GetStream · oliverlaz · Sep 11, 2026 · Sep 10, 2026 · Sep 10, 2026 · Sep 11, 2026
@@ -20,14 +20,17 @@ permissions:
 jobs:
   lint:
     runs-on: ubuntu-latest
-    name: ESLint & Prettier
+    name: ESLint, Prettier & Types
     steps:
       - uses: actions/checkout@v6
 
       - uses: ./.github/actions/setup-node
 
       - run: yarn lint
 
+      - name: Typecheck the library
+        run: yarn types
+
       # scripts/ is outside the src tsconfigs and is not linted; Node 24 strips the types in
       # the .mts build scripts without checking them, so check them here.
       - name: Typecheck build scripts

@@ -4,9 +4,6 @@ on:
   pull_request:
     branches:
       - master
-      # The v15 release branch. Without it this workflow does not run on any PR stacked onto it, so the
-      # i18n consolidation's central size claim -- that moving the runtime into `stream-chat/i18n`
-      # shrinks the root bundle -- goes unmeasured for the whole release.
       - release-v15
     paths-ignore:
       - '**.test.*'

@@ -50,7 +50,7 @@ Respect any repo-specific rules. Do not suppress rules broadly; justify and scop
 
 1. Install dependencies (root + all workspaces): yarn install
 2. Build: yarn build
-3. Typecheck: yarn types
+3. Typecheck: yarn types (the library, via tsconfig.lib.json)
 4. Lint: yarn lint
 5. Fix lint issues: yarn lint-fix
 6. Unit tests: yarn test

@@ -25,8 +25,8 @@ yarn test <pattern>       # Run specific test (e.g., yarn test Channel)
 yarn lint-fix             # Fix all lint/format issues (prettier + eslint)
 
 # Type checking
-tsc -p tsconfig.lib.json --noEmit   # The library. THIS is the real check.
-yarn types:scripts                  # scripts/*.mts (Node strips types, it does not check them)
+yarn types                # Typecheck the library (tsc -p tsconfig.lib.json --noEmit)
+yarn types:scripts        # scripts/*.mts (Node strips types, it does not check them)
 
