Customers / Lithic

Stainless’ knowledge about API design is second to none.”

saved annually in engineer salaries
20 mins
for new customers to start issuing cards
1 full-time
engineer’s time saved per language
2 weeks
to refine their OpenAPI spec

API-first fintech company delivers on their brand promise

We always had customers asking us, ‘Do you have client libraries?’, and 'What languages do you support?’ And with Alex’s prior experience at Stripe, we knew we could finally offer them best-in-class SDKs.”

Kamil Sindi
Head of Engineering at Lithic

Lithic is a financial technology platform dedicated to simplifying online payments. They make it easy for their clients to issue debit and credit cards to employees, customers, and vendors. Developers at Lithic’s clients work hands-on to integrate with Lithic’s API in order to access and manage the cards. With API interactions at the heart of their business, Lithic needed to provide a great developer experience as part of their brand promise.

Before Stainless, customers had to build their own integrations to connect to Lithic’s API. But this was time consuming and customers were demanding more. Lithic knew something had to change. Their OpenAPI spec wasn’t perfect, so as a first step, they needed to make their APIs more restful before they could begin any SDK generation.

Stainless rose to the challenge to help refine their OpenAPI spec as well as generate SDKs, and Lithic became their first customer.


“The fact that we can scale across multiple languages is a really big deal.”

Having worked at other API-centric companies, Lithic’s Head Engineer, Kamil, knew the amount of effort that it takes to manually build SDKs. The fact that Stainless SDKs are initially auto-generated was a big selling point, especially as they plan to grow across multiple languages.

Automated updates also help free Lithic developers to focus on building their core products. Lithic is now able to maintain their OpenAPI spec and update client libraries on the fly—saving their team from managing the details of every new update themselves.

5 SDK languages available
Automated releases

“We’re about launching cards really quickly, and Stainless SDKs make that a promise.”

The core of Lithic’s brand promise to their customers is offering a better developer experience. The Stainless SDK helps developers streamline the integration with the Lithic API by reducing boilerplate code and giving them less to figure out on their own. With the new SDKs, Lithic is now seeing businesses be able to issue cards in just 20 minutes. 

Their customers often give feedback like, “Our developers love you”. Having client libraries is a big part of that, but the fact that they don’t get any complaints or bug reports from them is an even bigger deal. Lithic sees a lot of great naming and consistency, and believes “This is what a good client library looks like”.

Rich types
Consistent naming

“It’s saved us a lot of money to have something like this.”

During the process of finding an SDK solution, Lithic couldn’t find anything to rival Stainless in terms of value—for the same level of support. Lithic estimates they’ve saved the time and salary of one full-time, highly experienced developer—per language. They currently generate in Node / Typescript, Python, Java, Kotlin, and Go.

The idea of maintaining that many SDKs without Stainless would be difficult and not financially logical. Lithic shares that if you consider yourself an API-first company, Stainless is a “no-brainer” for the SDKs.

Don’t waste time building your own libraries. Stainless will do a better job. The support, responsiveness, and care we get is next level.”

Kamil Sindi
Head of Engineering at Lithic