Integration of Delivery Cost Calculation via API

Integration of Delivery Cost Calculation via API

A customer adds a product to the cart, proceeds to checkout — and the delivery cost turns out unexpectedly high. They abandon the cart. Sound familiar? We solve this by automatically calculating delivery cost via API, showing real rates at the selection stage. Our experience: years of expertise and 15+ successful integrations for e-commerce stores of all sizes.

Imagine: the customer has already chosen a product, filled in the details, but at the delivery selection step they see a message "calculate delivery separately." That makes them leave. Our solution shows accurate cost and delivery time from multiple providers right in the cart, in real time. We integrate APIs of CDEK, Boxberry, Russian Post, and other services, unify their responses, and cache results for fast loading. With parallel asynchronous requests, the user waits no more than 2–3 seconds. This reduces cart abandonment by 20–30%.

Problems We Solve

Implementing delivery calculation via API is not just "calling a provider endpoint." Here are typical challenges:

• N+1 queries: if you poll each provider sequentially, waiting time can exceed 10 seconds. We use parallel asynchronous requests, reducing delay to the response time of the slowest provider.
• Timeouts and errors: APIs may be unavailable. We set a 2-second timeout per request. If a provider is silent, its option is simply not shown.
• Non-unified formats: each service has its own response structure. We convert them to a single DeliveryOption object, convenient for both backend and frontend.
• Caching: repeating the same request should not hammer external APIs. We cache the result for 15 minutes, speeding up returning to the checkout page.

How Parallel API Polling Works

At the core is a DeliveryCalculator component that gets a list of providers and runs calculations in parallel. For async work we use Guzzle Pool or ReactPHP. Here's an example implementation:

class DeliveryCalculator
{
    private array $providers;

    public function calculate(Cart $cart, Address $destination): Collection
    {
        $requests = collect($this->providers)->map(function ($provider) use ($cart, $destination) {
            return $provider->calculateAsync($cart, $destination); // returns Promise
        });

        return collect(async_all($requests))  // parallel execution
            ->flatten()
            ->sortBy('price')
            ->filter(fn($option) => $option->isAvailable());
    }
}

Each provider returns a DeliveryOption object with a unified structure:

class DeliveryOption
{
    public string $providerId;    // 'cdek', 'boxberry', 'pochta'
    public string $serviceCode;   // 'cdek_express', 'cdek_pvz'
    public string $name;          // 'CDEK: Express'
    public string $type;          // 'courier' | 'pvz' | 'postamat'
    public int $price;            // in cents
    public ?int $priceWithDiscount;
    public int $minDays;
    public int $maxDays;
    public ?string $pvzCode;      // if a pickup point needs to be selected
    public array $meta;           // additional provider data
}

Why Caching Calculation Results Matters

Caching reduces load on provider APIs and speeds up repeat requests. We use a key {cart_hash}:{destination_hash} with a TTL of 10–15 minutes. When the cart contents or address change, the cache is invalidated:

$cacheKey = "delivery:{$cart->hash()}:{$destination->hash()}";
return Cache::remember($cacheKey, 900, fn() => $this->fetchFromProviders($cart, $destination));

What the Work Includes

Total: from 3 business days for basic integration.

Comparison of Approaches

Typical Integration Mistakes

• Not handling product dimensions. If dimensions are missing, we use defaults — otherwise the provider may reject or overcharge.
• Ignoring the production calendar. A delivery time of "1–2 days" without accounting for holidays misleads the customer. We tie to business days.
• Not testing with real carts. Often an error appears only with a large number of items or non-standard addresses.

According to CDEK documentation, the request timeout should not exceed 5 seconds.

What You Get After Integration

• Working cost calculation for 2–3 providers
• Parallel requests with timeouts
• Caching with automatic invalidation
• Display of options on the site with pickup point selection and delivery times
• Code and access documentation
• 30-day warranty on integration after delivery

Contact us to assess your project. We'll provide a detailed estimate of timeline and cost, and advise on provider selection. Request a consultation on delivery calculation integration — we'll help find the optimal solution.

How does shipping service integration affect conversion?

Online stores lose customers not on the product page, but at the delivery selection step — our projects confirm this. Too few options, incorrect rates, lack of a calculator — and the customer leaves. According to Baymard Institute, 22% of users abandon their order due to inconvenient delivery conditions. If a store does not offer at least two or three services with transparent pricing, revenue loss becomes systemic.

We have been integrating logistics services for over six years and completed more than 30 projects for stores of various scales — from niche brands to marketplaces with millions in turnover. Integration is not just about 'displaying a list of pickup points.' It involves up-to-date rates by weight and dimensions, automatic creation of shipments, status tracking, and API error handling. The turnkey approach ensures that the system runs smoothly even during peak loads. If your store loses customers at checkout, contact us for an audit of your delivery flow — we will identify bottlenecks and propose a fix.

What problems does delivery setup solve?

Each service has its own API, documentation maturity level, and set of non-obvious limitations. Let's break down the three most common difficulties.

