Signal programs

Signal programs

The signal service is not implemented yet. This page describes the intended first version and marks the boundary between that plan and the current runtime.

Intended first version

The Rust host will calculate supported indicators with ta-rs and provide the resulting values to a QuantFlow program. QuantFlow will handle the bounded analysis decision, such as checking whether price crossed a supplied line. The service will own market data, indicator inputs, scheduling, and signal emission; the user program will return a decision for the host to interpret.

Declarative rules are not planned as a second way to write signal or bot logic. The intended user-authored logic is a QuantFlow program.

Example: price crosses an MRC line

For an upward crossing, the input needs the previous and current close and the previous and current MRC line value. The program compares the two bars:

previous_close = $.previous.close
previous_mrc = $.previous.mrc_middle
current_close = $.current.close
current_mrc = $.current.mrc_middle

crossed_up = previous_close <= previous_mrc && current_close > current_mrc
return crossed_up

In this example, the host calculates and supplies mrc_middle. It is not a QuantFlow indicator built-in. The program returns a boolean; the signal service would decide whether and how that result becomes a signal.

Current limitations

The first signal-service contract is not implemented. The current runtime does not provide the signal input shape, signal emission, or MRC calculations as built-ins. ta-rs integration with this service is still planned.

User-defined indicator functions written in QuantFlow and a TA-Lib C backend are possible later extensions. WASM may suit high-load or broader-language workloads, such as AI models. None of these extensions is part of the current QuantFlow runtime contract.