Doxx.net, a Miami-based startup that builds private networks for AI agents, has raised $38 million in a Series A round led by Andreessen Horowitz, SecurityWeek reported Saturday. Animo Ventures and Focal.vc also took part, and the company opened its Agentic Defined Networking platform to the public in beta alongside the announcement.

What Happened

Doxx.net was founded in 2025 by Barrett Lyon, a serial founder who serves as CEO. Its product, Agentic Defined Networking, or ADN, places AI agents inside a private network environment where the destinations they can reach are defined in advance. Known malicious destinations are blocked at the DNS level, so the connection never starts.

The company runs its own stack rather than renting it. According to SecurityWeek, doxx.net operates owned bare-metal servers and IP address space, its own DNS root, its own certificate authority and 196 custom top-level domains. It also offers serverless, end-to-end peer-to-peer messaging, native apps for iOS, macOS and Android, and support for Windows and Linux. Accounts are created through a proof-of-work process instead of passwords.

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Doxx.net said it blocked more than 38 million threats during a closed beta that began in December 2025. It did not disclose how many users or paying customers it has, or how it plans to use the new funding.

Lyon criticized privacy providers that route customer traffic through rented infrastructure they neither own nor can verify, and he said privacy at doxx.net comes from the architecture rather than a policy document. Joel de la Garza, a partner at Andreessen Horowitz, praised the company for building its privacy stack from first principles.

Why It Matters

AI agents increasingly act on a user's behalf: browsing, filling in forms, calling APIs and downloading files. SecurityWeek framed the core problem as agents that carry their user's authority but cannot tell a safe destination from a dangerous one. Most current controls focus on what an agent is allowed to do inside an application. Doxx.net is betting on the network layer instead, limiting where an agent can go at all.

The approach has become more relevant after a run of incidents in which AI agents under test reached systems they were never meant to touch, including outside websites and third-party services. Restricting outbound connectivity is one of the oldest tools in network security, and doxx.net is applying it to software that makes its own decisions about what to visit.

The Founder

Lyon previously founded Prolexic, a company that protected websites from distributed denial-of-service attacks and was acquired by Akamai in 2014. That background in running large internet-facing infrastructure helps explain doxx.net's decision to own its servers, address space and naming system rather than build on a cloud provider.

What to Watch

The key questions are pricing, whether enterprises adopt ADN beyond the open beta and how the company's private DNS root and custom top-level domains interoperate with the public internet that agents ultimately need to reach. Investors will also look for the first customer numbers now that the product is publicly available.