Circuit Tracer

In plain words

Circuit Tracer is an open-source tool from Anthropic that helps researchers understand how large language models work by visualizing their internal computations as attribution graphs. Users can explore these visualizations on Neuronpedia or use the library directly. The tool is designed for AI researchers and developers seeking transparency into how LLMs make decisions and process information.

written from the facts on this page · September 2026

From the sources

Anthropic's open-source Circuit Tracer helps researchers understand LLMs by visualizing internal computations as attribution graphs. Explore on Neuronpedia or use the library. Aims for AI transparency.

Anthropic is an AI safety and research company that's working to build reliable, interpretable, and steerable AI systems.

In our recent interpretability research, we introduced a new method to trace the thoughts of a large language model. Today, we’re open-sourcing the method so that anyone can build on our research. Our approach is to generate attribution graphs , which (partially) reveal the steps a model took internally to decide on a particular output. The open-source library we’re releasing supports the generation of attribution graphs on popular open-weights models—and a frontend hosted by Neuronpedia lets you explore the graphs interactively. This project was led by participants in our Anthropic Fellows program, in collaboration with Decode Research . To get started, you can visit the Neuronpedia…from anthropic.com

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