Swedish Startup Opper AI Secures €2.5 Million In Pre-Seed Round

“The success of chatbots, agents, or data tasks comes down to how reliably they interact with models,” said Göran Sandahl, Co-founder and CEO. “Opper removes the guesswork from prompt engineering and gives developers a tool that just gets the job done.”

Opper AI was founded in 2023 by the team behind Unomaly (acquired in 2020). The company builds tools to help developers turn large language models into reliable, production-ready systems.

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Its founders—Göran Sandahl, Johan Gustafsson, and former Unomaly engineers—bring over 50 years of combined experience in building automated and scalable tech systems.

“We’re seeing again and again that our customers can go confidently from beta to reliable production deployments,” added Johan Gustafsson, Co-founder and CRO.

The Opper API introduces a new way to work with AI using "task contracts." Instead of writing and fine-tuning prompts manually, developers simply define tasks in structured JSON—outlining inputs, expected outputs, and success criteria. Opper then takes care of the rest using smart prompt generation, feedback loops, and compatibility with multiple models to ensure accurate and consistent results.

Key features include writing tasks instead of prompts, built-in evaluations and feedback systems for continuous improvement, and access to over 80 AI models through a single API with smart fallback routing. Developers also get full visibility into every token, cost, and model interaction to optimize performance and manage spending.

Early users like GetTested.io have already used Opper to streamline their AI pipeline for generating automated blood test reports.

“We traded a patchwork of home-grown prompts and frameworks for Opper,” said Adam, AI Engineer at GetTested. “It clearly works – and we’re now rolling out our pipelines across 62 countries including the US and India.”

About Opper AI

Founded in 2023, Opper is a full-stack platform for building AI-powered applications. It offers access to Large Language Models (LLMs) with features like function calling, retrieval via indexes, tracing, evaluations, and automatic prompt optimization—all through a single API key.