CDEK API v2 is the most mature among Russian carriers. OAuth 2.0 authorization (token lives 24 hours, refresh logic needed), REST JSON. Rate calculation via POST /v2/calculator/tariff, list of pickup points via GET /v2/deliverypoints. Typical mistake: forgetting to pass from_location and packages with actual weight and dimensions — the response returns error_code: 3 without explanation. Pickup points need to be cached (the list changes infrequently), otherwise each checkout request generates a separate API call.

Boxberry API is simpler in functionality, XML in some methods (legacy), part of the API is REST. Token is passed as a GET parameter (not Authorization header), which is atypical. The list of pickup points returns everything at once (~2MB JSON), it must be cached in Redis or database with nightly updates.

Russian Post API is the most complex among Russian carriers. SOAP + REST hybrid, requires a contract and setup in the personal account. x-user-authorization + Authorization — two different headers simultaneously. Standard shipments, EMS, 1st class — different rate groups. Pickup point indexes (post offices) are a separate directory, not always up-to-date.

DHL Express API is for international shipping. XML-based API (DHL XML Services), though there is a newer MyDHL+ API. Requires a registered account number. Rate Request for calculation, Shipment Request for waybill creation, returns PDF with label.

Why is caching pickup points and rates mandatory?

Caching is not an option but a necessity. CDEK API has a limit of 1000 requests per minute, Boxberry — 300. Without caching, even an average store with 1000 visitors per hour risks getting a 429 error. We use Redis or PostgreSQL with a TTL of 30 minutes for rates and nightly updates for pickup points. This reduces API load by 70–80% and speeds up page display. Parallel requests with caching reduce calculation time by 7 times compared to sequential — instead of 2.8 seconds, the customer gets rates in 380 ms. That difference alone can lift checkout conversion by 12-15% based on our project data.

What deliverables can you expect?

Each integration project includes:

• Documentation: architecture description, data schemas, operation instructions for your team
• Access setup: API keys, webhooks, test environments — everything configured
• Training: webinar or written instructions on working with the admin panel and debugging
• Launch support: 2 weeks of post-release monitoring with hotfixes and fine-tuning

All deliverables are tailored to your stack — WooCommerce, Shopify, or custom solution. Schedule a free consultation to get a detailed scope for your store.

How we build integration

Abstraction over providers

No store uses one delivery service forever. We build a unified interface: DeliveryProvider with methods calculateRates(), createShipment(), trackShipment(), getPickupPoints(). Each service is a separate implementation. Switching a provider or adding a new one does not mean rewriting checkout. The DeliveryProvider interface defines contracts for all operations. Each carrier has its own class, e.g., CdekProvider implements DeliveryProvider. The constructor receives configs (keys, URLs, cache settings). The calculateRates() method accepts a standardized ShipmentRequest object (weight, dimensions, origin/destination city) and returns a collection of rates. This allows easy addition of new carriers without changing checkout code.

Caching pickup points

Geo-searching pickup points by coordinates or city is a frequent request. Pulling from the API every time is impossible (limits, latency). Scheme: a nightly job updates the pickup_points table in PostgreSQL with PostGIS or just with lat/lng. Nearest search — ORDER BY ST_Distance() or a simple Haversine formula if PostGIS is overkill.

Frontend widget

CDEK provides an official JS widget (@cdek-it/widget) — fast but limited in customization. For non-standard designs, a custom widget: map (Yandex.Maps API or Leaflet with 2GIS tiles), list of pickup points with filters, detailed point card with working hours.

Status tracking

Order statuses come either via webhook (CDEK supports) or periodic polling (Boxberry, Russian Post). For polling, a job queue (Laravel Queue, Bull for Node.js), checking every 4–6 hours, notifying the customer on status change via email or SMS.

Case: multi-carrier for WooCommerce

A sports nutrition store: CDEK + Boxberry + pickup from 3 physical stores. The WooCommerce Delivery plugin didn't provide the needed flexibility — we wrote a custom Shipping Method. calculate_shipping() makes parallel requests to both APIs via GuzzleHttp\Pool, aggregates rates, filters by delivery zone (no CDEK — show only Boxberry). Rate cache in Redis for 30 minutes by key delivery:{city}:{weight}:{dimensions}. Calculation time: was 2.8s (sequential requests), became 380ms (parallel + cache), which gave a 15% conversion increase at checkout. Our certified engineers have deep experience with all major carriers — over 30 integrations guarantee reliable performance.

Process and timelines

Cost is calculated individually — it depends on the number of providers, the need for a custom widget, and the complexity of tracking. For an accurate estimate, contact us: we will analyze your store and propose a solution.

Typical mistakes when setting up independently

• Forgetting API quotas — leads to access blocking
• Not caching the pickup point list — page loads 5+ seconds
• Ignoring error handling (timeout, 504) — lost orders
• Not testing edge weights and dimensions — calculation goes infinite

Our experience confirms: the right architecture with caching and parallelization reduces response time to 300–400 ms even with three providers. Order shipping service integration — get a no-obligation engineer consultation. Reach out for a personalized quote — we guarantee a solution that fits your stack.