Loki: An Open-Source Tool for Fact Verification

TL;DR

Loki is an open-source, human-centered fact verification tool that decomposes claims into steps to assist users in combating misinformation efficiently and cost-effectively.

Contribution

It introduces a five-step pipeline for fact verification that balances automation with human judgment, optimized for practical deployment.

Findings

Supports human decision-making in fact-checking

Optimized for latency, robustness, and cost

Available as open-source on GitHub

Abstract

We introduce Loki, an open-source tool designed to address the growing problem of misinformation. Loki adopts a human-centered approach, striking a balance between the quality of fact-checking and the cost of human involvement. It decomposes the fact-checking task into a five-step pipeline: breaking down long texts into individual claims, assessing their check-worthiness, generating queries, retrieving evidence, and verifying the claims. Instead of fully automating the claim verification process, Loki provides essential information at each step to assist human judgment, especially for general users such as journalists and content moderators. Moreover, it has been optimized for latency, robustness, and cost efficiency at a commercially usable level. Loki is released under an MIT license and is available on GitHub. We also provide a video presenting the system and its capabilities.