Automating ML for Science: Can Frontier Agents Climb Scientific Hills in the Wild?
Organizations: Anthropic Fellows Program · Anthropic
Abstract
Frontier coding agents are increasingly framed as end-to-end automated researchers, and ML for science offers a demanding test of that promise: improving a scientific model often requires domain insight beyond routine ML engineering. We introduce Agent4Sci, a long-horizon testbed for measuring how far today's agents can improve the published best models on scientific ML benchmarks, spanning 20 benchmarks across 11 domains. Rather than ranking agents on a leaderboard, Agent4Sci asks what kinds of progress agents can make on these tasks under in-the-wild conditions, and where they fall short. Empirically, today's frontier agents advance the published best on every benchmark, with Claude Opus reaching 10.4% mean relative improvement and no run flagged for academic misconduct. These gains, however, come almost entirely from a bag of ML-engineering tricks rather than research-level insight. Trajectory analysis surfaces three recurring limitations in this setting: novelty miscalibration, resource under-utilization, and rapid collapse into local engineering sweeps. Lightweight plug-in skills for research ideation, experiment management, and scheduled checklists raise Claude Opus from 10.4% to 20.1% and Codex from 4.4% to 8.1%, while yielding more diverse, domain-relevant interventions. Agent4Sci gives the community a way to track and push frontier agents from ML engineering toward domain insight on real-world ML-for-science problems. Code and data are available on GitHub (https://github.com/maszhongming/agent4sci) and Hugging Face (https://huggingface.co/datasets/MingZhong/agent4sci).
Figures & tables
| Benchmark | Domain | Task | Modality | Train Time | Best Agent | |
| ATAT [ 9 ] | Astronomy | Transient classification | Time series | 4.5 h 5 | Sonnet | 1.5 |
| [0.5pt/3pt] CarbonGlobe [ 60 ] | Ecology | Carbon forecasting | Time series | 4.5 h | Opus | 14.7 |
| [0.5pt/3pt] CheMixHub [ 46 ] | Chemistry | Olfactory similarity | Mixture | 3 min | ||
| Fuel octane (MON) | 1 min | |||||
| Polymer conductivity | 45 min | Gemini | 17.4 | |||
| [0.5pt/3pt] CosmoBench [ 20 ] | Cosmology | Cosmo regression | Tree | 20 min |
| Benchmarks | Metrics | Baseline | Claude Opus 4.6 | Opus + Skills | Codex (GPT-5.4) | Codex + Skills | ||||
| Abs. | % | Abs. | % | Abs. | % | Abs. | % | |||
| ATAT | Avg Macro F1 | 82.79 | 83.47 | 0.8 | 85.58 | 3.4 | 83.47 | 0.8 | 82.69 | -0.1 |
| CarbonGlobe | RMSE | 0.604 | 0.515 | 14.7 | 0.391 | 35.3 | 0.612 | -1.3 | 0.496 | 17.9 |
| CheMixHub | MAE | 1.679 | 1.388 | 11.9 | 1.338 | 23.1 | 1.506 | 15.4 | 1.439 | 16.7 |
| CosmoBench | R 2 /Acc | 0.604 | 0.631 | 4.8 | 0.643 | 6.9 | 0.627 | 3.0 | 0.643 | 7.7 |
| DART-Eval | Spearman | 0.544 | 0.577 | 6.1 | 0.598 | 9.9 | 0.547 | 0.6 | 0.551 | 1.3 |
Appendix figures & tables24 assets
Supplementary material from the paper’s appendix.
