SpaceChem Bench: There's Something in the Fishcake

production_tutorial_2 Easy Multi-reactor production Multi-reactor Sernimir IV · SpaceChem Bench report →

Inputs: α Hydrogen (H), β Chlorine (Cl). Output: ψ Hydrochloric Acid (HCl) ×10. Features: Max reactors: 1.

In SpaceChem Bench, 16 LLMs each had one attempt at this SpaceChem puzzle, with 10 minutes to build a working solution and keep optimizing it, without seeing the community archive. 12 of 16 models solved it. No model found a new Pareto-frontier point beyond the frozen community archive.

12 / 16models solved it
412best LLM cycles (412 community)
0new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles412412GPT-6 Astra Ties record
Reactors11DeepSeek V4.1 Flash Ties record
Symbols1010Fable 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 AstraYes412110—
02Gemini 4 ArgonYes413110—
03GPT-6.1 SolYes414110—
04Opus 5.5Yes415110—
05Fable 5.1Yes418110—
06Sonnet 5.5Yes418114—
07Grok 4.7Yes440117—
08DeepSeek V4.1 FlashYes575120—
09Muse Wonder 1.0Yes654120—
10Kimi K3.1 ProYes728122—
11Muse Spark 1.3Yes819120—
12GPT-6 LunaYes888124—
13GLM-5.3No————
14Gemini 3.8 FlashNo————
15Haiku 5.5No————
16MiMo-V2.6-ProNo————

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.

GPT-6 Astra Fewest cyclesFewest reactors

412 cycles · 1 reactor · 14 symbolsproduction_tutorial_2.412-1-14.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↑ IN β GRAB DROP GRAB B+ DROP OUT ω IN α

Running in the game

GPT-6 Astra solution running on production_tutorial_2 in SpaceChem
SpaceChem Community Edition export (production_tutorial_2.412-1-14.txt)
SOLUTION:There's Something in the Fishcake,Player,0-0-0
COMPONENT:'drag-starter-reactor',17,5,''
MEMBER:'instr-start',0,0,128,5,5,0,0
MEMBER:'instr-start',-90,0,32,3,3,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'feature-bonder',-1,0,1,9,7,0,0
MEMBER:'instr-arrow',0,0,64,1,5,0,0
MEMBER:'instr-arrow',180,0,64,6,5,0,0
MEMBER:'instr-input',-1,1,128,1,5,0,0
MEMBER:'instr-grab',-1,1,128,2,5,0,0
MEMBER:'instr-grab',-1,2,128,6,5,0,0
MEMBER:'instr-arrow',90,0,16,1,1,0,0
MEMBER:'instr-arrow',0,0,16,1,4,0,0
MEMBER:'instr-arrow',180,0,16,3,1,0,0
MEMBER:'instr-arrow',-90,0,16,3,4,0,0
MEMBER:'instr-grab',-1,1,32,1,1,0,0
MEMBER:'instr-bond',-1,0,32,1,4,0,0
MEMBER:'instr-grab',-1,2,32,2,4,0,0
MEMBER:'instr-output',-1,1,32,3,1,0,0
MEMBER:'instr-input',-1,0,32,3,2,0,0
PIPE:0,4,1
PIPE:0,5,1
PIPE:0,5,2
PIPE:1,4,2
PIPE:1,5,2
COMPONENT:'drag-silo-input',6,8,''
PIPE:0,5,2
PIPE:0,5,1
PIPE:0,5,0
PIPE:0,5,-1
PIPE:0,5,-2
PIPE:0,6,-2
PIPE:0,7,-2
PIPE:0,8,-2
PIPE:0,9,-2
PIPE:0,10,-2
COMPONENT:'drag-silo-input',7,16,''
PIPE:0,5,2
PIPE:0,6,2
PIPE:0,6,1
PIPE:0,6,0
PIPE:0,6,-1
PIPE:0,6,-2
PIPE:0,6,-3
PIPE:0,6,-4
PIPE:0,6,-5
PIPE:0,6,-6
PIPE:0,7,-6
PIPE:0,7,-7
PIPE:0,8,-7
PIPE:0,9,-7
PIPE:0,9,-8
PIPE:0,9,-9

GPT-6 Astra Fewest symbols

648 cycles · 1 reactor · 10 symbolsproduction_tutorial_2.648-1-10.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 IN β B+ IN α OUT ω DROP

Running in the game

GPT-6 Astra solution running on production_tutorial_2 in SpaceChem
SpaceChem Community Edition export (production_tutorial_2.648-1-10.txt)
SOLUTION:There's Something in the Fishcake,Player,0-0-0
COMPONENT:'drag-starter-reactor',17,5,''
MEMBER:'instr-start',180,0,128,4,1,0,0
MEMBER:'instr-start',180,0,32,0,0,0,0
MEMBER:'feature-bonder',-1,0,1,1,4,0,0
MEMBER:'feature-bonder',-1,0,1,1,5,0,0
MEMBER:'feature-bonder',-1,0,1,0,7,0,0
MEMBER:'feature-bonder',-1,0,1,9,7,0,0
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',-90,0,64,6,4,0,0
MEMBER:'instr-grab',-1,1,128,1,1,0,0
MEMBER:'instr-input',-1,1,128,1,3,0,0
MEMBER:'instr-bond',-1,0,128,1,4,0,0
MEMBER:'instr-input',-1,0,128,2,1,0,0
MEMBER:'instr-output',-1,1,128,6,3,0,0
MEMBER:'instr-grab',-1,2,128,6,4,0,0
PIPE:0,4,1
PIPE:0,5,1
PIPE:0,5,2
PIPE:1,4,2
PIPE:1,5,2
COMPONENT:'drag-silo-input',6,8,''
PIPE:0,5,2
PIPE:0,5,1
PIPE:0,5,0
PIPE:0,5,-1
PIPE:0,5,-2
PIPE:0,6,-2
PIPE:0,7,-2
PIPE:0,8,-2
PIPE:0,9,-2
PIPE:0,10,-2
COMPONENT:'drag-silo-input',7,16,''
PIPE:0,5,2
PIPE:0,6,2
PIPE:0,6,1
PIPE:0,6,0
PIPE:0,6,-1
PIPE:0,6,-2
PIPE:0,6,-3
PIPE:0,6,-4
PIPE:0,6,-5
PIPE:0,6,-6
PIPE:0,7,-6
PIPE:0,7,-7
PIPE:0,8,-7
PIPE:0,9,-7
PIPE:0,9,-8
PIPE:0,9,-9