 # i18n (see the i18n System section)
 yarn build-translations   # Regenerate src/i18n/keys.ts from the t() call sites
@@ -41,9 +41,14 @@ yarn examples:build       # Build all examples
 yarn lint-fix             # ALWAYS run this first
 ```
 
-> **`yarn types` checks nothing — do not rely on it.** It runs `tsc` with no `--project`, so it
-> picks up the root `tsconfig.json`, which is a solution file with `"files": []`. It exits 0 even
-> with a deliberate type error in `src/`. Use `tsc -p tsconfig.lib.json --noEmit`.
+> **`yarn types` is `tsc -p tsconfig.lib.json --noEmit`** — it typechecks the library and nothing
+> else. It used to run `tsc` with no `--project`, which picked up the root `tsconfig.json` (a
+> solution file with `"files": []`) and exited 0 even with a deliberate type error in `src/`; that
+> is fixed. `tsconfig.lib.json` excludes `__tests__`, `stories` and `mock-builders`, so those are
+> not covered here.
+>
+> **CI runs it** in the `ESLint, Prettier & Types` job, alongside `yarn lint` and
+> `yarn types:scripts` — the cheapest job to fail in, since it needs no build.
 >
 > `yarn types:tests` (`tsconfig.test.json`) reports ~1200 pre-existing errors and is not wired into
 > CI. Treat it as unenforced.
@@ -283,7 +288,7 @@ Closes #123
 
 - [ ] `yarn lint-fix` passed
 - [ ] `yarn test` passed
-- [ ] `tsc -p tsconfig.lib.json --noEmit` passed (NOT `yarn types` — see Essential Commands)
+- [ ] `yarn types` passed (typechecks the library)
 - [ ] `yarn validate-translations` passed, if any `t()` call changed
 - [ ] Tests added for changes
 - [ ] No new warnings (zero tolerance)
@@ -326,6 +331,26 @@ See `examples/vite/src/index.scss` for reference implementation. Layers eliminat
 
 ## i18n System
 
+**The runtime is `@stream-io/i18n`**, shared with the React Native SDK — one `Streami18n`, one set
+of formatters, one date layer. This package owns only what is genuinely its own: the generated key
+catalog, `runtimeDefaults.ts`, the React context/hook binding, and the notification translation
+topic. `src/i18n/Streami18n.ts` is a thin subclass injecting this SDK's bundled data.
+
+It is a **regular dependency**, not a peer: an integrator never imports `@stream-io/i18n` — they
+import `Streami18n` from this package, which subclasses it. Peer dependencies are for things the
+app itself constructs and hands back (`react`, `stream-chat`), which is not the case here.
+
+Two resolved copies of `i18next` would be harmless anyway — `Streami18n` calls
+`i18next.createInstance()` and registers dictionaries on that instance, never on a global. `dayjs`
+is the one that genuinely wants a single copy, because locale registration _is_ global: an app
+adding a language does `import 'dayjs/locale/de.js'`, and that has to land in the same registry the
+SDK reads. Keeping the range identical (`^1.11.23`) is what makes them dedupe. Do not add
+`i18next` as a direct dependency here.
+
+The `language.*` names (`languageNameDefaults`, `LanguageNameCatalog`) still come from
+`stream-chat`, not from `@stream-io/i18n` — they enumerate the languages the Chat API can
+auto-translate a message into, so they are Chat API metadata.
+
 **English only.** Every other language is supplied by the integrator via
 `Streami18n.registerTranslation()`.
 
@@ -365,8 +390,11 @@ renders English — and it keeps the copy visible at the call site.
 - **Runtime keys:** the ~10 keys resolved from a runtime value (a `stream-chat`
   `notification.message`, slash-command metadata, a language code, an integrator prop) go through
   `asDynamicKey()`. That brand is required, so every escape is deliberate and greppable.
-  `src/i18n/externalStrings.ts` maps the `stream-chat` messages we recognise onto stable keys.
-- **`yarn build-translations`** parses the `t()` call sites (`scripts/i18n-call-sites.mts`), joins
+  A `stream-chat` notification is resolved by its stable `type` identifier
+  (`CORE_NOTIFICATION_TYPE`) through `src/i18n/TranslationBuilder/notifications/`, not by matching
+  its English prose — the `externalStrings.ts` table that used to do the latter is gone.
+- **`yarn build-translations`** parses the `t()` call sites (via `@stream-io/i18n/codegen`, driven by
+  `scripts/generate-i18n-keys.mts`), joins
   them with `runtimeDefaults.ts`, and regenerates `keys.ts`. It hard-fails on three things:
   a key used with two different inline copies; a key called with no inline default and no
   `runtimeDefaults` entry (it would render as the raw dotted key); and a key present in _both_

