RapidAPI, a startup that has developed a marketplace through which developers can easily discover, test, and start using publicly available application programming interfaces (APIs), is announcing today that it has raised a $3.5 million seed round.

RapidAPI founder and chief executive Iddo Gino dropped out of Technion – Israel Institute of Technology to work on the startup, after building and using an early version of the service to operate a traveling hackathon activity in Israel.

Gino believes this sort of thing can help developers more quickly get up and running with multiple third-party services. Otherwise, “downloading packages would take up probably a few days,” Gino told VentureBeat in a recent interview. The startup offers free and open-source adapters to connect APIs.

There aren’t a whole lot of places to quickly explore lots of APIs, although MuleSoft’s ProgrammableWeb does have an API directory.

Meanwhile, the concept of API management — which enables people to expose new APIs and then track and restrict usage — has gained traction. Google recently acquired publicly traded Apigee, and before that Red Hat acquired 3scale. Earlier,¬†Intel bought Mashery before selling it off to Tibco. Public cloud market leader Amazon Web Services (AWS) fields the API Gateway service.

RapidAPI started in 2015 and is based in San Francisco, with 15 employees. Andreessen Horowitz led the round. SV Angel also invested in the startup, which was part of 500 Startups’ 16th batch.

The service supports more than 100 APIs, and it has a backlog of 300 that users have requested, Gino said. Around 20,000 developers are using the free version of the service, and a few companies are paying for an enterprise tier that can be deployed in companies’ on-premises data centers to manage internal APIs, Gino said.

The startup’s website provides a convenient central repository for all of a developer’s connections to APIs. But it does provide a way to export account information in CSV format.

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