A Happy Sandboy product · Phase 1 · Cambodia

Zettlein. The AI transaction layer for real estate.

A portable AI broker, lawyer and transaction desk. Zettlein lives inside Brokher.com, writes into Proassistly, and guides buyers, sellers, banks and lawyers from first click to keys in hand.

Open the prototype View the pitch Developer brief →

01 · How it fits together

One product, three surfaces, one Happy Sandboy stack.

HAPPY SANDBOY (studio · parent) │ ┌───────────────────────┼───────────────────────┐ │ │ │ BROKHER.com ZETTLEIN PROASSISTLY marketplace AI transaction desk system of record (public front) (this product) (backend engine) │ │ │ │ reads listings │ reads + writes │ owns data, │ from Proassistly │ via /rpc/v1 │ contracts, │ embeds Zettlein │ T0 / T1 / T2 │ ledger, KYC │ │ │ └───────────── one continuous transaction ──────┘

B / already built

Brokher.com

Public marketplace

Your existing Lovable project. Lists properties, ranks in search, embeds the Zettlein widget on every detail page.

Z / building now

Zettlein

AI transaction desk · this product

Portable agent fleet — broker, lawyer, banker, notary. T0 autonomous, T1 human-reviewed, T2 principal-signed. Handles every party across the deal.

P / already built

Proassistly

Backend engine

Your developer's system of record. Owns users, listings, contracts, ledger, events. Zettlein talks to it via versioned RPC — never touches the DB directly.

02 · End-to-end flow

Every step, one system.

seller ─▶ scan ─▶ AI media ─▶ listing ─▶ Brokher.com │ ▼ buyer ◀─ Zettlein advisor ◀────── discovery ◀── SEO / map / search │ ▼ offer ─▶ negotiate ─▶ reservation ─▶ due diligence │ ▼ escrow (ABA/Acleda/Wing/Wise) ─▶ contract e-sign │ ▼ closing ─▶ funds transferred ─▶ post-sale services

03 · Property categories

Every property type, from day one.

Residential

Cambodia · Phase 1

Condominiums

Cambodia · Phase 1

Apartments

Cambodia · Phase 1

Villas

Cambodia · Phase 1

Borey houses

Cambodia · Phase 1

Land

Cambodia · Phase 1

Commercial

Cambodia · Phase 1

Development land

Cambodia · Phase 1

Investments

Cambodia · Phase 1

04 · Explore the design

→ Vision & thesis → Products in depth → User journeys → System architecture → Database → AI architecture → CRM → Marketplace → Banking hub → Legal engine → Service marketplace → Roadmap