Overledger 2.1.7 makes smart contract creation easy


New release enables the deployment of QRC20 smart contracts and payment capabilities. 

3 February 2022

Quant’s Overledger is the world’s leading blockchain gateway providing interoperability between blockchains with a single API. With Overledger 2.1.7, customers can easily create smart contracts for payments using tokenised money within our API. Overledger natively supports twelve programming languages, so that no additional programming or blockchain language is required. Furthermore, QRC20 smart contracts can be deployed straight to the Ethereum Ropsten testnet directly by the UI.

This new smart contract functionality in Overledger is an important milestone. QRC20 smart contracts can act as programmeable money across an interoperable blockchain payment system. This is the first phase in developing new digital payment instruments that move money more efficiently domestically and across borders -- evolving the world of finance to what the future needs, today.

Version 2.1.7 allows customers to deploy smart money and perform basic payment operations with REST/JSON APIs, including:  

  • Create a QRC20 smart contract on the Overledger User Interface (UI). Developers can set the attributes of their smart contract on the UI. Overledger will then generate the smart contract byte code to deploy the smart contract via Metamask.  
  • Make a credit transfer to initiate a QRC20 token payment. Developers can use a dedicated API to create a QRC20 token payment. With this API, developers can set their token unit and payee address. Overledger then issues the request payload for signing and execution.  
  • Initiate a debit transfer to pull a payment of the QRC20 token. Developers can apply a dedicated API to generate a QRC20 token payment. Then, developers can input their token unit and payee address with this API. Overledger will then convert the request payload for signature and execution.
  • Pre-approve a debit transfer to pull a payment of the QRC20 token. Developers can use a dedicated API to create a QRC20 token payment. Then, developers can easily input their token unit and payee address. Finally, Overledger will convert the request payload for signing and execution.

Once the QRC20 contract is deployed, a new set of QRC20 APIs will be automatically updated on Overledger to support the newly generated QRC20 token.  

Quant’s enterprise-grade smart contracts are highly secure and tested, developed by our team of PhDs and verified with external experts. They conform to the ERC20 standard for smart contracts and are production-ready for financial services applications. Quant is building additional smart contract templates and functionality in upcoming Overledger releases for payment and non-payment use across multiple blockchain platforms. 

For more details, see the full release notes: Release Notes 2.1.7
Get started today: Join the Developer Programme


Overledger 2.x

Overledger 1.x


OAuth 2.0 standard (allowing SSO)

Proprietary (BPI Keys)


In API, seamless updates

In SDK, re-download for updates


Full abstraction across all DLTs

Partial, DLT-specific edge cases

RCG Framework

REST / JSON APIs from OVL Core

Proprietary P2P (experimental)

Time to Deploy

32 minutes (CI / CD pipelines)

1-2 weeks

QNT Utility Token / Treasury

Optimised, audited smart contracts

Experimental smart contracts


Optimised to scale fast – 23 Microservices

Hardened proof of concept
– 9 Microservices

Transaction Routing Algorithm

6 factor, game theory optimised

Experimental P2P emergent


Cloud native (scaling / resilience)

Standalone DB deployments

Cross-DLT Implementation

REST API calls direct to OVL, integrated smart contract back end

SDK-based Javascript 
apps call smart contract functions
via OVL

2021 Achievements

50% Quant team has grown by over 50% and will continue to do so 

OVL1.0 to 2.0 Release schedule accelerated, moved to much more frequent automated updates
– Previously, last major update was seven months, then in early 2021 moved to three months (Jan and March)
and then to monthly (April and May). We’re now moving to fortnightly releases. 

2.5X Overledger is now 2.5x bigger (April)  

2.0 Re-engineered the entire 2.0 architecture

Open API 3.0 for easy integration into developer workflows

OAuth 2.0 for single sign on for enterprise customers    

Cloud Native Scalable and resilient already, now deployable automatically 

Native Transactions 

OVL 2.0 Developer portal 2.0