News Summary

• Plumbline is an MCP server that makes AI coding agents work against your project's reality — not their priors.
• It injects project knowledge before the agent writes, runs mutation testing before you commit, and keeps multi-step work from going off the rails.
• It includes a spotter hook that fires before every file write.
• It doesn't wait for the agent to ask for help — it injects relevant context when the agent is about to edit a file.
• We measured this across 49 tool invocations, 9 controlled experiments, and 5 production projects.