HLTC Protocol: Developer Implementation Packet — Software Build Specification, Logic Architecture, and System Definitions

This standalone developer-facing packet serves as the implementation specification for the HLTC Protocol. It is designed to support accurate software construction, testing, and verification by defining the protocol’s logic architecture, task engine behavior, timing constraints, routing rules, breakpoint computation, rule-access logic, screen flow, and data capture structure in explicit operational terms. Unlike the primary manuscript, this document is not conceptual. It functions as a build document. It provides deterministic implementation rules, pseudocode, conditions-file schemas, variable definitions, export-layer requirements, and standardized participant-facing screen language to eliminate developer ambiguity and support reproducible execution across environments. The packet includes a system logic overview, PsychoPy Builder implementation structure, expanded implementation guidance, breakpoint and routing pseudocode, a variable dictionary, conditions architecture, a developer test checklist, and a complete screen-by-screen execution walkthrough. The HLTC protocol is a structured behavioral framework designed to observe performance under progressive temporal constraint, breakpoint emergence, rule-access dynamics, and recovery behavior under fixed administration rules. This developer packet exists to support implementation fidelity at the software level. This document is also referenced as Supplement S1 in the primary HLTC Protocol manuscript, while being released here as a standalone implementation specification.