CEO @bespokelabsai. RL/Envs/Posttraining/Agents. Created Generative Retrieval at @GoogleDeepMind.

Inside an RL Env
AutoResearch is critical in unlocking new knowledge and accelerate discovery. And it's an important ingredient in our quest to RSI. Today we at @bespokelabsai are happy to announce a new benchmark that's tailored to measure agents' ability to do autoresearch: AutoResearchExam. As part of this benchmark, we release 29 tasks that measure progress over 24 hours for agents to do sustained ML research and model training. Please check out for more info: benchmarks.bespokelabs.ai/au… This line of work is especially timely, given the recent advances in math and science, such as solving the Navier-Stokes Millennium Prize Problem, which needs sustained autoresearch and test-time scaling.
We are releasing AutoResearchExam, a benchmark on open-ended machine learning and engineering tasks. Our benchmark covers seven research areas including model training, data curation, AI safety and interpretability. benchmarks.bespokelabs.ai/au… In each task, we give agents 24 hours with a CPU or GPU machine to develop and improve their solutions through experiments and feedback. We measure both speed and quality with a combined score. Our benchmark has a unique feature: testing if agents create improvements that hold up on data they never see. We find that AI research agents often overfit as they try to improve. We see an interesting head-to-head comparison at the frontier: Astra starts the strongest and holds the lead for up to 19 hours but Fable 5.1 catches up and gets the top performing spot in the final hours. Qwen3.8 Max, Gemini 3.8 Flash and Grok 4.6 all sit on the cost-performance Pareto frontier, giving strong options at lower API budgets. Anthropic's Opus and Fable retain nearly all their validation performance on hidden tests, with gaps of 1.1% and 2.9%. Astra's improvement over Sol extends to generalization too, with that gap falling from 6.9% to 1.7%. (1/n)
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Mahesh Sathiamoorthy retweeted
"Additionally: ~40% of the issues found were already tracked in the upstream repo - including 21 tasks with outstanding fix PRs!" Bespoke has found several issues using our internal QC agent, and has been working on improving Terminal Bench over the months. Here are the 25 issues we filed, and there are PRs corresponding to them. A subset of these were what @EpochAIResearch also used in their report: epoch.ai/benchmarks/terminal… All of this shows that building RL envs is hard, and building a benchmark is harder github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… and more below
The @SnorkelAI team did an audit of these findings using our internal QC platform. Tl/dr: We agree with many of the findings, but ~55% of the fixes from @preferencemodel had their own issues with reward hacking or over-prescriptiveness. Additionally: ~40% of the issues found were already tracked in the upstream repo - including 21 tasks with outstanding fix PRs! Building datasets like this - and maintaining ambitious open benchmarks around them - is hard. We believe it requires open, collaborative review with community maintainers and relevant domain experts to get right. @terminalbench was one of the first community efforts to build an open, continuous benchmark, and drive a vision of how OSS contributes to the rapidly advancing frontier of AI. We hope that the community will invest in working collaboratively with benchmark maintainers and task authors to keep this vision alive. --- Some takeaways + details of our preliminary audit: (1) We confirm 100% of the reward hacking / verification gap findings using our QC system. However, we find that 17/44 (39%) of the corrected tasks are just as or more reward hackable. Additionally, we don’t yet see evidence that these verification gaps meaningfully affected benchmark rollouts within CIs, though our analysis here is still ongoing. (2) Our preliminary review raises questions about the underspecification findings for 22/41 (54%) of the flagged tasks, including 7 explicitly marked by task authors as intentional design choices. These cases warrant expert peer review and adjudication: balancing over/under-specification is a critical and tricky design decision - much of human intelligence concerns dealing correctly with reasonable and realistic underspecification - and we believe these corrections made to the tasks are likely too over-specified, reducing realism and difficulty relative to spec. (3) Around 40% of the issues found were already tracked in the upstream repo (including 21 tasks with outstanding fix PRs)! OSS projects require community efforts to correct identified open issues, and ideally audits like these are done collaboratively with task authors and maintainers directly, in the traditional community spirit that has kept OSS alive for decades.
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Love this!
