chore(ci): Move monorepo to nx (#19325)

- Replace lerna with Nx for all monorepo task execution (`lerna run` →
`nx run-many`). Lerna was already using Nx under the hood, so this
removes the wrapper layer and uses Nx directly.
- Replace `lerna version` with a custom `scripts/bump-version.js` for
release version bumping. The script replicates `lerna version
--force-publish --exact --no-git-tag-version --no-push` – bumps all
workspace package versions and updates internal dependency references to
exact versions. Also added some unit tests.
- Remove lerna dependency (`lerna.json`, `lerna` devDependency) and add
`nx` as a direct devDependency (22.5.0).
- Move lockfile stability check to its own CI jo (`job_check_lockfile`)
that runs in parallel with the build.
- Configure Nx TUI to auto-exit so `yarn build` doesn't hang waiting for
ESC.
- Adds a `.version.json` as a single source of truth for the current
version (this works well with triggering gitflow)
- Update docs (`CLAUDE.md`, `CONTRIBUTING.md`, `.cursor/rules`) to
reflect the migration.

Closes #19340 (added automatically)

Author: chargome

.cursor/rules/sdk_development.mdc

@@ -23,7 +23,6 @@ You are working on the Sentry JavaScript SDK, a critical production SDK used by
 - `yarn build:dev` - Development build (transpile + types)
 - `yarn build:dev:watch` - Development build in watch mode (recommended)
 - `yarn build:dev:filter <package>` - Build specific package and dependencies
-- `yarn build:types:watch` - Watch mode for TypeScript types only
 - `yarn build:bundle` - Build browser bundles only
 
 ### Testing
@@ -59,7 +58,7 @@ This repository uses **Git Flow**. See [docs/gitflow.md](docs/gitflow.md) for de
 
 ## Repository Architecture
 
-This is a Lerna monorepo with 40+ packages in the `@sentry/*` namespace.
+This is a monorepo with 40+ packages in the `@sentry/*` namespace, managed with Yarn workspaces and Nx.
 
 ### Core Packages
 
@@ -111,7 +110,7 @@ This is a Lerna monorepo with 40+ packages in the `@sentry/*` namespace.
 
 - Uses Rollup for bundling (`rollup.*.config.mjs`)
 - TypeScript with multiple tsconfig files per package
-- Lerna manages package dependencies and publishing
+- Nx orchestrates task execution across packages with caching
 - Vite for testing with `vitest`
 
 ### Package Structure Pattern

.github/workflows/build.yml

@@ -307,16 +307,29 @@ jobs:
         uses: ./.github/actions/restore-cache
         with:
           dependency_cache_key: ${{ needs.job_build.outputs.dependency_cache_key }}
-      - name: Check for duplicate dependencies in lockfile
-        # Run `yarn dedupe-deps:fix` locally to resolve any duplicates.
-        run: yarn dedupe-deps:check
       - name: Lint source files
-        run: yarn lint:lerna
+        run: yarn lint:eslint
       - name: Lint for ES compatibility
         run: yarn lint:es-compatibility
 
+  job_check_lockfile:
+    name: Check lockfile
+    needs: [job_get_metadata]
+    timeout-minutes: 10
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Check out current commit (${{ needs.job_get_metadata.outputs.commit_label }})
+        uses: actions/checkout@v6
+        with:
+          ref: ${{ env.HEAD_COMMIT }}
+      - name: Set up Node
+        uses: actions/setup-node@v6
+        with:
+          node-version-file: 'package.json'
       - name: Check that yarn.lock is stable
-        run: yarn && git diff --exit-code yarn.lock
+        run: yarn install --frozen-lockfile --ignore-engines
+      - name: Check for duplicate dependencies in lockfile
+        run: yarn dedupe-deps:check
 
   job_check_format:
     name: Check file formatting
@@ -1204,6 +1217,7 @@ jobs:
         job_e2e_tests,
         job_artifacts,
         job_lint,
+        job_check_lockfile,
         job_check_format,
         job_circular_dep_check,
         job_size_check,

.github/workflows/gitflow-sync-develop.yml

@@ -4,8 +4,8 @@ on:
     branches:
       - master
     paths:
-      # When the version is updated on master (but nothing else)
-      - 'lerna.json'
+      # When versions are bumped on master (written by scripts/bump-version.js)
+      - '.version.json'
       - '!**/*.js'
       - '!**/*.ts'
   workflow_dispatch:

.gitignore

@@ -24,7 +24,6 @@ packages/*/sentry-*.tgz
 # logs
 yarn-error.log
 npm-debug.log
-lerna-debug.log
 local.log
 
