Prefactor
A platform for agent-runtime evaluation, risk control, and version management
About Prefactor
The Prefactor page describes checking every step of an agent run at runtime, detecting errors promptly, and bringing evaluation and risk control into actual execution. Through an SDK or API, users can pause high-risk runs at runtime, enforce policies, or block, rate-limit, and require human approval when limits are exceeded; every decision is recorded. The page also describes agent versions, schema tracking, and progression through development, staging, and production, with support for TypeScript and Python SDKs. The official page states that the first 25,000 spans each month are free.
Best for
Best use cases
Evaluate agents at runtime
Intercept high-risk runs
Promote agent versions
Integrate with an existing agent stack
Features
Runtime checks
Inspect every step of an agent run and detect errors promptly.
Evaluation and risk control
Connect evaluation and risk policies to runtime via an SDK or API to pause, block, rate-limit, or route runs for human approval.
Agent version progression
Create versions for agents and track them by schema, supporting progression through development, staging, and production.
Multilanguage and ecosystem integration
Provides TypeScript and Python SDKs with native support for LangChain, Claude, Vercel AI, OpenClaw, and LiveKit.
Pros
- Supports TypeScript and Python SDKs
- Can pause, block, or rate-limit runs at runtime
- Includes the first 25,000 spans each month free
Pricing Plans
Free
- First 25,000 spans each month
* Pricing information is for reference only. Please refer to the latest announcement on Prefactor's official website.