How Do I Get IDX on My Website?

The Short Answer

Getting IDX on your website takes four things in order: MLS participation through a broker, a signed IDX authorization from that MLS, an approved data feed delivered over the RESO Web API, and a listing display that follows the MLS rules on attribution, refresh frequency, and excluded records. The paperwork comes before the code, and in most cases the MLS reviews the finished display before it is allowed to go live.

The build is the easy part. Feed approval is what sets your timeline.

Step One: Establish MLS Participation

IDX data belongs to the MLS and its participants, and access flows from a participation agreement. A brokerage gets this through its designated broker. An individual agent displays IDX under their broker's participation, not independently. An association usually arranges display under the participation of the MLS itself or of its participating brokers, which is a different conversation and worth starting early.

If you operate in more than one market, you need this per MLS. Coverage in one region tells you nothing about the next one, and multi-market brokerages routinely discover that four markets means four applications, four rule sets, and four review cycles.

Step Two: Sign the IDX Authorization

This is the document that turns participation into permission to display. It typically covers which listings are eligible, which fields may be shown publicly, required attribution and disclaimer language, how quickly you must reflect status changes and removals, and how sellers who have opted out of internet display are handled.

Read it rather than filing it. These are the rules your site has to keep following for as long as it is live, and they are the ones that change. Whoever builds your site should have read it too.

Some MLSs also offer VOW authorization for a broader display behind a registered login, or a broker feed for your own listings. Those are separate permissions with separate rules.

Step Three: Get the Feed

Once authorization is in place, the MLS issues credentials for a data feed. Here is the part worth getting right.

The current standard is the RESO Web API. It is a REST-style API over HTTP that returns JSON, uses OData version 4 query syntax, and exposes standardized resources such as Property, Member, and Office with field names defined by the RESO Data Dictionary. That standardization is the practical benefit: a Data Dictionary field means the same thing in one MLS as in the next, which is what makes multi-market integration feasible at all.

RETS is deprecated. The Real Estate Transaction Standard was the previous transport, and RESO deprecated it in 2018 and no longer supports it. Retirement across the industry has continued since, with vendors and MLSs shutting off legacy endpoints. You may still encounter a RETS endpoint on an MLS mid-migration, but building a new integration on it is building on something with a scheduled end.

Ask which Data Dictionary version. RESO Data Dictionary 2.0 was approved in 2024, with NAR-affiliated MLSs required to certify against it. Knowing the version each of your MLSs certifies on tells you how much per-market mapping work is actually in front of you.

Decide replication or live query. Some integrations pull the authorized data on a schedule and store it locally, which makes search fast and gives you control over how pages render. Others query the API on request. Replication is the usual choice for sites that need indexable, server-rendered listing pages, and your MLS agreement will set limits on storage and refresh.

Step Four: Build the Display

Two paths, and the choice has consequences well beyond convenience.

Vendor platform. A provider holds the feed integration, handles rule updates, and gives you a search interface. Fastest to launch. The questions to ask are whether listing content is server rendered or delivered through a script or iframe, what a search crawler sees on a property page, and who owns the lead records. Those points are unpacked in is IDX Broker legit, which turns into an evaluation framework for any provider.

Direct integration. You or your development partner consume the Web API and render listing pages as part of your own site. More work up front, and you own feed maintenance. In return you control markup, URLs, page speed, and indexability, which is the entire argument for doing it this way.

Whichever path you take, the display has to keep honoring the rules: attribution on every listing, the MLS disclaimer where required, refresh within the stated window, prompt removal of withdrawn or opted-out records.

The Two Things That Decide Whether It Was Worth It

Embedded search interfaces, map tiles, and photo galleries are among the heaviest things you can put on a page, and they are a frequent cause of failing Core Web Vitals on real estate sites. Read Core Web Vitals for real estate before deciding where a search widget goes, because placement is a performance decision.

The second is whether the listing content exists in a form crawlers and AI answer systems can read. Content inside a third-party embed is often invisible to both.

Where to Go Next

If you are still scoping, what IDX is used for covers the underlying model and how much IDX costs per month breaks down the cost components. To talk through a specific market list, see IDX and MLS integration or get in touch through contact.

Frequently Asked Questions

Do I need to be an MLS member to add IDX to my website?

Yes. IDX data comes from the MLS under a participation agreement, so a broker participant relationship is the starting point. Agents display IDX under their broker's participation, and associations typically arrange it under the participation of the MLS or its participating brokers. There is no legitimate path to a live IDX feed that skips this step.

Is RETS still used for IDX feeds?

It is on its way out. RESO deprecated RETS in 2018 and no longer supports it, and the RESO Web API is the current standard for MLS data delivery. A small number of MLSs may still run legacy RETS endpoints during migration, but any new integration should be built against the Web API, which uses REST over HTTP with JSON payloads, OData query syntax, and standardized RESO Data Dictionary field names.

How long does it take to get IDX live?

The technical work is rarely the long pole. Feed approval is, because it involves an application, a signed IDX agreement, credential issuance, and in many MLSs a compliance review of the finished display before it can go public. Plan the paperwork first and build the site around that timeline rather than the other way round.