Polarity

What is Polarity?

Polarity is an evaluation infrastructure platform designed specifically for AI agents running in production. Its core engine, Keystone, spins up each agent task inside an isolated Docker sandbox pre-loaded with real backing services — Postgres, Redis, S3, and internal APIs — rather than mocked dependencies. This real-service approach allows Polarity to accurately detect the stateful, multi-step failure patterns that lightweight prompt-level evaluation tools like Braintrust, LangSmith, or Langfuse typically overlook. Every detected failure ships with a seed reproducer that re-creates the exact sandbox locally in a single command, dramatically shortening debugging cycles.

Key Features

• Real-Service Sandbox Isolation

  Each agent task runs inside a dedicated Docker sandbox pre-loaded with live Postgres, Redis, S3, and internal API instances, ensuring evaluations reflect actual production conditions rather than simulated ones.

• Behavioral Invariant Scoring

  Keystone scores every agent run against configurable behavioral invariants and forbidden-action rules, giving teams a structured signal on whether agents are operating within intended boundaries.

• Non-Determinism Measurement

  Runs are replicated automatically to quantify how much an agent's output varies across identical inputs, exposing reliability issues before they surface in production.

• One-Command Failure Reproduction

  Every failed run ships with a seed reproducer that recreates the exact sandbox environment locally, allowing developers to debug complex agent failures without manual environment reconstruction.

• Automated Code Review & Testing

  Built-in pull request review via @paragon-review and end-to-end testing infrastructure that catches regressions and bugs before they reach production.

• Real-Time Monitoring & CLI Assistant

  Application monitoring with live alerting, complemented by a terminal-based assistant (Paragon CLI) for writing, reviewing, and managing code directly from the command line.

Use Cases

• Production Agent Evaluation : Engineering teams running AI agents in production use Polarity to continuously evaluate agent behavior across real stateful services, catching failure modes that only appear under realistic conditions.
• Complex Multi-Step Agent Testing : Teams building long-running, multi-step agentic workflows rely on Polarity to validate correct sequencing, state persistence, and service interaction across the full execution chain.
• Agent Reliability Benchmarking : Organizations can measure and compare non-determinism across agent versions or configurations, helping prioritize stability improvements before wider rollout.
• Rapid Failure Debugging : Developers use seed reproducers to instantly re-create exact failure conditions locally, cutting investigation time on hard-to-reproduce stateful bugs.
• CI/CD Pipeline Integration : Development teams embed Polarity's code review and testing tools into their pull request workflows to enforce quality gates automatically on every code change.

FAQs