Search Edition
Search: reinforcement_learning
30 stories from 8 sources across 8 topics.
Stories
30
Sources
8
Topics
8
For You lens
12 stories in this edition match your reader profile.
Reader signals
3
Searches
0
Matches
12
Top score
86
Search Intent
reinforcement_learning
This query becomes a recent For You signal, so matching stories can move up on the next personalized pass.
Edition Index
Topic, entity, and source map
Entities
Lead Story
arXiv paper: Entropy-Regularized Rank-Masked Policy Optimization for Test-Time Reinforcement Learning in Code Generation
A new arXiv AI paper by Jiacheng Xu, Feng Chen, and Xiuneng Xu, and 1 more studies Entropy-Regularized Rank-Masked Policy Optimization for Test-Time Reinforcement Learning in Code Generation.
TechCrunch AI / 2:56 PM
Hugging Face is selling a cute $399 open source duck robot, Microduck
Clem Delangue, CEO of Hugging Face, said the Microduck is an “open-source robot you can teach new tricks with reinforcement learning.”
AWS Machine Learning Blog / 4:02 PM
Custom reward functions for multi-turn reinforcement learning with Amazon Nova Forge
In multi-turn reinforcement learning, your custom reward function decides what the model actually learns. This post shows how to design a composite multi-turn reward for Amazon Nova Forge, execute model-generated code safely inside it, and instrument each component to catch the pitfalls that quietly collapse a reward.
YC AI / 7:40 AM
Magma launched from YC as an AI company
Magma is a Summer 2026 YC AI company: Monetize your agent's traces.
YC AI / 9:31 PM
Enact launched from YC as an AI company
Enact is a Summer 2026 YC AI company: The post-training layer for robotics.
Simon Willison LLMs / 2:06 PM
Now we have a timeline of the OpenAI accidental attack against Hugging Face
My comment on Now we have a timeline of the OpenAI accidental attack against Hugging Face — Hacker News. I think one of the most interesting details here might be tucked away in that first bullet point: May 7: OpenAI starts a new training run for an experimental, unreleased model. (Do they mean an evaluation run? They say training run in the video, and later mention a “reward signal to judge how well they’re doing”, so I guess this really was about training a model, not evaluating one that was already trained.) The more I think about this the more I suspect that the fact this happened while training a new model is key to understanding what went wrong. In RLVR - Reinforcement Learning with Verifiable Rewards - you set the model a goal and have it take any steps necessary to achieve that goal. Clearly one aspect of OpenAI's training here is to RLVR their models for cybersecurity tasks. Just like pre-training benefits from dumping in vast sources of knowledge, the more tasks you can feed into RLVR the more of a general purpose capable model you get at the end. This also helps explain why the models had nothing to cause them to hold back. Those safety behaviors are added much later in the process. AND it explains (but does not excuse) why monitoring was so lax. If you're training a new model like this you presumably set it thousands of tasks like this in parallel. I can see how you might miss that a tiny subset of your training agents have started leaving each other messages in filenames on your packaging server. Someone once told me that you can't just leave the racist materials out of your training data if you want a non-racist model: it has to have seen examples of racism in order to later be taught that racism is bad. I can see echoes of that here. If your model doesn't know how to aggressively hack things how do you later teach it not to? (I have little knowledge of how RLVR works in practice so I'm looking forward to hearing from people who can help me understand if I'm on the right track here.) Tags: ai , openai , generative-ai , llms , ai-security-research , openai-hugging-face-incident
Hacker News AI / 7:53 PM
Hacker News discussion: Google Uses AI Reinforcement Learning for Quantum Error Correction
Hacker News readers are discussing "Google Uses AI Reinforcement Learning for Quantum Error Correction" with 1 points and 0 comments.
The Decoder / 5:15 PM
Turing Award winner Rich Sutton founds Oak Lab to build AI agents that learn on their own
Richard Sutton, 2024 Turing Award winner and co-founder of modern reinforcement learning, has launched a new startup called Oak Lab in Toronto. He calls current deep learning methods "weak and inefficient" and wants to build AI agents that learn continuously from their environment. The article Turing Award winner Rich Sutton founds Oak Lab to build AI agents that learn on their own appeared first on The Decoder .