Appendix
| Benchmark | Paper Title | Venue |
| ATAT [ 9 ] | ATAT: Astronomical Transformer for Time Series and Tabular Data | Astronomy & Astrophysics 2024 |
| [0.5pt/3pt] CarbonGlobe [ 60 ] | CarbonGlobe: A Global-Scale, Multi-Decade Dataset and Benchmark for Carbon Forecasting in Forest Ecosystems | NeurIPS 2025 D & B |
| [0.5pt/3pt] CheMixHub [ 46 ] | CheMixHub: Datasets and Benchmarks for Chemical Mixture Property Prediction | NeurIPS 2025 D & B |
| [0.5pt/3pt] CosmoBench [ 20 ] | CosmoBench: A Multiscale, Multiview, Multitask Cosmology Benchmark for Geometric Deep Learning | NeurIPS 2025 D & B |
| [0.5pt/3pt] DART-Eval [ 42 ] | DART-Eval: A Comprehensive DNA Language Model Evaluation Benchmark on Regulatory DNA | NeurIPS 2024 D & B |
| [0.5pt/3pt] ESCAPE [ 39 ] | A Standardized Benchmark for Multilabel Antimicrobial Peptide Classification | NeurIPS 2025 D & B |
| Benchmark | Metric | Paper | Ours | Baseline Method |
| ATAT | Avg Macro F1 | 83.50 | 82.79 | ATAT, 5-fold CV |
| CarbonGlobe | RMSE | 0.571 | 0.604 | DeepED |
| CheMixHub | MAE | 1.638 | 1.679 | Best-per-task models, 5-fold CV |
| CosmoBench | R 2 /Acc | 0.604 | 0.604 | GNN, -NN, and velocity GNN baselines |
| DART-Eval | Spearman | 0.515 | 0.544 | Nucleotide Transformer with full fine-tuning |
| ESCAPE | mAP | 72.10 | 71.80 | ESCAPE, 2-fold CV 3 seeds |
| Benchmarks | Metrics | Baseline | Gemini 3.1 Pro | Codex (GPT-5.4) | Claude Sonnet 4.6 | Claude Opus 4.6 | ||||
| Abs. | % | Abs. | % | Abs. | % | Abs. | % | |||
| ATAT | Avg Macro F1 | 82.79 | 82.60 | -0.2 | 83.47 | 0.8 | 84.07 | 1.5 | 83.47 | 0.8 |
| CarbonGlobe | RMSE | 0.604 | 0.629 | -4.1 | 0.612 | -1.3 | 0.529 | 12.4 | 0.515 | 14.7 |
| CheMixHub | MAE | 1.679 | 1.355 | 17.4 | 1.506 | 15.4 | 1.439 | 8.9 | 1.388 | 11.9 |
| CosmoBench | R 2 /Acc | 0.604 | 0.630 | 3.1 | 0.627 | 3.0 | 0.625 | 2.3 | 0.631 | 4.8 |
| DART-Eval | Spearman | 0.544 | 0.547 | 0.6 | 0.547 | 0.6 | 0.591 | 8.6 | 0.577 | 6.1 |
| Unrestricted | Restricted | |||||
| Benchmark | Paper | Run 1 | Run 2 | Run 3 | Mean Std | HPO-only |
| ATAT | 0.8 | 0.5 | 0.9 | -0.3 | 0.5 0.5 | 0.2 |
| DART-Eval | 6.1 | 5.8 | 6.4 | 6.2 | 6.1 0.3 | 2.7 |
| TIDMAD | 7.4 | 7.7 | 7.1 | 7.8 | 7.5 0.3 | 3.5 |
| CheMixHub | 11.9 | 12.4 | 10.7 | 11.3 | 11.6 0.7 | 1.4 |
| Mars-Bench | 46.4 | 45.1 | 47.6 | 44.3 | 45.9 1.5 | 4.3 |
| Treatment of the reproduced baseline | Count | Benchmarks |
| Explicit HPO search (grid, random, or Bayesian) | 7 | CheMixHub, CosmoBench, GEO-Bench-2, Mars-Bench, MOTIVE, PFDelta, SR-CACO-2 |
| Tuned on validation | 3 | ATAT, MassSpecGym, ProteinGym (via marginal likelihood) |
| Fixed hyperparameters only | 10 | CarbonGlobe, DART-Eval, ESCAPE, GTPBD, LITHOS, NeuroGraph, TIDMAD, TreeFinder, UniSite, gRNAde |
| Claude Opus 4.6 + Skills | Codex (GPT-5.4) + Skills | |
| Experiments | 60 | 253 (of 1226 launched) |
| Approach | Switch to GNS-S, scale hidden dim 20 128, continued training with decreasing LR | CANOS-PF + SmoothL1 + PCGrad multi-task, then dense GPU Newton-Raphson with condition-aware adaptive step policy |
| Baseline PBL | 1.180 | 1.157 |
| Best PBL | 0.139 | 0.006 |
| Improvement | 88% | 99.5% |
| Batched latency | 3.3 ms/sample | 54 ms/sample (NN + NR) |
| Claude Opus 4.6 + Skills | Codex (GPT-5.4) + Skills | |
| Training experiments | 35 | 80–100 |
| [0.5pt/3pt] Approach | BPTT-SA curriculum autoregressive | 80–100 diverse architecture checkpoints |
| training: progressively train LSTM | (Informer, PatchTST, iTransformer, ), then | |
| on its own predictions to fix | cellwise additive greedy blending over 277 | |
| 40-year exposure bias | stages from 1449 candidate predictions | |
| [0.5pt/3pt] Improvement on val | 12% (0.604 0.531) | 37% (0.604 0.379, ensemble) |
AI Agents for Scientific Discovery
AI agents for scientific discovery use language models, tools, and experiments to generate, test, and refine scientific knowledge.
See all 284 papers