# Privacy Triage: Apple - CPM Extension Health Pixels

Status: **DRAFT**

**Name:** Alex M  
**Email:** amartemyanov@duckduckgo.com  
**Objective:** O-E  
**PR:** [Add PR link]  
**Project:** https://app.asana.com/1/137249556945/project/1163321984198618/task/1216761517055116?focus=true

## Pixels

| Pixel                                                                      | Trigger                                                               | Frequency       |
| -------------------------------------------------------------------------- | --------------------------------------------------------------------- | --------------- |
| `m_debug_web_extension_cpm_initialization_missed_after_session_restore`    | Restored tabs do not receive the initial CPM response.                | Daily           |
| `m_debug_web_extension_cpm_initialization_recovered_after_session_restore` | CPM later responds after the restoration miss.                        | Daily           |
| `m_debug_web_extension_cpm_initialization_failed_after_tab_crash`          | CPM fails on the first eligible navigation after a tab crash.         | Daily + count   |
| `m_debug_web_extension_cpm_initialization_failed_after_extension_reload`   | CPM fails on the first eligible navigation after an extension reload. | Daily + count   |
| `m_debug_web_extension_cpm_messaging_stuck_session_restoration`            | Messaging remains stuck after a restoration-originated failure.       | Daily + count, once/episode |
| `m_debug_web_extension_cpm_messaging_stuck_tab_crash`                      | Messaging remains stuck across attempts associated with a tab crash.  | Daily + count, once/episode |
| `m_debug_web_extension_cpm_messaging_stuck_other`                          | Messaging remains stuck across other independent navigations.         | Daily + count, once/episode |
| `m_debug_web_extension_cpm_messaging_recovered_without_extension_reload`   | A stuck episode recovers without an extension reload.                 | Daily + count, once/episode |
| `m_debug_web_extension_cpm_messaging_recovered_after_extension_reload`     | A stuck episode recovers after an extension reload.                   | Daily + count, once/episode |
| `m_debug_web_extension_cpm_messaging_extension_reload_failed`              | Reload fails or CPM remains stuck after reload.                       | Daily + count, once/episode |

iOS and macOS send the exact same pixel names. Parameters distinguish `platform=ios|macos` and `form_factor=phone|tablet|desktop`.
`appVersion` is included; macOS also includes `pixelSource` and `channel`.

## Detection Rules

- Check only finished, current, main-frame HTTP(S) document navigations after a grace period.
- Treat all `.sessionRestoration` navigations from one app launch as one batch, not one failure per restored tab.
- A redirected restoration still belongs to the restoration batch when `.sessionRestoration` appears in its navigation history.
- After restoration, any independent eligible document navigation can be the next attempt: reload, typed URL, link, new-tab navigation, or a real back/forward load.
- Redirects do not count separately. Same-document, failed, non-HTTP(S), and BFCache navigations do not count when CPM is not expected to initialize again.
- A tab crash marks only the next eligible navigation in that tab.
- A successful extension reload marks only the next eligible CPM attempt.
- `stuck` retains the strongest contributing reason: tab crash, then session restoration, then other.
- Any successful CPM initialization closes the episode. Pixels are fired for episode transitions, never for every failed tab.

## Privacy Questions

**Do the pixels use transparent names?**  
Yes.

**Do they share parameters with other pixels?**  
Yes. They use `platform` and `form_factor` to combine both apps under the same pixel names.

**Could the parameters link pixels to the same user?**  
No. Both parameters are coarse enums and contain no identifier.

**Do the pixels include a URL or search query?**  
No. They also exclude hostnames, page titles, tab IDs, document IDs, navigation types, errors, and CPM rules.

**Are the pixels temporary?**  
The session-restoration and post-crash/reload pixels are diagnostics. The stuck-state and recovery pixels are permanent health monitoring.

**Why are the permanent pixels needed?**  
To measure how often CPM messaging becomes stuck and whether extension reload recovers it.

**Do any parameters or suffixes fall outside the standard criteria?**  
`platform` and `form_factor` are explicit enum parameters used instead of platform-specific pixel names.

**Do the pixels fire on sensitive user events?**  
No. They report only CPM extension health states.

**Can occurrences be tied to the same user or a small group?**  
No. There is no correlation identifier or browsing data.

**Does this meet the self-service criteria?**  
Yes.