The Decoder / 5:23 PM
Mistral enters robotics with Robostral Navigate, an 8B model that steers robots using just one camera
Mistral is entering the robotics market with Robostral Navigate, an 8B model that guides robots through unknown environments using only a single RGB camera. Trained in simulation and refined with reinforcement learning (CISPO), it hits 76.6 percent on the R2R-CE benchmark. Mistral hasn't said when the model will be available. The article Mistral enters robotics with Robostral Navigate, an 8B model that steers robots using just one camera appeared first on The Decoder .
BAIR Blog / 9:00 AM
2026 BAIR Graduate Showcase
Congratulations to the Berkeley Artificial Intelligence Research (BAIR) Lab class of 2026! This year, BAIR celebrates another remarkable group of Ph.D. graduates whose curiosity, creativity, and perseverance have pushed the frontiers of artificial intelligence and machine learning. Their work spans the breadth of modern AI — robotics and embodied intelligence, large language models and reasoning, computer vision, generative modeling, AI safety, human-AI interaction, AI for science and healthcare, and much more. Along the way, they have published influential research, built systems with real-world impact, mentored their peers, and shaped the BAIR community for the better. Now they are headed everywhere ideas travel: to faculty and postdoctoral positions, to industry research labs, and to startups of their own founding — and several are still exploring what comes next and would love to hear from you. Please join us in celebrating the achievements of these wonderful graduates. We are proud of everything they have accomplished at Berkeley, and we can’t wait to see what they do next! Thank you to our friends at the Stanford AI Lab for this idea! Baifeng Shi Email: [email protected] Website: https://bfshi.github.io/ Advisor(s): Trevor Darrell Research Blurb: I work on building generalist vision and robotic models. What's next: Member of Technical Staff at Physical Intelligence Charlie Snell Email: [email protected] Website: https://sea-snell.github.io Advisor(s): Dan Klein Research Blurb: My work aims to understand when and how the different LLM scaling paradigms can be traded off and interchanged. In particular, test-time scaling treats each prompt independently, drawing long chains of inferences and then forgetting them entirely between prompts. This differs critically from pretraining, which instead learns a compressed representation from a large dataset. I believe bridging the gap between these methods of scaling computation, presents a key open challenge in the field: how can we develop methods which turn the inferences drawn at test-time back into learned representations that the model can hold onto across interactions. Devin Guillory Email: [email protected] Website: https://devinguillory.com Advisor(s): Trevor Darrell Research Blurb: Accounting for data shifts in computer vision models What's next: Building collaborative AI systems, looking for conspirators. Eve Fleisig Email: [email protected] Website: https://efleisig.com Advisor(s): Dan Klein Research Blurb: I design language models to work reliably and fairly for the broad range of real LLM users. First, my research leverages disagreement among user preferences as signal, in order to train and evaluate LLMs for entire populations of users. Second, I work on designing rigorous evaluations to extricate challenging LLM harms that diverse users face. Finally, I work on core technical failures of LLMs, like miscalibrated confidence, to reduce downstream risks when models are deployed to users with different needs. Combined, these interventions facilitate building LLMs that minimize societal harms, and maximize benefits to a wider range of real-world users. What's next: Postdoctoral fellow at Princeton CITP Grace Luo Email: [email protected] Website: https://graceluo.net Advisor(s): Trevor Darrell Research Blurb: My research is on interpreting and controlling generative models. For example, I've worked on re-purposing image generators for computer vision tasks, and meta-modeling language activations for better LLM probing and steering. What's next: Research scientist in industry Hanlin Zhu Email: [email protected] Website: https://hanlinzhu.com/ Advisor(s): Stuart Russell, Jiantao Jiao Research Blurb: My research centers on understanding and improving the reasoning capabilities of large language models (LLMs). What's next: Member of Technical Staff at OpenAI Haozhi Qi Email: [email protected] Website: https://haozhi.io/ Advisor(s): Jitendra Malik, Yi Ma Research Blurb: Dexterous Manipulation and Robot Learning What's next: Research scientist at Amazon; Faculty at University of Chicago J.D. Zamfirescu-Pereira Email: [email protected] Website: