Prefactor

Prefactor is an observability and evaluation platform for AI agents running in production. It captures every agent run as structured trace data — each LLM call, tool invocation, and decision — so you can see exactly what an agent did, how well it performed, and what it cost. It then continuously scores agent outputs against evals you define (LLM-as-judge, technical checks, or qualitative metrics) on real production traffic, catching drift and regressions before they reach users.

The platform is built around least privilege, full auditability, and integration with your existing identity stack, positioning itself as the enforcement layer beneath the reliability story: every sensitive action (like issuing a refund) passes through a documented check and approval within milliseconds. It ships TypeScript and Python SDKs with native integrations for LangChain, Claude, Vercel AI, OpenClaw, and LiveKit, installed with a single command (prefactor init).

Prefactor took #1 on Product Hunt on its July 28, 2026 launch, targeting engineering teams running dozens of AI agents in production with no reliable way to tell which ones are still doing their job.