Age-check errors previously blocked Buzz startup. Normal app startup now
proceeds immediately; only a valid under-18 response from the current
launch request can restrict access.
Age check enforcement remains disabled at compile time by default.
Builds can opt in with `--dart-define=BUZZ_AGE_GATING_ENABLED=true`.
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
### What changed?
Buzz mobile checks the app-store age signal at launch and hard-blocks
the app behind a full-screen 18+ notice when the store says the
signed-in person is under 18.
No age signal (e.g. declined permission, indeterminate value,
unsupported OS versions) results in no block.
The age value is never persisted. It is read, used to compute one
boolean, and discarded. Nothing is written to disk, and neither the age
value nor the range is logged or sent to analytics.
Platform notes:
- **New dependency `com.google.android.play:age-signals:0.0.4`.** This
is the only way to read the Play signal. Its AAR declares `minSdkVersion
23`, below the app's 24, so it forces **no minSdk bump**, and it
self-declares its own consent activity, so **no AndroidManifest change**
is needed.
- **iOS entitlement and linking.** `DeclaredAgeRange` autolinks from the
import. `Runner.entitlements` now declares
`com.apple.developer.declared-age-range`, and the call remains behind
`#available(iOS 26.0, *)`.
### Why?
App stores now expose a declared-age range, and Buzz's Terms require
users to be 18 or older. This wires the store signal to that rule with
the smallest change that is defensible.
Absent signals, declined or undeterminable results, and unsupported OS
versions allow the app through. A transient native request failure does
not become evidence that access is allowed: the app remains gated until
a retry produces a result. Only an affirmative under-18 signal produces
the permanent restriction screen.
### How is it tested?
Added tests:
-
[`age_signal_provider_test`](https://github.com/block/buzz/tree/main/mobile/test/features/age_gate)
covers the 17/18 boundary, open-ended ranges, no-signal, transient
recovery, bounded retry exhaustion, malformed payloads, and request-once
behavior
-
[`age_gate_app_test`](https://github.com/block/buzz/tree/main/mobile/test/features/age_gate)
proves authenticated content remains unmounted while the signal is
pending or retryable, and verifies the retry path
-
[`age_restriction_page_test`](https://github.com/block/buzz/tree/main/mobile/test/features/age_gate)
asserts the block screen offers no bypass affordance
-
[`community_provider_test`](https://github.com/block/buzz/tree/main/mobile/test/shared/community)
verifies age restriction clears push state, persists inactive leases,
and retries a failed tombstone
-
[`AgeSignalPayloadTest`](https://github.com/block/buzz/tree/main/mobile/android/app/src/test/kotlin/xyz/block/buzz/mobile)
pins the Android success payload to exactly `{status, ageUpper}` and
verifies failures return the distinct retryable platform error
### Deployment note
Enable the Declared Age Range capability and regenerate signing profiles
carrying the entitlement. This relops/App Store Connect task is not
performed by this PR.
*🤖 This PR was authored [with an
agent](codex://threads/019e5128-536b-73b3-8348-88651123f6da).*
| Age restriction screen |
| --- |
| <img
src="https://github.com/user-attachments/assets/5b0f48b1-df9b-4a60-9800-80b33f128535"
alt="Age restriction screen" width="320"> |
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
Co-authored-by: npub12wpjffj7q5qjsky5jvk4ldwlxmse5xll3d8gytk4wqd0c5y7jvwspg37n6 <538324a65e0501285894932d5fb5df36e19a1bff8b4e822ed5701afc509e931d@buzz.block.builderlab.xyz>
Co-authored-by: npub1tquskdu6yc4h8l7xxtceculxw600grekeq0xg2ukqfrwl7vrzg3quz3gmp <58390b379a262b73ffc632f19c73e6769ef40f36c81e642b960246eff9831222@buzz.block.builderlab.xyz>
Co-authored-by: Codex <noreply@openai.com>
This PR implements MVP, iOS-only,
[NIP-PL](8d2d0ff5ad/docs/nips/NIP-PL.md)-compliant
push notifications.
A relay with `BUZZ_PUSH_ENABLED` will send a push notification for any
message that appears in the in-app Notifications tab.
