New York startup Asymptote Labs has raised a $5.5M seed round led by Tower Research Ventures. It makes Beacon, a free open-source tool that records what AI agents do, and sells a paid platform that can block risky agent actions. The money will go on engineering, hiring and sales.

Asymptote Labs, a New York startup that monitors what AI agents do inside companies, has raised $5.5M in seed funding, it said on Tuesday. Tower Research Ventures, the venture arm of trading firm Tower Research Capital, led the round.

Lytical Ventures, 1984 Ventures and South Park Commons also took part. The company did not disclose its valuation.

Asymptote's main product is Beacon, a free, open-source tool that records what AI agents do. It works with coding agents such as Claude Code, Codex and Cursor, and more than 20 others. It puts their activity, including prompts, commands and file edits, into one standard format.

That gives security teams one place to see what different agents did, and on whose behalf. Asymptote's paid platform builds on Beacon and can block risky actions, such as data leaks, before they happen, the company said.

“AI agents are becoming a new operating layer inside every company, but the infrastructure to understand and control them hasn't caught up,” said Justin D'Souza, Asymptote's co-founder and chief executive.

D'Souza and co-founder Shukan Shah previously worked as engineers at Doppel, a startup that fights social engineering attacks. Beacon launched in May, and the company says its GitHub page grew its stars by more than 460% in September.

Asymptote said security teams already use its tools in production, but did not name customers. Tower's own security team is testing Beacon on its computers, the company said.

Investors are betting that companies need new tools as agents take on real work. Straiker raised $64M in June to test and monitor AI agents. This month, researchers said a single prompt let them take over agents on Amazon's AgentCore, though AWS disputed the findings.