SpaceChem Bench: An Introduction to Sensing

sensing_1 Medium Sensing Single-reactor Alkonost Random inputs · SpaceChem Bench report →

Random inputs: α Neon (Ne) / Argon (Ar). Output: ψ Neon (Ne) ×10, ω Argon (Ar) ×10. Features: Bonders (4), Sensor, Random inputs.

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 40 minutes to build a working solution and keep optimizing it, without seeing the community archive. 16 of 16 models solved it. Together they found 2 new Pareto-frontier points beyond the frozen community archive.

16 / 16models solved it
136best LLM cycles (136 community)
2new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles136136Gemini 4 Argon Ties record
Reactors11DeepSeek V4.1 Flash Ties record
Symbols1111Fable 5.1 Ties record

Community records from the community archive when we froze it on October 18, 2026. A point counts only after fresh-game replay and SChem’s precognition check.

Pareto frontier

Pareto explorer

Lower is better ↙
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Community archiveModel frontier pointNew frontier point
Select a point with the mouse or keyboard to inspect its scores and reactor blueprint.

Search over time

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Every model

ModelSolvedBest cyclesBest reactorsBest symbolsNew frontier points
01GPT-6 AstraYes1371112
02GPT-6.1 SolYes1371111
03Sonnet 5.5Yes1371111
04Gemini 4 ArgonYes136111—
05Fable 5.1Yes137111—
06Kimi K3.1 ProYes137111—
07Muse Wonder 1.0Yes137111—
08Opus 5.5Yes137111—
09Gemini 3.8 FlashYes156111—
10Grok 4.7Yes156113—
11GLM-5.3Yes159113—
12DeepSeek V4.1 FlashYes160112—
13Muse Spark 1.3Yes167113—
14Haiku 5.5Yes197116—
15MiMo-V2.6-ProYes296111—
16GPT-6 LunaYes314112—

Best scores can come from different solutions. New frontier points are not matched or beaten on all three scores by any community solution.

Best model solutions

These solutions are in SpaceChem Community Edition export format and released under the MIT License. All of this puzzle’s model solutions are on GitHub and Hugging Face.

Gemini 4 Argon Fewest cycles

136 cycles · 1 reactor · 27 symbolssensing_1.136-1-27.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 → ↑ → ↓ ← ↑ → ↑ → ↓ ← ↑ S↑ S→ G/D G/D IN α IN α IN α ?Ar↓ ?Ar↓ DROP DROP OUT ψ OUT ψ OUT ω OUT ω DROP DROP

Running in the game

Gemini 4 Argon solution running on sensing_1 in SpaceChem
SpaceChem Community Edition export (sensing_1.136-1-27.txt)
SOLUTION:An Introduction to Sensing,Player,0-0-0
COMPONENT:'drag-advanced-reactor',2,0,''
MEMBER:'instr-start',-90,0,128,1,4,0,0
MEMBER:'instr-start',0,0,32,0,1,0,0
MEMBER:'feature-sensor',-1,0,1,5,1,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'feature-bonder',-1,0,1,9,7,0,0
MEMBER:'feature-bonder',-1,0,1,4,7,0,0
MEMBER:'feature-bonder',-1,0,1,6,7,0,0
MEMBER:'instr-arrow',0,0,64,1,1,0,0
MEMBER:'instr-arrow',-90,0,64,1,2,0,0
MEMBER:'instr-arrow',0,0,64,5,4,0,0
MEMBER:'instr-arrow',90,0,64,6,1,0,0
MEMBER:'instr-arrow',180,0,64,6,2,0,0
MEMBER:'instr-arrow',-90,0,64,6,4,0,0
MEMBER:'instr-grab',-1,0,128,1,1,0,0
MEMBER:'instr-input',-1,0,128,1,2,0,0
MEMBER:'instr-input',-1,0,128,1,3,0,0
MEMBER:'instr-sensor',90,0,128,5,1,0,18
MEMBER:'instr-grab',-1,2,128,6,1,0,0
MEMBER:'instr-output',-1,0,128,6,2,0,0
MEMBER:'instr-output',-1,1,128,6,3,0,0
MEMBER:'instr-grab',-1,2,128,6,4,0,0
MEMBER:'instr-arrow',0,0,16,1,1,0,0
MEMBER:'instr-arrow',-90,0,16,1,2,0,0
MEMBER:'instr-arrow',0,0,16,5,4,0,0
MEMBER:'instr-arrow',90,0,16,6,1,0,0
MEMBER:'instr-arrow',180,0,16,6,2,0,0
MEMBER:'instr-arrow',-90,0,16,6,4,0,0
MEMBER:'instr-grab',-1,0,32,1,1,0,0
MEMBER:'instr-input',-1,0,32,1,2,0,0
MEMBER:'instr-sensor',90,0,32,5,1,0,18
MEMBER:'instr-grab',-1,2,32,6,1,0,0
MEMBER:'instr-output',-1,0,32,6,2,0,0
MEMBER:'instr-output',-1,1,32,6,3,0,0
MEMBER:'instr-grab',-1,2,32,6,4,0,0

