Property Listing & MLS Integration

Part of the worlds-biggest-software-project initiative.

An AI-native, open-source IDX and MLS integration platform that turns RESO Web API feeds into a searchable, syndicatable, SEO-friendly listing experience on the agent's own domain.

Property Listing & MLS Integration is a candidate project to build a unified listing search, syndication, and lead capture stack for real estate agents, brokerages, and PropTech developers. It targets the gap between thin developer APIs (SimplyRETS, Spark, Bridge) and closed SaaS suites (IDX Broker, Showcase IDX, iHomefinder) by offering a self-hostable, standards-compliant, AI-augmented alternative.

Why Property Listing & MLS Integration?

Leading IDX SaaS platforms charge $50–$200/month per agent and $10,000+/year for enterprise brokerage deals, with limited data control and dated default UI.
IDX Broker and similar tools render listings on third-party subdomains, harming the host site's SEO; only Showcase IDX delivers true server-side rendering, and only on WordPress.
Developer APIs like SimplyRETS, Spark, and Bridge ship no front-end, no lead capture, and no CRM — every team rebuilds the same consumer surface from scratch.
Most platforms still rely on checkbox-and-filter search; natural-language property discovery, listing quality auditing, and predictive syndication routing are absent across the incumbent landscape.
The only notable open-source option, OpenRESync, covers the data sync layer alone and has a small contributor base; no full-stack open IDX solution exists.

Key Features

MLS Data Layer

RESO Web API (OData v4) client with multi-MLS connection support
Side-by-side support for legacy RETS feeds where MLSs have not yet migrated
Normalised listing data model aligned with the RESO Data Dictionary 2.x
Configurable sync intervals and field-level mapping per MLS feed
Self-hosted storage so listing data resides on the operator's own infrastructure

Search & Discovery

Full-text and faceted filter search (price, beds/baths, property type, status, location)
Map-based search with clustering, zoom-to-search, and polygon (draw-a-shape) selection
Saved searches with automated new-listing email alerts
Server-side rendered listing detail pages indexed under the operator's own domain
Mobile-responsive listing display with required MLS attribution and compliance fields

Lead Capture & CRM

Forced, delayed, and optional registration gates on listing access
Lead records enriched with full IDX search and alert activity
Behaviour-based lead scoring to surface hot prospects
Speed-to-lead notifications and round-robin routing for brokerage teams
CCPA and GDPR consent tracking on every registration event

Syndication & Compliance

Listing distribution to major portals via ListHub or direct feed
Per-publisher opt-in / opt-out controls for selective syndication
MLS compliance display engine that enforces attribution and display rules per board
Brokerage multi-agent management with configurable lead routing
International feed support, including Canadian DDF

AI-Native Advantage

A natural-language search layer translates queries like "3-bed near good schools under $600k within 20 min commute" directly into RESO OData calls, replacing checkbox-heavy forms. LLM-driven listing description generation produces copy from structured MLS fields and photos, and an automated data quality audit flags stale, incomplete, or inconsistent records before they syndicate. Predictive syndication routing selects portals based on property type, price point, and predicted buyer audience overlap — capabilities absent across the incumbents reviewed.

Tech Stack & Deployment

The project is designed around the RESO Web API (OData v4) as the primary integration surface, with a fallback RETS gateway for MLSs still on the legacy protocol. A self-hosted deployment path keeps MLS data on the operator's own infrastructure, in line with the "organic import" pattern pioneered by Realtyna. Server-side rendering of listing pages is a first-class requirement so listings are indexed under the operator's domain. Open-source precedents include OpenRESync (MIT, Node.js + MySQL/Solr) for the sync layer.

Market Context

The broader real estate software market exceeded $15 billion globally in 2025, with the IDX and listing syndication sub-segment estimated at $1–2 billion in annual recurring revenue across vendors and portal lead programs. IDX SaaS subscriptions run $50–$200/month for individual agents, enterprise brokerage deals exceed $10,000/year, and portal lead programs (Zillow, Realtor.com) cost $200–$1,000+ per ZIP code per month. Primary buyers are individual agents, multi-agent brokerages, PropTech startups consuming raw MLS data, and franchise brands needing white-label listing search.

Project Status

This project is in the research and specification phase.
Contributions, feedback, and domain expertise are welcome.

Contributing

We welcome contributions from developers, domain experts, and potential users. See CONTRIBUTING.md for guidelines.

Important: All contributions must be your own original work or clearly attributed open-source material with a compatible licence. Copyright infringement and licence violations will not be tolerated and will result in immediate removal of the offending contribution. If you are unsure whether a piece of code, text, or other material is safe to contribute, open an issue and ask before submitting.

Licence

Licence to be determined. See discussion for context.