We've all hit that moment: the model works on prompt A, breaks silently on prompt B, and there's no log line, no stack trace, no clue what changed inside the model.
I'm launching OpenInterpretability in a few hours on Product Hunt. It's a mech interp toolkit that runs inside Claude Code, Cursor, and Cline via MCP plus drop-in probes for hallucination and agent-failure detection. The project started because I needed a way to see what was happening when a coding agent kept making the same silent tool-call mistake.
The first mech interp toolkit that runs inside Claude Code, Cursor, and Cline via MCP. Production probes (FabricationGuard, agent-probe-guard) catch hallucinations + agent failures. ProbeBench leaderboard, SAE training from 30-min free Colab to paper-grade. Apache-2.0.