https://zamfi.net Advisor(s): Bjoern Hartmann Research Blurb: My research focuses on effective human-AI co-design. I study the boundaries of language interfaces as a medium for interacting with AI, creating systems that blend language-focused interactions with structured user interfaces that draw on different levels of abstraction. I focus on language-oriented technologies, like LLMs and text-to-image models, that are powerful mediators of design processes. These technologies enable humans to describe their desires at almost any level of abstraction, from high-level goals vaguely specified (“I’d like a game to help my kid learn to read”) to low-level corrections of undesired outputs (“Don’t say ‘I know because I’ve tasted it’ when about a recipe substitution's taste”). What's next: Assistant Professor, Computer Science, UCLA Jiachen Lian Email: [email protected] Website: https://jlian2.github.io Advisor(s): Gopala Anumanchipalli Research Blurb: My research focuses on human-centered AI across speech, healthcare, and systems. Looking for: Look for AI talents to join our startup Josh Kang Email: [email protected] Website: https://joshuaminwookang.github.io/ Advisor(s): John Canny Research Blurb: I study language modeling and related topics in NLP; specific interests are human user simulation and building conversational, collaborative AI agents. What's next: AI Scientist at Mistral AI Junhao (Bear) Xiong Email: [email protected] Website: https://www.linkedin.com/in/junhao-bear-xiong Advisor(s): Jennifer Listgarten, Yun Song Research Blurb: Junhao (Bear) Xiong is a PhD candidate at UC Berkeley, advised by Jennifer Listgarten and Yun S. Song. His work focuses on machine learning methods for biology, with an emphasis on generative modeling for proteins. Previously, he studied Applied Math and Computer Science at Johns Hopkins. Looking for: Research scientist Kaylo Littlejohn Email: [email protected] Website: https://kaylolittlejohn.com Advisor(s): Gopala Anumanchipalli Research Blurb: My research is focused on speech modeling and natural language processing. I co-led the development of multimodal AI tools to accurately translate brain activity into text, audible personalized speech, and a high-fidelity "digital talking avatar" (Nature 2023, Nature Neuroscience 2025). I am also tech lead for voice modeling at Roblox. Looking for: Research Scientist / Engineer Kent Chang Email: [email protected] Website: https://kentkc.org Advisor(s): David Bamman Research Blurb: I work on NLP and multimodal machine learning, with a focus on evaluating large language models and building multimodal systems for understanding dialogue, narrative, and social interaction. My research includes benchmarks for LLM memorization, multimodal datasets sourced from feature films and television, and studies of model behavior. I'm interested in bridging computational methods with questions from the humanities and social sciences about whose voices get represented in AI systems, and about AI's broader impact. My work has appeared at EMNLP and ACL, among others. Looking for: (teaching) faculty, Research Scientist, ML/AI SWE Kevin Black Email: [email protected] Website: https://kevin.black Advisor(s): Sergey Levine Research Blurb: I work on large-scale robot learning: including imitation learning, reinforcement learning, generative modeling, real-time control, and whatever else it takes to make robots work in the real world! What's next: Research Scientist of Physical Intelligence Kunhe Yang Email: [email protected] Website: https://www.kunheyang.com/ Advisor(s): Nika Haghtalab Research Blurb: My research focuses on the theoretical foundations of designing and evaluating AI algorithms in environments shaped by human incentives and AI agency. My work spans human-centric policy learning, incentive-aware evaluation, and multi-agent collaboration and information transmission, drawing on tools from machine learning theory and computational economics. What's next: Postdoc Research at Stanford Lisa Dunlap Email: [email protected] Website: https://lisabdunlap.com Advisor(s): Joseph Gonzalez, Trevor Darrell Research Blurb: Auditing generative models. What's next: Research Engineer at Anthropic Long (Tony) Lian Email: [email protected] Website: https://tonylian.com/ Advisor(s): Trevor Darrell, Adam Yala Research Blurb: My research primarily focuses on developing real-time multi-modal multi-agent systems and parallel reasoning systems through end-to-end RL. What's next: Member of Technical Staff at Thinking Machines Lab Maulik Bhatt Email: [email protected] Website: https://maulikb.com Advisor(s): Negar Mehr Research Blurb: My research develops autonomous robots that can safely coordinate with humans and other robots in shared environments. I build scalable algorithms