Mainline/.opencode/skills/mainline-sensors/SKILL.md

name, description, compatibility, metadata

name	description	compatibility	metadata
mainline-sensors	Sensor framework for real-time input in Mainline	opencode	audience source_type developers codebase

What This Skill Covers

This skill covers Mainline's sensor framework - how to use, create, and integrate sensors for real-time input.

Key Concepts

Sensor Base Class (engine/sensors/init.py)

class Sensor(ABC):
    name: str
    unit: str = ""
    
    @property
    def available(self) -> bool:
        """Whether sensor is currently available"""
        return True
    
    @abstractmethod
    def read(self) -> SensorValue | None:
        """Read current sensor value"""
        ...
    
    def start(self) -> None:
        """Initialize sensor (optional)"""
        pass
    
    def stop(self) -> None:
        """Clean up sensor (optional)"""
        pass

SensorValue Dataclass

@dataclass
class SensorValue:
    sensor_name: str
    value: float
    timestamp: float
    unit: str = ""

SensorRegistry

Discovers and manages sensors globally:

from engine.sensors import SensorRegistry
registry = SensorRegistry()
sensor = registry.get("mic")

SensorStage

Pipeline adapter that provides sensor values to effects:

from engine.pipeline.adapters import SensorStage
stage = SensorStage(sensor_name="mic")

Built-in Sensors

Sensor	File	Description
MicSensor	sensors/mic.py	Microphone input (RMS dB)
OscillatorSensor	sensors/oscillator.py	Test sine wave generator
PipelineMetricsSensor	sensors/pipeline_metrics.py	FPS, frame time, etc.

Param Bindings

Effects declare sensor-to-param mappings:

class GlitchEffect(EffectPlugin):
    param_bindings = {
        "intensity": {"sensor": "mic", "transform": "linear"},
    }

Transform Functions

• linear - Direct mapping to param range
• exponential - Exponential scaling
• threshold - Binary on/off

Adding a New Sensor

1. Create engine/sensors/my_sensor.py
2. Inherit from Sensor ABC
3. Implement required methods
4. Register in SensorRegistry

Example:

class MySensor(Sensor):
    name = "my-sensor"
    unit = "units"
    
    def read(self) -> SensorValue | None:
        return SensorValue(
            sensor_name=self.name,
            value=self._read_hardware(),
            timestamp=time.time(),
            unit=self.unit
        )

Using Sensors in Effects

Access sensor values via EffectContext:

def process(self, buf, ctx):
    mic_level = ctx.get_sensor_value("mic")
    if mic_level and mic_level > 0.5:
        # Apply intense effect
        ...

Or via param_bindings (automatic):

# If intensity is bound to "mic", it's automatically 
# available in self.config.intensity