AI Papers of the Week
Every paper worth reading in AI, hand-picked one week at a time.
SkillOpt
Microsoft Research treats a compact natural-language skill document as the trainable state of a frozen agent, then learns that document through rollouts, reflection, and bounded edits gated by held-out validation. The argument is direct: most engineers handwrite agent skill docs and hope they generalize, when the doc itself should be optimized like a parameter. SkillOpt reframes the SKILL.md file as an external parameter of a model whose weights never change.
Compiling Agentic Workflows into Weights
This paper shows that a full agentic workflow can be distilled into the weights of a small model and run at roughly two orders of magnitude lower inference cost while preserving near-frontier task quality. Instead of keeping an external orchestrator above the LLM, the procedure is compiled into the weights of a fine-tuned model, producing what the authors call a subterranean agent.
AutoScientists
AutoScientists, from Harvard, is a decentralized team of AI agents for long-running computational science that drops the central planner entirely. Rather than following one research trajectory coordinated from the top, agents self-organize around promising hypotheses, critique each other's proposals before spending experimental compute, and record both successes and failures so the system avoids redundant exploration as evidence accumulates over hours or days.
Language Models Need Sleep
Attention scales badly with context length, so long-horizon agents keep paying a growing cost as their context grows. This paper studies a sleep-like consolidation mechanism: the model periodically converts recent context into persistent fast weights, then clears its key-value cache. During the sleep phase it performs offline recurrent passes over the accumulated context and updates fast weights in its state-space blocks through a learned local rule.
Adapting the Interface, Not the Model
When a frozen LLM agent repeatedly fails in a deterministic, rule-governed environment, do you have to retrain the model? Life-Harness argues no. Many failures come from mismatches at the model-environment interface, not from the model's reasoning, so the fix belongs in the runtime harness. Life-Harness is a lifecycle-aware harness that improves frozen agents without touching model weights or the evaluation environment.
The Efficiency Frontier
Context costs dominate production LLM bills, and the right strategy depends on how often preprocessing gets reused. This paper models context-strategy selection as a deployment-aware optimization problem that jointly accounts for task performance, token cost, and reuse, then uses it to compare retrieval-based and preprocessing-based approaches under realistic constraints.
Forecasting Scientific Progress with AI
Can frontier models predict where science is going? This work introduces CUSP, a cutoff-conditioned benchmark built from 4,760 real scientific events across multiple disciplines, each grounded against a verified knowledge cutoff. For every event, models are tested on four tasks: feasibility assessment, mechanistic reasoning, generative solution design, and temporal prediction. The headline is sobering: models recognize plausible directions but cannot forecast outcomes.
Your Agents Are Aging Too
AgingBench is a longitudinal reliability benchmark for agent lifespan engineering, built on the observation that long-lived agents are still evaluated like freshly initialized models. It organizes agent degradation into four mechanisms: compression aging, where write-time summarization drops future-relevant details; interference aging, where accumulated similar memories crowd out the target fact; revision aging, where changed or derived state is not updated correctly; and maintenance aging from routine lifecycle events. Using a temporal dependency DAG to encode cross-session structure, it produces aging curves over an operational lifetime rather than a single day-one score, and points to where repair should target.
Harnesses Are Not Uniformly Better
This paper studies LLM agent harnesses through the lens of inference-time trajectory alignment, separating a harness into two mechanisms: task decomposition, which structures a task into sub-goals, and guided execution, which reshapes local action distributions during execution. The key finding is that more elaborate harnesses are not uniformly better. Increasing decomposition or guidance can improve execution but can also reduce final task success, producing concrete failure modes like over-decomposition, over-pruning, and hallucinated execution. Strikingly, partial harnesses that specify only the initial steps and leave the rest to the agent can reach a higher pass rate than fully structured workflows.
Epicure
Epicure trains a family of multilingual ingredient embeddings from scratch on 4.14 million recipes aggregated from 11 sources across seven languages, with raw ingredient strings normalized to 1,790 canonical entries via an LLM-augmented pipeline. It ships three skip-gram (Metapath2Vec) variants that share architecture but differ in what they walk: recipe co-occurrence only, chemical-compound structure from FlavorDB only, or a blend of both, placing each model at a different point on the chemistry-versus-recipe-context spectrum. The result is a compact, downloadable map of the emergent geometry of food, a clean reminder that representation learning generalizes well beyond text into surprisingly everyday domains.
Code as Agent Harness
A 100+ page survey treating the agent harness as a first-class research object rather than glue around an LLM. The authors argue that code-as-harness is the most promising path to general-purpose agency, and that future agent systems should satisfy four properties: executable, inspectable, stateful, and governed. The report consolidates methods, applications, and open problems across the harness layer.
OpenAI Disproves the Unit Distance Conjecture
An OpenAI internal reasoning model produced a counterexample to Erdős's 1946 unit distance conjecture, the first time an AI system has autonomously resolved a prominent open problem in mathematics. For nearly 80 years, mathematicians believed square grids were essentially optimal for placing n points to maximize unit-distance pairs. The new construction beats grids using an infinite unramified tower of totally real number fields with 3-power Galois groups, producing n-point sets with more than n^(1.014) unit distances. A human-verified companion paper was prepared by nine external mathematicians including Noga Alon, Tim Gowers, and Melanie Matchett Wood.
