D707 - A scripted pad is a configuration source

Status: decided Date: 2026-09-26

A scripted pad is a controller source, Source::Script { path }, read from a file relative to the configuration, validated before entry, and installed on the entry path so its clock starts at guest entry. A step sets the pad and holds until the next; steps out of order or at one instant are refused, and a script carries typed pad state, never bytes.

Why: a scripted controller is a setting, which may come from a file, not a diagnostic, which may not. A pad has a sampled position rather than events, so a held level matches how a guest polls. Installing at entry keeps step times independent of placement and linking time, and typed state keeps scripts valid whatever the byte layout turns out to be.

Rejected:

• An environment variable: diagnostics never come from a file and cannot travel with a title.
• An event queue: invents a sampling rate and drifts against the guest's polling.
• Sorting disordered steps: silently runs a different script.
• Installing at process start: steps fire during loading.