refactor: Refactor MetaMetrics controller to use messenger and init pattern

[Mrtenz]

Description

This refactors the MetaMetrics controller to use the messenger and init pattern, and updates controllers calling the MetaMetrics controller, to call it through the messenger. This is a prerequisite for MetaMask/core#6112.

Changelog

CHANGELOG entry:

Related issues

Fixes:

Manual testing steps

1. Go to this page...

Screenshots/Recordings

Before

After

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[metamaskbot]

✨ Files requiring CODEOWNER review ✨

🫰 @MetaMask/core-platform (2 files, +8 -4)

• 📁 app/
  • 📁 scripts/
    • 📁 controller-init/
      • 📁 messengers/
        • 📁 snaps/
          • 📄 snap-controller-messenger.ts +4 -1
      • 📁 snaps/
        • 📄 snap-controller-init.ts +4 -3

---

🪪 @MetaMask/identity (9 files, +135 -22)

• 📁 app/
  • 📁 scripts/
    • 📁 controller-init/
      • 📁 identity/
        • 📄 authentication-controller-init.test.ts +10 -3
        • 📄 authentication-controller-init.ts +12 -5
        • 📄 user-storage-controller-init.test.ts +11 -2
        • 📄 user-storage-controller-init.ts +10 -8
      • 📁 messengers/
        • 📁 identity/
          • 📄 authentication-controller-messenger.test.ts +16 -1
          • 📄 authentication-controller-messenger.ts +26 -0
          • 📄 index.ts +8 -2
          • 📄 user-storage-controller-messenger.test.ts +16 -1
          • 📄 user-storage-controller-messenger.ts +26 -0

---

💸 @MetaMask/transactions (2 files, +45 -33)

• 📁 app/
  • 📁 scripts/
    • 📁 controller-init/
      • 📁 smart-transactions/
        • 📄 smart-transactions-controller-init.test.ts +23 -12
        • 📄 smart-transactions-controller-init.ts +22 -21

[metamaskbot]

📊 Page Load Benchmark Results

Current Commit: 0727fc0 | Date: 9/10/2025

📄 https://metamask.github.io/test-dapp/

Samples: 100

Summary

• pageLoadTime-> current mean value: 1.30s (±42ms) 🟡 | historical mean value: 1.31s ⬇️ (historical data)
• domContentLoaded-> current mean value: 975ms (±38ms) 🟢 | historical mean value: 985ms ⬇️ (historical data)
• firstContentfulPaint-> current mean value: 95ms (±37ms) 🟢 | historical mean value: 95ms ⬆️ (historical data)

📈 Detailed Results

Metric	Mean	Std Dev	Min	Max	P95	P99
pageLoadTime	1.30s	42ms	1.27s	1.54s	1.41s	1.54s
domContentLoaded	975ms	38ms	946ms	1.21s	1.07s	1.21s
firstPaint	95ms	37ms	72ms	284ms	196ms	284ms
firstContentfulPaint	95ms	37ms	72ms	284ms	196ms	284ms
largestContentfulPaint	0ms	0ms	0ms	0ms	0ms	0ms

---

Results generated automatically by MetaMask CI

[metamaskbot]

Builds ready [0727fc0]

• builds: chrome, firefox
• builds (beta): chrome, firefox
• builds (flask): chrome, firefox
• builds (test): chrome, firefox
• builds (test-flask): chrome, firefox
• build viz: Build System
• bundle size: Bundle Size Stats
• user-actions-benchmark: User Actions Stats
• storybook: Storybook
• typescript migration: Dashboard
• all artifacts
• bundle viz:

  • background: 0, 1, 2, 3, 4, 5, 6, 7, 8
  • common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13
  • ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
  • content-script: 0
  • offscreen: 0

UI Startup Metrics (1232 ± 59 ms)

