Custom Triggers

[fubuloubu]

Overview

Sometimes there is a need to have custom triggers, which allows defining logic in response to off-chain events such as CEX websocket feeds, Pyth API updates, etc.

Specification

Define a new module .triggers where we define BaseTrigger that is inherited by all of our supported triggers, then add new method SilverbackBot.on_trigger that accepts *triggers: BaseTrigger defined as a handler for OR combination of all trigger condition execution. Lastly, redefine SilverbackBot.on_ and SilverbackBot.cron to re-map to this new class system, and simplify the internal logic of handling different operational modes for backtesting, etc.

Usage:

...

from pydantic import BaseModel
from silverback import SilverbackBot
from silverback.triggers import BaseTrigger


bot = SilverbackBot()


class CustomAPIModel(BaseModel):
    pair: str
    time: datetime
    price_updates: list[float]


class CustomTrigger(BaseTrigger):
    def __init__(self, *custom_args):
        ...

    # NOTE: For "backtesting" use (aka historical data)
    async def backfill(
        self, start_time: datetime, stop_time: datetime
    ) -> AsyncIterator[CustomAPIModel]:
        yield from map(
            CustomAPIModel.model_load,
            await self.api.get(
                "/historical",
                params=dict(start_time=str(start), stop_time=str(stop)),
            ).json(),
        )

    # NOTE: For "runtime" use
    async def __aiter__(self) -> AsyncIterator[CustomAPIModel]:
        async for item in self.api.get("/streaming", stream=True):
            yield CustomAPIModel.model_load(item.json())


# NOTE: This allows defining OR triggers (whenever one OR the other has an update)
@bot.on_trigger(CustomTrigger("ETH/USD"), CustomTrigger("BTC/USD"), ...)
async def on_custom_trigger(value: CustomAPIModel):
    ...  # do stuff

Using this, we can also refactor how we use the data from Ape for events logs and blocks, also how we represent cron triggers internally

Dependencies

n/a

[linear]

SBK-685 Custom Triggers