License Overview
BYD EV Pro uses relay-backed license checks to gate features such as Companion App access, Home Assistant, Telegram, and keep-alive behavior.
Current source code supports an explicit 14-day app-tier trial. The relay creates a trial only when the Car App sends an activate action and the device/VIN is eligible.
The relay tries to enforce one trial per VIN when the VIN is available. If no VIN is available, it falls back to an installation/device identity.
License checks
Section titled “License checks”- The Car App checks licenses through Cloud.
- License responses are HMAC-signed and verified by the Car App.
- The Car App caches verified license data locally.
- Feature gates fail closed if the cached license cannot be verified or if the last successful check is outside the grace window.
- The relay can push license updates over Cloud.
Grace period
Section titled “Grace period”The Car App source defines a 72-hour grace window from the last successful license check. After that, feature verification fails until the app can refresh the license.
Tiers and feature flags
Section titled “Tiers and feature flags”The relay synthesizes legacy feature flags from license tiers:
| Tier | Synthesized features in current relay source |
|---|---|
app | telegram, ha, keepalive, comp_app |
web | telegram, ha |
Companion access is allowed only for active/trial app tier in the current relay service. Telegram access is allowed for active/trial app or web tier.
TODO: Product clarification needed — What public names, prices, durations, and purchase channels should be shown for app and web tiers?
Paid activation and renewal
Section titled “Paid activation and renewal”The current Car App source does not show a complete end-user purchase or renewal flow inside the Car App. Public docs should not describe internal license-issuing tools as user-facing product behavior.
TODO: Product clarification needed — What end-user renewal flow and public support channel should be documented?
Support
Section titled “Support”When reporting a license problem, include the Car App license status, valid-until date if shown, and whether the issue affects Companion App, Home Assistant, Telegram, or T-Box behavior.