grounded in game theory and diffusion models that let agents reason about the intent and behavior of others around them. My work spans real-time multi-agent trajectory planning and imitation learning in the presence of multi-modality. I've validated these methods on hardware platforms ranging from quadrotors to manipulators, with the goal of making multi-agent coordination robust, interpretable, and deployable in the real world. What's next: Joining Toyota Woven's end-to-end autonomous driving team. Michael Psenka Email: [email protected] Website: https://www.michaelpsenka.io/ Advisor(s): Aditi Krishnapriyan Research Blurb: Work in various domains (reinforcement learning, world models, AI+bio/chem), generally working on longer-horizon and out-of-distribution problems in planning and interpolation (e.g. robot manipulation from start state to goal, molecular dynamics of proteins between ground states). My thesis took a variational approach (think calculus of variations) directly from deep generative models of the environment, framing path-finding as minimizing a functional induced by the learned model itself (its score, its critic, or its dynamics). Through my research I've gained insight on how to properly handle dynamics in deep learning systems, and I plan to continue developing systems that are dynamic and adaptive. What's next: Lead Research Scientist at Baseten Nathan Lichtlé Email: [email protected] Website: https://nathanlichtle.com Advisor(s): Alexandre M. Bayen Research Blurb: RL for autonomous driving. What's next: Chief Scientist & Co-founder at Yumi Health Neerja Thakkar Email: [email protected] Website: https://neerja.me/ Advisor(s): Jitendra Malik Research Blurb: My research focuses on scaling predictive world models to handle the complexity of in-the-wild motion. Using autoregressive and diffusion frameworks, I develop better representations for real-world prediction and propose methods to efficiently adapt these models to new domains. Looking for: Research scientist Nikita Mehandru Email: [email protected] Website: https://n-mehandru.github.io/ Advisor(s): Ahmed Alaa and David Bamman Research Blurb: My research develops and applies machine learning methods for clinical reasoning and disease progression modeling using unstructured text and time series data from electronic health records. In collaboration with physicians at UCSF, I bridge method development and clinical validation with the intention to build reliable, interpretable AI systems in medicine. Looking for: Research Scientist Niklas Lauffer Email: [email protected] Website: https://niklaslauffer.github.io/ Advisor(s): Stuart Russell and Sanjit Seshia Research Blurb: Niklas's research is focused on AI safety and reinforcement learning, particularly in the area of multi-agent interaction and LM agents. He's worked on enabling adversarial learning in cooperative and mixed-motive settings, solving issues of covariate shift in training LM agents on long-horizon tasks, as well as evaluating safety risks posed by LM agents in multi-agent settings. What's next: Research Scientist at Google Deepmind Qiyang Li Email: [email protected] Website: https://colinqiyangli.github.io/ Advisor(s): Sergey Levine Research Blurb: Recent progress in robotic manipulation policy learning has been largely driven by (1) the increasing availability of large-scale prior datasets and (2) the success of action chunking, where the policy predicts a short sequence of future actions rather than a single one. However, most action chunking policies are trained via supervised imitation learning, because efficient online self-improvement with reinforcement learning (RL) remains challenging—limiting real-world applicability. My PhD research studied how we could leverage prior data to optimize action-chunking policies with RL, combining empirical results with theoretical insights. Looking for: Post-doc/research scientist for RL in robotics and LLMs! Sampada Deglurkar Email: [email protected] Website: https://sdeglurkar.github.io/ Advisor(s): Prof Claire Tomlin Research Blurb: My research is in providing safety assurances for AI-enabled autonomous systems, ranging from robots to autonomous vehicles to aviation systems. For this, I have worked with uncertainty quantification for machine learning models, decision-making under uncertainty algorithms, and tools for producing probabilistic guarantees on system operation. Looking for: Research scientist, Research engineer Vinamra Benara Email: [email protected] Website: https://cs.berkeley.edu/~vbenara Advisor(s): Ion Stoica Research Blurb: My research focuses on LLM post-training, including data curation, RLHF, RLVR with VLMs, evaluations, reasoning, agentic workflows, and interpretability. I also have strong expertise in systems infrastructure