Building apps for cars: A beginner's guide to car APIs

Winona Rajamohan

Content Marketing Manager

From Tesla to Stellantis to Ford and General Motors, automakers are fueling their revenue engines by doubling down on software services. But innovation in the mobility industry cannot solely rest on automakers — it must be accessible to all developers with a vision to move the needle for vehicle owners.

Unfortunately, third-party developers have traditionally lacked standardized resources to build innovative apps that integrate with vehicles.

Some mobility businesses are forced to build and maintain fragmented connections with multiple APIs to serve their target audiences. Others are forced to turn to hardware devices to retrieve vehicle data despite the strain it imposes on overhead costs.

These challenges can pigeonhole products to limit their offerings to one or two vehicle brands. When apps aren’t built on an agile infrastructure for future expansion, it becomes difficult to serve emerging markets and new business models.

In this guide, you will learn how mobility companies accelerate market readiness by building their apps and services with a car API platform.

What does a car API look like in action?

Turo, the world’s biggest peer-to-peer marketplace, found that 36% of hosts list more than one car on the platform, making it difficult for hosts to show up in person for conflicting booking times. To help vehicle owners with unused cars find the most success with a peer-to-peer car sharing model, Turo needed a solution that could:

  1. Help hosts accommodate clashing bookings and rentals that take place after traditional operating hours
  2. Make it convenient for renters to find and access a vehicle without meeting hosts in-person
  3. Ensure vehicle security, customer safety, and smooth transactions in a contactless environment

To deliver this value to hosts, the company launched Turo Go to offer a contactless car sharing feature with vehicle integrations powered by a car API.

What is a car API?

A car API is a software intermediary that allows software applications and vehicles to talk to each other. When a mobility app sends an API request to a vehicle, data is retrieved to enable a particular functionality for end-users.

In the case of a vehicle owner linking cars to Turo Go, an API request is used to access a vehicle’s location and lock or unlock the vehicle’s doors. Turo uses Smartcar’s platform to manage these API integrations across multiple vehicle makes and models.

Smartcar’s car API platform helps businesses work with a suite of standardized integrations to over 112 million cars across 23 vehicle brands — much like how Plaid and Stripe have simplified payment integrations to different credit cards and banks.  

This allows the mobility industry to expand on traditional services and offer new customer-driven models like peer-to-peer car sharing.

📖 Additional reading:

What is Smartcar? 👉 Learn how mobility businesses use Smartcar's APIs to scale services across vehicle makes and models.


How car APIs are redefining EV apps 👉 Examples of how are EV apps using car APIs to reduce friction in EV ownership

How does a connected car API integrate with vehicles?

Integrating a mobility app to vehicles with an API removes the need for devices plugged into a car’s onboard diagnostics port. But the absence of a hardware component does not make vehicle data less accurate or valuable.

Roughly 90% of innovation in the automotive space comes from software. So, it’s not a surprise to see more vehicles built with software-upgradeable features and wireless connectivity instead of ports for pluggable hardware devices.

What makes this possible? Here are a few important concepts you need to know:

Connected cars 🚗

A connected car is equipped with a 3G, 4G, or 5G cellular modem right from the factory. Internet connectivity in cars enables communication between vehicles and apps.

Beyond safety, infotainment, and navigation features, connected cars give drivers the ability to personalize their vehicle experience with digital solutions for auto insurance, car-sharing, EV charging, and more. Businesses have more opportunities to customize their services to better cater to a driver’s frequency of travel, location, and budget.

Here’s a popular question: “How many connected cars are on the road?”

Today there are approximately 237 million connected cars owned worldwide. Connected cars made up 41% of new car sales globally in 2020. Researchers expect 96% of new vehicles worldwide to be shipped with vehicle connectivity in 2030.

The growth of the connected car market is driven by a shift in consumer expectations. A survey conducted by PwC found that drivers in the United States do want vehicle connectivity, especially to improve navigation, road safety, and on-demand functions.

The importance of connected car services for consumers
Source: Digital Auto Report 2021

Embedded telematics 📶

“Telematics” is the technology that transfers information between telecommunication devices, computers, GPS satellite systems, and objects.

Embedded telematics is used to describe telematics technology found in automotive vehicles. Vehicle data — like GPS locations, odometer readings, or battery levels — are uploaded to a vehicle manufacturer’s cloud through the built-in cellular modem.

When the connected vehicle is linked to a cellular network, it becomes a device that can connect with other internet-connected devices.

