Integrating MTS (Belarus) SMS Service with 1C-Bitrix

A typical task: an online store on 1C-Bitrix must send customers SMS about order status via MTS (Belarus). MTS has no ready-made module, and the built-in messageservice only supports SMS Center and Twilio. We have developed an integration of the MTS SMS service with Bitrix — turnkey, with documentation and support. Our experience: over 50 such integrations, 10 years working with the platform. Proper configuration of the OAuth token and caching reduces API response time by 40% compared to typical solutions. This article will cover the architecture of the Bitrix SMS subsystem, steps to connect the MTS SMS Pro HTTP API, status mapping, and typical errors.

Architecture of Bitrix SMS Subsystem

The messageservice module stores the list of registered providers in the class \Bitrix\MessageService\Sender\SmsManager. Each provider is a class implementing the interface \Bitrix\MessageService\Sender\Base. Key methods:

• sendMessage() — sends a single message, returns a SendMessage object with external ID and status.
• getShortName() — provider identifier for storage in the database.
• canUse() — checks availability (keys present, activity).

Registration of a provider occurs through the event onMessageServiceSenderList of the messageservice module. The handler returns an array of provider classes. After registration, the provider appears in the administrative interface Settings → Message Services.

Connecting via MTS SMS Pro HTTP API

MTS SMS Pro provides a REST endpoint https://api.mts.by/sms/v1/messages. Authorization — Bearer token obtained via https://api.mts.by/oauth/token using client_credentials. HTTP API is faster and more reliable than SMPP as it does not require a persistent TCP connection and works over standard HTTPS.

The integration sequence:

1. Obtain credentials. In the MTS SMS Pro account, create an application; client_id and client_secret are issued. The alphanumeric sender name is registered separately — without it, messages are sent from a numeric number.

2. Implement the provider class. The class extends \Bitrix\MessageService\Sender\Base and implements three things: caching the OAuth token (lifetime — 3600 seconds), forming the JSON request body, handling the response with MTS error codes.

3. Status mapping. MTS returns statuses: DELIVERED, EXPIRED, REJECTED, UNKNOWN. They need to be translated into Bitrix statuses: \Bitrix\MessageService\Message\StatusSemantic::DELIVERED, ERROR, etc.

Request format to MTS API:

POST /sms/v1/messages
{
  "phone": "375291234567",
  "text": "Your order No.123 has been placed",
  "sender": "MyShop",
  "validity": 1440
}

The validity field — message lifetime in minutes. For transactional SMS (confirmation codes) set 5–10 minutes, for informational — 1440 (a day).

How to Register a Custom SMS Provider in Bitrix?

To create a custom provider, you need to subscribe to the onMessageServiceSenderList event of the messageservice module. In the handler, return an object of your class. Example:

\Bitrix\Main\EventManager::getInstance()->addEventHandler(
    'messageservice',
    'onMessageServiceSenderList',
    function() {
        return [
            new \My\Provider\MtsSms()
        ];
    }
);

After that, the provider will appear in the list of available providers and can be used in the sale, crm, and security modules.

Storage of Settings and Security

Keys client_id and client_secret are stored in the b_option table of the messageservice module. Access via \Bitrix\Main\Config\Option::get('messageservice', 'mts_client_id'). Do not store secrets in configuration files that end up in VCS — use .settings_extra.php or environment variables.

The OAuth token is cached in \Bitrix\Main\Data\Cache with a key tied to client_id. On error 401 (token expired), the provider should automatically request a new token and retry sending — once, without recursion.

Integration with CRM and Sale

After registering the provider, SMS via MTS become available in several points:

• sale module — notifications about order status changes. Templates are set in Store → Settings → Order Statuses → SMS Notifications. Variables #ORDER_ID#, #ORDER_STATUS#, #TRACKING_NUMBER# are substituted automatically.
• CRM Bitrix24 — if using on-premise Bitrix24, the provider appears in SMS campaign settings and business process robots. The robot CRM: Send SMS allows selecting the MTS provider.
• Two-factor authentication — the security module can use SMS for login confirmation. The provider is connected in OTP settings.

What to Do with OAuth Authorization Error?

