Keeping corporate data off OpenAI, Microsoft, or Anthropic servers is a legitimate concern for many organizations. MZLA Technologies, the for-profit subsidiary of Mozilla Foundation behind Thunderbird, is taking a shot at solving this with Thunderbolt: an open source AI client (Mozilla Public License 2.0) designed to run on your own infrastructure without tying you to proprietary platforms.

The project is backed by Mozilla and kept separate from Thunderbird, developed by a dedicated internal team focused on enterprise AI products.

What it does and how it works

Thunderbolt positions itself as a unified AI workspace: chat, search, automation of recurring tasks. It supports commercial models from Anthropic, OpenAI, and Mistral, plus local models via Ollama and custom providers. Native apps cover Linux, Windows, macOS, iOS, and Android, with a web client available.

The application relies on Haystack from deepset to connect the client to existing agent pipelines and RAG systems in your organization. Model Context Protocol support is in preview, while Agent Client Protocol is under active development.

The telemetry issue

One detail deserves attention: Thunderbolt ships with telemetry enabled by default. As documented in the GitHub repository, it uses PostHog to collect data on chat activity, model selection, settings changes, and location information. You can disable it in settings, and the project claims no personally identifiable information is collected without explicit consent, but it’s a questionable default for a tool selling data sovereignty as its main pitch.

A real alternative or another enterprise project?

In the open source ecosystem, Thunderbolt enters an already crowded space. Open WebUI and LibreChat have offered self-hostable frontends for AI models for some time. MZLA’s positioning aims higher, though, with explicit focus on large organizations with compliance requirements: hospitals, law firms, financial institutions.

The business model is classic open core: the code is free, but MZLA plans to monetize through enterprise environments by offering professional support, deployment assistance, and custom development.

A version for individual users is mentioned in the GitHub FAQ without a timeline.

Source code is on GitHub, and the official site is thunderbolt.io.