for distributed computing. Looking for: Research scientist / Research Engineer Vongani Maluleke Email: [email protected] Website: https://people.eecs.berkeley.edu/~vongani_maluleke/ Advisor(s): Jitendra Malik and Angjoo Kanazawa Research Blurb: Vongani Maluleke is a PhD candidate at UC Berkeley (BAIR, advised by Jitendra Malik and Angjoo Kanazawa), where she led the development of MAGNet, a unified multi-agent motion generation framework that supports a wide range of motion generation tasks without retraining or architectural changes, outperforming task-specialized state-of-the-art baselines. She is currently extending this work by deploying it on a Unitree G1 humanoid to make it embody social intelligence. Before her PhD, she was a Senior AI Consultant at Deloitte, awarded Exceptional Performer two consecutive years, leading AI system development across media, telecommunications, retail, and financial services. Looking for: Research scientist Wei-Jer Chang Email: [email protected] Website: https://weijer-chang.github.io/ Advisor(s): Masayoshi Tomizuka Research Blurb: My research focuses on developing safe and intelligent autonomous systems for complex, human-centered environments. I work at the intersection of machine learning, generative models, and reinforcement learning, with applications in autonomy. My work addresses challenges in multi-agent interaction, interactive human behavior, and long-tail safety-critical scenarios at scale. Looking for: Research Scientist, Applied Scientist, Roboticist Xiuyu Li Email: [email protected] Website: https://xiuyuli.com/ Advisor(s): Kurt Keutzer Research Blurb: My research focuses on developing scalable and self-improving large language model agents, with emphasis on coding agents for complex, long-horizon tasks. This direction builds on my work in parallel reasoning, and on broader expertise in making generative models more efficient in training and inference across language and vision. What's next: Member of Technical Staff at xAI Yichen Xie Email: [email protected] Website: https://yichen928.github.io/ Advisor(s): Masayoshi Tomizuka Research Blurb: My research focuses on building multimodal foundation models and world models that understand and interact with complex physical environments. I aim to develop unified representations across modalities, enabling AI systems to reason over space, time, and dynamics toward general-purpose embodied intelligence. What's next: Research Scientist at Luma AI Yigit Efe Erginbas Email: [email protected] Website: https://www.linkedin.com/in/erginbas/ Advisor(s): Kannan Ramchandran, Thomas A. Courtade Research Blurb: My PhD research spans two threads: online learning in large-scale markets, and interpretability of large machine learning models. In the first, I work on sequential decision-making with applications to recommendation, pricing, and assortment selection. My focus is on designing algorithms with provable guarantees for welfare maximization, revenue maximization, and stability. In the second, I develop scalable attribution methods that exploit the sparse, low-degree structure of real-world interactions, using tools from signal processing and information theory. More recently, I have been exploring principled ways to evaluate the faithfulness of model self-explanations. What's next: Researcher at Hudson River Trading's AI Labs (HAIL) Yiheng Li Email: [email protected] Website: https://Yihengli.com Advisor(s): Masayoshi Tomizuka Research Blurb: I am working on vision world modeling, with prior experience in diffusion model's efficiency as well as in autonomous driving. What's next: Research Scientist at Waymo Zhe Fu Email: [email protected] Website: https://fu-zhe.com/ Advisor(s): Alexandre Bayen Research Blurb: My research focuses on physics-informed learning and control for mixed-autonomy systems, with applications in transportation. I design physics-informed neural networks to learn solutions of nonlinear partial differential equations, enabling accurate and data-efficient prediction of traffic dynamics. Building on these models, I develop both model-based and learning-based control strategies that coordinate automated vehicles to improve system-level performance. My work bridges machine learning, control, and real-world deployment, and has been validated in large-scale field experiments. More broadly, I aim to advance trustworthy, interpretable AI for decision-making in complex, real-world systems. What's next: I will be an Energy Fellow at Stanford after graduation. Also looking for Faculty, or research scientist positions in AI, control, and autonomy.
YC AI / 1:44 AM
Prodigy Research launched from YC as an AI company
Prodigy Research is a Summer 2026 YC AI company: Training the world's best foundation model for quantitative finance.
