Circuit Tracing: Revealing Computational Graphs in Language Models

Emmanuel Ameisen, Jack Lindsey, Adam Pearce, Wes Gurnee, Nicholas L. Turner, Brian Chen, … (+21 more) — 2025-03-27 — Anthropic — Transformer Circuits Thread

Summary

Introduces cross-layer transcoders (CLTs) and attribution graphs methodology for understanding language model computations by tracing computational steps through an interpretable replacement model, with extensive validation and applications to both toy models and Claude 3.5 Haiku.

Key Result

Cross-layer transcoders match the underlying model’s next-token completion on 50% of diverse pretraining prompts while enabling interpretable attribution graphs that trace feature-to-feature interactions through frozen attention patterns.

Source