Find circular deps, TFM mismatches, orphan projects, platform mismatches
analyze_project_properties	Inspect evaluated properties with source tracking (which file, which line)
compare_configurations	Diff Debug vs Release (or any two configs) — properties, packages, references
analyze_impact	"What breaks if I remove project X?" — direct + transitive dependents
check_package_versions	NuGet package version consistency, CPM detection, VersionOverride tracking
get_build_order	Lightweight build order (topological sort) with critical path length
list_projects	Fast project listing without MSBuild evaluation — instant response

Supported Clients

✅ Works with

Client	Config file	Details
VS Code + GitHub Copilot	.vscode/mcp.json	Copilot agent mode calls MCP tools directly
VS Code + Continue.dev	.vscode/mcp.json	Works with Claude, GPT, or any LLM backend
Cursor	.cursor/mcp.json	Built-in AI calls MCP tools natively
Windsurf	Settings UI	Native MCP support via stdio transport
Claude Desktop	claude_desktop_config.json	Full tool + prompt support
Claude Code (terminal)	CLI: claude mcp add	Inline with terminal workflow
Visual Studio 2026 + Copilot	.mcp.json in solution dir	Native MCP support in VS 2026 Preview

❌ Not supported

Client	Reason
Visual Studio 2022	Copilot in VS 2022 does not support MCP protocol
ChatGPT	OpenAI uses a different protocol (function calling, not MCP)
Gemini	Google uses a different protocol (not MCP)

Quick Start

Install

dotnet tool install -g MsBuildGraphMcp

Configure

Claude Desktop — add to %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "msbuild-graph": {
      "command": "msbuild-graph-mcp"
    }
  }
}

Claude Code:

claude mcp add msbuild-graph -- msbuild-graph-mcp

VS Code — add to .vscode/mcp.json:

{
  "servers": {
    "msbuild-graph": {
      "type": "stdio",
      "command": "msbuild-graph-mcp"
    }
  }
}

Cursor — add to .cursor/mcp.json:

{
  "mcpServers": {
    "msbuild-graph": {
      "command": "msbuild-graph-mcp"
    }
  }
}

Requirements

• .NET SDK 8.0+ (or Visual Studio 2022+)
• Windows (MSBuildLocator discovers VS/.NET SDK installations)

Example Output

get_project_graph

{
  "metrics": {
    "nodeCount": 4,
    "edgeCount": 3,
    "uniqueProjectCount": 4,
    "maxDepth": 2,
    "constructionTimeMs": 297
  },
  "projects": [
    {
      "name": "WebApp",
      "targetFrameworks": ["net8.0"],
      "outputType": "Exe",
      "isRoot": true,
      "references": ["DataLib\\DataLib.csproj", "CoreLib\\CoreLib.csproj"]
    }
  ],
  "topologicalOrder": [
    "CoreLib\\CoreLib.csproj",
    "DataLib\\DataLib.csproj",
    "WebApp\\WebApp.csproj"
  ]
}

detect_build_issues

{
  "totalIssues": 2,
  "frameworkMismatches": [{
    "project": "OldApp.csproj",
    "projectTfm": "net6.0",
    "dependency": "NewLib.csproj",
    "dependencyTfm": "net8.0",
    "reason": "net6.0 cannot consume net8.0"
  }],
  "orphanProjects": [{
    "name": "UnusedLib",
    "reason": "Library with no referencing projects"
  }]
}

Features

• Pre-build analysis — no build required, evaluates MSBuild project files directly
• .sln / .slnx / .slnf — supports all solution formats including the new .slnx (VS 17.10+)
• Multi-targeting aware — correctly handles TargetFrameworks (plural) with outer/inner build deduplication
• TFM compatibility — NuGet.Frameworks-based checking (net8.0-windows vs net8.0, netstandard2.0 vs net48, etc.)
• Property source tracking — shows which file and line number defined each MSBuild property
• Configuration diffing — compares any two configurations (Debug/Release, custom configs)
• Circular dependency detection — catches both MSB4251 and CircularDependencyException
• Shared import discovery — identifies Directory.Build.props, Directory.Build.targets, Directory.Packages.props
• CPM detection — recognizes Central Package Management (ManagePackageVersionsCentrally)

Security

All tools are read-only — no builds are triggered, no files are modified.

Measure	Description
IsBuildEnabled = false	Prevents MSBuild target execution during evaluation
MSBUILDENABLEALLPROPERTYFUNCTIONS guard	Server refuses to start if this dangerous env var is set
Path validation	UNC paths rejected, extension whitelist, existence check
Fresh ProjectCollection per call	No state leakage between tool invocations
try/finally cleanup	Projects always unloaded, even on exception

Important: MSBuild property functions execute during evaluation (by design). Functions like $([System.IO.File]::ReadAllText(...)) run when a project is loaded. Only analyze projects you trust.

Architecture

┌──────────────────┐     stdio (JSON-RPC)   ┌─────────────────────┐
│ Claude / Copilot │◄──────────────────────►│ msbuild-graph-mcp   │
│ VS Code / Cursor │                        │                     │
└──────────────────┘                        │ MSBuildLocator      │
                                            │ ► ProjectGraph      │
                                            │ ► ProjectCollection │
                                            │ ► SolutionPersist   │
                                            └─────────────────────┘

Key architectural decisions:

• MSBuildLocator JIT trap pattern — RegisterInstance() in Main(), MSBuild types only in [NoInlining] method
• EvaluationContext.Shared via ProjectInstanceFactoryFunc — 2-5x speedup for large solutions
• Parallelism capped at 8 — prevents memory exhaustion on high-core machines
• Microsoft.Build 17.13.9 with ExcludeAssets="runtime" — avoids 17.14.8 dependency publishing bug

Testing

333 tests across 35 test files, sourced from 5 rounds of internet research covering 20+ sources:

dotnet test tests/MsBuildGraphMcp.Tests/
# Passed! - Failed: 0, Passed: 333, Skipped: 0, Total: 333, Duration: 12s

Test categories: validation, core tools, TFM compatibility, security (OWASP/CVE), solution formats, production resilience, concurrency, path edge cases, JSON serialization, real-world scenarios.

8 production bugs found and fixed during testing.

Complementary Tools

This server provides pre-build analysis. For post-build analysis (requires a completed build), see:

• BinlogInsights.Mcp — 26 MCP tools + 13 CLI commands for MSBuild binary log analysis (build times, errors, performance, analyzers)
• baronfel/mcp-binlog-tool — MSBuild binary log analysis (build times, errors, targets)

Contributing

See CONTRIBUTING.md for guidelines.

License

MIT - FlorinVica