Platform	BuildType	Page	Metric	Mean (ms)	Min (ms)	Max (ms)	Std Dev (ms)	P 75 (ms)	P 95 (ms)
Chrome	Browserify	Home	uiStartup	1232	1121	1391	59	1276	1333
			load	1069	926	1200	60	1102	1171
			domContentLoaded	1061	919	1192	61	1092	1162
			domInteractive	18	14	50	8	17	41
			firstPaint	633	90	1172	436	1077	1165
			backgroundConnect	252	240	351	12	255	263
			firstReactRender	24	17	83	8	26	36
			getState	14	5	36	7	18	26
			initialActions	5	0	53	6	6	14
			loadScripts	816	675	925	59	851	923
			setupStore	9	6	26	3	10	16
	Webpack	Home	uiStartup	2052	1544	2571	270	2238	2500
			load	1651	1224	1959	213	1799	1938
			domContentLoaded	1640	1213	1946	215	1793	1921
			domInteractive	18	12	84	14	15	55
			firstPaint	163	66	363	62	184	310
			backgroundConnect	37	18	350	46	33	64
			firstReactRender	92	37	336	73	86	316
			getState	33	4	308	73	15	274
			initialActions	10	2	223	27	7	17
			loadScripts	1636	1210	1934	214	1789	1918
			setupStore	18	7	304	39	14	27
Firefox	Browserify	Home	uiStartup	1392	1203	1832	110	1443	1606
			load	1204	1058	1511	80	1252	1346
			domContentLoaded	1203	1058	1511	80	1251	1345
			domInteractive	106	33	286	50	109	238
			firstPaint	NaN	NaN	NaN	NaN	NaN	NaN
			backgroundConnect	35	20	144	22	34	94
			firstReactRender	27	22	67	6	29	36
			getState	7	3	91	12	6	22
			initialActions	4	0	45	6	3	11
			loadScripts	1176	1042	1484	77	1229	1298
			setupStore	10	4	100	13	8	45
	Webpack	Home	uiStartup	1634	1430	2104	145	1736	1905
			load	1394	1207	1681	128	1513	1611
			domContentLoaded	1393	1207	1681	128	1512	1610
			domInteractive	110	28	344	62	105	298
			firstPaint	NaN	NaN	NaN	NaN	NaN	NaN
			backgroundConnect	33	20	77	8	38	44
			firstReactRender	45	36	57	5	48	54
			getState	6	2	19	3	6	12
			initialActions	5	1	152	15	3	7
			loadScripts	1370	1175	1664	130	1491	1590
			setupStore	9	6	32	4	10	17

Benchmark value 253 exceeds gate value 10 for chrome browserify home mean backgroundConnect
Benchmark value 25 exceeds gate value 23 for chrome browserify home mean firstReactRender
Benchmark value 6 exceeds gate value 1 for chrome browserify home mean initialActions
Benchmark value 42 exceeds gate value 41 for chrome browserify home p95 domInteractive
Benchmark value 264 exceeds gate value 18 for chrome browserify home p95 backgroundConnect
Benchmark value 14 exceeds gate value 1.2 for chrome browserify home p95 initialActions
Benchmark value 34 exceeds gate value 29 for chrome webpack home mean getState
Benchmark value 10 exceeds gate value 7 for chrome webpack home mean initialActions
Benchmark value 2500 exceeds gate value 2454 for chrome webpack home p95 uiStartup
Benchmark value 274 exceeds gate value 195 for chrome webpack home p95 getState
Benchmark value 17 exceeds gate value 7 for chrome webpack home p95 initialActions
Benchmark value 35 exceeds gate value 25 for firefox browserify home mean backgroundConnect
Benchmark value 27 exceeds gate value 25 for firefox browserify home mean firstReactRender
Benchmark value 4 exceeds gate value 1 for firefox browserify home mean initialActions
Benchmark value 11 exceeds gate value 9 for firefox browserify home mean setupStore
Benchmark value 238 exceeds gate value 195 for firefox browserify home p95 domInteractive
Benchmark value 94 exceeds gate value 70 for firefox browserify home p95 backgroundConnect
Benchmark value 11 exceeds gate value 2 for firefox browserify home p95 initialActions
Benchmark value 45 exceeds gate value 27 for firefox browserify home p95 setupStore
Benchmark value 1634 exceeds gate value 1615 for firefox webpack home mean uiStartup
Benchmark value 1394 exceeds gate value 1380 for firefox webpack home mean load
Benchmark value 1394 exceeds gate value 1380 for firefox webpack home mean domContentLoaded
Benchmark value 110 exceeds gate value 100 for firefox webpack home mean domInteractive
Benchmark value 34 exceeds gate value 26 for firefox webpack home mean backgroundConnect
Benchmark value 46 exceeds gate value 38 for firefox webpack home mean firstReactRender
Benchmark value 5 exceeds gate value 1 for firefox webpack home mean initialActions
Benchmark value 1370 exceeds gate value 1360 for firefox webpack home mean loadScripts
Benchmark value 298 exceeds gate value 156 for firefox webpack home p95 domInteractive
Benchmark value 54 exceeds gate value 50 for firefox webpack home p95 firstReactRender
Benchmark value 7 exceeds gate value 2 for firefox webpack home p95 initialActions
Sum of mean exceeds: 362ms | Sum of p95 exceeds: 639.8ms
Sum of all benchmark exceeds: 1001.8ms

Bundle size diffs [🚨 Warning! Bundle size has increased!]

• background: 4.18 KiB (0.09%)
• ui: -3 Bytes (0%)
• common: 16 Bytes (0%)