TestThread: Open Source Testing Framework for AI Agents

What TestThread Does

TestThread is an open source testing framework designed specifically for AI agents, similar to how pytest works for traditional code. It addresses the problem of agents breaking silently in production with wrong outputs, hallucinations, or failed tool calls that only become apparent when downstream systems crash.

Key Features

• 4 match types including semantic matching where AI judges meaning rather than just text
• AI diagnosis on failures that explains why tests failed and suggests fixes
• Regression detection that flags when pass rates drop
• PII detection that automatically fails tests if agents leak sensitive data
• Trajectory assertions that test agent steps in addition to final outputs
• CI/CD GitHub Action that runs tests on every push
• Scheduled runs at hourly, daily, or weekly intervals
• Cost estimation per run

Installation and Setup

Install via package managers:

pip install testthread

npm install testthread

The framework includes a live API, dashboard, and Python/JavaScript SDKs. It's part of the Thread Suite alongside Iron-Thread, which validates outputs while TestThread tests behavior.

How It Works

You define what your agent should do, run it against your live endpoint, and receive pass/fail results with AI-powered explanations of failures. This approach helps catch issues before they impact production systems.