Judgeval

Open source post-building layer for agents with evals and monitoring.

GrowingOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Stable

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is Judgeval?

Judgeval is an open-source tool that provides a post-training evaluation environment for AI agents, supporting reinforcement learning (RL) and supervised fine-tuning (SFT). It helps in monitoring and improving the performance of trained models through continuous evaluation.

Key differentiator

Judgeval stands out as an open-source solution specifically designed for evaluating and continuously improving AI agents after their initial training, offering a unique focus on post-building evaluation.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

Post-training evaluation environment for AI agentsmedium

Supports reinforcement learning and supervised fine-tuningmedium

Continuous monitoring of model performancemedium

↓ Weaknesses

Steep learning curve for non-Python developershigh

API requires Python-specific patterns, TypeScript SDK is community-maintained

Frequent breaking changes between versionsmedium

v0.1 to v0.2 migration required rewriting chain definitions

Limited language support beyond Pythonhigh

Primary development and maintenance focus is on Python, with limited official support for other languages

Documentation lacks depth and examplesmedium

Core concepts are briefly covered but lack detailed walkthroughs or advanced use cases

Fit analysis

Who is it for?

✓ Best for

Teams needing a robust evaluation framework for their AI agents post-training

Data science teams focused on improving model performance through iterative testing and monitoring

✕ Not a fit for

Projects requiring real-time feedback during the training phase (Judgeval focuses on post-training)

Applications where continuous monitoring is not critical to the success of the project

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Judgeval

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →