Exclusive: H Company quietly acquires open-source AI agents startup

Secretive French AI startup H Company has quietly acquired Mithril Security, another Paris-based business, Sifted has learned. 

H Company has stayed out of the public eye since raising a $220m seed round in May 2024, when hype around AI startups appeared to reach its zenith. The company launched to build AI agents — systems that automate complicated tasks without a human in the loop. Since then, H has lost three of its five cofounders and shared scant updates via social media.  

Now, two sources with direct knowledge of the matter tell Sifted that H has quietly acquired Mithril Security, a French startup developing open-source tools to create AI agents. The deal closed in the second half of 2024, the sources say. 

As part of the deal, Mithril Security founder Daniel Huynh and part of his team joined H, but he has since left, according to one source with knowledge of the startup’s operations.

Huynh did not reply to a request for comment. H did not reply.

What does Mithril Security do?

Mithril Security launched in 2021, initially promising to build open source privacy-protecting tools that make AI safer. The objective at the time was to help AI providers like OpenAI build models that users could trust with sensitive data.

In early 2024, however, Huynh announced a change of direction for the company in a blog post. “Mithril Security resources will be poured into developing LaVague, our new automation framework leveraging LLMs,” he wrote.

LaVague offers open source tools to create models for AI agents, with a focus on building web agents — AI systems that can navigate and interact with web environments. 

A key use case for web agents is web automation, which occurs when developers need to test web browsers, pages and mobile apps by simulating and repeating human interactions such as clicking buttons and filling forms. Developers typically automate these tasks using software.

LaVague says that its tools let developers “automate automation” by helping them create agents for web automation using natural language instructions.

Tester H

At the end of 2024, H released a first product dubbed Runner H, which it said focuses on the web “as its initial environment”. 

Runner H is a generalist web agent meaning it can carry out a number of tasks, including automating web automation pipelines for developers thanks to natural language commands.

One source with knowledge of H’s operations says that after the acquisition of Mithril Security, H increased its focus on web testing automation. 

The company is preparing to release a new agent dubbed Tester H, they said, which is dedicated to web automation. Another source with knowledge of the matter confirmed to Sifted that Tester H is operational and is currently in private beta with some customers.

Competing agents

H is building in a field that is becoming increasingly competitive. At the time of its release, Runner H boasted a score of 67% on WebVoyager, the industry benchmark for browser agents — ahead of competitors like Anthropic’s Claude, which scored 52%.

Since then Runner H has fallen behind, with OpenAI’s agent Operator scoring 87%, Google’s Project Mariner scoring 83.5% and UK startup Proxy scoring 82%.

One source with knowledge of the matter told Sifted that H has developed a new version of Runner H, which is not publicly available, and has scored 91% on WebVoyager.