It started as a personal need
A while back I was working on a project with a few MCP servers wired into it. Every so often something would go subtly wrong. The server hadn't crashed, the logs were clean, but the AI client on the other end just behaved oddly. It would skip a tool, misread a result, or wander off. And every time, I'd lose an hour or two bisecting commits and re-reading the spec, trying to figure out which small thing my server had quietly stopped doing correctly.
After the third or fourth time, I got tired of debugging the same class of problem by hand. What I actually wanted was something that would connect to the server, check it against the spec, and just tell me plainly what broke and where, before it ever reached a client. I couldn't find a tool that did that the way I wanted, so I built one.
What vexyo does
vexyo is a CI-native testing harness for MCP servers. It does two things.
