# Thunderbolt

> Cross-platform AI client you can deploy on-prem, with your own model providers

- Category: App UIs & Builders / Chat UIs
- Language: TypeScript
- Licence: MPL-2.0
- Repository: https://github.com/thunderbird/thunderbolt
- Website: https://thunderbolt.io
- Canonical page: https://ai-tldr.dev/tools/thunderbolt/
- Updated: 2026-04-16

## In short

Thunderbolt is an open-source AI client from the Thunderbird project, built around one idea: you choose the models and you keep the data. It sits in the Chat UIs category of the App UIs & Builders tools and is open-source, written in TypeScript and licensed MPL-2.0. To get started: check your toolchain.

## Overview

Thunderbolt is an open-source AI client from the Thunderbird project, built around one idea: you choose the models and you keep the data. It runs on every major desktop and mobile platform — web, macOS, Linux, Windows, iOS and Android — and it is designed to be deployed on-premises anywhere rather than consumed as someone else's hosted service.

There is no bundled inference endpoint. You point Thunderbolt at the providers you already have: Ollama or llama.cpp for free local inference, or an API key for any OpenAI-compatible provider entered in the app's settings. That keeps frontier, local and on-prem models behind the same interface, which is the vendor-lock-in problem the project is explicitly aimed at.

The project is early and says so up front. It is under active development, undergoing a security audit, and currently targets enterprise customers who want an on-prem deployment; the team's stated plan is to become fully offline-first, but today the app still depends on authentication and on search (which can be disabled from the integrations screen). The stack is a TypeScript frontend with a Tauri shell, a backend, Postgres and PowerSync, all licensed MPL 2.0.

## What it does

- Runs on web, iOS, Android, macOS, Linux and Windows from one codebase
- Bring your own models — frontier APIs, on-prem endpoints, or local inference through Ollama or llama.cpp
- Any OpenAI-compatible provider can be added with an API key from the settings screen
- Designed for on-prem deployment, with Docker Compose and Kubernetes paths documented under deploy/
- MPL 2.0 licensed, with published telemetry and privacy documentation
- Enterprise features, support and forward-deployed engineers offered by the Thunderbird team

## Getting started

The repo ships a Makefile that walks you through a local development environment. Run `make doctor` first — it checks your toolchain and prints the exact install command for anything missing. For a real deployment, follow deploy/README.md instead.

1. Check your toolchain

   make doctor verifies the tools Thunderbolt needs and prints install commands for anything you are missing.

```bash
make doctor
```

2. Install dependencies

   Installs frontend and backend dependencies and wires up the agent symlinks.

```bash
make setup
```

3. Start the services

   Brings up Postgres and PowerSync in Docker, then runs the backend on :8000 and the frontend on :1420.

```bash
make up
make run
```

4. Add a model provider

   Thunderbolt ships no public inference endpoint. Add your own provider in the app settings — Ollama or llama.cpp for local inference, or an API key for any OpenAI-compatible provider. Search can be turned off on the integrations screen if you want less network dependency.

5. Self-host it properly

   For a real deployment, follow deploy/README.md, which covers Docker Compose and Kubernetes. You deploy your own backend and sign up against it.

## When to use it

- Give an organisation a single AI client across desktop, mobile and web while keeping inference and data inside its own infrastructure
- Run a private chat client entirely against local models via Ollama or llama.cpp
- Avoid vendor lock-in by putting frontier APIs, on-prem endpoints and local models behind one interface you can switch between
- Evaluate an on-prem AI client in a regulated environment where a hosted assistant is not an option

## Version history

- 2026-04-16: Thunderbird released Thunderbolt as an open-source, self-hostable AI client for web, desktop and mobile under MPL 2.0, working against any OpenAI-compatible provider or local inference through Ollama and llama.cpp.