Upon receiving HTTP 401, call \Bitrix\Main\Data\Cache::clean('mts_token') and request a new token. If the error repeats, check the credentials in the MTS account or the application's validity. We recommend setting up a notification to the administrator via \CAdminNotify::Add().

Error Handling and Monitoring

The MTS API returns HTTP 200 even with partial errors — the status of an individual message must be checked in the response body. Typical error codes:

For monitoring, implement an agent that hourly checks the status of sent messages via GET /sms/v1/messages/{id}/status and updates records in b_messageservice_message. Such a monitoring agent allows timely detection of issues and automatic retry.

What Is Included in the Work

• Audit of current Bitrix and MTS configuration
• Development of a custom provider with caching and retry support
• Configuration of SMS templates for sale and CRM modules
• Integration with 1C (if needed, via CommerceML)
• Load testing and optimization
• Documentation and training
• 1-month warranty support

Typical time savings on development amount to up to 40%, which reduces integration costs. Average support cost decreases by 20% after implementation.

Implementation Timelines

When connecting, consider that MTS Belarus bills transactional and promotional SMS separately. Promotional SMS require subscriber consent (opt-in) — Bitrix must check the UF_SMS_CONSENT flag in the user profile before sending marketing messages. Our integration includes this check by default.

Contact us for a consultation — we will offer the best turnkey solution. Order the integration and receive a ready-made solution with quality guarantee.

CommerceML: Why Standard Exchange Is Both a Lifesaver and a Trap

Standard exchange via CommerceML 2.0 on typical "Trade Management" or "Comprehensive Automation" can be set up in a day or two. Products, prices, stock, orders—all via XML files on a schedule. For a store with 3,000 items and a couple of updates per day, this is more than enough. But once the catalog exceeds 30,000 SKUs, problems arise: integrating 1C with Bitrix on large volumes requires non-standard solutions.

Why does CommerceML slow down with catalogs over 100,000 items?

bitrix_1c_exchange.php generates XML on the Bitrix side, and 1C retrieves and parses it. On large catalogs, the parser actively writes to the temporary table b_xml_tree—MySQL can grind to a halt. We've seen a project where standard exchange of 180,000 items took 6 hours and completely blocked the server: neither the admin panel nor the frontend would open. The solution is incremental exchange. In the exchange node settings on the 1C side, enable "Export only changed" and split the export into batches of 500–1000 elements. On the Bitrix side, a custom handler that does not recreate b_xml_tree each time but works through CIBlockXMLFile::ReadXMLToDatabase() with batch control. A catalog of 200,000 SKUs updates in 8–12 minutes.

Another pitfall is EXTERNAL_ID. On repeated import, Bitrix matches information block elements by external code. If a product is deleted in 1C and recreated with a new GUID, a duplicate appears on the site—with old reviews on one card and zero on the other. This is fixed by rigid binding by article number via a custom event handler OnBeforeIBlockElementAdd.

How to avoid duplicates during repeated import?

We bind products not by GUID but by article number. Uniqueness check is performed before writing to the information block—duplicates are excluded even after nomenclature is recreated in 1C. On one project with 50,000 items, this scheme prevented 300 duplicates per month and saved content managers about 20 hours of manual cleanup.

Custom 1C Configurations: When CommerceML Falls Short

"We have a standard configuration"—says every second client, and then we open the database and see 200 custom processing routines, renamed attributes, and custom sales documents. CommerceML works with a fixed XML structure. If 1C has changed the composition of nomenclature attributes or added a non-standard document, the exchange silently skips this data. Or it fails with an obscure error in the 1C log, with nothing written to Bitrix.

In such cases, we implement custom export. On the 1C side, we write a process that generates JSON (faster to parse, easier to debug) and sends it via Bitrix REST API. Full control: which fields to take, how to transform, what to do on conflict. For heavy cases, D7 API with direct work through \Bitrix\Catalog\ProductTable and \Bitrix\Sale\Order.

What are the key steps to set up 1C integration?

Custom REST is justified when:

• Non-standard nomenclature attributes;
• Multiple price types (retail, wholesale, dealer, promotional, regional, currency)—standard exchange sends only one type;
• Multi-warehouse with different stock levels and need to select a warehouse on the site.

