Bitrix24 Mobile App Integration via REST API and Webhooks

Bitrix24 Mobile App Integration via REST API and Webhooks

Imagine a manager updates a deal in the web version while the mobile app still shows stale data. Clients complain about delays, and employees waste time manually re-entering information. Without integration, synchronization lags by hours. We solve this using the Bitrix24 REST API, webhooks, and push notifications, delivering real-time updates to your app. With over 5 years of integration experience and 30+ successful projects, we deliver robust solutions.

The OAuth 2.0 Authorization Process

According to Bitrix24 documentation, OAuth 2.0 is the recommended authorization method for mobile apps. Bitrix24 uses the Authorization Code Flow. The mobile app opens a WebView or Chrome Custom Tab with the authorization URL:

https://{portal}.bitrix24.ru/oauth/authorize/?
  client_id={app_id}&
  response_type=code&
  redirect_uri={deeplink}

After successful authorization, a code is returned, which is exchanged for access_token and refresh_token. The access_token lives for 1 hour, the refresh_token for 30 days. Token refresh uses the standard grant_type=refresh_token. Store the refresh_token in Keychain/Keystore for security.

How to Set Up OAuth 2.0 for Your Mobile App: Step-by-Step

1. Register your app in Bitrix24 (Developers → Applications).
2. Specify the redirect URI as a deep link (e.g., myapp://oauth).
3. Implement a WebView or Chrome Custom Tab with the authorization URL containing client_id, response_type=code, redirect_uri.
4. After receiving code, send a POST request to https://oauth.bitrix24.ru/oauth/token/ with grant_type=authorization_code, client_id, client_secret, code, redirect_uri.
5. Save the obtained access_token and refresh_token in Keychain/Keystore. Refresh the token every hour using grant_type=refresh_token.

Incoming webhooks are a simpler option without OAuth. The webhook URL contains an access token that allows API calls without user authorization. This is convenient for server-side integration, but storing a webhook on a mobile client is risky: a leak gives full portal access. OAuth 2.0 is safer for mobile apps.

Core API Methods

Work with deals via Retrofit:

interface Bitrix24Api {
    @GET("crm.deal.list")
    suspend fun getDeals(
        @Query("auth") token: String,
        @Query("filter[STAGE_ID]") stageId: String,
        @Query("select[]") fields: List<String>,
        @Query("start") offset: Int
    ): Bitrix24ListResponse<Deal>
}

The start parameter is the offset for pagination. Bitrix24 returns a maximum of 50 records per request. The response includes next for the next offset and total for the total count. To load the full list, request pages sequentially until next is null.

Request limit: 2 requests per second for both OAuth and incoming webhooks. Batch processing groups up to 50 calls into one HTTP request, increasing effective throughput 50x.

{
  "halt": 0,
  "cmd": {
    "get_deals": "crm.deal.list?filter[STAGE_ID]=NEW",
    "get_contacts": "crm.contact.list?filter[TYPE_ID]=CLIENT"
  }
}

What Is the Batch Method and How Does It Speed Up Sync?

The batch method allows up to 50 REST calls in one HTTP request. Pass a JSON with a cmd parameter where keys are arbitrary names and values are methods with parameters. The response contains results of all commands. This reduces the number of requests, helps bypass limits, and speeds up synchronization of large data volumes. For 1000+ records, combine batch with pagination.

How Outbound Webhooks Provide Real-Time Notifications

An outbound webhook in Bitrix24 sends a POST request to a specified URL when an event occurs: deal change, new lead, task update. The server receives the event, identifies the type, and sends a push notification to the device. Bitrix24 sends only the ID and event type; to get full data, an additional crm.deal.get request is needed. This adds a 1-2 second delay but ensures data accuracy.

Commonly used events:

For tasks: ONTASKADD, ONTASKUPDATE. For activities: ONCRMACTIVITYADD.

