7 min read
RESO is a standard and a hundred dialects: building MLS integrations that don't break.
RESO · Integration
_industries / Real Estate: PropTech
The data is scattered across five systems. We've made it agree.
iFlux connects the systems a real estate business actually runs on: listing feeds, valuation and underwriting tools, the outside data feeds they plug into, and the CRM everyone works out of. We build the data layer that reconciles those sources into one queryable truth, keeps listings and pricing in sync with the source, and keeps valuation models defensible under Fair Housing scrutiny.
// from MLS and RESO feeds to CRM and PropTech APIs.
// from AVM valuation to portfolio analytics.
// from listing freshness to Fair Housing compliance.
We connect the data layer so decisions get made on truth, not the last export.
Tell us about your PropTech challenge →// from AVM valuation to portfolio analytics.
// from listing freshness to Fair Housing compliance.
We connect the data layer so decisions get made on truth, not the last export.
MLS / IDXRESO Web APIAVM / ValuationCRM IntegrationProperty ManagementPortfolio AnalyticsUnderwritingListings Sync
_problems we've actually solved
// data fragmentationthe single source
Decisions made on whoever exported a spreadsheet last
Your data lives across MLS (multiple listing service) feeds, PropTech (real estate technology) APIs, and a CRM that was never meant to talk to any of them. So the number in the meeting depends on who pulled it and when. We build the connected data layer that makes one version of the truth queryable in real time — so decisions stop riding on the freshness of the last export.
// RESO / MLSthe standard, in practice
The standard everyone implements slightly differently
RESO is a standard on paper and a hundred dialects in production. Every MLS and IDX (Internet Data Exchange) feed has its quirks, its custom fields, its rate limits. We build resilient RESO Web API integrations that normalize the dialects, survive feed changes, and reconcile against the source — so your platform isn't one MLS schema change away from an outage.
// valuationAVM & underwriting
Valuation models that hold up to Fair Housing scrutiny
An AVM (automated valuation model) that quietly encodes a protected characteristic isn't just inaccurate — it's a legal exposure. We build valuation and underwriting models with documented features, fairness testing, and explainability that stands up to review under the Fair Housing Act — accuracy you can defend, not just a number the model happened to produce.
// listings syncfreshness
The listing that's stale the moment it leaves the source
A price change, a status flip to pending, a photo update — if your platform shows yesterday's state, you're eroding trust one listing at a time. We build near-real-time sync with change detection and reconciliation so what your users see matches the MLS, not a cache that drifted overnight.
// portfolio analyticstruth across sources
Portfolio truth across a data layer that was never designed to agree
Rent rolls in one system, maintenance in another, valuations in a third, market data in a feed. Portfolio-level answers require all of them to reconcile. We build the analytics layer that unifies the fragmented sources so occupancy, NOI (net operating income), and performance reflect reality instead of whichever system was queried.
// algorithmic fairnesscompliant by design
Algorithmic decisions that can't discriminate, by construction
Tenant screening, lead routing, pricing, and recommendations all touch Fair Housing territory. We design these systems with protected-class awareness, bias testing, and an auditable decision record — so an algorithm helping your business grow never becomes the reason you're in a compliance conversation.
In real estate, the data isn't wrong — it's just scattered. And a decision made on the wrong copy of the truth costs the same as one made on no data at all.
// we unify first.
// then we build on something that agrees with itself.
_the standards
layer// a listing
// feed and a
// fair housing
// rule are both
// constraints.
layer// a listing
// feed and a
// fair housing
// rule are both
// constraints.
RESO Data Dictionary
The common schema for real estate data. We normalize every MLS dialect to it, so downstream systems consume one shape, not fifty.
RESO Web API
Standards-based feed integration with the resilience to survive rate limits, schema changes, and the quirks each MLS ships.
Fair Housing Act
Valuation, screening, and targeting models built to avoid protected-class proxies, with fairness testing and explainability documented.
MLS / IDX Rules
Display, attribution, and data-use rules enforced per MLS agreement, so your listings integration stays in good standing.
