SpaceChem Bench: Like a Boss

mining_2 Medium Bonding & routing Single-reactor Hephaestus IV · SpaceChem Bench report →

Inputs: α Hydrogen (H), β Carbon (C). Output: ψ Methane (CH4) ×10. Features: Bonders (2).

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. 9 of 16 models solved it. Together they found 1 new Pareto-frontier point beyond the frozen community archive.

9 / 16models solved it
199best LLM cycles (152 community)
1new frontier point

Records

ScoreCommunity bestBest LLMModel
Cycles152199Opus 5.5 · +31%
Reactors11Fable 5.1 Ties record
Symbols1821GPT-6.1 Sol · +17%

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

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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-6.1 SolYes2541211
02Opus 5.5Yes199128—
03Sonnet 5.5Yes210128—
04GPT-6 AstraYes334122—
05Gemini 4 ArgonYes447121—
06Fable 5.1Yes455128—
07Gemini 3.8 FlashYes633135—
08Muse Wonder 1.0Yes728134—
09Kimi K3.1 ProYes729134—
10DeepSeek V4.1 FlashNo————
11GLM-5.3No————
12GPT-6 LunaNo————
13Grok 4.7No————
14Haiku 5.5No————
15MiMo-V2.6-ProNo————
16Muse Spark 1.3No————

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.

Opus 5.5 Fewest cyclesFewest reactors

199 cycles · 1 reactor · 29 symbolsmining_2.199-1-29.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→ CW IN α B+ B+ IN α CW SYNC GRAB IN β CW DROP GRAB IN α SYNC IN α DROP OUT ψ

Running in the game

Opus 5.5 solution running on mining_2 in SpaceChem
SpaceChem Community Edition export (mining_2.199-1-29.txt)
SOLUTION:Like a Boss,Player,0-0-0
COMPONENT:'drag-reduced-reactor',2,0,''
MEMBER:'instr-start',180,0,128,2,6,0,0
MEMBER:'instr-start',0,0,32,0,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,2,0,0
MEMBER:'instr-arrow',90,0,64,0,1,0,0
MEMBER:'instr-arrow',0,0,64,0,2,0,0
MEMBER:'instr-arrow',180,0,64,1,1,0,0
MEMBER:'instr-arrow',-90,0,64,1,6,0,0
MEMBER:'instr-arrow',90,0,64,3,2,0,0
MEMBER:'instr-arrow',180,0,64,3,6,0,0
MEMBER:'instr-rotate',-1,0,128,0,1,0,0
MEMBER:'instr-input',-1,0,128,0,2,0,0
MEMBER:'instr-bond',-1,0,128,1,2,0,0
MEMBER:'instr-input',-1,0,128,1,3,0,0
MEMBER:'instr-sync',-1,0,128,1,4,0,0
MEMBER:'instr-grab',-1,1,128,1,5,0,0
MEMBER:'instr-input',-1,1,128,1,6,0,0
MEMBER:'instr-rotate',-1,0,128,2,2,0,0
MEMBER:'instr-grab',-1,2,128,3,2,0,0
MEMBER:'instr-arrow',90,0,16,0,2,0,0
MEMBER:'instr-arrow',0,0,16,0,3,0,0
MEMBER:'instr-arrow',0,0,16,1,1,0,0
MEMBER:'instr-arrow',-90,0,16,1,3,0,0
MEMBER:'instr-arrow',90,0,16,7,1,0,0
MEMBER:'instr-arrow',180,0,16,7,2,0,0
MEMBER:'instr-input',-1,0,32,0,3,0,0
MEMBER:'instr-bond',-1,0,32,1,2,0,0
MEMBER:'instr-rotate',-1,0,32,1,3,0,0
MEMBER:'instr-sync',-1,0,32,2,1,0,0
MEMBER:'instr-grab',-1,1,32,3,2,0,0
MEMBER:'instr-input',-1,0,32,4,2,0,0
MEMBER:'instr-grab',-1,2,32,7,1,0,0
MEMBER:'instr-output',-1,0,32,7,2,0,0

GPT-6.1 Sol Fewest symbols

322 cycles · 1 reactor · 21 symbolsmining_2.322-1-21.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← CW IN α CW GRAB DROP IN α GRAB IN α CW IN β DROP OUT ψ B+

Running in the game

GPT-6.1 Sol solution running on mining_2 in SpaceChem
SpaceChem Community Edition export (mining_2.322-1-21.txt)
SOLUTION:Like a Boss,Player,0-0-0
COMPONENT:'drag-reduced-reactor',2,0,''
MEMBER:'instr-start',180,0,128,3,5,0,0
MEMBER:'instr-start',180,0,32,1,0,0,0
MEMBER:'feature-bonder',-1,0,1,1,1,0,0
MEMBER:'feature-bonder',-1,0,1,1,2,0,0
MEMBER:'instr-arrow',0,0,64,0,1,0,0
MEMBER:'instr-arrow',-90,0,64,0,3,0,0
MEMBER:'instr-arrow',0,0,64,1,0,0,0
MEMBER:'instr-arrow',-90,0,64,1,5,0,0
MEMBER:'instr-arrow',90,0,64,2,0,0,0
MEMBER:'instr-arrow',180,0,64,2,3,0,0
MEMBER:'instr-arrow',90,0,64,7,1,0,0
MEMBER:'instr-arrow',180,0,64,7,5,0,0
MEMBER:'instr-input',-1,0,128,0,2,0,0
MEMBER:'instr-rotate',-1,0,128,0,3,0,0
MEMBER:'instr-rotate',-1,0,128,1,0,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-grab',-1,2,128,1,2,0,0
MEMBER:'instr-input',-1,0,128,1,3,0,0
MEMBER:'instr-grab',-1,1,128,1,5,0,0
MEMBER:'instr-input',-1,0,128,2,2,0,0
MEMBER:'instr-rotate',-1,0,128,2,3,0,0
MEMBER:'instr-input',-1,1,128,2,5,0,0
MEMBER:'instr-grab',-1,2,128,6,1,0,0
MEMBER:'instr-output',-1,0,128,7,1,0,0
MEMBER:'instr-bond',-1,0,32,0,0,0,0