A new version of NCrunch is now available.  v5.24 includes a range of fixes and improvements, mostly targeting the new MCP server allowing AI agents to make use of the NCrunch engine.

MCP Server Improvements

v5.24 includes a large number of fixes for the NCrunch MCP server released 4 months ago.  These fixes target problems identified through heavy use of the MCP server, and those reported by people using it themselves in the real world.

Particularly notable changes include better handling of session lifecycles.  It was found that having multiple sessions targeting the same solution could cause instability, so this is now specifically blocked by the server.  Sessions now have a timeout period after which they are automatically cleaned up if there is no activity (defaults to 12 hours).  This should resolve situations where agents start sessions and forget to unwind them.

The way in which agents now select tests for targeted operations has also changed.  Previously, there was a complex parameter object applied to every test-related function that could be used to select tests.  Unfortunately, this caused massive bloat of the schema, resulting in token waste.  Under the new design, tests are selected using a separate function that sets state within the server.  This change reduced the size of the protocol schema by more than 60%, saving valuable tokens.

There are also two new MCP functions introduced that surface RDI data to agents.  This allows agents to debug tested code without needing to drive a debugger.

SelectRDIFrame - Allows an agent to open an RDI frame for a particular line of code in a source file.  The frame contains the execution sequence through the related method, execution times, and relevant data values.  This is similar to what you see when opening the RDI overlay in the IDE, only data-centric to be easier understood by AI models.  Agents can call this multiple times to get information on sub-frames (usually caused by loops).  If an agent has selected multiple tests before calling this function, the data is aggregated for all tests.

GetDataPointValues - Lets an agent query up the data values read from a given parameter, variable, field, property or method.  This is the same data you see when clicking on one of the data point markers in an open RDI overlay.  It also has search and de-duplication options.

.NET 11 Support

NCrunch v5.24 introduces support for .NET 11, which is now becoming generally available.  It should now be possible to target this platform with your projects and NCrunch should be able to build them and run tests from them without any issues.

Rider 2026.3 Support

Integration with Rider has now also been bumped to 2026.3.  As part of this release, I'm happy to announce that NCrunch's Rider support is no longer in Beta.  After several years of real-world testing and fixing, I feel that it's no longer fair to say that NCrunch's Rider integration is in a testing state and I think it's safe to say that it's stable.  This doesn't mean that it's perfect.  Unfortunately needing to pipe the UI between processes means that it will never be as reliable as the existing VS support, but I believe we're close enough to reliable now that the 'Beta' caveat no longer really applies.

Other Stuff

As is typical with every release, v5.24 also contains some fixes for other reported problems that have shown up since the last published build.  I strongly recommend updating as soon as you can.