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CrossBeam

CrossBeam tackles California's ADU permit crisis.

Code Video Cerebral Valley

Core trick

Vision model reads plan sheets and a corrections letter, then parallel skills match each correction to cited state and city code.

Tags

legalvisionagents

Description

CrossBeam tackles California's ADU permit crisis. 429,000+ permits issued since 2018, 90%+ sent back for corrections — each cycle costing weeks and thousands of dollars. Upload your corrections letter and construction plans. CrossBeam reads blueprints using vision, interprets every correction with code citations, cross-references state and city law via live web research, and drafts a response package ready for your engineer to sign. Built on the Claude Agents SDK with 13 custom skills covering state ADU law, city-level research, blueprint extraction, and corrections interpretation — all running concurrently.
mikeOnBreeze/cc-crossbeam★ 29796 forksPythonMITCreated Feb 11, 2026 · last push Mar 2, 2026

README excerpt

# CrossBeam

### Winner — Anthropic's Global Claude Code Hackathon "Built with Opus 4.6"

[Official announcement](https://x.com/claudeai/status/2024986294820958647?s=20)

AI-powered ADU permit assistant for California. Upload your architectural plans and corrections letter — get back a professional response package ready for resubmission.

**Built for the Built with Opus 4.6: Claude Code Hackathon (Feb 10-16, 2026)**

### For Other Builders

If you're curious about the build process, check out `progress.md` — I kept voice logs of my thinking throughout the hackathon while Claude was building. It's a raw, unfiltered look at the decision-making and problem-solving that went into this project.

### Contact

Questions? Reach out:
- X/Twitter: [@breezwoods](https://x.com/breezwoods)
- LinkedIn: [Michael Brown](https://www.linkedin.com/in/michael-t-brown-034aaa22/)

## The Problem

California's ADU permits have a **90%+ rejection rate** on first submission. Most rejections aren't engineering failures — they're bureaucratic: missing signatures, incorrect code citations, incomplete forms. The average 6-month permit delay costs homeowners **$30,000**.

Contractors aren't lawyers. Cities are understaffed. Nobody wins.

## What CrossBeam Does

CrossBeam uses Claude Opus 4.6 as an AI agent that reads your architectural plans, interprets city corrections letters, cross-references California state law, and generates a professional response package.

### Flow 1: Corrections Letter Interpret

Team