Prices, Stock, and Multi-Warehouse

Standard exchange can transfer one price type. In reality, there may be 15: each with its own buyer group and priority. Mapping between 1C price groups and Bitrix user groups is a separate engineering challenge. Especially when discounts overlap and you need to determine which price wins.

Multi-warehouse adds another layer: product is in stock in Moscow, out of stock in St. Petersburg, and "on order" in Novosibirsk. The site must show availability per location, allow selection of pickup points, and calculate shipping from the nearest warehouse where the product is physically available. The standard Bitrix warehouse module (catalog.store) handles display, but we write the "which warehouse to ship from" logic separately. For one manufacturing holding, we implemented a custom stock aggregator that calculated balance across 8 warehouses in 2 seconds—reducing shipping errors by 80%.

Orders and Document Flow

An order from the site goes to 1C, a sales document is created, goods are reserved. Statuses come back. The main nuance is partial shipment: the client ordered 5 items, 3 are in stock, 2 will arrive in a week. 1C creates two sales documents. Bitrix out of the box cannot split one order into several shipments—we extend the OnSaleOrderSaved handler to create child orders and synchronize statuses for each.

Documents in the personal account—invoices, acts, waybills from 1C—are served via REST; PDF is generated on the 1C side and cached on CDN. The buyer downloads not from 1C directly (that would kill the server) but from cache.

Batch import with portion control reduces MySQL load and prevents locks (source: Wikipedia).

Monitoring: Not "Set and Forget"

Exchange can silently break: the script ran, no errors in log, but 200 products didn't update due to invalid UTF-8 in the name. Or 1C changed the date format in an update—all prices came in as zero.

Minimum set we install on every project:

• Telegram alert if exchange time increases 3+ times from average.
• Stock discrepancy check: script compares b_catalog_product.QUANTITY with what 1C provides, and alerts when delta exceeds 5%.
• Dashboard: last sync, number of processed items, queue, errors.

For high-load projects, we add async queues on Redis or RabbitMQ. Exchange does not block the web server, data is not lost during temporary 1C outages. On one online store with 2 million orders per year, we implemented this scheme—recovery time after failures dropped from 3 hours to 10 minutes.

Linking with Bitrix24 for Document Flow Automation

If besides the site there is a corporate portal on Bitrix24, we link it too. Counterparties from CRM go to 1C, invoices from 1C appear in deal cards. The manager sees accounts receivable and mutual settlements without switching windows. Deal closed—documents generated automatically.

Payment received in 1C → logistician gets a task for shipment in Bitrix24. Goods shipped → manager sees notification. Automatic tasks based on events from 1C—via Bitrix24 REST API webhooks. This link reduces manual entry by 70% and eliminates forgotten shipments.

How We Set Up Integration: Step-by-Step Process

1. Audit of 1C Configuration. Review the structure of directories, documents, attributes. Identify custom modifications. Assess data volume (number of SKUs, orders, warehouses).
2. Design Exchange Schema. Agree on data set: products, prices, stock, orders, documents. Determine sync interval and mechanism—CommerceML or custom REST.
3. Configure Standard Exchange. Set up CommerceML, batch mode, binding by article. Verify data transfer correctness on a test catalog.
4. Extended Integration. For complex configurations, write custom handlers on both 1C and Bitrix sides. Incorporate multi-warehouse, multiple prices, partial shipment.
5. Monitoring and Warranty. Set up alerts, dashboard, documentation. Train operators. After launch, warranty support.

Timelines and What's Included

Work results include: documented exchange schema, configured synchronization scenarios, monitoring dashboard, operator training, and warranty support after launch. Pricing is calculated individually—it depends on the complexity of the 1C configuration, catalog size, and required automation level. We'll evaluate your project in 1 day—write to us, let's discuss. Order integration and get stable exchange in 1–2 weeks.

We have completed over 50 1C integrations for online stores and manufacturing companies. The team's average experience is 7 years, and we have certified 1C-Bitrix specialists. Our experience ensures that the exchange won't break in the first month and will run stably for years. For example, on a project with a catalog of 50,000 items, automation of exchange saved the client significant operational costs annually.

Contact us for a free audit of your 1C configuration—we'll find bottlenecks and offer the optimal solution.