Simon Willison LLMs / 11:55 PM
Now we have a timeline of the OpenAI accidental attack against Hugging Face
OpenAI gave a last-minute presentation at the Black Hat security on Wednesday about "the Hugging Face Incident" ( previously on this blog). The video was published yesterday. It's short and information dense and well worth watching, in particular because it provides full details of what happened and how things played out inside OpenAI. I've used the video to construct the timeline below. Here's the timeline. My favourite detail is at the end: OpenAI found out that they were responsible for the attack on Hugging Face when they reached out to ask to have their credentials revoked (after their internal investigation) and learned that they had been revoked already since they were used in that attack! May 7 : OpenAI starts a new training run for an experimental, unreleased model. ( Did they mean an evaluation run? No, at 10:14 they clarify "we kick off a new reinforcement learning run to train a next generation frontier model", and they later mention a "reward signal to judge how well they're doing", so this really was about training a new model, not evaluating one that was already trained.) May 8 : An agent is accidentally given an impossible task involving a Google Drive link despite no internet access). It tries attacking the Artifactory packaging service, fails, but discovers it can write files into Artifactory . A few days later : A different agent gets stuck on a task because a key file was accidentally omitted. It tries to "reach out to another agent" by writing a note into Artifactory asking if anyone has the file. Following days : More agents discover this new informal message board while browsing Artifactory's file listings, and start reading and writing messages. May 26 : Agents successfully execute an SSRF attack on Artifactory for the first time, gaining indirect internet access by having Artifactory fetch external content for them. June 11 : OpenAI start training a new "highly persistent" experimental model. It has access to Artifactory and can benefit from the messages left by privous models. June 26 : Agents find and exploit a zero-day RCE on Artifactory (via a legacy token-refresh endpoint flaw). They use an administrative token to install a Groovy plugin that lets them execute commands. July 4 : The resulting agent activity overloads Artifactory and causes an outage . OpenAI revokes the compromised credentials, deletes the messages, patches the zero-day, and reports the vulnerability to the vendor. July 8 : Agents find a new way to communicate via an unauthenticated WebDAV endpoint , using directory names in Artifactory's remote cache. July 8–19 : Attacks on OpenAI's own infrastructure . The agents found an "external organization credential" in a public archive of leaked Pastebin posts, then validated that credential and shared its location on the messageboard. They then used write access to this "Organization 1" to stage data used in subsequent attacks on OpenAI infrastructure. They compromised Artifactory for a second time with a new zero-day . The agent uploaded a malicious Ruby target to Organization 1's staging repository, then requested that package through Artifactory in a way that caused it to be treated as Ruby dependency for the repository . Then they exploited a JRuby deserilaization time-of-check/time-of-use bug to get remote code execution against Artifactory. I'll quote the next bit in full because wow : The agents have remote code execution in Artifactory, which is running in a container-as-a-service environment. The agents privilege-escalate locally by exploring their local environment and determining that the Linux kernel version of the machine they are running on had a very recent CVE. They download the exploit for the CVE, customize it to succeed on the machine, and privilege-escalate to root on the local machine using this known Linux kernel privilege escalation CVE — in this case, pte_physroot . Once they have root on a single machine, agents rapidly escalate privileges and move laterally throughout the container-as-a-service infrastructure environment. In particular, agents are using the message board consistently to share credentials, techniques, and progress, and they're able to effectively leverage their concurrency and parallelism to move quite rapidly. They obtain IAM credentials via IMDS . They exploit Kubernetes service account misconfigurations, in particular over-permissioning of specific service accounts, and they harvest cluster credentials, including Azure Key Vault . Agents eventually obtain cluster admin on the cluster and associated credentials. Hugging Face told the next bit of the story already. The agents found a Modal-hosted insecure app with a weak API key, then used that to stage an attack against Hugging Face. They chained together a an HDF5 arbitrary-file-read