SlowLab: Benchmarking Autonomous AI Agents on a Year of Experiments They Cannot Undo
Organizations: College of Informatics, Huazhong Agricultural University
Abstract
AI agents are increasingly proposed as autonomous experimenters, yet the benchmarks that test them mostly offer cheap experiments that answer at once. Experiments in physical facilities are different: they take months, occupy scarce equipment and cannot be undone. We present SlowLab, a benchmark in which an agent runs a one-year campaign in four simulated greenhouse compartments on a site whose crop, facility and prices are hidden. The agent decides when to plant which climate policy, whether to stop a crop and which measurements to read while crops grow, and at the end recommends one policy, which a private evaluator scores in weather the agent never saw. In a preregistered study on 48 unseen sites, three low-cost language-model agents ended near a standard grower setting and clearly below a Bayesian-optimisation baseline that starts from that setting. They ran the facility as two synchronous batches, so measurements taken during the season never changed what they planted, and these measurements improved no method's result. Letting other methods re-read the evidence a campaign had collected did not yield significantly better recommendations, which points to where the models start and which experiments they try. Code is released under the MIT license.
Figures & tables
| Delayed | Irrevers- | Parallel | Mid-run | Hidden | Unseen-con- | Non-LLM | Pre- | |
| outcomes | ible | units | signals | instance | dition score | baseline | registered | |
| BoxingGym ( Gandhi et al., 2025 ) | – | – | – | – | ✓ | – | ||
| SciGym ( Duan et al., 2025 ) | – | – | – | – | ✓ | ✓ | – | – |
| CARE ( Liu et al., 2026 ) | – | – | – | – | – | ✓ | ||
| LLMs for BO ( Gupta et al., 2025 ) | – | – | – | – | ✓ | – | ||
| Vending-Bench ( Backlund and Petersson, 2025 ) | ✓ | ✓ | – | – |
| Method | Full | Endpoint | Pre-experiment |
|---|---|---|---|
| Prior-informed local BO (baseline) | 33.62 | 34.34 | – |
| GLM-5.3 Flash | 29.62 | 30.38 | 28.35 |
| MiMo V2.6 Flash | 28.90 | 29.24 | 26.86 |
| DeepSeek V4.1 Flash | 28.02 | 28.31 | 25.36 |
| Fixed reference (no experiments) | 29.34 | 29.34 | 29.34 |
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
| Test | Original | Corrected |
|---|---|---|
| E1 DeepSeek baseline | 3.09 [ 4.35, 1.80], 0.001 | 5.60 [ 6.91, 4.00], 0.001 |
| E1 GLM baseline | 1.43 [ 2.93, 0.03], 0.29 | 3.99 [ 5.34, 2.41], 0.001 |
| E1 MiMo baseline | 2.05 [ 3.57, 0.72], 0.044 | 4.71 [ 6.39, 3.23], 0.001 |
| E2 DeepSeek Full Endpoint | 0.30 [ 1.07, +0.29], 1.00 | 0.30 [ 1.07, +0.29], 0.81 |
| E2 GLM Full Endpoint | 0.71 [ 1.49, +0.03], 0.32 | 0.76 [ 1.61, +0.11], 0.39 |
| E2 MiMo Full Endpoint | 0.19 [ 1.74, +0.65], 1.00 | 0.34 [ 1.88, +0.49], 0.81 |
| Day | Action | Stated reason |
|---|---|---|
| 0 | advance to day 10 | Let the crops establish before reading climate and canopy data. |
| 10 | observe (2 channels) | Check climate tracking in compartment 0 so far. |
| 30–120 | observe, advance (9 steps) | Check canopy growth progress toward maturity. |
| 150 | advance to day 180 | Let the baseline crops finish their 180-day cycle so totals are released. |
| 180 | runs, observe (4 steps) | Get accrued resources and contribution margin for the two completed baseline crops. |
| 180 | start (C3, C4; 2 steps) | Now let me explore a more aggressive policy in compartments 2 and 3, and start planning. |
| Element | Specification | Basis |
|---|---|---|
| Facility | 4 independent compartments of 96 m 2 ; GreenLight fa502ed ; Cabauw weather | simulator; audited weather |
| Calendar | 365-day campaign; crop 180 d; cleaning 2 d; last start day 183; control step 300 s | benchmark design |
| Policy | day 18–26 ∘ C; night 15–22 ∘ C ( day); CO 2 400–1200 ppm; light 0–16 h; vent offset 2–6 ∘ C; RH limit 70–90% | design bounds |
| Actions | start, stop (crop discarded), advance, observe, recommend; analysis tools incl. process predictor | benchmark design |
| Observations | air temperature, RH, CO 2 , canopy LAI proxy; cumulative harvest, heat, light, CO 2 dosing; every 300 s | sensor noise v0 (assumed) |
| Feedback | Full: all records at any time; Endpoint: status while running, totals at close | experimental factor (E2) |