Output Provenance: Proving What Your AI Agent Actually Said

The Problem A sports prediction agent tells you: "Bayern will beat Dortmund, 87% confidence." Bayern wins. The agent's track record looks impressive. But was that prediction actually made before the match? Or was the confidence quietly adjusted from 0.55 to 0.87 after the result was known? Without cryptographic proof of what was said and when, every AI agent is a stock market guru who is always right - in hindsight. Predictions, recommendations, trade signals - none carry provable today.