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"Additionally: ~40% of the issues found were already tracked in the upstream repo - including 21 tasks with outstanding fix PRs!" Bespoke has found several issues using our internal QC agent, and has been working on improving Terminal Bench over the months. Here are the 25 issues we filed, and there are PRs corresponding to them. A subset of these were what @EpochAIResearch also used in their report: epoch.ai/benchmarks/terminal… All of this shows that building RL envs is hard, and building a benchmark is harder github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… github.com/harbor-framework/… -> github.com/harbor-framework/… and more below
The @SnorkelAI team did an audit of these findings using our internal QC platform. Tl/dr: We agree with many of the findings, but ~55% of the fixes from @preferencemodel had their own issues with reward hacking or over-prescriptiveness. Additionally: ~40% of the issues found were already tracked in the upstream repo - including 21 tasks with outstanding fix PRs! Building datasets like this - and maintaining ambitious open benchmarks around them - is hard. We believe it requires open, collaborative review with community maintainers and relevant domain experts to get right. @terminalbench was one of the first community efforts to build an open, continuous benchmark, and drive a vision of how OSS contributes to the rapidly advancing frontier of AI. We hope that the community will invest in working collaboratively with benchmark maintainers and task authors to keep this vision alive. --- Some takeaways + details of our preliminary audit: (1) We confirm 100% of the reward hacking / verification gap findings using our QC system. However, we find that 17/44 (39%) of the corrected tasks are just as or more reward hackable. Additionally, we don’t yet see evidence that these verification gaps meaningfully affected benchmark rollouts within CIs, though our analysis here is still ongoing. (2) Our preliminary review raises questions about the underspecification findings for 22/41 (54%) of the flagged tasks, including 7 explicitly marked by task authors as intentional design choices. These cases warrant expert peer review and adjudication: balancing over/under-specification is a critical and tricky design decision - much of human intelligence concerns dealing correctly with reasonable and realistic underspecification - and we believe these corrections made to the tasks are likely too over-specified, reducing realism and difficulty relative to spec. (3) Around 40% of the issues found were already tracked in the upstream repo (including 21 tasks with outstanding fix PRs)! OSS projects require community efforts to correct identified open issues, and ideally audits like these are done collaboratively with task authors and maintainers directly, in the traditional community spirit that has kept OSS alive for decades.
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Gemini has improved quite a bit for autoresearch/ RSI with Argon. Congrats!
We added Gemini 4 Argon to our AutoResearchExam Pareto curve. It is 2-3 times cheaper compared to the other frontier models for almost the same ML engineering performance. Congratulations to the GDM team.
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Very cool work by Pref model! We have an internal QA system which has been finding issues as well, and we have submitted several fixes to Terminal Bench so that Terminal Bench continues to improve. This story is not just for Terminal Bench, wink wink.
We looked at TerminalBench 4.0 and found a lot of issues. After fixing the issues Sonnet 5.5 scores 89.2%. So, TerminalBench is already mostly saturated. Along the way we found a lot of crazy stuff, including reward hacks in the published transcripts.
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Garden harvest. Lots and lots of tomatoes this time. The tomato plant needed a harness..
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People outside the labs don't know the numbers, but here's what people believe: * GPT 3.5 was around 175B * Largest models today are getting to 10T, if not already this size. So it went up by 50x in 3 years. So we could hit 100T params by 2030, and that's a serious model size, which has many many ramifications for so many things (pre-training, post-training, rl envs, data centers, software industry, cyber security, and the society at large).
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Mahesh Sathiamoorthy retweeted
We are excited to announce that we post-trained NVIDIA Nemotron-3.5-Super-VL to be an autonomous ML researcher. We show that our post-trained model goes from 28% to 35% on AutoResearchExam, matching Qwen 3.8 Max, a model with 20× the total parameters. The tasks are long horizon, open ended AI and ML research: building a faster executor for a transformer compute graph, training a RL control policy, creating new uncertainty quantification methods, etc. The model gets to submit once, and it doesn't see its score until the end. We curated SFT data using Self-context distillation. This means that we let the Nemotron model to solve a problem with hints, then we SFT on these trajectories but without the hints. This gave us +11% on AutoResearchExam. As a next step, we added reflection: We ask the Nemotron model to review its own past attempts and writes concrete lessons learned. Then we SFT on these reflections. Surprisingly, training on these lessons improved the performance to +25% compared to the base model. The hardest part was choosing the right data. We selected traces based on task scores, completion checks, and runtime, then refined the sampling across training rounds to address failures in the base and fine-tuned models. We removed hints and filtered out steps that relied on information available only in those hints. The goal was to teach decisions supported by the task and history the model would actually see at inference. Full write-up: bespokelabs.ai/blog/teaching… Thanks to @NVIDIAAI for early access and collaborating on this.
