DotNetDevMCP

Troubleshooting

Start the server with --log-level Debug --log-directory <dir> to get logs for any of these. Didn’t find your problem? Open a bug report and add it here once it’s solved.

The server doesn’t start, or the client shows no tools

• dotnet --version must be 10.x. DotNetDevMCP needs the .NET 10 SDK (your solution can target older frameworks).
• 'dnx' is not recognized or the client fails silently on Windows. Use "command": "dotnet" with "args": ["dnx", "DotNetDevMCP", "--yes"]. Some clients start servers without a shell and can’t run dnx.cmd.
• Nothing on stdout but no tools either. Logs go to stderr; your client usually shows them in its MCP log view.
• Corporate NuGet feed. dnx uses your NuGet configuration. If nuget.org is blocked, install once with dotnet tool install -g DotNetDevMCP --add-source <feed> and use dotnetdevmcp as the command.

“No solution loaded”

Code-intelligence and affected-test tools need a loaded solution. Ask the agent to load it (“Load C:/src/MyApp/MyApp.sln”) or start the server with --load-solution.

Loading the solution is slow or fails

• Large multi-targeted solutions take 30 s or more: every target framework is a separate Roslyn project.
• Run dotnet restore first. Roslyn loads projects the way MSBuild sees them, so a solution that doesn’t restore won’t load.
• .slnx is supported.

Affected tests

• selectionComplete: false, whole solution ran. Your change reaches code that too much depends on to trace within maxSelectionSeconds (default 10). This is by design. The first call of a session is also slower: run it again, or raise maxSelectionSeconds.
• ranWholeSolution: true with a complete selection. The selection was more than 20% of your tests, where a filtered run isn’t faster. Change with maxSelectedFraction.
• A test you expected isn’t selected. Check with dryRun: true. Reflection, string-keyed lookups and DI by convention are invisible to the walk. A very long call chain may need more than maxDepth (8) hops. Please report it with the via output: it helps improve the walk.
• Slow on a multi-targeted solution. Pass framework: "net10.0" (or ask “net10.0 only”): each target framework otherwise starts its own test host.

Tests

• “Zero tests ran” on a Microsoft.Testing.Platform repo. The filter matched nothing; check the names with dryRun.
• Run killed after 600 s. A test hung. The error names the test modules that never finished; timeoutSeconds changes the limit.
• Wrong SDK or test mode. DotNetDevMCP runs dotnet from your project’s directory, so the global.json there applies. If a test run behaves differently from your terminal, run the same command from that directory.

Edits

• SharpTool_Undo says it needs git integration. Start the server with --git-commit-edits; undo reverts the commit each edit makes.
• An edit reformatted my file. Edit tools format only the lines they change, following your .editorconfig. If more changed, it’s a bug: please report it.

--clean-env and rejected values

• A build or restore fails only with --clean-env. Something it needs lives in an environment variable that isn’t on the allow-list (a private feed token not named NUGET_*, or any other variable your build reads). Rename it to an allowed prefix, or run without --clean-env for that repository. --log-level Debug lists the names of the variables that were dropped.
• A tool rejects my value (framework, configuration, runtime, branch). Values are validated so they can’t add options to dotnet or git: use plain names like net10.0, Release, win-x64, feature/login.

Too many tools / token use

37 tools are on by default. Git and monitoring (16 more) are opt-in with --enable. See Configuration.

This site is open source. Improve this page.