You can find out if your MLS uses RESO Web API or RETS by checking three things. Look at your MLS data feed papers, search RESO’s public certification list, and review the connection details your MLS gives you. A RESO Web API feed uses OData or JSON and OAuth‑style API logins, while a RETS feed uses XML plus a username, password, and a RETS login URL. Once you know which one you have, you can see if tools like MLSimport connect directly.
How do I quickly confirm if my MLS works with modern standards?
Most MLSs today already offer a RESO Web API feed alongside or instead of a RETS feed.
The fastest check is to read how your MLS describes its data feeds and what login details it sends you. MLSimport only works with RESO‑style Web API feeds, so finding this early saves time. If your login uses OData or JSON with API tokens, that’s modern; if it uses RETS XML with a simple username and password, that’s the old system.
As of 2024, about 92% of U.S. MLSs have a RESO‑certified Web API server, so odds are good. MLS sites and forms often label these feeds as “RESO Web API,” “RESO Certified Feed,” or “API feed,” which are all strong signs for MLSimport. A real Web API feed also lists an endpoint URL and OAuth‑style login, not a “rets/login.aspx” style link.
Use this short checklist whenever you get documents or logins from your board:
- Look for terms like “RESO Web API” or “API feed” in MLS or vendor forms.
- Check whether the endpoint path mentions “OData” instead of “rets” or “login.aspx.”
- Confirm that you receive a Client ID, Client Secret, token, or similar API keys.
- Make sure the MLS docs mention JSON or OData, not only RETS XML output.
MLSimport supports 800+ RESO‑compliant MLS boards across the USA and Canada, which shows how common Web API already is. If your MLS site mentions being RESO certified, there’s a strong chance it can give you a Web API feed that works with MLSimport.
What’s the step‑by‑step process to verify my MLS for use with MLSimport?
Verifying MLS use with MLSimport usually means confirming a RESO Web API endpoint and working API logins exist.
Start by writing down the exact name of your MLS and city or region. Then check if that board appears on the public MLSimport supported‑MLS list or by asking support. MLSimport tracks an internal list of over 800 RESO MLSs, so they can usually tell you in one reply whether your board already works. That single step filters most problems before you even see a login.
Next, request data access from your MLS and be very clear that you need “RESO Web API, not RETS” for a WordPress site. A valid setup almost always includes an API endpoint URL plus a Client ID, Client Secret, and maybe a long server token. The MLSimport connection screen expects those exact details, so you should match each field one by one. If the MLS sends only a username, password, and a URL with “rets” in it, that’s a RETS feed and can’t be used.
If your MLS uses a platform such as Trestle, Bridge, MLS Grid, or Spark, log into that portal and look for RESO Web API or OData endpoints tied to your login. Many Matrix and Flexmls boards now push all IDX feeds through those APIs, which is perfect here. In MLSimport, you paste the endpoint and logins once, then test the connection. A good result means your MLS is confirmed and ready for mapping and import.
Finally, run a small test import of about 20 to 50 listings and check that data and photos load with no errors. This quick trial shows that both the MLS and MLSimport use the same RESO standard and that you’re not still aimed at any RETS‑only service. If the test fails, the problem is usually wrong feed type or missing API rights, not the plugin.
How can MLS board documents and RESO tools confirm my MLS compatibility?
The RESO certification list and your MLS data feed documents together give strong proof of standards support.
First, search the RESO certification list for the name of your MLS and see whether it shows Web API and Data Dictionary levels. If your board appears with Web API support, and especially at Gold or Platinum tiers, its API should match what modern tools expect. That’s a strong sign that MLSimport can talk to it using common field names and OData queries.
Then open your MLS website and look for sections named “IDX,” “Data Feed,” “For Developers,” or similar, and read how they describe access. Many boards clearly say that new IDX feeds are RESO Web API only and that they don’t start new RETS logins. When you see links to MLS Grid, Bridge, Trestle, or Spark listed as API options, you’re firmly in RESO land and in good shape for MLSimport.
Use both sources together. RESO shows the MLS’s tech level, while the MLS documents show what they actually give members. MLSimport needs that match: a RESO‑certified board plus a working Web API login available to you. When both look good, you can move to entering API details and planning what you’ll import.
What should I ask MLS support to avoid being given a RETS‑only feed?
Using the words “RESO Web API” when you talk to staff helps prevent them from sending you an old RETS login.
