Hi Product Hunt! I'm Key, solo founder from China. Most founders ask ChatGPT "will my product succeed?" and get a polite "yes." That's useless. So I built MarketFish — a multi-agent market simulator. Instead of asking ONE LLM, it deploys 128 AI consumers with different identities, budgets, emotions, and biases. They shop across 30 rounds. Their purchase decisions, churn patterns, and social influence tell you what real users might do. How it works: Seed data (8 real-time sources — GitHub, HN, Product Hunt, World Bank, China retail, etc.) 128 AI agents generated across 6 LLMs (DeepSeek, Qwen, OpenAI, Anthropic, etc.) 30 rounds of market simulation with coupling, RL adaptation, memory Evidence report — who bought, why, what killed competitors What we found running it: With real data showing consumer spending -0.6% YoY, only 1 out of 7 product directions survived — a Pinduoduo-style group-buy AI platform. Everything else died. The market is brutal, and MarketFish showed exactly why. Built on 6 papers: Generative Agents (UIST 2023), OASIS (2025), TwinMarket (NeurIPS 2025), Agent Bazaar (Princeton 2026), EconSimulacra (2026), SMIF (ETASR 2026) Open source, MIT. 11 LLM providers. Chinese/English. 3 minutes to run: git clone → pip install → streamlit run Happy to answer questions!

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p/marketfish

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9h ago

Hi hunters! Solo founder here — AMA about building a market simulator with 128 AI shoppers 🐟

Hi hunters! I'm Key, solo founder of MarketFish.

I built this because I was tired of guessing whether a product would succeed. MarketFish simulates 128 AI consumers with real budgets, emotions, and biases they shop for 30 rounds, and their purchase data tells you what real users would do.

Today's simulation top pick: an auto-haggle app consumers in a downturn love saving money.

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MarketFish

Don't guess. Simulate.

Don't guess. Simulate.

Forum Threads

Hi hunters! Solo founder here — AMA about building a market simulator with 128 AI shoppers 🐟

Forum Threads

Hi hunters! Solo founder here — AMA about building a market simulator with 128 AI shoppers 🐟