MLSync.io

Going direct to the RESO Web API means owning the full stack: learning RESO standards and per-MLS quirks, implementing error handling and rate-limit logic, normalizing data, designing schemas and migrations, building change tracking and incremental sync, and keeping it all running as providers change their APIs and schemas. That work usually adds up to several months before you can ship product.

With MLSync.io you skip that build. We run sync, normalization, and infra; you get a dedicated PostgreSQL database, a fast REST Search API, full SQL access (including AI/LLM-generated queries from natural language), real full-text search, and full change history, plus virtual fields and MCP for AI integration. Many customers are syncing within 24 hours and can be in production in weeks.

Multi-MLS providers that offer unified RESO access have the advantage of providing a single API endpoint for multiple MLSs, which can simplify integration when working across different markets. However, they typically expose raw OData endpoints, which can be complex to work with and require deep understanding of OData query syntax.

MLSync.io takes a different approach: we provide an easy-to-configure REST Search API that's built on top of your synced data. Our API is straightforward to use, with a user-friendly dashboard where you can configure response formats to match your exact needs. Unlike raw OData, you don't need to learn complex query syntax—our REST Search API handles the complexity for you.

Additionally, MLSync.io includes built-in advanced features that you'd need to build yourself with raw OData: full-text search across all fields, intelligent typeahead with typo tolerance, configurable fields for optimized response sizes, and minimum latency responses. You also get your own PostgreSQL database with full SQL access, complete change tracking, and AI-ready features with MCP support—all without the complexity of managing OData queries.

Open source RESO sync tools can speed up the initial build, but the ongoing burden stays on you. You have to configure sync for each MLS (credentials, mappings, quirks), keep it running 24/7, and apply upstream and MLS changes that happen often. You also own the rest of the stack: maintaining the database or Elasticsearch, configuring indexes for performance, scaling as data grows, building a search API on top, and running migrations when schemas or dependencies change. You spend time filling in missing features (full-text search, typeahead, change tracking, etc.) instead of shipping product.

MLSync.io provides a managed sync, a ready-to-use REST Search API, and a maintained data layer—so you can focus on your app instead of operating and extending open source sync and search.

Unfortunately, not as these data are protected by MLS boards.
To access MLS data legally, you need to partner with a licensed agent or broker (depending on MLS provider) who has RETS/RESO Web API credentials from their MLS. Services like MLSync.io do not provide raw MLS access; they only synchronize listings that you already should have access to under specific agreements with MLS boards.

Yes! We provide sandbox MLS access for development and testing using our existing connections. This lets you start building immediately while you work through the MLS approval process.

For production use, you'll need MLS membership through a licensed broker and proper board approval. We guide you through this process and can connect you with brokers who specialize in working with PropTech companies. Most approvals take 1-4 weeks and may be subject to pass-through fees from MLS platforms or additional charges based on the complexity of the MLS feed.

Setting up your feed is straightforward. In the MLSync.io backend, you can securely configure your RESO Web API or RETS credentials. Our system uses these to access the data on your behalf, handling all synchronization tasks automatically. We also manage credential rotation seamlessly, so you don't have to worry about service interruptions if your credentials are required to be updated periodically.

You own your data. The MLS data synced to your database belongs to you, and you have full control over how you use it within the terms of your MLS agreement. MLSync.io acts as a synchronization service—we help you import and maintain the data, but we don't claim ownership of your synced MLS data.

However, it's important to note that the original MLS data is owned by the respective MLS boards and is subject to their terms of service and data use agreements. You must comply with your MLS provider's rules regarding data usage, display requirements, and any restrictions on how the data can be used or shared.

With BYOD (Bring Your Own Database) plans, you maintain complete control over your database infrastructure, ensuring your data remains in your own environment.

Yes! We provide sandbox MLS access for development and testing using our existing connections. This lets you start building immediately while you work through the MLS approval process.

For production use, you'll need MLS membership through a licensed broker and proper board approval. We guide you through this process and can connect you with brokers who specialize in working with PropTech companies. Most approvals take 1-4 weeks and may be subject to pass-through fees from MLS platforms or additional charges based on the complexity of the MLS feed.