Connected services accounts 📱

A connected services account allows you to remotely monitor and control your car using your car manufacturer’s mobile app. Each car manufacturer offers its own connected services account with a dedicated mobile app.

If your car is connected and uses embedded telematics, vehicle telemetry can be accessed by downloading your car manufacturer’s connected services application.

For example, Jeep’s connected services account and mobile app are both called Uconnect. On the other hand, BMW’s connected services account is called BMW ConnectedDrive while their mobile app is called BMW Connected.

You can find a more comprehensive list here of connected services and mobile apps. You can also head over to connectyourcar.com to check if your vehicle is eligible to integrate with Smartcar.

API access tokens ⚙

A third-party app can access vehicle data by either obtaining the login credentials to a connected services account, or by generating an access token to make an API request to the vehicle.

The latter option helps apps and services:

  • Reduce the risk of jeopardizing a customer’s private data
  • Implement a granular permissions system to authorize access based on user preferences

All requests made to a car API like Smartcar require an access token. The access token gives apps a secure way to make the API request, authorize connectivity to a vehicle, and then interact with that vehicle.

Smartcar’s platform is built to help apps send API requests to vehicles across different brands with a single integration.

The first step our customers take is by adapting Smartcar Connect — our OAuth 2.0 authorization flow — to their application architecture. From there, Smartcar can begin communicating with vehicles after a few clicks from the driver’s end.

📖 Additional reading:

Smartcar integration guide: 👉 Take a look at our docs to see how companies integrate with Smartcar to communicate with vehicles

Integrating with an API vs hardware devices

Mobility businesses build with a connected car API to avoid the following bottlenecks:

  • High cost of buying, installing, and shipping hardware like OBD-II dongles
  • Complex technical support for vehicle owners installing hardware themselves
  • Limited access to data from a wide range of vehicles
  • Difficulty customizing and evolving service areas for critical use cases

For battery report software Recurrent, retrieving data from connected vehicles saves time and lowers the cost of building large pools of battery health data across different vehicle makes and models. By streamlining API integrations with Smartcar, Recurrent was able to accelerate production by 6 to 12 months while saving millions of dollars in engineering resources.

How car APIs empower Mobility-as-a-Service

According to the MaaS Alliance, Mobility-as-a-Service (MaaS) is the integration of different types of transport services into a mobility service that’s accessible on demand. The apps we’ve talked about in this example are a few examples of how MaaS is changing the way consumers can interact with cars and transportation using technology.

The MaaS sector is expected to reach $40.1 billion by 2030. What drives this rapid growth? Automotive manufacturers, service providers, and partners that work together to innovate beyond typical offerings.

Capitalizing on API-driven software connectivity eases the crossover between sectors like automotive, technology, and government. This leads to better funding, technology, and research and development to create improved consumer experiences.

Today, the intersection of software and technology through a car API is helping businesses in several ways:

Strengthen existing revenue streams: Businesses are using APIs to improve customer services, like how Axiom is streamlining auto warranty management through their app, Axiom Connected.

Build new revenue streams: Coastr uses API integrations to enable keyless car entry, empowering small rental businesses to introduce new target audiences or adopt peer-to-peer car sharing.

Create new business models: Software-based integrations open up the door for new players and services in the mobility ecosystem, like pay-per-mile road taxes and solutions to help drivers calculate insurance premiums and discounts.

Is a car API platform the right choice for you?

A car API will prove helpful if your business is building a mobility app that:

  • Integrates with more than one car brand: Rolling Energy Resources (RER) works with utilities to power demand response with comprehensive EV load research. A car API platform helps RER gather data from a broad range of EVs to build insightful datasets.
     
  • Gives customers the choice of consenting to shared data: Tolling solution, Emovis, launched a pay-per-mile road tax program for the state of Utah. Consent-based data collection helps Emovis ease digital privacy concerns for drivers participating in a new form of tax collection.
     
  • Competes in a high-growth sector: We mentioned how Recurrent sped up production by 6 to 12 months by retrieving data with a car API platform. This speed to market was important for them as a pre-seed startup in the EV battery software space.
     
  • Requires heavy developer resources on product development: Managed charging app, Optiwatt, expanded vehicle support without building multiple third-party API connections on their own. This allowed them to focus on building product value for users rather than integration management.

Smartcar’s API is used by mobility services in many industries, from auto insurance to EV charging, car sharing, and even web3. To get started with our API, take a look at our docs or talk to our team today!

Everything you need to know about car APIs. Delivered monthly.

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