@@ -320,7 +320,7 @@ with no dictionary behind it.
 
 Also now internal, none of them documented before: `translations`, `dayjsLocales`,
 `isCustomDateTimeParser`, `localeExists()`, `addOrUpdateLocale()`, `validateCurrentLanguage()`. To
-register a dayjs locale directly, `stream-chat/i18n` exports `addOrUpdateDayjsLocale()`.
+register a dayjs locale directly, `@stream-io/i18n` exports `addOrUpdateDayjsLocale()`.
 
 ### `useChat` no longer returns `translators`
 

@@ -16,7 +16,7 @@
     "emoji-mart": "^5.6.0",
     "react": "^19.2.6",
     "react-dom": "^19.2.6",
-    "stream-chat": "10.0.0-rc.9",
+    "stream-chat": "^10.0.0-rc.10",
     "stream-chat-react": "workspace:^"
   },
   "devDependencies": {

@@ -10,14 +10,15 @@
   },
   "dependencies": {
     "@emoji-mart/data": "^1.2.1",
+    "@stream-io/state-store": "^1.1.6",
     "clsx": "^2.1.1",
-    "dayjs": "^1.11.20",
+    "dayjs": "^1.11.23",
     "emoji-mart": "^5.6.0",
     "human-id": "^4.1.3",
     "modern-normalize": "^3.0.1",
     "react": "^19.2.6",
     "react-dom": "^19.2.6",
-    "stream-chat": "10.0.0-rc.9",
+    "stream-chat": "^10.0.0-rc.10",
     "stream-chat-react": "workspace:^"
   },
   "devDependencies": {

@@ -1,4 +1,4 @@
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 import { useStateStore } from 'stream-chat-react';
 
 import { DEFAULT_LANGUAGE, streamI18n } from '../i18n';

@@ -94,6 +94,8 @@
     "@braintree/sanitize-url": "^7.1.2",
     "@floating-ui/react": "^0.27.19",
     "@react-aria/focus": "^3.22.0",
+    "@stream-io/i18n": "^1.0.2",
+    "@stream-io/state-store": "^1.1.6",
     "clsx": "^2.1.1",
     "emoji-regex": "^9.2.2",
     "fix-webm-duration": "^1.0.6",
@@ -116,7 +118,7 @@
     "unified": "^11.0.5",
     "unist-builder": "^4.0.0",
     "unist-util-visit": "^5.1.0",
-    "use-sync-external-store": "^1.6.0"
+    "use-sync-external-store": "^1.7.0"
   },
   "optionalDependencies": {
     "@stream-io/transliterate": "^1.5.5"
@@ -129,7 +131,7 @@
     "modern-normalize": "^3.0.1",
     "react": "^19.0.0 || ^18.0.0 || ^17.0.0",
     "react-dom": "^19.0.0 || ^18.0.0 || ^17.0.0",
-    "stream-chat": "10.0.0-rc.9"
+    "stream-chat": "^10.0.0-rc.10"
   },
   "peerDependenciesMeta": {
     "@breezystack/lamejs": {
@@ -183,7 +185,7 @@
     "@vitest/eslint-plugin": "^1.6.20",
     "concurrently": "^9.2.1",
     "conventional-changelog-conventionalcommits": "^9.3.1",
-    "dayjs": "^1.11.13",
+    "dayjs": "^1.11.23",
     "emoji-mart": "^5.6.0",
     "eslint": "^9.39.4",
     "eslint-plugin-import": "^2.32.0",
@@ -199,7 +201,7 @@
     "react-dom": "^19.2.6",
     "sass": "^1.100.0",
     "semantic-release": "^25.0.3",
-    "stream-chat": "10.0.0-rc.9",
+    "stream-chat": "^10.0.0-rc.10",
     "typescript": "^6.0.3",
     "typescript-eslint": "^8.59.4",
     "vite": "^8.1.3",
@@ -227,7 +229,7 @@
     "postinstall": "node -e \"require('fs').existsSync('scripts/install-husky.mjs') && import('./scripts/install-husky.mjs')\"",
     "test": "vitest run",
     "test:watch": "vitest",
-    "types": "tsc --emitDeclarationOnly false --noEmit",
+    "types": "tsc -p tsconfig.lib.json --noEmit",
     "types:tests": "tsc --project tsconfig.test.json --noEmit",
     "validate-translations": "yarn build-translations && git diff --exit-code -- src/i18n/keys.ts",
     "validate-cjs": "concurrently 'node scripts/validate-cjs-node-bundle.cjs' 'node scripts/validate-cjs-browser-bundle.cjs'",

@@ -2,14 +2,14 @@
 // copy. The i18n types derive `TranslationKey` / `StreamTFunction` from it, so a typo'd key is a compile
 // error rather than a string that silently stops rendering.
 //
-// The generator itself lives in `stream-chat/i18n/codegen`, shared with the React Native SDK. Only this
+// The generator itself lives in `@stream-io/i18n/codegen`, shared with the React Native SDK. Only this
 // package's paths and prefixes are configured here; the call-site reader, the four hard-fail guards and
 // the emitter are all core's.
 //
 // Run by `yarn build-translations`, from the package root — every path below is relative to it.
 // `yarn validate-translations` runs it and fails on any diff, which is the drift gate.
 import ts from 'typescript';
-import { generateI18nKeys } from 'stream-chat/i18n/codegen';
+import { generateI18nKeys } from '@stream-io/i18n/codegen';
 
 const jsonFlag = process.argv.indexOf('--json');
 const jsonOut = jsonFlag === -1 ? undefined : process.argv[jsonFlag + 1];
@@ -22,7 +22,7 @@ if (jsonFlag !== -1 && (!jsonOut || jsonOut.startsWith('--'))) {
 try {
   generateI18nKeys({