 # ide

.version.json

@@ -0,0 +1,4 @@
+{
+  "_comment": "Auto-generated by scripts/bump-version.js. Used by the gitflow sync workflow to detect version bumps. Do not edit manually.",
+  "version": "10.39.0"
+}

CLAUDE.md

@@ -22,7 +22,6 @@ You are working on the Sentry JavaScript SDK, a critical production SDK used by
 - `yarn build:dev` - Development build (transpile + types)
 - `yarn build:dev:watch` - Development build in watch mode (recommended)
 - `yarn build:dev:filter <package>` - Build specific package and dependencies
-- `yarn build:types:watch` - Watch mode for TypeScript types only
 - `yarn build:bundle` - Build browser bundles only
 
 ### Testing
@@ -58,7 +57,7 @@ This repository uses **Git Flow**. See [docs/gitflow.md](docs/gitflow.md) for de
 
 ## Repository Architecture
 
-This is a Lerna monorepo with 40+ packages in the `@sentry/*` namespace.
+This is a monorepo with 40+ packages in the `@sentry/*` namespace, managed with Yarn workspaces and Nx.
 
 ### Core Packages
 
@@ -102,7 +101,7 @@ This is a Lerna monorepo with 40+ packages in the `@sentry/*` namespace.
 
 - Uses Rollup for bundling (`rollup.*.config.mjs`)
 - TypeScript with multiple tsconfig files per package
-- Lerna manages package dependencies and publishing
+- Nx orchestrates task execution across packages with caching
 - Vite for testing with `vitest`
 
 ### Package Structure Pattern

CONTRIBUTING.md

@@ -19,7 +19,7 @@ We use [Volta](https://volta.sh/) to ensure we use consistent versions of node,
 Make sure to also enable [pnpm support in Volta](https://docs.volta.sh/advanced/pnpm) if you want to run the E2E tests
 locally.
 
