EchoKit Server

EchoKit Server is the central component that manages communication between the EchoKit device and AI services. It can be deployed locally or connected to preset servers, allowing developers to customize LLM endpoints, plan the LLM prompt, configure speech models, and integrate additional AI features like MCP servers.

You will need an EchoKit device, or create your own ESP32 device with the EchoKit firmware.

Features

EchoKit Server powers the full voice–AI interaction loop, making it easy for developers to run end-to-end speech pipelines with flexible model choices and custom integrations.

ASR → LLM → TTS Pipeline

Seamlessly connect ASR → LLM → TTS for real-time, natural conversations. Each stage can be configured independently with your preferred models or APIs.

Model Compatibility

• ASR (Speech Recognition): Works with any API that’s OpenAI-compatible.
• LLM (Language Model): Connect to any OpenAI-spec endpoint — local or cloud.
• TTS (Text-to-Speech): Use any OpenAI-spec voice model for flexible deployment.
  • ElevenLabs (Streaming Mode)

End-to-End Model Pipelines

Out-of-the-box support for:

• Gemini — Google’s multimodal model
• Qwen Real-Time — Alibaba’s powerful open LLM

Developer Customization

• Deploy locally or connect to remote inference servers
• Define your own LLM prompts and response workflows
• Configure speech and voice models for different personas or use cases
• Integrate MCP servers for extended functionality

Set up the EchoKit server

Build

git clone https://github.com/second-state/echokit_server

Edit config.toml to customize the VAD, ASR, LLM, TTS services, as well as prompts and MCP servers. You can see many examples.

cargo build --release

Note for aarch64 (ARM64) builds: When cross-compiling for aarch64, the required fp16 target feature is automatically enabled via .cargo/config.toml. If building natively on aarch64, you may need to set:

RUSTFLAGS="-C target-feature=+fp16" cargo build --release

Configure AI services

The config.toml can use any combination of open-source or proprietary AI services, as long as they offer OpenAI-compatible API endpoints. Here are instructions to start open source AI servers for the EchoKit server.

• ASR: https://llamaedge.com/docs/ai-models/speech-to-text/quick-start-whisper
• LLM: https://llamaedge.com/docs/ai-models/llm/quick-start-llm
• Streaming TTS: https://github.com/second-state/gsv_tts

Alternatively, you could use Google Gemini Live services for VAD + ASR + LLM, and even optionally, TTS. See config.toml examples.

You can also configure MCP servers to give the EchoKit server tool use capabilities.

Configure the voice prompt

The hello.wav file on the server is sent to the EchoKit device when it connects. It is the voice prompt the device will say to tell the user that it is ready.

Run the EchoKit server

export RUST_LOG=debug
nohup target/release/echokit_server &

Test on a web page

Go here: https://echokit.dev/chat/

Click on the link to save the index.html file to your local hard disk.

Double click the local index.html file and open it in your browser.

In the web page, set the URL to your own EchoKit server address, and start chatting!

Configure a new device

Go to web page: https://echokit.dev/setup/ and use Bluetooth to connect to the GAIA ESP332 device.

Configure WiFi and server

• WiFi SSID (e.g., MyHome)
• WiFi password (e.g., MyPassword)
• Web Socket server URL for echokit_server
  • US: ws://indie.echokit.dev/ws/
  • Taiwan: ws://tw.echokit.dev/ws/
  • Rest of the world: ws://edge.echokit.dev/ws/

Use the device

Chat: press the K0 button once or multiple times until the status bar shows "Ready". You can now speak and it will show "Listening ...". The device answers after it decides that you have done speaking.

Config: press RST. While it is restarting, press and hold K0 to enter the configuration mode. Then open the configuration UI to connect to the device via BT.