I built a replay testing tool for MCP servers —...

When your AI agent does something unexpected, where do you look? For most teams right now: stderr noise, missing logs, or vendor black boxes. The execution path disappears, you have no idea what the agent actually sent to the tool, and there's no way to reproduce the failure in a test. I kept hitting this wall while building MCP agents, so I built mcpscope — an open source observability and replay testing layer for MCP servers. The problem MCP (Model Context Protocol) is becoming the standard wa