# sim francisco

- **Event:** [Claude Build Day](https://cerebralvalley.ai/e/claude-startups-build-day)
- **When:** Sat, Jun 13 at 9:00 AM – 10:00 PM (PDT)
- **Where:** San Francisco, CA
- **Placement:** 2nd Place
- **Team:** [Tejas Prabhune](https://cerebralvalley.ai/u/tejasprabhune), [Tanmayi Priya Dasari](https://cerebralvalley.ai/u/tanmayi2)
- **GitHub:** https://github.com/tejasprabhune/simfrancisco
- **Website:** https://tejasprabhune.github.io/simfrancisco/
- **Demo video:** https://www.youtube.com/watch?v=eVS9s_C7QR8
- **Gallery:** https://cerebralvalley.ai/e/claude-startups-build-day/hackathon/gallery
- **Page:** https://cerebralvalley.ai/e/claude-startups-build-day/hackathon/gallery/90

Sim Francisco: a living digital twin of San Francisco's population: poll a representative, Census-seeded synthetic city in seconds, and run what-if futures before they happen.

Sim Francisco is a live simulated digital twin of the entire population of San Francisco. We seeded thousands of agents sampled from the US Census Data to represent the population of SF. These agents each represent one human, complete with demographic data (like age, gender, religion, occupation, etc), and personal history (where they grew up, schools attended, hobbies, formative experiences) that gives them a coherent worldview. They don't just hold opinions; they reason from a life. They live on a map of SF, going about their day and reacting to the news in real time.

Ask the city anything and you poll the whole synthetic electorate at once, watching verdicts accumulate neighborhood by neighborhood. That same panel forecasts prediction markets: point it at a market question — "Will this measure pass?", "Who wins this race?" — and it returns a probability you can hold up against the real result. 

Below are some historically predictive examples:

2024 Presidency
Question: In November 2024 do you vote for the Democratic presidential ticket (Harris) over the Republican (Trump)?
Actual: 83.8% Dem
Predicted: 81.3% Dem

March 2024 Prop A
Question: There's a measure on your March ballot, Proposition A, that would let the City borrow up to $300 million through general obligation bonds to build and preserve affordable housing, for low-income families, seniors, and working residents. It's backed by Mayor Breed and would need a two-thirds supermajority to pass. Are you voting yes or no?
Actual: 70.38%
Predicted: 70% yes

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Markdown version of https://cerebralvalley.ai/e/claude-startups-build-day/hackathon/gallery/90. Site index for agents: https://cerebralvalley.ai/llms.txt · full text: https://cerebralvalley.ai/llms-full.txt