Blockchain API


Blockchain technology is the perfect tool to avoid middlemen in transactions, to solve issues with counterparty trust, and to secure information on a tamper-proof ledger, to name just a few key examples. The CoreLedger TEOS API gives you all this blockchain functionality and more in an accessible programming interface so you can quickly build or beef-up almost any digital use case. It’s ideal for web applications, accounting and banking software, tools for notarization, or supply chain management and logistics

API Integration

Typical use case

Businesses use API’s to save time and money in development and to leverage expertise. The typical use cases for API integration are:

Integration into Existing Software

Integrating blockchain functionality into existing software via an API. This is typically for running businesses that just want to enrich their software with core blockchain functions to leverage their business and reach new customers.

Building a New Application

Building a brand new web application. This is typically startups or enterprises with a new business idea that want to go to market quickly and save years of backend development.

With our TEOS API, you can add an unforgeable timestamp and property to any artifact, document or financial asset. You can build and integrate entire ecosystems, payment methods (your own utility token) or digital access control mechanisms. The API is extremely useful to extend existing apps with blockchain functionalities or to add token-handling to financial applications or even to an entire banking infrastructure. The TEOS API can also be used in programs for common computing platforms like Windows/Mac/Linux.

What does a typical project look like?


API integration projects usually start with a catalog of business requirements, both functional and non-functional. Our experts as well as our consulting partners can help you with this. An Active Sandbox may also be helpful to see the functions in a graphical user interface, and save you time and money in structuring the business requirements.


When you’re ready to build, you will need a TEOS Development Subscription. You can unsubscribe at any time, but it is recommended to have a development environment for the entire lifecycle of your application in case of upgrades, updates, and bugfixes. Development can be done by our own team or with one of our software development partners.

Go Live

To go live you need a productive subscription to the TEOS API. Our TEOS API is a cloud-based solution. We can assist with a cloud environment for your new blockchain application or -backend.


The TEOS API is constantly maintained, updated, and extended with new features. Everything is properly versioned, and the versions exist in parallel. We support the three most recent versions, so it requires minimal maintenance and testing from time to time. For more information, visit our API Documentation.

Benefits of using the CoreLedger TEOS API


The API puts all the core blockchain functions into a building-block system. Instead of writing the entire stack, from smart contract to off-chain/on-chain data synchronization and transaction handling, you can simply call a web service function. This reduces development cost by approximately 75%.

Save time & money

Using our existing blockchain functionality instead of developing your own saves you 70-80% from the concept stage to going live and avoids all the usual issues of newly developed software.

Low Maintenance

Legacy software requires a minimum of 5% of overall development cost in maintenance per year and 10-15% in the first year after launch. The TEOS API can save you more than 50% in maintenance cost per year.


If you require custom smart contract functions we have a smart way to extend the TEOS contracts so that you can use your own functions together with our existing ones.

We recommend that you get clarification from a legal advisor on whether your business idea requires regulatory approval or not.​