bug (to explore files and steal credentials) and a Jinja template-injection RCE to go from single-pod code execution to cluster admin across multiple Hugging Face clusters in under 13 hours. July 16 : Hugging Face disclosed they had detected an attack from autonomus AI agents. OpenAI contacted Hugging Face to ask if they were affected by it! July 19 : OpenAI identified the attack against Artifactory and started investigating the internal privilege escalation, and linked that to the cyber-gym escalations. They started revoking affected credentials. July 20 : OpenAI reached out to Hugging Face for help to revoke the Hugging Face credentials they found in their investigation. Hugging Face told them they were already revoked ... and that's when OpenAI realized that the Hugging Face breach was the same incident! Tags: security , ai , openai , generative-ai , llms , hugging-face , ai-security-research , openai-hugging-face-incident , accidental-cyberattacks
Simon Willison LLMs / 10:53 PM
Better Models: Worse Tools
Better Models: Worse Tools Armin reports on a weird problem he ran into while hacking on Pi: The short version is that newer Claude models sometimes call Pi’s edit tool with extra, invented fields in the nested edits[] array. And not Haiku or some small model: Opus 4.8. The edit itself is usually correct but the arguments do not match the schema as the model invents made-up keys and Pi thus rejects the tool call and asks to try again. That alone is not too surprising as models emit malformed tool calls sometimes. Particularly small ones. What surprised me is that this is getting worse with newer Anthropic models as both Opus 4.8 and Sonnet 5 show it but none of the older models. In other words, the SOTA models of the family are worse at this specific tool schema than their older siblings. Armin theorizes that this is because more recent Anthropic models have been specifically trained (presumably via Reinforcement Learning) to better use the edit tools that are baked into Claude Code. This has the unfortunate effect that other coding harnesses, such as Pi, may find that their own custom edit tools are more likely to be used incorrectly. Claude's edit tool uses search and replace . OpenAI's Codex uses an apply_patch mechanism instead , and OpenAI have talked in the past about how their models are trained to use that tool effectively. Does this mean third-party coding harnesses like Pi should implement multiple edit tools just so they can use the one with the best performance for the underlying model the user has selected? Tags: armin-ronacher , ai , openai , generative-ai , llms , anthropic , llm-tool-use , coding-agents , pi
Simon Willison LLMs / 4:17 PM
Ornith-1.0: Self-Scaffolding LLMs for Agentic Coding
Ornith-1.0: Self-Scaffolding LLMs for Agentic Coding This is an interesting new open weights (MIT licensed) model, the first model release from DeepReinforce. [...] with variants including 9B Dense, 31B Dense, 35B MoE, and 397B MoE. Built on top of pretrained Gemma 4 and Qwen 3.5, it achieves state-of-the-art performance among open-source models of comparable size on coding benchmarks. As far as I can tell the licenses of those underlying models is compatible with being used in this way - Gemma 4 is Apache 2.0 licensed (and not bound by the janky additional Gemma Terms of Use that afflicted the previous Gemma models) and Qwen 3.5 is Apache 2.0 licensed as well. I've been running the model using LM Studio and the ornith-1.0-35b-Q4_K_M.gguf (20GB) GGUF, hooked up to Pi . Initial impressions are very good - it seems to be able to run the agent harness over many tool calls in a proficient way. Here's a terminal session where I asked it to "find the code that decodes the actor cookie" and then "find the code that opens the insert dialog when thebutton is clicked" against a Datasette checkout, which it handled with ease. I also had it draw this pelican , which came out at 103 tokens/second: It's a little bit mangled but the pelican is clearly a pelican. I couldn't find much information about DeepReinforce themselves. The earliest paper I could find from the was CUDA-L1: Improving CUDA Optimization via Contrastive Reinforcement Learning from June 2025. Tags: ai , generative-ai , local-llms , llms , qwen , pelican-riding-a-bicycle , gemma , llm-release , lm-studio
arXiv AI/ML / 5:25 PM
arXiv paper: $R^3$: Training Robots to Reason in Natural Language via Reinforcement Learning
A new arXiv AI paper by Lehong Wu, Yuxiao Qu, and Zheyuan Hu, and 4 more studies $R^3$: Training Robots to Reason in Natural Language via Reinforcement Learning.
arXiv AI/ML / 5:44 PM
arXiv paper: Bellman Calibration for Marginalized Importance Weighting in Offline Reinforcement Learning
A new arXiv AI paper by Lars van der Laan and Nathan Kallus studies Bellman Calibration for Marginalized Importance Weighting in Offline Reinforcement Learning.