Memory as a Model
MeMo augments any frozen LLM with a separately trained memory model that stores, retrieves, and integrates facts on the base model's behalf. Memory updates are decoupled from base-model weight updates, so the system supports continual learning without catastrophic forgetting, a property RAG fails to deliver because a vector store is just a database with a learned encoder bolted on.
AIRA
Meta's AIRA is an agent system that autonomously discovers neural architectures, producing models that beat Llama 3.2 at 350M, 1B, and 3B scales under a 24-hour compute budget. The search is split across two specialized agents: AIRA-Compose searches macro architecture, and AIRA-Design implements the low-level mechanisms. The split outperforms a single end-to-end agent on this non-toy search problem.
Weak-Model Critic-Comparator
GPT-5.4 nano wrapped in a critic-comparator orchestration loop reaches 76.4% on SWE-bench Verified, matching standalone Gemini 3 Pro and Claude Opus 4.5 Thinking. The trick is to sample k=8 candidate patches from the weak model and select the winner using execution and proof signals rather than asking the model to self-rank.
MetaCogAgent
MetaCogAgent equips a multi-agent system with metacognition, so each agent decides whether it should answer or delegate. The bottleneck in current multi-agent systems is over-delegation and under-delegation, and a metacognitive gate is a principled way to manage both. The Metacognitive Unit (MCU) at each agent produces confidence scores that drive routing to a delegation hub.
Production Agent Architecture Methodology
A methodology paper on selecting and composing runtime architecture patterns for production LLM agents. The core argument is that most teams accidentally let framework defaults make critical architecture decisions for them. The paper introduces the stochastic-deterministic boundary (SDB) as a named primitive and presents a six-pattern catalog organized by the three runtime concerns of coordination, state, and control.
NanoGPT-Bench
A new evaluation of whether coding agents can do real AI R&D. Intology runs Codex, Claude Code, and Autoresearch on the NanoGPT-Bench suite and reports that the agents recover only 9.3% of human progress on the same problems. Coding agents spend the bulk of their compute on hyperparameter tuning and rarely attempt algorithmic research. Claude Code and Autoresearch reason about algorithmic changes more often, but still tend to dodge implementing them. The headline result tempers the current wave of "self-improving agent" claims: producing real research progress requires a different distribution of effort than the one current coding agents converge to under their default scaffolds.
General-Agent
Prime Intellect's General-Agent is a fully synthetic reinforcement learning environment whose task corpus self-evolves and grows harder over time. The release ships with 4,504 tool-use tasks across 1,040 domains and 8,159 unique tools. Synthetic task creation is formulated as a two-player game between a Synthesizer that proposes new task families and a Solver that runs rollouts to measure pass rates. Tasks whose pass rate falls inside a calibrated difficulty band are accepted into the corpus, and hard tiers seed the next round of extensions. The framing turns RL environment creation, historically a major bottleneck, into an automated agentic search problem in its own right.
Contrastive Neuron Attribution
Nous Research releases Contrastive Neuron Attribution (CNA), a method for steering LLM behavior by identifying and ablating sparse circuits in the MLP basis without training a sparse autoencoder, modifying weights, or degrading general capability benchmarks. Given a small set of contrastive prompt pairs that elicit a target behavior and its opposite, CNA isolates the top 0.1% of MLP neurons whose activations differ most between the two sets. Ablating that small circuit removes the behavior while leaving the rest of the model intact. The intervention remains robust at high strengths where residual-stream methods like Contrastive Activation Addition (CAA) start to degrade. Validated on the refusal circuit across 8 instruct-tuned models including Llama-3.1-70B, Llama-3.2-3B, Qwen2.5-72B, and Qwen2.5-14B.
Lighthouse Attention
Nous Research proposes a training-only attention wrapper for long-context pretraining. Lighthouse Attention wraps standard SDPA with a hierarchical, gradient-free selection layer that compresses and decompresses queries, keys, and values symmetrically while preserving left-to-right causality. The wrapper is removed near the end of training in a short recovery phase, so the deployed model runs vanilla attention with no architectural change at inference. Preliminary LLM experiments report faster total training time and lower final loss than full-attention baselines.
Is Grep All You Need?
The paper evaluates grep-style text search against embedding-based retrieval inside coding agents. When wrapped in a suitable agent harness, grep matches or exceeds embedding retrieval on coding-agent tasks. The study isolates the contribution of the harness from the contribution of the retrieval primitive, and finds that harness design accounts for most of the performance differential typically attributed to embeddings.
A Geometric Calculator Inside a Neural Network
Goodfire reports mechanistic interpretability work identifying a geometric calculator inside an LLM. The model represents numbers as Fourier features, where circles in activation space correspond to numbers modulo a given base. Arithmetic operations are implemented as rotations of these circles, forming a variant of a residue number system that does not require coprime moduli. The same circuit appears to be reused beyond arithmetic.
δ-mem
δ-mem augments a frozen full-attention model with a compact online associative-memory state. The state is a fixed-size matrix updated by delta-rule learning during generation, and its readout produces low-rank corrections to the backbone's attention output. There is no fine-tuning, no backbone swap, and no context extension.