RikkaHub is a native Android LLM chat client, written in Kotlin and released under the AGPL-3.0 licence, that lets a single user switch between different AI providers inside the same conversation.

What it is

RikkaHub is a native Android chat client for large language models. It lives in the Android app ecosystem and is built with Kotlin, Jetpack Compose, Koin for dependency injection, Room for its database, DataStore for preference storage, Coil for image loading, and Material You for its design language. The application targets Android directly rather than running as a mobile view over a web service, and it ships a web access mode so that the same workspace can be reached from other platforms. The interface supports Material You theming, dark mode, Markdown rendering with code highlighting, LaTeX formulas, tables, and Mermaid diagrams.

The concrete problem it solves is provider lock-in inside a chat client. Most chat apps either fix the user to one vendor or force a choice of provider at sign-in, so a conversation started against one model cannot be continued against another. RikkaHub replaces that arrangement with a configurable provider list: custom API endpoints, custom URLs, and custom models, covering any API that is OpenAI, Google, or Anthropic compatible. Because providers are configuration rather than hard-coded integrations, a user can point the same client at OpenRouter, DeepSeek, Gemini, or a private gateway without reinstalling or maintaining a fork.

Key capabilities

• Multiple AI provider support, with custom API, URL, and model definitions for any OpenAI-, Google-, or Anthropic-compatible endpoint.
• Workspace, a proot-based Linux agent environment that runs inside the app for agent tasks.
• MCP support for connecting external tool servers to conversations.
• Multimodal input covering images, text documents, PDF, and Docx files.
• Search capabilities through Exa, Tavily, Zhipu, LinkUp, Brave, and Perplexity.
• QR code export and import for provider configuration, plus custom HTTP request headers and request bodies.
• Message branching, ChatGPT-like memory, prompt variables such as model name and time, AI translation, and Silly Tavern character card import.

Who uses it and how

• Android users who hold keys for several providers and want one client to hold them all, rather than installing a different app per vendor.
• Privacy-conscious users who self-configure endpoints, since provider settings can be exported and imported by QR code instead of being re-entered on each device.
• People running agent tasks who need the Workspace environment, a proot-based Linux sandbox, on a phone or tablet.
• Multi-device users who rely on the web access mode to reach the same setup away from their phone.
• Contributors building from source in Android Studio, following the contribution guidelines and the documented Kotlin, Koin, Jetpack Compose, DataStore, Room, Coil, Material You, and Navigation 3 stack.

Getting started

Download from the project website at rikka-ai.com/download, which the README marks as the recommended route, or install from Google Play under the package id me.rerere.rikkahub. Building from source requires Android Studio.

How it compares

No list of paid products that RikkaHub replaces is given in the facts, and no directly comparable chat client is named either, so on the evidence available it stands alone in this registry. The project does warn that forked versions circulate and that issues with forks are unrelated to the upstream app, and users are advised to treat forks with caution because of possible privacy leaks or excessive permission requests. Choosing the upstream build is therefore the safer default.

When to use it — and when not to

Pick RikkaHub if Android is your platform and provider switching inside a single conversation is the requirement; the AGPL-3.0 licence permits study and modification, and the provider list is configuration rather than code. Do not pick it if you need an iOS or native desktop client, since the facts describe an Android app with a web access mode and nothing else, or if you cannot accept a project carrying 282 open issues alongside its 7,655 stars. Anyone installing a third-party fork rather than the website or Google Play build takes on that risk directly.