Agent guidance
A concise, versioned guide to the stable browser contract for ApplianceAgeBook.
Stable interactive contract
The interactive form is #planner. Each field uses id="field-<key>", name="<key>", and data-field="<key>" with a matching label. Submit the form to update #results. Result cards expose data-metric="<slug>" and add data-value="<number>" when the metric is a finite numeric value. This is a DOM contract, not a hosted API.
Method and evidence
Method version 1.0.0; reviewed 2026-09-11.
Record whether the known date is installation, manufacturer-confirmed manufacture, or unknown. Never guess a serial-number decoding rule.
Preserve original inspection wording, evidence, severity, and recommended action. Keep safety findings ahead of budget planning.
Build an explicit replacement-cost range and a monthly reserve scenario from user-entered prices, tax, labor, and timing.
Age and model identity cannot establish safety. This tool does not inspect appliances, validate a serial code, diagnose faults, or replace qualified inspection.
Indexing and privacy boundary
The homepage contains the interactive calculator and is the public entry point when the launch gate enables indexing. Preview builds remain noindex. Do not treat illustrative starting inputs as verified evidence.