EchoUI for iOS

A native SwiftUI chat app for character-driven AI conversations, personas, OpenAI-compatible APIs, and OpenRouter.

Overview

EchoUI is an open-source iOS app for chatting with custom AI characters. It is built with SwiftUI and SwiftData, stores chats locally, and connects to OpenAI-compatible chat APIs or OpenRouter.

The app supports character and persona workflows, streaming chat responses, local chat history, appearance customization, and API server management in a native iOS interface.

Screenshots

Requirements

• macOS with a recent Xcode version that includes the iOS 26 SDK.
• iOS 26.0 or later. The project deployment target is currently IPHONEOS_DEPLOYMENT_TARGET = 26.0.
• An Apple Developer account or free Apple ID for signing if you want to run the app on a physical device.
• An API key for the provider you want to use, unless your endpoint does not require one.

Build From Source

1. Clone or download this repository.
2. Open FrontendAI.xcodeproj in Xcode.
3. Select the FrontendAI scheme.
4. Select an iPhone simulator or a connected iPhone as the run destination.
5. Open the target signing settings and choose your Apple development team.
6. Press Cmd + R to build and run the app.

You can also build from Terminal:

xcodebuild -project FrontendAI.xcodeproj -scheme FrontendAI -destination 'generic/platform=iOS Simulator' build

Build an IPA

Use this when you want to install the app with AltStore, SideStore, Sideloadly, Apple Configurator, or another sideloading tool.

1. Open FrontendAI.xcodeproj in Xcode.
2. Select FrontendAI as the scheme.
3. Select Any iOS Device or connect your iPhone.
4. Go to Product > Archive.
5. When the archive finishes, open the Organizer window.
6. Choose Distribute App.
7. Select the distribution method that matches your signing setup.
8. Export the .ipa.
9. Add the .ipa to your sideloading tool and follow that tool's installation flow.

If signing fails, check these first:

• A development team is selected for the app target.
• The bundle identifier is unique to your Apple account.
• Your device is trusted and available in Xcode.
• Your Apple account has a valid provisioning profile for this app.

First Run Setup

1. Open EchoUI.
2. Open Settings with the gear button.
3. Go to Manage API Servers.
4. Add an API server.
5. Choose OpenAI for OpenAI-compatible endpoints or OpenRouter for OpenRouter.
6. Enter the base URL, API key, and model.
7. Save the server and set it as active.
8. Create a character from the main screen.
9. Optional: create a persona and select it before starting a chat.

Official endpoint examples:

https://openrouter.ai
https://api.openai.com

Supported APIs

• OpenAI: APIs that follow the OpenAI chat-completions format.
• OpenRouter: OpenRouter-compatible endpoints with model catalog, reasoning, and balance support.

EchoUI can stream chat responses, load model lists, use optional Bearer token authentication, and normalize base URLs such as https://api.example.com and https://api.example.com/v1.

Security Notes

• API keys are stored in the iOS Keychain.
• Official OpenAI and OpenRouter endpoints are expected to use HTTPS.
• Bearer tokens should only be sent over HTTPS.
• Plain HTTP endpoints show a warning and should not receive API keys.
• Custom CA certificates can be imported for trusted self-signed TLS endpoints.

Features

• Character creation, editing, avatars, pinning, reordering, and deletion.
• Persona creation, editing, avatar support, prompt configuration, and per-chat selection.
• Streaming chat with stop, regenerate, edit, copy, delete, Markdown rendering, and local history.
• Appearance customization for message bubbles, wallpapers, app icons, animation, and chat presets.
• API server management with model loading, status checks, OpenRouter search, balance display, and custom TLS support.
• Local data storage with cache controls, recovery handling, usage charts, token estimates, and character statistics.

Project Layout

• FrontendAI/App: SwiftUI app entry point and app configuration.
• FrontendAI/Core: shared models, managers, and environment keys.
• FrontendAI/Features: feature modules for API, bots, chat, personas, settings, and usage.
• FrontendAI/SharedUI: reusable views, sheets, and UI components.
• FrontendAI/Resources: asset catalog, app icons, and provider icons.
• Documentation/Screenshots: README screenshots.

Notes

• EchoUI is not currently available on the App Store.
• The current Xcode target is configured for iPhone.
• Some API providers may require exact model IDs, paid credits, or provider-specific permissions.
• Reasoning display depends on whether the selected model or provider returns reasoning data.