Redwood Research Proposes Reporting Architecture Monitorability
Redwood Research proposed that AI companies transparently report architecture information affecting the monitorability of latent reasoning and communication, warning that opaque recurrence or latent-based agent communication could reduce chain-of-thought oversight. They also operationalized a measure of opaque serial depth, based on a concept from a 2026 paper by Brown-Cohen et al., as a proxy for unverbalized serial cognition.
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Redwood ResearchRyan Greenblatt
Architectures that incorporate opaque recurrence or allow for agents to communicate with each other using latents could rapidly make it much harder to monitor chains of thought or communication (we’ll refer to this property as “monitorability” going forward). [1] As companies begin to explore such architectures, we believe it is important to transparently share evidence about how monitorability varies with architecture and training method. To inform the scientific debate on how to make tradeoffs between performance and monitorability, we believe AI companies should: Regularly report externally verified information about the degree to which their architectures may allow for latent reasoning or communication. Companies should publicly disclose enough information about architectures to allow external scientists to determine whether they could potentially enable models to perform much more complex reasoning without this reasoning appearing in the chain of thought (“latent reasoning”) or al
Currently, chain-of-thought (CoT) is a valuable tool for overseeing AI models. However, some architectural shifts could significantly reduce CoT monitorability . We have recently proposed that AI companies should transparently share information about the degree to which their architectures may allow for latent reasoning and communication. To assist with this proposal, this document operationalizes a measure that serves as a proxy for the amount of unverbalized serial cognition a model can perform. Our measure is a specific instantiation of the notion of “opaque serial depth”, originally defined in a recent paper from GDM ( Brown-Cohen et al, 2026 ). To measure the opaque serial depth of a computation, Brown-Cohen et al. propose measuring the longest path in the computational graph which doesn’t pass through some form of “interpretable bottleneck”. Centrally, if one considers CoT tokens as “interpretable” but transformer hidden states as “non-interpretable”, then the opaque serial dep
