Testing

Prefactor

Real-time AI agent evaluation and enforcement — catch failing agents live, not after the fact

prefactor.tech

Verified API available Free tier

Quick facts
What is it	Real-time AI agent evaluation and enforcement — catch failing agents live, not after the fact
Pricing	Freemium — from $250/mo
Free tier	Yes
Platform	Web Application
API	Yes
Best for	Catching AI agents that leak PII or make risky decisions in production, Gating agent promotions from dev to staging to prod based on evaluation scores
Domain registered	2024

Data updated Aug. 1, 2026

What does Prefactor do?

Prefactor is a real-time evaluation and enforcement platform for AI agents. It scores every agent run in production the moment it happens, measuring quality, drift, and risk. Instead of just showing you a dashboard after something goes wrong, Prefactor wires those evaluations directly into action — pausing a risky run for human approval, blocking a policy violation, or throttling an agent that's gone off the rails. It catches failing agents live, not charted after the fact.

The tool works by instrumenting your agents with TypeScript or Python SDKs that integrate natively with frameworks like LangChain, Claude, Vercel AI, OpenClaw, and LiveKit. Every model call, tool use, and decision becomes a traceable span. You define the evaluations that matter — LLM-as-judge, technical checks, qualitative metrics — and Prefactor scores each run against them. Custom spans let you pull context from any datasource (GitHub, Linear, Jira, your database) into the run, so every evaluation is grounded in real data. The enforcement layer can block, throttle, or require approval automatically at runtime, with every decision logged.

Prefactor is built for AI engineers, ML teams, and DevOps teams who need to ship reliable agents at scale. It's especially useful for teams running customer support bots, financial analysis agents, or any system where a bad action has real consequences. The agent lifecycle management feature versions agents and promotes them through dev, staging, and prod only when evals pass, so you can compare scores version-to-version and prove each release is better than the last.

Developer Tools Testing

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Key features

What makes it stand out

Scores every agent run in production for quality, drift, and risk the moment it happens

Wires evaluations into action: pause, approve, or block risky runs automatically or with human-in-the-loop

Drops into your stack in minutes with TypeScript and Python SDKs, native for LangChain, Claude, Vercel AI, OpenClaw, and LiveKit

Custom spans pull context from any datasource (GitHub, Linear, Jira, databases) into the run for grounded evaluations

Versions agents and promotes them through dev, staging, and prod only when evals pass

Who is Prefactor for?

Who benefits most from this tool

Catching AI agents that leak PII or make risky decisions in production

Gating agent promotions from dev to staging to prod based on evaluation scores

Enforcing human approval for high-risk agent actions like issuing refunds or exporting data

Pricing

Free tier available — start without a credit card

Dev

Free

25k per month spans included
Every step recorded
Scored and risk-checked live
Hold, approve or block
SDK install in minutes

Scaleup

$250.0/month

Everything in Dev, plus:

100k per month spans included
$2.50 per 1k up to 4M a month additional span cost
100% of activity, real time
Dev, staging and prod
Unlimited seats

Enterprise

Custom

Everything in Scaleup, plus:

SSO and audit retention
SLA and named engineer
Pay by invoice or PO

Trust & presence

Domain Domain registered 2024

Gallery

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