Show HN: NERDs – Entity-centered long-term memory for LLM agents

tdaltonc 13 points 5 comments March 06, 2026
nerdviewer.com · View on Hacker News

Long-running agents struggle to attend to relevant information as context grows, and eventually hit the wall when the context window fills up. NERDs (Networked Entity Representation Documents) are Wikipedia-style entity pages that LLM agents build for themselves by reading a large corpus chunk-by-chunk. Instead of reprocessing the full text at query time, a downstream agent searches and reasons over these entity documents. The idea comes from a pattern that keeps showing up: brains, human cognition, knowledge bases, and transformer internals all organize complex information around entities and their relationships. NERDs apply that principle as a preprocessing step for long-context understanding. We tested on NovelQA (86 novels, avg 200K+ tokens). On entity-tracking questions (characters, relationships, plot, settings) NERDs match full-context performance while using ~90% fewer tokens per question, and token usage stays flat regardless of document length. To highlight the methods limitation, we also tested it on counting tasks and locating specific passages (which aren't entity-centered) where it did not preform as well. nerdviewer.com lets you browse all the entity docs we generated across the 86 novels. Click through them like a fan-wiki. It's a good way to build intuition for what the agent produces. Paper: https://www.techrxiv.org/users/1021468/articles/1381483-thin...

Discussion Highlights (3 comments)

elevaes

This is fascinating, I'm wondering if it works as well with other use cases like papers, conversations, or any other human written text.

mmayberry

If the agent builds entity pages incrementally while reading, how do you prevent early incorrect assumptions about relationships or attributes from propagating through the entity graph? Is there support for belief revision?

rnunery13

I agree with Elevaes, this was absolutely fascinating and I love the use of books to help understand the concepts. I could relate right away. The token usage reduction potential is massive especially when it comes to enterprise usage and costs - many companies are experiencing sticker shock because they weren't prepared / didn't anticipate the usage. The potential for better costing and estimation with the process could have widespread impacts to financials (in a good way) and allow for more accurate pricing estimates and models.

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