How to Bypass Bitrix24 Request Limits

Regardless of the authorization method, Bitrix24 limits to 2 requests per second. Exceeding returns a WRONG_REQUEST error. Batch processing effectively increases throughput 50x. For large data sync, combine batch and pagination.

Telephony and Calls

Bitrix24 logs calls via voximplant.infocall.startwithsound or telephony.call.attachbyqueue. For a mobile app, you can initiate click-to-call: telephony.externalcall.register creates a call record in Bitrix24 linked to the client. After the call, telephony.externalcall.finish with duration and result. For VoIP calls in the app, integrate with Voximplant or Twilio via REST.

What’s Included in Integration Work?

• Analytics: Review current processes, select entities to synchronize.
• Design: Integration architecture, protocol choice (REST/Webhook/Batch), token scheme.
• Implementation: OAuth setup, API client development, pagination and offline buffer.
• Testing: Integration testing, load testing up to 1000 deals.
• Documentation: API methods description, data schemas, support instructions.
• Post-release support: 2 weeks monitoring, bug fixes.

We ensure stable integration compliant with App Store Review Guidelines (Section 5.1) and Google Play Store policies.

Timeline and Cost

Basic integration (deals, contacts, tasks) with OAuth and pagination: 1-2 weeks. Adding webhooks, push notifications, and offline buffer: +1 week. Cost is calculated individually — request a project assessment in 1 day.

Case Study: Real Results

For a logistics client with 50+ managers, we integrated Bitrix24 with their custom mobile app. Using batch processing and webhooks, we cut the sync delay from 10 minutes to under 2 seconds, reducing manual data entry by 95%. The integration paid for itself in three months through operational efficiency.

Common Pitfalls to Avoid

• Storing webhook tokens on mobile: Always use OAuth 2.0 for mobile clients.
• Ignoring refresh token expiry: Renew tokens before the 30-day window to avoid disruption.
• Not using batch for bulk operations: Batch calls reduce limit errors and speed up sync.
• Forgetting to handle offline scenarios: Implement an offline buffer to avoid data loss.

Contact us for a consultation. Share your requirements, and we’ll assess your project within one business day.

How to Start Integrating API into a Mobile App?

The request goes out, the response doesn't come, timeout — 30 seconds. The user stares at the spinner. No network — mobile card in the subway. Or the network is there, but the server returns 200 with an HTML error page instead of JSON — and the app crashes on JSONDecoder.decode(). We see such cases on every second project. So integrating API into a mobile app is not just calling an endpoint, but designing a reliable network layer: error handling, caching, offline mode, certificate pinning. Order an audit of your current network layer — we will evaluate the project in 1 day. Our team guarantees a thorough analysis and provides a detailed roadmap.

Standard libraries like URLSession and OkHttp provide basic HTTP clients, but for production you need retries with exponential backoff, status code validation, typed deserialization, and network state monitoring. Without this, the app loses data and users. We have been doing mobile development for 5 years and implemented more than 30 projects with API integration on iOS, Android, and Flutter — from startups to enterprise solutions.

How to Choose a Protocol for API Integration?

REST remains the standard for most projects. But when a profile screen needs 5 fields out of 40, GraphQL eliminates over-fetching and reduces traffic by 30–60%. gRPC is justified for thousands of requests per minute (trading, IoT) — binary serialization is 3–5 times faster than JSON. WebSocket is the only choice for real-time without polling (messages, notifications).

Practical example: For a fintech app, we replaced REST (40 fields) with GraphQL — response size dropped from 12 KB to 2.5 KB, screen render time decreased by 70%. Traffic savings were significant. Our certified iOS and Android developers have deep experience with all these protocols — you can rely on proven solutions.

How to Ensure Reliable Connection and Offline-First?

Users lose network in the subway, elevator, tunnel. A mobile app must work without internet — at least in read-only mode. We implement the offline-first pattern:

1. On screen open, first show data from the local cache (Core Data / Room).
2. Simultaneously perform a network request, update UI after response.
3. If network is unavailable — show cached data and a 'no connection' label.
4. When network is restored, automatically synchronize changes.

