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5 min read

Accelerating Development & Scaling API Reach

How to Serve a Diverse & Growing Developer Community

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Check out Formance's SDKs
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Open Source Ledger for money-moving platforms.

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Key Takeaways

Rapid time-to-market, minimal eng burden: SDKs in 2 weeks -- without dedicated engineering resources

Embedded SDKs as part of their OSS Monorepo

High-quality API integrations with SDKs for five languages

The Formance (opens in a new tab) team is on a mission to build the Open Source Ledger for money-moving platforms. Since coming out of YC W’21, the Paris-based team has scaled its platform to support dozens of fintech companies, like Carbon, Shares, and Cino. These companies trust the Formance stack to provide their critical payments infrastructure.

The Formance team relies on Speakeasy to create and maintain SDKs that accelerate their internal development and help scale the reach of their external API, which is critical for product adoption.

As a result of working with Speakeasy, the Formance team was able to:

  • expand to 5+ languages: Typescript, Python, Go, Java, PHP;
  • start supporting OAuth workflows and BigInt types;
  • embed their SDKs as part of their OSS Monorepo;
  • get set up in 2 weeks without dedicated engineering resources.

“Because we are providing core infrastructure to other fintech companies, most of the interactions are going to be machine to machine. We need to provide a really high-quality API experience. Three tenants of a good API experience are 1) discoverability, 2) request & response transparency, and 3) elimination of ambiguity.”


Clément Salaün, Formance Co-Founder & CEO

SDKs Are a Critical Component of API DevEx

A core element of delivering that ideal API experience was offering SDKs to their API users, but for a long time, Formance struggled to do this sustainably.

“We tried to use some other toolkits to develop SDKs, but it was very tough for the team to handle the mental load that came with supporting the SDKs… We were always busy with adding new features or improving the performance of the core platform. We never had time to spend on patching and updating the SDKs, and so they weren’t in good shape and weren’t having the impact we wanted.”


Clément Salaün, Formance Co-Founder & CEO

Thanks to Speakeasy, automating SDKs via their CI/CD allowed them to gain the advantage of SDKs without sacrificing team time to maintain them.

“Right before adopting Speakeasy, SDK maintenance was getting out of control. We had one developer spending at least 5 hours/week generating new SDKs for every API release. And now that mental load is just gone. We know Speakeasy is going to take care of it, and when we have ideas, we can just ask the Speakeasy team. And frankly, that's awesome.”


Clément Salaün, Formance Co-Founder & CEO

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