## Enrollment flow
The first time the client first connects to a relay with
`BUZZ_PUSH_ENABLED`:
```mermaid
sequenceDiagram
autonumber
participant App as Buzz iOS app
participant iOS
participant Relay as Buzz relay
participant Attest as Apple App Attest
participant Gateway as Push gateway
App->>Relay: Fetch NIP-11 push capability
Relay-->>App: Push profile, current relay public key, and limits
par
App->>iOS: Request notification permission
iOS-->>App: Permission result
and
App->>iOS: Register for remote notifications
iOS-->>App: Device token
end
App->>Gateway: Request installation challenge
Gateway-->>App: Single-use challenge
App->>Attest: Attest installation transcript
Attest-->>App: Attestation proof
App->>Gateway: Enroll device token and proof
Gateway-->>App: Installation handle
App->>Gateway: Request delegation challenge
Gateway-->>App: Single-use challenge
App->>Attest: Assert relay-key delegation
Attest-->>App: Assertion
App->>Gateway: Create delegation
Gateway-->>App: Opaque endpoint grant
App->>Relay: Publish encrypted push lease and filters
Relay-->>App: Lease acknowledged
```
## Push-time flow
When a notification-eligible event is received by the relay:
```mermaid
%%{init: {
"sequence": {
"actorMargin": 20,
"width": 110,
"messageMargin": 18,
"diagramMarginX": 8,
"wrap": true
}
}}%%
sequenceDiagram
autonumber
participant Relay as Buzz relay
participant Gateway as Push gateway
participant APNs as Apple Push<br/>Notification service
participant iOS
participant NSE as Notification service<br/>extension
Relay->>Gateway: POST /v1/deliveries/apns<br/>opaque endpoint grant, request ID, expiry, NIP-98 authorization
Gateway->>APNs: POST /3/device/{device-token}<br/>topic, request ID, expiry, constant mutable-content payload
APNs-->>Gateway: 200 OK: request accepted
Gateway-->>Relay: 200 OK: accepted status
APNs-->>iOS: Notification: constant reconnect alert<br/>mutable-content = 1
iOS->>NSE: Invoke extension<br/>original notification content
NSE->>Relay: POST /query: subscription filters, limit 10<br/>NIP-98 authorization
Relay-->>NSE: 200 OK: signed Nostr events<br/>kinds 9, 40002, 45001, or 45003
NSE->>iOS: Complete notification: title, body, subtitle<br/>thread ID, exact-message target
```
relay → push gateway → APNs -> NSE -> Notification Center
## Known limitations
The APNs wake payload is intentionally constant and opaque: it contains
no originating community or message identifier, in keeping with the
implemented NIP-PL privacy design.
The Notification Service Extension must therefore reconnect to the relay
and resolve eligible messages after each wake. Around overlapping wakes,
timing boundaries, or resolution windows, notification presentation may
occasionally omit an expected message or display a message more than
once.
This best-effort behavior is deliberately accepted for the current
implementation and will be measured during the internal rollout to
determine whether the user experience is acceptable before any broader
deployment; the implementation does not claim exactly-once presentation.
## Validation
Live end-to-end hardware validation used an internal remotely hosted
development relay and push gateway, the APNs sandbox, and a physical
iPhone 12 mini:
- A second real Buzz client published a uniquely marked message through
the hosted relay.
- The relay matched the message and sent the constant opaque wake
through the hosted gateway. The gateway made an actual APNs request; no
`simctl push` or simulated notification was used.
- The iPhone received the notification on its lock screen. The
Notification Service Extension reconnected to the relay, fetched the
event, verified its ID and signature, and replaced the placeholder
content with the real notification title and body.
- After the app populated its shared presentation cache, a final marked
notification visibly showed the sender display name, sender avatar, and
hashtag-prefixed channel name.
- Tapping a lock-screen notification opened Buzz and exercised the
notification-response path and navigated to the corresponding message.
Final validation with a dogfood-signed artifact and production App
Attest/APNs configuration remains a release step.
## Independent pre-reviews
- **First pass:**
[Carl](buzz://message?channel=18882f4c-289f-41db-942f-81f6f8066da1&id=74ab9a93bb227f3e762568f1cf9fee66d7495b0edc3918735ff787238b9cc585)
found missing transient retries, executor-key rotation suppression,
duplicate installation renewal, and an unauthenticated challenge write
amplifier. These were resolved by [retry-safe
bootstrap](https://github.com/block/buzz/pull/6269/changes/12c66ea62)
and [authenticated renewal plus a cross-replica
quota](https://github.com/block/buzz/pull/6269/changes/8e5ece0bd).
[sol-max](buzz://message?channel=ad83385f-8e9e-4461-9a35-c1bf2e208532&id=d26d53daa4684669e2ed354638241f13f36c3a97027fe8b4dd738aff09038962)
found delegation generation burning and an edited applied migration,
resolved by [exact-generation
revocation](https://github.com/block/buzz/pull/6269/changes/c26d2159d)
and a [forward-only
migration](https://github.com/block/buzz/pull/6269/changes/956c1d099).
[k3-max](buzz://message?channel=5e46055d-a766-4065-ae25-05d1e4aaa6b2&id=d43139138a0b15f806cbdbeeedd8f69d992cadf2e805876db6fdde6a34c7eda1)
found no blockers.
- **Exact-head re-review:**
[Carl](buzz://message?channel=18882f4c-289f-41db-942f-81f6f8066da1&id=a897721673459301b0cf26e8b85a1478d7ebbb56a4621f93d774c98d395b8f68),
[sol-max](buzz://message?channel=ad83385f-8e9e-4461-9a35-c1bf2e208532&id=fb2159f709ec68f74f7b21459acd76da0e8a7c5c0f3d469f99826b0cc2380849),
and
[k3-max](buzz://message?channel=5e46055d-a766-4065-ae25-05d1e4aaa6b2&id=2ce2842910435f562e9d9cc718595848f281b122c94605e523a4b964254b8bfb)
independently returned **NO BLOCKERS** at `7eb3a650b`; k3-max also
revalidated every remediation and the endpoint-specific App Attest
enrollment bound.
---------
Signed-off-by: Tom Brow <tomb@squareup.com>
Signed-off-by: Tom Brow <tomb@block.xyz>
Co-authored-by: Tom Brow <tomb@squareup.com>
Co-authored-by: Codex <noreply@openai.com>
Co-authored-by: Jordan Mecom <jm@squareup.com>
Tom Brow