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Mahesh Sathiamoorthy retweeted
We developed a model reaching frontier-level multimodal performance, matching or exceeding Astra on 5 of 12 benchmarks, all with 17x lower token prices. The model is smaller and cheaper than Gemini 3.8 Flash while dominating it in real world vision workloads. We achieved this by inventing a technique for visual reasoning, where the model is no longer restricted to text chain-of-thought. Conditioned on visual tokens, Glimpse can perform recurrent computation over latent internal representations and can even orchestrate subagents that send messages over internal visual states. Really proud of what our small team and only hundreds of GPUs could accomplish. elorian.ai/blog/introducing-…
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We at @bespokelabsai have a solid blog post for you guys with details on how to train a model towards becoming an autonomous ML researcher. We curated high quality RL envs and used some new post-training techniques to improve Nemotron Super to be as good as a model 20x the size. Details: bespokelabs.ai/blog/teaching… We partnered with @NVIDIAAI for this work: developer.nvidia.com/blog/nv…
We are excited to announce that we post-trained NVIDIA Nemotron-3.5-Super-VL to be an autonomous ML researcher. We show that our post-trained model goes from 28% to 35% on AutoResearchExam, matching Qwen 3.8 Max, a model with 20× the total parameters. The tasks are long horizon, open ended AI and ML research: building a faster executor for a transformer compute graph, training a RL control policy, creating new uncertainty quantification methods, etc. The model gets to submit once, and it doesn't see its score until the end. We curated SFT data using Self-context distillation. This means that we let the Nemotron model to solve a problem with hints, then we SFT on these trajectories but without the hints. This gave us +11% on AutoResearchExam. As a next step, we added reflection: We ask the Nemotron model to review its own past attempts and writes concrete lessons learned. Then we SFT on these reflections. Surprisingly, training on these lessons improved the performance to +25% compared to the base model. The hardest part was choosing the right data. We selected traces based on task scores, completion checks, and runtime, then refined the sampling across training rounds to address failures in the base and fine-tuned models. We removed hints and filtered out steps that relied on information available only in those hints. The goal was to teach decisions supported by the task and history the model would actually see at inference. Full write-up: bespokelabs.ai/blog/teaching… Thanks to @NVIDIAAI for early access and collaborating on this.
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Mahesh Sathiamoorthy retweeted
Official documentation from Google for MaxText (library for training/inferencing on TPUs) features Nimble. maxtext.readthedocs.io/en/la…
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Mahesh Sathiamoorthy retweeted
We’re giving away $1 million to agents. Introducing Composio Instant: the easiest way for agents to pay for their own tools. Claim your agent's share: composio.dev/instant
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Today, we are announcing Nimble-v4 and Nimble-v4-max which are pushing the frontier of decision models, outperforming Jev and other variants. On the Decision Index public scores, nimble-v4-max and nimble-v4 score +10 and +6 against Jev 1.13, making nimble-v4-max the #1 model. Beyond benchmarks, we have done a lot of internal evals, and see meaningful improvements: 43% fewer mistakes than Jev, 50pp improvement on model routing decisions, being great at coding use cases, fact checking etc. The models are available via our API service. Go build nimbly: console.bespokelabs.ai
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We at @bespokelabsai have moved nimbly in the past few weeks and made substantial improvements in data curation and modeling techniques, allowing us to push the frontier. This journey will continue. Please try out, give us feedback, and refer your friends (and get credits)! console.bespokelabs.ai docs.bespokelabs.ai And oh, no paid promotions, so please help amplify 😅
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Nimble-v4 is 9B and it beats several other models that are much larger.
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