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Multi-State Linear Attention with Generalized Second-Order Routing

MERLIN adds mean and variance estimates to how multi-state linear attention routes information from long-context segments. It improves reported RULER and LongBench results on two model variants, including against baselines using four times more memory.

arXiv · Oct 27, 2026
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Source Summary

MERLIN tracks the first and second moments of each segment’s keys, letting a query estimate both mean and variance in its alignment with that segment. On **Gated DeltaNet-1.3B** and **Mamba-2-780M**, it improves reported RULER and LongBench results, including over some baselines using **4× more memory**.

Practical Implication

Builders exploring long-context models can watch this approach as a way to improve how compressed segment memories are read. It suggests routing quality may matter alongside the amount of memory available.

Agent-Ready Context
MERLIN tracks the first and second moments of each segment’s keys, letting a query estimate both mean and variance in its alignment with that segment. On **Gated DeltaNet-1.3B** and **Mamba-2-780M**, it improves reported RULER and LongBench results, including over some baselines using **4× more memory**.

Builders exploring long-context models can watch this approach as a way to improve how compressed segment memories are read. It suggests routing quality may matter alongside the amount of memory available.

These are results on multi-state variants and specific long-context evaluations. The material does not say how the method behaves in deployed agent workloads or across other model families.
Connected Context · Feed7 Judgment

MERLIN adds first- and second-moment routing to compressed segment memories and reports gains on two long-context model families. It suggests that how a model reads stored segments can matter alongside memory capacity, while leaving performance in deployed agent workloads unestablished.

Context Map
modelresearch#open-models#context-engineering#retrieval
Uncertainty
These are results on multi-state variants and specific long-context evaluations. The material does not say how the method behaves in deployed agent workloads or across other model families.