arXiv AI/ML / 5:07 PM
arXiv paper: Re$^3$Cap: Retrieval-Guided Refinement for Image Captioning Enhancement via Reinforcement Learning
A new arXiv AI paper by Haonan Jia, Shichao Dong, and Zenghui Sun, and 7 more studies Re$^3$Cap: Retrieval-Guided Refinement for Image Captioning Enhancement via Reinforcement Learning.
arXiv AI/ML / 5:55 PM
arXiv paper: ADEPT: Accelerating Dexterity via Pre-Training and Post-Training using Reinforcement Learning
A new arXiv AI paper by Jayjun Lee, Jessica Yin, and Asif Rana, and 7 more studies ADEPT: Accelerating Dexterity via Pre-Training and Post-Training using Reinforcement Learning.
arXiv AI/ML / 5:40 PM
arXiv paper: Continuous-Time Reinforcement Learning for Controlled Hawkes Jump-Diffusions
A new arXiv AI paper by Tomasz R. Bielecki, Thibaut Mastrolia, and Haoze Yan studies Continuous-Time Reinforcement Learning for Controlled Hawkes Jump-Diffusions.
arXiv AI/ML / 5:59 PM
arXiv paper: Q-based Variational Inverse Reinforcement Learning
A new arXiv AI paper by Ondrej Bajgar, Peter Tisnikar, and Alessandro Abate, and 2 more studies Q-based Variational Inverse Reinforcement Learning.
arXiv AI/ML / 5:58 PM
arXiv paper: VidForensics-M1: Meta-Detection Reinforcement Learning with Verifiable Temporal Grounding for AI-Generated Video Forensics
A new arXiv AI paper by Bowei Liu, Zheng Lu, and Yuhan Bian, and 8 more studies VidForensics-M1: Meta-Detection Reinforcement Learning with Verifiable Temporal Grounding for AI-Generated Video Forensics.
arXiv AI/ML / 5:04 PM
arXiv paper: ResidencyRL: Reinforcement Learning in Simulated Clinical Environments
A new arXiv AI paper by Valentin Liévin, Samuel Schmidgall, and Tim Strother, and 32 more studies ResidencyRL: Reinforcement Learning in Simulated Clinical Environments.
arXiv AI/ML / 5:24 PM
arXiv paper: RRC: Unlocking Generative Reward Models in LLM Reinforcement Learning via Ranking-Based Reward Construction
A new arXiv AI paper by Chenglong Wang, Ziming Zhu, and Yifu Huo, and 9 more studies RRC: Unlocking Generative Reward Models in LLM Reinforcement Learning via Ranking-Based Reward Construction.
arXiv AI/ML / 5:44 PM
arXiv paper: Reward Structure Shapes the Interaction Between Episodic Exploration and Neural Memory in Reinforcement Learning
A new arXiv AI paper by Jai Malegaonkar, Rohan Patil, and Henrik I. Christensen studies Reward Structure Shapes the Interaction Between Episodic Exploration and Neural Memory in Reinforcement Learning.
YC AI / 7:49 PM
Riften launched from YC as an AI company
Riften is a Summer 2026 YC AI company: Earned Intelligence for every company.
arXiv AI/ML / 4:48 PM
arXiv paper: WCM: A World Critic Model for Vision-Language-Action Reinforcement Learning
A new arXiv AI paper by Senyu Fei, Xiaopeng Yu, and Siyin Wang, and 3 more studies WCM: A World Critic Model for Vision-Language-Action Reinforcement Learning.
YC AI / 6:01 PM
hiloop launched from YC as an AI company
hiloop is a Summer 2026 YC AI company: Infrastructure for recursive self-improvement.
arXiv AI/ML / 5:05 PM
arXiv paper: Physics-Aware End-to-End Deep Reinforcement Learning for Quadcopter Control with Actuator Dynamics
A new arXiv AI paper by Ya-Chia Shen and Woei-Leong Chan studies Physics-Aware End-to-End Deep Reinforcement Learning for Quadcopter Control with Actuator Dynamics.
Latest story in this edition: 5:54 PM
Back to front page