-`sentry-javascript` is a monorepo containing several packages, and we use `lerna` to manage them. To get started,
+`sentry-javascript` is a monorepo containing several packages, managed with Yarn workspaces and Nx. To get started,
 install all dependencies, and then perform an initial build, so TypeScript can read all of the linked type definitions.
 
 ```

lerna.json

@@ -10,6 +10,9 @@
     "production": ["default", "!{projectRoot}/test/**/*", "!{projectRoot}/**/*.md", "!{projectRoot}/*.tgz"]
   },
   "targetDefaults": {
+    "build:dev": {
+      "dependsOn": ["^build:transpile", "^build:types"]
+    },
     "build:bundle": {
       "inputs": ["production", "^production"],
       "dependsOn": ["build:transpile"],
@@ -58,5 +61,8 @@
     }
   },
   "$schema": "./node_modules/nx/schemas/nx-schema.json",
-  "cacheDirectory": ".nxcache"
+  "cacheDirectory": ".nxcache",
+  "tui": {
+    "autoExit": true
+  }
 }

nx.json

@@ -1,49 +1,49 @@
 {
   "private": true,
   "scripts": {
-    "build": "node ./scripts/verify-packages-versions.js && lerna run build:transpile,build:types,build:bundle",
-    "build:bundle": "lerna run build:bundle",
-    "build:dev": "lerna run build:types,build:transpile",
-    "build:dev:filter": "lerna run build:dev --include-filtered-dependencies --include-filtered-dependents --scope",
-    "build:transpile": "lerna run build:transpile",
-    "build:types": "lerna run build:types",
-    "build:watch": "lerna run build:watch",
-    "build:dev:watch": "lerna run build:dev:watch",
-    "build:types:watch": "ts-node scripts/build-types-watch.ts",
+    "build": "node ./scripts/verify-packages-versions.js && nx run-many -t build:transpile build:types build:bundle",
+    "build:bundle": "nx run-many -t build:bundle",
+    "build:dev": "nx run-many -t build:types build:transpile",
+    "build:dev:filter": "nx run-many -t build:dev -p",
+    "build:transpile": "nx run-many -t build:transpile",
+    "build:types": "nx run-many -t build:types",
+    "build:watch": "nx run-many -t build:watch",
+    "build:dev:watch": "nx run-many -t build:dev:watch",
     "build:tarball": "run-s clean:tarballs build:tarballs",
-    "build:tarballs": "lerna run build:tarball",
+    "build:tarballs": "nx run-many -t build:tarball",
     "changelog": "ts-node ./scripts/get-commit-list.ts",
     "generate-changelog": "ts-node ./scripts/generate-changelog.ts",
-    "circularDepCheck": "lerna run circularDepCheck",
+    "circularDepCheck": "nx run-many -t circularDepCheck",
     "clean": "run-s clean:build clean:caches",
-    "clean:build": "lerna run clean",
+    "clean:build": "nx run-many -t clean",
     "clean:caches": "yarn rimraf eslintcache .nxcache .nx",
-    "clean:deps": "lerna clean --yes && rm -rf node_modules && yarn",
+    "clean:deps": "rimraf packages/*/node_modules dev-packages/*/node_modules && rm -rf node_modules && yarn",
     "clean:tarballs": "rimraf {packages,dev-packages}/*/*.tgz",
     "clean:watchman": "watchman watch-del \".\"",
     "clean:all": "run-s clean:build clean:tarballs clean:caches clean:deps clean:watchman",
-    "fix": "run-s fix:oxfmt fix:lerna",
-    "fix:lerna": "lerna run fix",
+    "fix": "run-s fix:oxfmt fix:eslint",
+    "fix:eslint": "nx run-many -t fix",
     "fix:oxfmt": "oxfmt . --write",
     "format:check": "oxfmt . --check",
     "format": "oxfmt . --write",
-    "lint": "run-s lint:oxfmt lint:lerna",
-    "lint:lerna": "lerna run lint",
+    "lint": "run-s lint:oxfmt lint:eslint",
+    "lint:eslint": "nx run-many -t lint",
     "lint:oxfmt": "oxfmt . --check",
-    "lint:es-compatibility": "lerna run lint:es-compatibility",
+    "lint:es-compatibility": "nx run-many -t lint:es-compatibility",
     "dedupe-deps:check": "yarn-deduplicate yarn.lock --list --fail",
     "dedupe-deps:fix": "yarn-deduplicate yarn.lock",
-    "postpublish": "lerna run --stream --concurrency 1 postpublish",
-    "test": "lerna run --ignore \"@sentry-internal/{browser-integration-tests,e2e-tests,integration-shims,node-integration-tests,node-core-integration-tests,cloudflare-integration-tests}\" test",
-    "test:unit": "lerna run --ignore \"@sentry-internal/{browser-integration-tests,e2e-tests,integration-shims,node-integration-tests,node-core-integration-tests,cloudflare-integration-tests}\" test:unit",
-    "test:update-snapshots": "lerna run test:update-snapshots",
+    "postpublish": "nx run-many -t postpublish --parallel=1",
+    "test": "nx run-many -t test --exclude \"@sentry-internal/{browser-integration-tests,e2e-tests,integration-shims,node-integration-tests,node-core-integration-tests,cloudflare-integration-tests}\"",
+    "test:scripts": "vitest run scripts/bump-version.test.ts",
+    "test:unit": "nx run-many -t test:unit --exclude \"@sentry-internal/{browser-integration-tests,e2e-tests,integration-shims,node-integration-tests,node-core-integration-tests,cloudflare-integration-tests}\"",
+    "test:update-snapshots": "nx run-many -t test:update-snapshots",
     "test:pr": "nx affected -t test --exclude \"@sentry-internal/{browser-integration-tests,e2e-tests,integration-shims,node-integration-tests,node-core-integration-tests,cloudflare-integration-tests}\"",
     "test:pr:browser": "UNIT_TEST_ENV=browser ts-node ./scripts/ci-unit-tests.ts --affected",
     "test:pr:node": "UNIT_TEST_ENV=node ts-node ./scripts/ci-unit-tests.ts --affected",
     "test:ci:browser": "UNIT_TEST_ENV=browser ts-node ./scripts/ci-unit-tests.ts",
     "test:ci:node": "UNIT_TEST_ENV=node ts-node ./scripts/ci-unit-tests.ts",
-    "test:ci:bun": "lerna run test --scope @sentry/bun",
-    "yalc:publish": "lerna run yalc:publish"
+    "test:ci:bun": "nx run-many -t test -p @sentry/bun",
+    "yalc:publish": "nx run-many -t yalc:publish"
   },
   "volta": {
     "node": "20.19.2",
@@ -127,7 +127,7 @@
     "es-check": "^7.2.1",
     "eslint": "8.57.0",
     "jsdom": "^21.1.2",
-    "lerna": "8.2.4",
+    "nx": "22.5.0",
     "madge": "8.0.0",
     "nodemon": "^3.1.10",
     "npm-run-all2": "^6.2.0",
@@ -146,8 +146,7 @@
   },
   "//_resolutions_comment": [
     "Because new versions of strip-ansi, string-width, and wrap-ansi are ESM only packages,",
-    "we need to resolve them to the CommonJS versions.",
-    "This is a temporary solution until we can upgrade to a version of lerna that supports ESM packages"
+    "we need to resolve them to the CommonJS versions."
   ],
   "resolutions": {
     "gauge/strip-ansi": "6.0.1",