OpenThena

Free plan APILinuxSelf-hostedWeb

What OpenThena is

OpenThena is a free, MIT-licensed AI assistant that streams responses and keeps chat history in a browser. Xiaomi MiMo v2.5 is the default model, while configuration can select another provider. A LiteLLM-style gateway exposes an OpenAI-format model interface, and an optional LiteLLM proxy can centralize keys, budgets, and providers. Responses arrive token by token through the AI SDK data-stream protocol. OpenThena says it has no database, accounts, message-content server logs, analytics, fingerprinting, or advertising cookies. Conversation history is stored in browser localStorage and can be erased by clearing a conversation or browser data. Prompts are sent to the configured upstream provider, whose terms govern handling. The Next.js app can run wherever Node.js runs, with one-click Vercel deployment or full-stack self-hosting. Local setup requires Node.js 18+ and a Xiaomi MiMo API key.

Who it suits

It suits users who want a self-hostable, open-source assistant with configurable model providers. Developers can run it on Node.js, deploy through Vercel, or connect OpenAI-compatible endpoints.

What it does well

Free and MIT licensed
Token-by-token response streaming
Configurable providers and OpenAI-format gateway
No accounts, analytics, or advertising cookies
Supports Vercel deployment and self-hosting

What to know first

Model-provider charges may apply
Prompts follow the upstream provider’s terms
Local setup requires Node.js 18+ and an API key
Chat API accepts at most 50 messages per request

Plans

Plan	Billed and limits	Price
OpenThena	Free; model provider charges may apply · OpenThena itself is free · pay only for the model provider you use	Free

As openthena.com lists them, read 11 Oct 2026. The maker's own page has the final word.

Verdict

OpenThena focuses on configurable, self-hosted AI chat with minimal stated application data collection. Users remain responsible for provider costs and for how the selected model service handles prompts.

Facts from OpenThena's own pages

API limit: The chat API accepts at most 50 messages per request. · openthena.com, 5 Oct 2026
Chat storage: Chat history is saved in the browser's localStorage and can be erased by clearing a conversation or browser data. · openthena.com, 11 Oct 2026
Cost limit: OpenThena itself is free; users pay only for the model provider they choose. · openthena.com, 11 Oct 2026
Default model: It uses Xiaomi MiMo (mimo-v2.5-pro) by default, and the model can be changed through an environment variable. · openthena.com, 11 Oct 2026
Deployment: The documentation describes one-click Vercel deployment and self-hosting. · openthena.com, 11 Oct 2026
Free plan: Yes · openthena.com, 21 Sept 2026
Gateway: Its LiteLLM-style gateway provides an OpenAI-format interface to models. · openthena.com, 11 Oct 2026
History storage: Chat history is stored in browser localStorage and can be erased by clearing a conversation or browser data. · openthena.com, 5 Oct 2026
License: OpenThena is MIT licensed and described as auditable and open source. · openthena.com, 11 Oct 2026
Local setup: The quickstart requires Node.js 18+ and a Xiaomi MiMo API key to run locally. · openthena.com, 5 Oct 2026
Model: Xiaomi MiMo v2.5 is the default model, and the provider can be changed through configuration. · openthena.com, 5 Oct 2026
Model compatibility: The FAQ says any OpenAI-compatible endpoint works, including a self-hosted LiteLLM proxy or a local model. · openthena.com, 11 Oct 2026
Privacy: The maker says it has no database, accounts, message-content server logs, analytics, fingerprinting, or advertising cookies. · openthena.com, 11 Oct 2026
Product: OpenThena is an open-source AI assistant with a streaming chat experience. · openthena.com, 11 Oct 2026
Provider data: Prompts are sent to the configured upstream model provider, whose data handling is governed by that provider’s terms. · openthena.com, 5 Oct 2026
Provider data handling: Prompts are sent to the configured upstream model provider, whose data handling is governed by that provider's terms. · openthena.com, 11 Oct 2026
Self-hosting: OpenThena is a Next.js app that can run anywhere Node runs. · openthena.com, 11 Oct 2026
Streaming: Responses stream token by token. · openthena.com, 11 Oct 2026

Where OpenThena stands on Freedom251

AI chatbots and assistants#51 of 65