Follow-up to [#8294](https://github.com/block/buzz/pull/8294). Malformed
trailing thread tags could make a notification open the right thread
while Flutter indexed its reply elsewhere; uppercase references could
similarly miss lowercase event IDs.
Share one validated thread-reference parser between the mobile timeline,
Inbox, and feed helper. It ignores malformed markers, keeps the last
valid root/reply, and normalizes lookup IDs to lowercase. Native push
parsing now uses the same casing. Existing thread fixtures use valid
event IDs so they continue exercising real thread relationships.
Add RunnerTests coverage for the production native-to-Flutter argument
conversion, including buffered cold-start navigation and omitted
optional thread IDs, and run it in the native CI lane.
### Validation
- New parser and Inbox regressions cover malformed markers and uppercase
references. Widget regressions open and highlight the exact reply for
valid, uppercase, and trailing-malformed tags.
- After integrating [#8106](https://github.com/block/buzz/pull/8106),
Flutter analysis and the complete mobile suite pass: 3,337 tests, four
existing skips. Integration preserves per-event read predicates and
migrates incoming thread fixtures to valid IDs. An unchanged
keyboard-history test also failed with main's original parser; recording
reads before the scroll transition fixes its timing assumption while
retaining visibility assertions.
- Native package tests passed (127 tests), and both Runner bridge tests
passed on an iOS simulator with Xcode 26.5. Removing the production
`threadRootId` assignment made the bridge regression fail; restoring it
passed. Native code is unchanged by the main integration.
- [Current-head CI
passed](https://github.com/block/buzz/actions/runs/38659307247),
including Mobile and Mobile Swift. [Codex
review](https://github.com/block/buzz/pull/8332#issuecomment-6181458528)
and [security
review](https://github.com/block/buzz/pull/8332#issuecomment-6181449235)
found no issues on the integrated commit. [Owner
approval](https://github.com/block/buzz/pull/8332#pullrequestreview-5526812957)
covers the exact integrated commit.
- Standards and spec reviews found no blockers, including the merge
resolutions and test adjustments. Validation is scoped to mobile/native
per VISION_MOBILE; unrelated repository-wide checks were stopped, not
counted as passing.
The bridge test covers serialization and buffering, not end-to-end APNs
delivery or app launch. No new physical-device acceptance is claimed;
routine post-merge dogfood remains human-owned.
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
Tapping a push notification for a thread reply currently opens the
channel at its parent. Preserve the verified event's direct-parent
thread ID through the iOS notification payload and Flutter bridge so the
tap opens the containing thread and highlights that exact reply, even
when newer replies have arrived. This matches Inbox's destination
selection for nested replies; broadcast replies still open in the
channel.
Closest related work: https://github.com/block/buzz/pull/6159 (original
push-tap routing).
### Validation
- Follow-up
[5b70e1a](5b70e1a5cb)
selects the last valid 64-character ASCII-hex reply marker, matching
relay ingest. Regression tests failed before the fix; all 80 XCTest and
47 Swift Testing tests passed afterward with Xcode 26.5. [Current-head
CI](https://github.com/block/buzz/actions/runs/38607128406) passed,
including Flutter tests, Android build, native package tests, complete
iOS simulator and unsigned release builds, and native accessibility
tests. The [current-head security
review](https://github.com/block/buzz/pull/8294#issuecomment-6174205374)
reports no findings. Physical evidence below predates this
validation-only follow-up.
- [Baseline CI on
f465f91](https://github.com/block/buzz/actions/runs/38436936153) passed,
including Flutter and native package tests, Android build, complete iOS
simulator and unsigned release builds, and native accessibility tests.
- Full local validation passed on
[f465f91](f465f9196f),
including 3,215 Flutter tests (four skipped) and three unconfigured-push
tests. The 49 focused navigation tests also passed after the baseline
merge.
- Added coverage for cold/warm bridge delivery, exact reply highlighting
with newer arrivals, direct-parent and broadcast destinations, and
malformed optional thread IDs. The Codex finding for an empty reply
marker is fixed and resolved.
- Physical acceptance passed on the managed iPhone 12 mini using signed
Buzz Dev 10140, built from f465f91 with SDK 26.5. Real push taps and
Inbox opened the same containing thread and highlighted the exact reply.
An older alert retained its target after a newer reply arrived; a
retained alert also worked after terminating the app. Top-level push
navigation reached the channel.
- Installed in place with the existing identity, app data and pairing
retained. No key reset or rotation was performed. Notifications were
restored to off and device control released. Xcode 27 hits an unchanged
dependency compiler error; the matching Xcode 26.5 toolchain built and
signed this tested candidate successfully.
### Physical acceptance
| Warm push: older reply A | Inbox: reply B | Cold push: reply B |
| --- | --- | --- |
| 
| 
| 
|
[Physical test
details](https://github.com/block/buzz/pull/8294#issuecomment-6151991840).
### Before and after
Synthetic Flutter widget captures with a newer reply already present.
| Before: channel at outer parent | After: exact reply in containing
thread |
| --- | --- |
|
|
|
After merge, repeat warm/cold push versus Inbox in the integrated mobile
candidate, including older alerts, top-level and broadcast
notifications.
---------
Signed-off-by: Tom Brow <tomb@block.xyz>
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