For HTTP response caching we use URLCache (iOS) and OkHttp Cache (Android) with Cache-Control support. For structured data — SwiftData / Room. NWPathMonitor / ConnectivityManager.NetworkCallback monitor network state and trigger updates.

REST and Client Library Selection

Alamofire (iOS) — de facto standard for Swift projects. On top of URLSession it adds request chaining, response validation, automatic retry, certificate pinning via ServerTrustManager. AF.request() with .validate() returns an error for any status code outside 200–299. Without .validate(), Alamofire considers 404 and 500 as successful responses. With Swift Concurrency — async version via serializingDecodable.

Retrofit (Android) — annotation-based HTTP client on top of OkHttp. An interface with annotations compiles into implementation. @GET, @POST, @Path, @Query, @Body — declarative API description. OkHttp under the hood: connection pooling, transparent gzip, HTTP/2 multiplex. HttpLoggingInterceptor — logging in debug builds. Authenticator — automatic token refresh on 401.

Ktor (KMM/Flutter) — multiplatform HTTP client. On iOS it works via Darwin engine (URLSession), on Android — via OkHttp. Single code for both platforms with KMM architecture.

GraphQL: When REST Falls Short

REST returns a fixed structure. A profile screen needs name, avatar, email — the server sends 40 fields. Over-fetching. GraphQL solves this: the client requests exactly the needed fields. This is critical for mobile where traffic and parsing time are real constraints. Apollo iOS and Apollo Kotlin generate typed classes from schema: schema.graphql + query files → strict types at compile time. Subscriptions via WebSocket — real-time without polling. Limitation: GraphQL is harder to cache at the HTTP level. Apollo uses a normalized in-memory cache InMemoryNormalizedCache — requests with overlapping data update the cache without duplication.

WebSocket: Real-Time Without Extra Traffic

Polling (setInterval every 5 seconds) — battery and traffic waste. WebSocket is a persistent bidirectional connection. iOS: URLSessionWebSocketTask (native, iOS 13+). Android: OkHttp WebSocket. Mandatory reconnect handling: on onFailure — exponential backoff (1s → 2s → 4s → 8s → max 60s). Socket.IO is an overlay with automatic reconnect, but for new projects native WebSocket is preferable (fewer dependencies).

gRPC: For High-Load Services

gRPC with protobuf — binary serialization: smaller size, faster parsing. grpc-swift for iOS, grpc-kotlin for Android. The protobuf schema compiles to typed classes. Streaming (server-side, client-side, bidirectional) is a native feature. Application threshold: high request frequency (trading, IoT) or critical latency. For regular CRUD, REST is simpler to debug and monitor.

Certificate Pinning and Security

A corporate proxy can intercept HTTPS by substituting the certificate. Certificate pinning prevents this: the app accepts only a specific certificate or public key. Alamofire: ServerTrustManager with PinnedCertificatesTrustEvaluator. OkHttp: CertificatePinner with SHA-256 hash. Apple's App Transport Security documentation recommends pinning certificates for sensitive data. Operational complexity: on certificate rotation, older app versions stop working. Solution — pinning to the CA public key or support multiple pins with a grace period.

What Is Included in the Work

We deliver: source code of the network layer, documentation on used libraries, certificate rotation instructions, 2 weeks post-delivery support. Our experience guarantees that the solution will be stable and maintainable.

Timeline and Cost

Implementation of a network layer with REST, retry, caching, and offline mode — 1–2 weeks. Adding GraphQL or WebSocket — another 1–2 weeks. gRPC — 2–3 weeks, including code generation. The cost is calculated individually after analyzing the API and offline behavior requirements. We will evaluate the project in 1 day — contact us for a consultation. Get a reliable API integration with guaranteed quality.