We can backfill historic MLS data for a fee when your MLS does not provide it. This is subject to MLS board approval—we only offer backfill where the board allows it—and to data availability: we can supply historic data only when we have it in our systems. Contact us to check availability for your MLS and to get a quote.

Setting up your feed is straightforward. In the MLSync.io backend, you can securely configure your RESO Web API or RETS credentials. Our system uses these to access the data on your behalf, handling all synchronization tasks automatically. We also manage credential rotation seamlessly, so you don't have to worry about service interruptions if your credentials are required to be updated periodically.

On our side, setting up the synchronization is a matter of hours to a few days at most. It depends on whether we have already tested our system with the given MLS—if we have, it's typically very quick.

In practice, getting the feed approved by the MLS board usually takes longer than the technical setup. We'll guide you through the process and get sync running as soon as your credentials are approved.

OpenAPI (formerly Swagger) is a specification for describing REST Search APIs, which makes it easy to generate client code and test queries using tools like Swagger UI. OData is a protocol that excels at querying data, which the RESO Web API uses for complex filtering. MLSync.io leverages both: we provide an OpenAPI-documented REST Search API and a user-friendly dashboard where you can easily configure the response format to fit your exact needs.

RESO is indeed a good standardized format for real estate data, and the Real Estate Standards Organization has done excellent work creating a common data dictionary. However, RESO Web API implementations can be very complex and chatty, requiring multiple API calls to retrieve complete property information. This complexity makes direct integration challenging for many teams.

While the RESO organization provides client implementations in several programming languages, these libraries are not maintained regularly and may require workarounds or hacks for certain MLS providers that implement the standard differently. MLSync.io handles all of this complexity for you—we normalize the data, handle provider-specific quirks, and provide a clean, simple REST Search API that works consistently across all MLS providers.

For teams that prefer to work with the standard format, we are preparing support for RESO Common Format. This will provide an easy migration path for those already using RESO-compliant systems, though it comes at the expense of some of our advanced features and optimized latency. Our standard REST Search API remains the recommended choice for most use cases, offering better performance and additional capabilities like full-text search and intelligent typeahead.

You can easily generate client code for our REST Search API using its OpenAPI specification. This allows you to interact with the API in your preferred programming language without writing boilerplate code. Popular tools for this include Swagger Codegen, OpenAPI Generator, and Postman. These tools can generate SDKs for dozens of languages, complete with models and request/response handling.

RESO defines hundreds of fields per resource—most apps only need a fraction.

With our configurable response schema, you choose exactly which fields each endpoint returns. That means smaller payloads and faster responses: you only fetch what your app needs, reducing bandwidth and latency. Mobile and high-traffic apps benefit most; you can keep list views lean and load full details only when needed. Fewer fields also mean less parsing and simpler client code.

MLSync.io is designed for easy AI integration through its support for the Model Context Protocol (MCP). This allows AI models and agents to interact with your MLS data via a standardized protocol. Our customizable REST Search API makes it simple to expose your data—including virtual fields and labels—to AI applications, enabling you to build features like natural language search, property valuation models, and market trend analysis with ease.

With full SQL access, AI/LLM systems can construct complex queries automatically from natural language requests. This enables powerful use cases like generating sophisticated market analysis queries, building dynamic search filters, or creating custom reports—all through AI-assisted SQL query generation.

Absolutely! With full PostgreSQL SQL access, you can leverage AI/LLM tools to automatically generate complex SQL queries from natural language. Simply describe what you need—like "find all properties in downtown that sold in the last 6 months with price reductions"—and AI can construct the appropriate SQL query.

This is especially powerful for ad-hoc analysis, custom reporting, market research, and building sophisticated search features. AI/LLM systems understand your database schema and can generate optimized queries that handle joins, aggregations, filters, and complex conditions automatically.

We support all MLS providers in the US and Canada that offer RESO Web API or RETS access. Our system is adaptable to nearly any MLS data feed and can handle both modern RESO Web API imports and legacy RETS data imports. This includes major providers like Trestle, MLS Grid, Bridge Interactive, and hundreds of regional MLS boards.