Opus 5.5 Fewest reactors

137 cycles · 1 reactor · 24 symbolssensing_1.137-1-24.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 ↓ → ← ↑ ↑ ↓ → ← ↑ ↑ S← S← GRAB GRAB ?Ne→ ?Ne→ IN α IN α OUT ψ OUT ψ DROP DROP OUT ω OUT ω DROP DROP

Running in the game

Opus 5.5 solution running on sensing_1 in SpaceChem
SpaceChem Community Edition export (sensing_1.137-1-24.txt)
SOLUTION:An Introduction to Sensing,Player,0-0-0
COMPONENT:'drag-advanced-reactor',2,0,''
MEMBER:'instr-start',180,0,32,5,1,0,0
MEMBER:'instr-start',180,0,128,3,1,0,0
MEMBER:'feature-bonder',-1,0,1,7,6,0,0
MEMBER:'feature-bonder',-1,0,1,8,6,0,0
MEMBER:'feature-bonder',-1,0,1,8,7,0,0
MEMBER:'feature-bonder',-1,0,1,9,7,0,0
MEMBER:'feature-sensor',-1,0,1,1,2,0,0
MEMBER:'instr-arrow',90,0,64,1,1,0,0
MEMBER:'instr-arrow',0,0,64,1,4,0,0
MEMBER:'instr-arrow',180,0,64,6,1,0,0
MEMBER:'instr-arrow',-90,0,64,6,2,0,0
MEMBER:'instr-arrow',-90,0,64,6,4,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-sensor',0,0,128,1,2,0,10
MEMBER:'instr-input',-1,0,128,2,1,0,0
MEMBER:'instr-output',-1,0,128,6,1,0,0
MEMBER:'instr-grab',-1,2,128,6,2,0,0
MEMBER:'instr-output',-1,1,128,6,3,0,0
MEMBER:'instr-grab',-1,2,128,6,4,0,0
MEMBER:'instr-arrow',90,0,16,1,1,0,0
MEMBER:'instr-arrow',0,0,16,1,4,0,0
MEMBER:'instr-arrow',180,0,16,6,1,0,0
MEMBER:'instr-arrow',-90,0,16,6,2,0,0
MEMBER:'instr-arrow',-90,0,16,6,4,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-sensor',0,0,32,1,2,0,10
MEMBER:'instr-input',-1,0,32,2,1,0,0
MEMBER:'instr-output',-1,0,32,6,1,0,0
MEMBER:'instr-grab',-1,2,32,6,2,0,0
MEMBER:'instr-output',-1,1,32,6,3,0,0
MEMBER:'instr-grab',-1,2,32,6,4,0,0

GPT-6.1 Sol Fewest symbols

236 cycles · 1 reactor · 11 symbolssensing_1.236-1-11.txt on GitHub

Layout

α β ψ ω 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 ↑ → ← S↑ S↓ ?Ar↓ G/D DROP OUT ω DROP IN α GRAB OUT ψ

Running in the game

GPT-6.1 Sol solution running on sensing_1 in SpaceChem
SpaceChem Community Edition export (sensing_1.236-1-11.txt)
SOLUTION:An Introduction to Sensing,Player,0-0-0
COMPONENT:'drag-advanced-reactor',2,0,''
MEMBER:'instr-start',-90,0,128,6,2,0,0
MEMBER:'instr-start',90,0,32,0,0,0,0
MEMBER:'feature-sensor',-1,0,1,6,1,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'feature-bonder',-1,0,1,9,7,0,0
MEMBER:'feature-bonder',-1,0,1,4,7,0,0
MEMBER:'feature-bonder',-1,0,1,6,7,0,0
MEMBER:'instr-arrow',-90,0,64,6,4,0,0
MEMBER:'instr-sensor',90,0,128,6,0,0,18
MEMBER:'instr-grab',-1,0,128,6,1,0,0
MEMBER:'instr-output',-1,1,128,6,3,0,0
MEMBER:'instr-grab',-1,2,128,6,4,0,0
MEMBER:'instr-arrow',0,0,16,0,1,0,0
MEMBER:'instr-arrow',180,0,16,6,1,0,0
MEMBER:'instr-input',-1,0,32,0,1,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-output',-1,0,32,5,1,0,0
MEMBER:'instr-grab',-1,2,32,6,1,0,0