Headless collection

No TTY - or prompts supplied up front? The same form collects non-interactively: answers come from a JSON payload (a string, or a path to a file), per-question environment overrides and the declared defaults, with derives, conditions and fix-ups settled exactly as they would be in the TUI. Nothing about your form changes; only where the answers come from does.

$answers = $tui->collect('{"name":"Weekly Box"}');
$answers = $tui->run($prompts, '1.0.0'); // Headless when prompts are supplied; otherwise the TUI on a TTY.

Environment overrides are named <PREFIX><FIELD_ID> - the uppercased field id under a prefix. ->envPrefix('MYAPP_') declares that namespace on the form, a new Tui($form, env_prefix: 'MYAPP_') constructor argument overrides it, and if you set neither, the prefix is TUI_:

MYAPP_TIMEZONE=UTC php my-installer.php

Self-describing answers

The Answers set that comes back needs no form configuration to present or process: each answer carries a snapshot of its question (label, kind, panel trail) taken at collection time, plus its provenance - default, detected, edited, derived, or override (a user value pinning a derived one). $answers->toSummary() prints the provenance-badged, panel-grouped summary, $answers->toJson() the raw values, and $answers->items exposes the per-answer snapshots.

For automation and AI agents, the form describes itself: schema(), agentHelp() and validate() let a tool discover and drive it without prompting. See AI agents for the full surface, with the runnable scripts in playground/08-headless-*.