Summary

Remove the legacy MetaMetrics analytics system (app/core/Analytics/, useMetrics hook, withAnalyticsAwareness HOC, MetricsEventBuilder) and consolidate all analytics infrastructure into app/util/analytics/ + useAnalytics hook. Also rename the deprecated addTraitsToUser method to identify across the codebase.

The work is split into 22 PRs across 7 phases (A, C, D, E, N), ordered by dependency and scoped to minimize required reviewers (at most 1 additional code owner per PR beyond @MetaMask/mobile-platform). Phases E2–F2 were replaced by a 9-PR batch (N1–N9).

Known gap: MetaMetrics.events.ts is excluded from this issue (separate large migration).

Phase A: Infrastructure (platform-only, 3 PRs)

Foundation changes that enable all subsequent migrations. No consumer files touched.

PR A0 — Add identify() alias ✅

Add identify method to useAnalytics hook types + implementation, keeping addTraitsToUser as deprecated alias. Enables incremental consumer rename in later phases.

PR A1 — Move infrastructure files via git mv ✅

Move SegmentPersistor, PrivacySegmentPlugin, constants, whenEngineReady, snapKeyring helper from app/core/Analytics/ to app/util/analytics/. Rename files and exported constants. Create missing whenEngineReady.test.ts.

PR A2 — Split and relocate types ✅

Split MetaMetrics.types.ts into analytics.types.ts (transitional types, domain types) and analyticsDataDeletion.types.ts (data deletion types). Keep re-exports from old path for backward compat.

Phase C: useMetrics → useAnalytics migration — platform/unowned files (5 PRs, ~63 files)

Migrate all useMetrics consumers owned by @MetaMask/mobile-platform or with no specific CODEOWNER. Each PR absorbs 1 additional team CO where files follow the same migration pattern.

PR C1 — HW Wallet + Wallet Recovery + Onboarding + web3auth (~21 files) ✅

PR C2 — Network + Accounts + Permissions + accounts-engineers (~22 files) ✅

PR C3 — Security + Wallet UI + Nav + Settings + HOC removal + swaps (~17 files) ✅

PR C4 — Simulation + NFT + Hooks + Misc + perps (~21 files) ✅

PR C5 — Predict (~2 files) ✅

Phase D: useMetrics → useAnalytics migration — team-specific files (4 PRs, ~51 files)

Files fully owned by a single team. Each PR has its own team reviewer(s).

PR D1 — Rewards (~31 files) ✅

PR D2 — Earn/Stake (~14 files) ✅

PR D4 — Notifications + Mobile Core UX (~4 files) ✅

PR D5 — Ramps MetaMetrics.getInstance() → analytics.trackEvent (~2 files) ✅

Blocks F1: D5 must merge before MetaMetrics.ts can be deleted.

Phase E: addTraitsToUser → identify rename + missed useMetrics migrations (4 PRs)

Files already on useAnalytics that still call .addTraitsToUser, plus 3 useMetrics consumers that were missed in phases C/D. Requires A0 to land first. All 4 PRs must merge before F1 can land.

PR E1 — Rename in mobile-core-ux files + migrate AccountActions + stale mock cleanup 🔄 #30473

Phase E (continued) + Phase F: completed via new PRs

PR E2, E3, E4, F1, and F2 were cancelled and replaced by 9 scoped PRs executed in a single batch.
All 7 consumer-migration PRs are already merged; the 2 deletion PRs are open and awaiting merge.

PR N1 — Migrate unowned files ✅

Migrate useMetrics→useAnalytics, MetricsEventBuilder→AnalyticsEventBuilder,
addTraitsToUser→identify across unowned/platform files.

PR N2 — Migrate web3auth/onboarding files ✅

Migrate MetricsEventBuilder→AnalyticsEventBuilder and useMetrics→useAnalytics in web3auth and onboarding files.

PR N3 — Migrate assets files ✅

Migrate useMetrics→useAnalytics and MetricsEventBuilder→AnalyticsEventBuilder in assets files.

PR N4 — Migrate transaction controller metrics (confirmations) ✅

Migrate MetricsEventBuilder→AnalyticsEventBuilder in transaction controller event-handler metrics.

PR N5 — Remove stale MetricsEventBuilder mock (core-ux) ✅

Remove stale MetricsEventBuilder mock from AccountsMenu test.

PR N6 — Migrate MetricsEventBuilder→AnalyticsEventBuilder in TransactionField test (engagement) ✅

PR N7 — Rename addTraitsToUser→identify in EmptyStateCta test (earn) ✅

PR N8 — Delete legacy analytics symbols + remove saveDataRecording chain 🔄

Delete useMetrics hook, MetaMetrics.ts, MetricsEventBuilder, withAnalyticsAwareness HOC,
convert MetaMetrics.types.ts to re-export barrel, and remove the saveDataRecording persistence chain.

PR N9 — Remove saveDataRecording field/method from AnalyticsEventBuilder 🔄

Remove saveDataRecording from AnalyticsTrackingEvent interface and setSaveDataRecording from
AnalyticsEventBuilderInterface; sweep all mocks. Blocked on N8 merging first.

Overall Summary

Dependency Graph

graph LR
    A0[A0: identify alias] --> C["C1..C5\nplatform migrations"]
    A0 --> D["D1..D5\nteam migrations"]
    A0 --> E1[E1: core-ux rename]
    A1[A1: move files] --> N8
    A2[A2: split types] --> N8
    C --> N1 & N2 & N3 & N4 & N5 & N6 & N7
    D --> N1 & N2 & N3 & N4 & N5 & N6 & N7
    E1 --> N8[N8: delete legacy symbols]
    N1["N1: unowned ✅"] --> N8
    N2["N2: web3auth ✅"] --> N8
    N3["N3: assets ✅"] --> N8
    N4["N4: confirmations ✅"] --> N8
    N5["N5: core-ux mock ✅"] --> N8
    N6["N6: engagement ✅"] --> N8
    N7["N7: earn ✅"] --> N8
    N8 --> N9[N9: saveDataRecording removal]

Deferred (not in this issue)

• Move events/ subdirectory — blocked on MetaMetrics.events.ts migration
• Remove backward-compat types (IMetaMetricsEvent, ITrackingEvent, isTrackingEvent) — blocked on MetaMetrics.events.ts migration

Acceptance Criteria

• Zero imports from app/components/hooks/useMetrics/
• Zero imports from app/core/Analytics/MetaMetrics.ts
• Zero calls to .addTraitsToUser (all renamed to .identify)
• app/components/hooks/useMetrics/ directory deleted
• withAnalyticsAwareness HOC deleted
• MetricsEventBuilder deleted
• Backward-compat re-exports in app/core/Analytics/MetaMetrics.types.ts can remain until MetaMetrics.events.ts is migrated