Case Study:  Relai's Integration of Greenlight by Blockstream
Lightning Network

Case Study: Relai's Integration of Greenlight by Blockstream

Fernando Nikolic

Relai offers a frictionless way for users in Europe to buy and sell bitcoin within minutes without the need for registration, verification, or deposits. 

To scale its services, Relai integrated Greenlight by Blockstream, a solution enabling companies to incorporate Lightning Network capabilities without the complexities of building and maintaining bespoke infrastructure. 

This integration expands Relai's total addressable market by allowing for smaller transactions with lower fees, thereby increasing the frequency of buys and making the platform more attractive to a wider market segment.

Post-integration, Relai was able to efficiently scale its non-custodial Lightning offering to over 100,000 users, while simultaneously improving transaction speeds and reliability. It was also able to reduce operational costs, and reinforce user security and control over their funds, underlining Relai's commitment to innovation and empowering its users.

This case study explores the integration process, challenges, solutions, and outcomes of this strategic decision.


Relai faced significant challenges before integrating Greenlight. 

The company needed to scale its services to support Lightning transactions, ensuring users retained full control over their funds without compromising security or user experience. 

The main hurdles included technical complexity, scalability, and maintaining a non-custodial service model.


Greenlight by Blockstream offers a robust solution with features that aligned perfectly with Relai's needs:

  • Automated NodeOps: Ensuring minimal downtime and maintaining enterprise-grade reliability.
  • Developer-Friendly Integration: Allowing seamless integration with just a few API calls, simplifying the complex process of operating a Lightning node.
  • Scalability and Custom Liquidity Management: Facilitating easy scaling and liquidity management through the partnering LSPs, crucial for handling large user volumes.
  • Non-Custodial Service: Ensuring that user keys never leave their device, ensuring users maintain self-custody and reducing the regulatory burden.

Implementation Process

Scaling up always presents significant challenges and we anticipated both predictable and unforeseen issues with the influx of new users. With Relai's user base significantly larger than our previous one, the Greenlight team constantly monitored the integration to quickly identify and resolve any potential bottlenecks.

The integration experienced a series of technical challenges and solutions:

  • Scaling up was slow: Initially, the sudden influx of new nodes created database overload issues, and quickly exhausted the provisioned capacity. The Greenlight team responded by configuring additional node hosts, creating new databases to manage the load efficiently.
  • Scaling and Reliability Improvements: Throughout the go-live, the Greenlight team deployed a number of scalability improvements and database optimizations to enhance performance and reliability, such as increasing connection limits and managing node registrations more efficiently.

This involved not only managing a significant increase in user base size, but also adapting quickly to the operational demands created by this increase.


After implementing Greenlight, Relai successfully managed the onboarding of over 100,000 users to Lightning. 

Key benefits included:

  • Improved User Experience: Users experienced faster and more reliable transactions.
  • Cost Efficiency: Running a single lightning node can cost anywhere from $100 to $1,000 in infrastructure, plus the time invested by the operator. Managing non-custodial nodes for 100,000 users would be infeasible. Relai CTO, Adem Bilican, highlighted during his Blockstream Talk interview that integrating Greenlight required minimal effort. The only requirement was simply providing the Breez SDK with Greenlight credentials and thus eliminating ongoing maintenance costs that would otherwise run into the tens of thousands of dollars initially and hundreds to thousands of dollars monthly.
  • Operational Streamlining: The integration streamlined operations by removing the need for extensive node management. Instead of implementing and maintaining local nodes, which would involve updates and bug fixes, Greenlight provided a seamless solution, improving overall efficiency and reliability at scale.
  • User Sovereignty and Security: The non-custodial nature of Greenlight allowed users to retain full control over their funds, a significant advantage in the wake of issues faced by custodial services like Wallet of Satoshi.

Lessons Learned

The integration process provided valuable insights:

  • Scalability Is Key: The ability to dynamically scale services is crucial in managing large volumes of user nodes.
  • Monitoring and Alerts: Developing a robust monitoring system and alert mechanism is essential for early detection of issues and swift resolution.
  • User Education: Continuous user and app developer education on the benefits and responsibilities of non-custodial services like Greenlight is vital.

Looking ahead, Relai plans to further enhance its Lightning capabilities and explore new features to improve service delivery. Relai will continue efforts to improve latency and user interfaces, while working closely together with the Greenlight team from Blockstream.Greenlight is freely accessible with self-service certificates in the Greenlight Developer Console (GDC) to facilitate daily operations and access API keys. A free plan is available for hobbyists and small businesses, allowing the deployment of up to 1,000 on-demand nodes. Custom pricing plans are offered for enterprises with higher volumes requiring personal support.

Contact us on the official Greenlight site for more information and to schedule a meeting with the team.

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