Flatkey Raises $10M Series A After 10,000 Developers Sign Up
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Flatkey and Realset AI have raised $10 million in Series A funding, according to an announcement made on September 23, 2026.
Flatkey is headquartered in San Jose. It runs an AI infrastructure platform that puts models, tools and data behind a single API key. The California company launched in July 2026, and in the two months since, more than 10,000 developers have adopted it. They use one key and one balance to reach more than 100 official AI models and more than 1,000 AI tools.
The Series A money will go toward adding more official models and tools, and toward scaling the infrastructure that routes developer traffic to them.
Every request on Flatkey goes to the provider’s official endpoint. Because the company buys upstream capacity in volume, most models cost around 80% of the providers’ official list prices, and some sit at 60% or lower as part of ongoing promotions. Flatkey does not self-host modified or quantized versions of models and pass them off as the originals. The catalog covers models from OpenAI, Anthropic, Google, DeepSeek, Kimi, GLM and others, along with image and video models such as Seedance, and new models are added through official channels on the day they are released.
The pitch is simplicity for teams that mix several providers. A developer group running models from OpenAI, Anthropic, Google and DeepSeek, a video model like Seedance, plus a search tool and a browser tool would normally juggle seven or more provider relationships. On Flatkey, that becomes one key, one balance and one invoice, and trying a new model or tool is a parameter change rather than a new vendor contract. Hunter Guo is the company’s founder.
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