ReactorApp

The class you subclass to define a model. The runtime constructs it once, calls load(), then drives it one step at a time for as long as clients are connected.

from reactor_runtime import ReactorApp


class MyModel(ReactorApp):
    state: MyState
    fps = 24

    def load(self, config_path): ...
    def generate(self, input): ...

See Model Anatomy for the walkthrough. ReactorModel and ReactorPipeline are the old names for this class. Both still import, with a deprecation warning.

Declarations

InputState subclass

Annotate a subclass of InputState to give clients a set_<field> command per public field. The live instance is self.state, rebuilt each session and None between sessions.

MediaInput subclass

Annotate a subclass of MediaInput to receive tracks from clients. Found by its type, so the attribute name is yours; media is the convention.

float

default:"30.0"

Pin the playout rate. Leave it at the default and each chunk plays over the time its step took.

int | None

default:"None"

How many frames may sit between the model and each client. None accepts the runtime’s own bound. Never applied below one emitted batch.

Runtime handles

Two attributes the runtime binds on your instance. Read them from anywhere: a step, a command handler, a lifecycle hook, or your own run().

OutputStream

The handle onto playout. Change the frame rate, or cut what is queued so nothing from the old scene plays after a jump. See OutputStream.

@event(name="teleport", description="Jump to a new scene.")
def teleport(self, scene: str) -> None:
    self.engine.load_scene(scene)
    self.output.flush()          # drop frames from the old scene
    self.output.fps = 24         # re-paces what is queued

asyncio.Event

Set while at least one client is connected, cleared when the last one leaves. Await it to hold work back until a client is connected.

async def run(self) -> None:
    while True:
        await self.connected.wait()
        await self.emit(self.generate(self.state))

Methods you write

None

Runs once at startup, before any client connects. Load weights here. config_path is the file named by runtime.config in reactor.yaml, or None when none is configured.

Any

Optional and async. Returns whatever generate() should receive, or raises ApplicationError to skip the step. Defaults to returning self.state.

Any

One step of inference, synchronous. Returns the result, or raises when the step is invalid for the model. The default run() calls it, so you write either this or your own run().

Output | None

Optional and async. Receives a StepOutcome and returns the Output to stream, or None. Defaults to re-raising an error and otherwise calling outcome.to_output().

None

The loop that drives the three calls above. Override it to write your own; see Controlling the loop.

Methods you call

None

Put an Output on the tracks. Called for you by the default loop; call it yourself only from a hand-written run().

None

Send a ModelMessage to every connected client.

Get Started

CLI & Platform

Build a Model

Media & Transport

Releases

Declarations

Runtime handles

Methods you write

Methods you call

​Declarations

​Runtime handles

​Methods you write

​Methods you call

Declarations

Runtime handles

Methods you write

Methods you call