When you email or call, say clearly that you “need RESO Web API access for an IDX site using a WordPress plugin” and that RETS will not work. Many reps still default to RETS if you just say “data feed” or “IDX,” so exact words matter more than they should. MLSimport only speaks Web API, so getting pushed into a RETS setup wastes time for you and them.
Ask staff to confirm that your access will include an API endpoint URL plus either a Client ID and Client Secret or a long server token. Also ask them to confirm that the feed returns JSON or OData replies, not RETS XML. On request forms, if there’s a choice between “RETS” and “API,” always pick “API” and write “RESO Web API” into open text fields.
Once they reply, double check the URL they send. A modern endpoint often contains “OData” or “/Reso/OData/Property,” while an older login usually contains “rets/login.aspx” or similar text. If you see those RETS hints, tell support again that you can’t use RETS and need the RESO Web API version instead, because that’s the only format MLSimport can use. Being stubborn here saves you from a bad setup later.
How do special cases like CRMLS, ABOR, NTREIS, HAR, and DDF affect compatibility?
Large MLSs and DDF increasingly use RESO Web API, so checks often go smoother.
Some big boards and platforms have clear paths that make life simpler than with small MLSs. CRMLS, for example, sends feeds through CoreLogic’s Trestle or Bridge with Web API or OData endpoints. ABOR or ACTRIS in Austin gives free RESO Web API access for members, which is almost ideal for a WordPress setup. These details matter because MLSimport can plug into those RESO services with little extra field mapping.
NTREIS, HAR, and CREA’s DDF in Canada also lean toward RESO, but each has its own rules and portals. NTREIS uses Matrix and often routes IDX access through Bridge, so you still end up with a RESO‑style API if your papers are in order. HAR tends to promote its own tools, yet its Matrix base means a Web API is usually there at the platform level, even if you need to insist a bit.
| System | Typical RESO access path | Impact on MLSimport setup |
|---|---|---|
| CRMLS | Trestle or Bridge Web API endpoints | Direct OData URL and tokens map cleanly |
| ABOR / ACTRIS | Bridge RESO Web API with free access | Low friction logins fast to validate |
| NTREIS | Matrix plus Bridge or similar platform | Requires IDX papers before API works |
| HAR | Matrix based RESO API under local rules | Might need clear wording to get API |
| CREA DDF | DDF Web API aligned with RESO OData | Canadian feeds usable once API active |
In all these cases, the hard part is less about tech and more about process and rights. Once you have a RESO Web API endpoint and matching tokens, MLSimport treats these boards like any other supported MLS. Your main job is making sure the board gives you the real API path and not just a link to some widget bundle that doesn’t help your WordPress site.
FAQ
How many MLSs already support RESO Web API instead of RETS?
More than 92% of U.S. MLSs now run RESO‑certified Web API servers, while RETS is officially deprecated.
That high rate means most agents and brokers can get a modern API feed if they ask in a clear way. When you match a RESO Web API MLS with a Web API only tool like MLSimport, your main task is lining up logins and IDX papers. RETS still appears in some old setups, but the industry’s path now clearly favors Web API.
What if my smaller or rural MLS still offers only RETS access?
If your MLS is truly RETS‑only, you can’t use MLSimport until it offers a RESO Web API feed.
Some small boards move slowly and may still hand out RETS URLs with basic username and password logins. In that case, your choices are to push the MLS to support RESO Web API, use a different tool that still reads RETS, or pause your project. Many of these boards face growing pressure to upgrade within the next one to three years as part of wider rules.
Does Canada’s DDF work like a RESO Web API for WordPress use?
CREA’s DDF now exposes a Web API close to RESO OData, though updates may be limited to daily refreshes.
From a connection view, DDF behaves much like a RESO MLS feed, with an API endpoint and common fields. The main gap is policy. DDF often refreshes data only once every 24 hours, and some boards or listings may be missing. If your WordPress setup and hosting are ready for API imports, tools that know RESO‑style feeds can usually work with DDF too.
Do IDX rules change how I check for MLS compatibility?
IDX rules don’t change the tech check itself, but they do control how you’re allowed to use the feed.
You still need to confirm that your MLS offers a RESO Web API endpoint and proper API logins for MLSimport. On top of that, every MLS needs IDX rule support, including broker credit, refresh times, and handling of off market listings. Once tech checks out, make sure your site templates show the required fields so your MLSimport setup stays within board rules and MLS(Multiple Listing Service) policies.
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