modbender Speech to Text Skill for OpenClaw
Purpose
This skill recognizes speech from voice messages sent via any messenger connected to OpenClaw, using various STT providers, including Yandex SpeechKit.
When to Activate
Use this skill when:
- The user sends a voice message via any messenger connected to OpenClaw
- You need to convert speech to text
- Audio file transcription is required
- A text version of a voice message is needed
How It Works
1. Receive the audio file from OpenClaw
- OpenClaw provides a local path to the audio file
- Verify the file exists at the given path
- Validate the file format (OGG, WAV, MP3)
- Check file size (maximum 1 MB for Yandex SpeechKit v1 sync API)
Example path from OpenClaw:
/home/user_folder/.openclaw/media/inbound/file_1---9a53bac2-0392-41e7-8300-1c08e8eec027.ogg
2. Audio processing
- Validate the audio file at the local path
- Convert to a supported format if needed using ffmpeg
- Verify audio quality
3. Speech recognition
- Use the default provider (Yandex SpeechKit)
- If recognition fails, try alternative providers
- Return the recognized text with confidence information
4. Result handling
- Format the recognized text
- Include the detected language
- Provide metadata if needed
Quick Start
clawhub install sergei-mikhailov-stt
cd ~/.openclaw/workspace/skills/sergei-mikhailov-stt
bash setup.sh
The setup script creates a Python virtual environment, installs dependencies, and copies example configuration files. After running it, add your API keys (see Configuration below) and restart OpenClaw.
On Debian/Ubuntu, you may need to install the venv package first:
sudo apt install python3-venv
Configuration
1. Set API keys (recommended — via OpenClaw config)
Add credentials to ~/.openclaw/openclaw.json:
{
"skills": {
"entries": {
"sergei-mikhailov-stt": {
"env": {
"YANDEX_API_KEY": "your_api_key_here",
"YANDEX_FOLDER_ID": "your_folder_id_here"
}
}
}
}
}
2. Alternative — via .env file
Edit the .env file created by setup.sh in the skill folder:
YANDEX_API_KEY=your_api_key_here
YANDEX_FOLDER_ID=your_folder_id_here
STT_DEFAULT_PROVIDER=yandex
3. Restart OpenClaw to apply changes
openclaw gateway stop && openclaw gateway start
4. Provider configuration (optional)
The config.json file (also created by setup.sh) lets you tune provider parameters:
{
"default_provider": "yandex",
"providers": {
"yandex": {
"api_key": "${YANDEX_API_KEY}",
"folder_id": "${YANDEX_FOLDER_ID}",
"lang": "ru-RU"
}
}
}
Adding a New STT Provider
1. Create the provider class
# scripts/providers/new_provider.py
from .base_provider import BaseSTTProvider
class NewProvider(BaseSTTProvider):
name = "new_provider"
def recognize(self, audio_file_path: str, language: str = 'ru-RU') -> str:
# Recognition implementation
pass
def validate_config(self, config: dict) -> bool:
# Configuration validation
pass
def get_supported_formats(self) -> list:
return ['ogg', 'wav', 'mp3']
2. Register the provider
Add to scripts/stt_processor.py in the _get_provider method:
if provider_name == 'new_provider':
return NewProvider(provider_config)
3. Update configuration
Add the new provider section to config.json:
{
"providers": {
"new_provider": {
"api_key": "${NEW_PROVIDER_API_KEY}",
"model": "latest"
}
}
}
Usage Examples
Basic scenario
User: [sends a voice message]
OpenClaw: Recognized text: "Hello, how are you?"
With language specified
User: Transcribe this English voice message
OpenClaw: Recognized text (en-US): "Hello, how are you today?"
With metadata
User: Analyze this voice message
OpenClaw: Recognized text: "Meeting tomorrow at 3 PM"
Language: ru-RU
Confidence: 95%
Provider: Yandex SpeechKit
Error Handling
When the skill returns an error, explain it to the user in plain language and suggest a concrete next step. Do not show raw error messages or stack traces.
| Error | Say to the user | Next step |
|---|---|---|
File too large |
"The voice message is too long — maximum is about 30 seconds for now." | Ask them to send a shorter message |
Unsupported format |
"This audio format is not supported." | Tell them supported formats: OGG, WAV, MP3, M4A, FLAC, AAC |
API key invalid / HTTP 401 |
"There's a problem with the Yandex SpeechKit API key." | Ask owner to check YANDEX_API_KEY in openclaw.json |
Folder access denied / HTTP 403 |
"Access to Yandex SpeechKit is denied." | Ask owner to verify the service account has ai.speechkit.user role |
Too many requests / HTTP 429 |
"Yandex SpeechKit is rate-limiting us right now." | Try again in a few seconds |
FFmpeg not found |
"Audio conversion tool (FFmpeg) is not installed on the server." | Owner needs to run brew install ffmpeg or apt install ffmpeg |
API request timed out |
"Yandex SpeechKit did not respond in time." | Try again; if it repeats, the service may be down |
Missing YANDEX_API_KEY |
"The skill is not configured yet — API keys are missing." | Owner needs to add keys to ~/.openclaw/openclaw.json |
Troubleshooting (for the owner)
- Verify API key configuration in
~/.openclaw/openclaw.json - Ensure ffmpeg is installed:
ffmpeg -version - Check Yandex Cloud service account has role
ai.speechkit.user - Check gateway logs:
openclaw logs
Limitations
- Maximum file size: 1 MB (Yandex SpeechKit v1 sync API limit, ~30 seconds of voice)
- Supported formats: OGG, WAV, MP3, M4A, FLAC, AAC
- Languages: Russian (ru-RU), English (en-US)
- Processing time: up to 5 minutes
- Maximum audio duration: 30 minutes
Requirements
- Python 3.8+
- FFmpeg
- Configured API keys for STT providers
Result Metadata
On successful recognition:
{
"text": "Recognized text",
"language": "ru-RU",
"confidence": 0.95,
"provider": "yandex",
"processing_time": 2.5
}