Native Android / Wear companion - hub API first, who ships the Play app?

[heavygee]

Problem

I self-host HAPI (sometimes through relay) and want agent alerts and replies on Wear - ready, permission allow/deny, and text back to the session.

PWA + browser push on the watch is not viable: bridged notifications are missing reliable reply actions; inline reply has hit Chrome spam warnings. A usable wrist flow needs a native app (notification actions + text input) calling the same hub APIs as the web UI. Full UI stays in the PWA.

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Proposed hub contribution (PR, not Discussion-only)

I'd open a PR with no Android tree, no secrets:

• POST / DELETE /api/devices/register - FCM token, phone | wear, stable device id
• Optional FCM send when env is set - same events as Web Push (ready, permission + requestId, tasks), same "PWA visible → in-app toast" rule
• Contract doc in that PR - FCM data fields plus which existing REST endpoints the app calls for messages and permissions

Web Push unchanged. FCM optional - hubs that ignore it behave as today.

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Why Discussion before PR

FCM ≠ Web Push. VAPID is per hub; Android FCM locks one Firebase project per APK. So:

APK (Firebase project X)  →  user binds any hub URL  →  hub must send with project X credentials

• Official APK + self-hosted hub without matching server keys → no push (confusing if we pretend otherwise).
• DIY self-hosters need their own APK + Firebase, or central push (same class as relay.hapi.run for reachability).

Hub PR does not fix distribution by itself; I want alignment before implying "install and it works everywhere."

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Question for maintainers

You already run app.hapi.run and relay.hapi.run. A single official companion (one package, one FCM project, Play updates) feels like operator surface - not every fork's personal GCP.

Not a licence claim - AGPL allows forks. This is user clarity: official vs bring-your-own APK.

Option	Hub	Companion	Google side
A Contract only	Merge API + docs	Community / self-build	Each operator
B Official (you)	Merge	Your repo + store listing	Your Firebase / Play
C Partnership	Merge	Repo under your org; I help build Wear v1	You hold Console; shared releases

Google side cost: effectively $0 ongoing for FCM at normal volume; Play Console is a one-time ~$25 fee. Not per-notification billing - mainly project quota, abuse risk, and release duty.

I can land the hub PR either way. For B/C, I'd rather coordinate than ship a third-party "HAPI" on my Firebase.

I can offer: hub PR + prototype companion source for audit/handoff (no adoption of my dogfood keys).

Asks: (1) Hub FCM/device API acceptable upstream? (2) Want an official companion for install-and-bind users? (3) If yes - you own product, or collab repo?

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Thanks - HeavyGee (fork operate / dogfoodeater)

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Acronyms

Term	Meaning
FCM	Firebase Cloud Messaging - Google's push service for Android. One public APK is tied to one Firebase project; the hub needs that project's server credentials to send.
Web Push / VAPID	Browser push from the hub. Each hub already has its own VAPID keys - unlike FCM on Android.