SOC 2 / CCPA
Consumer data protection and access controls for the PII that flows through leads, applications, and transactions.
ADA / WCAG
Accessibility for public-facing search and listing experiences, engineered in — a real exposure area for consumer real estate sites.
_what a PropTech audit looks like
iflux: proptech_data_audit.sh
~/iflux/Industries/RealEstate $ audit --scope=proptech --data=true --fairness=true
→ Mapping data sources...
⚠ 3 systems report different unit counts for same portfolio. No source of truth.
⚠ CRM and MLS feed reconciled manually via nightly spreadsheet export.
→ Inspecting RESO Web API integration...
⚠ Custom MLS fields unmapped. Feed schema change on 2 markets breaks ingest.
→ Auditing valuation model for fairness...
✗ AVM uses ZIP-level feature correlated with protected class. Fair Housing risk.
⚠ No explainability output. Individual valuations cannot be justified on review.
→ Checking listing freshness...
⚠ Listing cache TTL 24h. Status and price drift from MLS observed.
→ Scanning public search accessibility...
✓ Core data pipeline healthy. Unification viable across all sources.
✓ Audit complete. 6 issues found. 1 critical Fair Housing exposure flagged.
→ Priority fix list generated. Compliance risk ranked first.
~/iflux/Industries/RealEstate $ _
_what we've built in real estate
✓
RESO Web API integrations that normalize MLS dialects and survive feed schema changes
✓
Connected data layers unifying MLS, CRM, and PropTech APIs into one queryable source of truth
✓
AVM & valuation models with fairness testing, explainability, and Fair Housing documentation
✓
Near-real-time listing sync with change detection and source reconciliation
✓
Portfolio analytics platforms unifying occupancy, NOI, and performance across fragmented systems
✓
Property management systems with maintenance, leasing, and accounting integration
✓
Underwriting & screening tools with auditable, bias-tested decision records
✓
Public search experiences built for accessibility, performance, and IDX compliance
_services we bring to Real Estate
Every PropTech engagement is backed by the full iFlux capability stack, matched to the fragmented data reality and compliance surface real estate actually operates in.
_frequently asked
Can you integrate MLS and RESO Web API feeds reliably?
Yes. We build RESO Web API integrations that normalize the dialect each MLS ships, handle rate limits and schema changes gracefully, and reconcile against the source so drift is caught. The goal is a platform that isn't one MLS schema change away from an outage.
How do you keep our AVM or underwriting model Fair Housing compliant?
We treat fairness as an engineering requirement. That means documented features, testing for protected-class proxies, explainability for every valuation or decision, and an auditable record. The model stays accurate while being defensible under the Fair Housing Act, rather than producing a number no one can explain.
Our data lives in MLS, a CRM, and several PropTech APIs. Can you unify it?
That is the core problem we solve in real estate. We build a connected data layer that ingests MLS feeds, CRM data, and PropTech APIs, normalizes them to a common schema, and exposes one queryable source of truth, so decisions stop depending on whoever exported a spreadsheet last.
How fresh is the listing data in the systems you build?
We build near-real-time sync with change detection, so price changes, status flips, and photo updates propagate quickly rather than sitting in a stale cache. What your users see reflects the current MLS state, which protects consumer trust and keeps you IDX compliant.
Do you handle accessibility and consumer data protection for public real estate sites?
Yes. Public-facing search and listing experiences are built to WCAG accessibility standards, which is a real exposure area for consumer real estate, and consumer PII is protected with SOC 2 aligned controls and CCPA rights handling built into the architecture.
_thinking / Real Estate
6 min read
Your AVM might have a Fair Housing problem. Here's how to find out before a regulator does.
Valuation · Fair Housing
8 min read
One source of truth in real estate, when the data lives in five systems that disagree.
Data · PropTech
Building on real estate data?
Talk to a Flux who's untangled it.
// no platform that breaks on the next MLS schema change.
// no valuation model you can't defend.
// just an honest conversation with someone
// who already knows where the data hides.