We use the RESO Web API to replicate and import MLS data from your MLS provider into your own infrastructure. We support both real-time sync and batch import modes, allowing you to choose the best approach for your needs.

Yes, we support legacy RETS connections, though it requires additional configuration and testing. While we have tools to help convert RETS data to modern structures, the process needs careful attention to ensure accurate mapping and data integrity. We recommend using RESO Web API when available, as it's more reliable and easier to maintain. Contact us for more information about RETS import support.

We support import of all standard RESO data including property listings, agents, offices, open houses, and media (photos, videos, virtual tours). We can also import custom fields specific to your MLS provider. The data is imported incrementally to capture all changes while maintaining historical records.

You can configure synchronization schedules up to every 15 minutes or hourly or daily batch updates, depending on your needs.

Yes! Our visual schema editor allows you to create virtual fields using simple SQL expressions, rename attributes, and optimize your data model exactly as needed for your imported MLS data. Virtual fields are computed on-the-fly, so you can add calculations like price per square foot, days on market, or custom scoring without storing duplicate data.

We also provide a set of common virtual fields that are pre-configured for you, including street name, full address, coordinates, property age, and more.

Our REST Search API is highly optimized for minimum latency and typically responds in under 100ms for most queries, even under high load. Startup and Business plans are designed to handle up to 1 million page views per month, providing reliable performance for growing applications. For Business and Enterprise plans, we also offer enhanced response schemas to reduce the number of required API calls and improve overall efficiency.

As RESO is a complex data standard, the primary database purpose is to be our primary source of truth, that can answer even the most complex queries. The basic database package is designed for standard operations and is not optimized for heavy use of advanced features like sophisticated AI/LLM querying—however, it can be easily upgraded to support these use cases. For building your own tools on top of MLS data, we recommend using our REST Search API with low latency and high performance.

We manage the database for you. We handle provisioning, schema design and migrations, performance tuning, backups, and ongoing maintenance so you can focus on your product.

You get read-only access to run SQL queries, build reports, and integrate with AI/LLM tools. Depending on your plan, we can grant partial write access to specific parts of the database (for example, your own tables or schemas) so you can store application data alongside synced MLS data—while we keep managing and protecting the core MLS data and schema.

We primarily support PostgreSQL as our database of choice for MLS data import. For BYOD (Bring Your Own Database) plans, other databases like MySQL may be supported - contact us to discuss your specific database requirements for MLS data import.

Yes! While Elasticsearch is a common choice, we also support other popular search engines like OpenSearch, Apache Solr, Meilisearch, and Typesense. Each has its own strengths and we can help you choose the best option for your specific needs.

We can help you migrate from your current service and customize our response format to match your existing structure, minimizing the changes you need to make. Our REST search service is highly flexible - you can define your own response format using SQL queries, making integration seamless.

Yes! Contact us for a 90-day demo account to explore MLSync.io's features and capabilities before making a commitment.

Yes, we offer a 30-day money-back for Explorer, BYOD and BYOE plans so you can fully try MLS synchronization with your MLS provider risk-free.

You keep all the database data you've already imported. When you cancel, you have several options:

• You can export your data in standard formats, or we can transfer your database instance ownership to you (when technically possible)
• You can keep all the database objects we automatically prepared for you—such as views, indexes, schema customizations, and virtual fields
• Any database functions and procedures you may have been using will be removed as they are part of our intellectual property

Regarding backups: we maintain 60 days of MLS data backups after service cancellation that we can provide upon request, and 14 days of full database backups for recovery purposes.

Our Startup, Business, and Enterprise plans include unlimited MLS access—you can sync data from as many MLS providers as you need without additional per-MLS charges. This makes these plans ideal for companies working with multiple markets or brokerages.

The Explorer, BYOD, and BYOE plans are priced per MLS (as shown in the pricing). If you need access to multiple MLSs on these plans, discounts may apply—contact us to discuss volume pricing for your specific needs.