     fixtureOut: 'src/i18n/__tests__/catalog.fixture.json',
-    // `language.*` names come from `stream-chat/i18n` rather than from this package's
+    // `language.*` names come from `@stream-io/i18n` rather than from this package's
     // runtimeDefaults, so they are excluded from the translator export alongside the formatter
     // expressions — a TMS should not be asked to translate the SDK's own language list.
     extraFormatterPrefixes: ['translationBuilderTopic.', 'language.'],

@@ -1,4 +1,4 @@
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 import throttle from 'lodash.throttle';
 import type { AudioPlayerPlugin } from './plugins';
 import type { AudioPlayerPool } from './AudioPlayerPool';

@@ -1,5 +1,5 @@
 import { AudioPlayer, type AudioPlayerOptions } from './AudioPlayer';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 export type AudioPlayerPoolState = {
   activeAudioPlayer: AudioPlayer | null;

@@ -1,5 +1,5 @@
 import { nanoid } from 'nanoid';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 export type GetDialogParams = {
   id: DialogId;

@@ -1,6 +1,7 @@
 import type { ComponentType } from 'react';
 import React, { forwardRef } from 'react';
-import type { PaginatorState, StateStore } from 'stream-chat';
+import type { StateStore } from '@stream-io/state-store';
+import type { PaginatorState } from 'stream-chat';
 
 import { useStateStore } from '../../store';
 import type { InfiniteScrollPaginatorProps } from './InfiniteScrollPaginator';

@@ -1,6 +1,6 @@
 import uniqBy from 'lodash.uniqby';
 import { useCallback, useEffect, useMemo } from 'react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 export type CursorPaginatorState<T> = {
   hasNextPage: boolean;

@@ -1,7 +1,7 @@
 import { act, renderHook } from '@testing-library/react';
 import { fromPartial } from '@total-typescript/shoehorn';
 import type { ChannelConfig, Command, MessageComposerState } from 'stream-chat';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 import { useMessageComposerCommands } from '../useMessageComposerCommands';
 

@@ -24,7 +24,8 @@ import { useChannel, useMessageContext, WithComponents } from '../../../context'
 import { EmptyStateIndicator as EmptyStateIndicatorMock } from '../../EmptyStateIndicator';
 import { mockedApiResponse } from '../../../mock-builders/api/utils';
 import { nanoid } from 'nanoid';
-import { msToNs, StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
+import { msToNs } from 'stream-chat';
 import type {
   Channel as ChannelType,
   Event,

@@ -1,6 +1,6 @@
 import React from 'react';
 import { act, fireEvent, render, screen, waitFor } from '@testing-library/react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 import type { Channel, StreamChat, Thread, UserResponse } from 'stream-chat';
 
 import { ScrollToLatestMessageButton } from '../ScrollToLatestMessageButton';

@@ -1,6 +1,6 @@
 import { renderHook } from '@testing-library/react';
 import { fromPartial } from '@total-typescript/shoehorn';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 import { useChatContext, useModalDialogManager } from '../../../../context';
 import { modalDialogId } from '../../../Dialog';

@@ -1,6 +1,6 @@
 import React from 'react';
 import { renderHook, waitFor } from '@testing-library/react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 import { GlobalModal } from '../../../Modal';
 import { useNotificationApi } from '../useNotificationApi';

@@ -1,6 +1,6 @@
 import React from 'react';
 import { renderHook } from '@testing-library/react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 import { useNotifications } from '../useNotifications';
 import { NotificationConfigurationProvider } from '../../NotificationConfigurationContext';

@@ -1,7 +1,7 @@
 import { act, cleanup, fireEvent, render, waitFor } from '@testing-library/react';
 import React from 'react';
 import { fromPartial } from '@total-typescript/shoehorn';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 import type {
   ChannelConfig,
   LocalMessage,

@@ -1,6 +1,6 @@
 import React from 'react';
 import { cleanup, render, screen } from '@testing-library/react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 import { fromPartial } from '@total-typescript/shoehorn';
 
 import { ThreadStart } from '../ThreadStart';

@@ -5,7 +5,7 @@ import React, {
   useMemo,
   useState,
 } from 'react';
-import { StateStore } from 'stream-chat';
+import { StateStore } from '@stream-io/state-store';
 
 import { DialogManager } from '../components/Dialog/service/DialogManager';
 import {