WunderGraph, a rising open source startup focused on addressing API sprawl in the GraphQL landscape, has announced a $7.5 million Series A funding round led by eBay Ventures, along with participation from Karma Ventures and Aspenwood Ventures. As part of the partnership, eBay is not only investing but also collaborating as a core design partner, aiding WunderGraph in building an open source alternative to GraphQL solutions from companies like Apollo.

The funding news was shared in an unconventional post on WunderGraph’s official blog, reflecting the team’s transparent and developer-first culture. In parallel, the company issued an official statement to TechCrunch offering additional insight into the strategic partnership with eBay and the broader vision for the product.

“Our investment in WunderGraph’s highly performant open source platform will help boost eBay’s API ecosystem and enable our teams to work faster and smarter in building products that help our sellers thrive,” said Bryan Woodruff, VP of Seller Experience Engineering at eBay.

Founded in 2020 by CTO Dustin Deus, CEO Jens Neuse, COO Björn Schwenzer, and CCO Stefan Avram, WunderGraph has maintained its U.S. incorporation from the outset. While most of the founding team is based in Germany, Miami-based Avram joined in 2022 to provide local leadership in the U.S.

Tackling API Sprawl With GraphQL

GraphQL, initially developed by Meta (then Facebook) in 2012 and open sourced in 2015, is a data query language for APIs designed to make data fetching more efficient. Rather than over-fetching or under-fetching data as is common with traditional REST APIs, GraphQL allows clients to request precisely the data they need. This efficiency has made it a cornerstone of modern software architecture, especially as companies adopt microservices.

However, with the proliferation of APIs, managing and orchestrating them at scale becomes increasingly complex. That’s where WunderGraph steps in. The company originally offered a software development kit (SDK) to help unify disparate APIs—including REST, SOAP, and databases like MySQL. In 2023, it secured a $3 million seed round to build what it dubbed a “GitHub for APIs,” a collaborative platform for discovering and sharing APIs.

At the same time, Apollo was making significant headway in GraphQL Federation, an approach to help multiple development teams collaborate on large, distributed applications. But Apollo’s shift in late 2021 from an open source MIT license to a proprietary Elastic License created an opening for competition.

“Our data showed that some people were really looking for an open source alternative to Apollo Federation,” Neuse told TechCrunch. “We figured our current approach is not working, so let’s just put out an open source alternative to Apollo Federation.”

In response, WunderGraph launched Cosmo in late 2023—a fully open source GraphQL federation platform.

Strategic Alignment With eBay

WunderGraph serves as the main maintainer of Cosmo and offers services like hosting, premium support, and integration assistance for analytics, authentication, and observability. While large enterprises can build their own in-house solutions, many prefer to rely on externally supported products like Cosmo, backed by service-level agreements (SLAs).

This is where the collaboration with eBay becomes pivotal. eBay gains the customization and openness of a flexible GraphQL federation solution, while WunderGraph benefits from eBay’s real-world design input and use case validation.

“I would say we are experts in federation, but we don’t have experience in eBay-scale problems,” Neuse explained. “By having this very close relationship, they taught us everything in terms of how we need to build our product so that it can be integrated into companies like eBay.”

This includes making Cosmo modular enough for companies to adopt only the components they need—something that aligns with enterprise concerns about vendor lock-in. According to Neuse, open source is the only viable path forward for widespread adoption:

“This market needs to be as wide as possible. How can we attract everybody? It must be open source. We cannot limit how people use it.”

Looking Ahead

With $7.5 million in fresh capital, WunderGraph aims to expand its 20-person team and enhance its open source GraphQL federation with tools tailored for collaboration and governance—critical for supporting distributed teams at enterprise scale.

“Open source is the future of API management, and enterprises are demanding transparency, flexibility, and control,” said co-founder Stefan Avram. “We’re building the essential plumbing for the world’s biggest platforms, and this funding allows us to scale while keeping our commitment to open source development.”