diff --git a/.github/workflows/main-ci.yml b/.github/workflows/main-ci.yml
index 271e8cc3d9d..e66324d200e 100644
--- a/.github/workflows/main-ci.yml
+++ b/.github/workflows/main-ci.yml
@@ -179,6 +179,9 @@ jobs:
               - 'pnpm-workspace.yaml'
               - 'knip.config.ts'
               - 'scripts/check-web-production-unused-after-knip-fix.mjs'
+              - '.npmrc'
+              - '.github/workflows/main-ci.yml'
+              - '.github/workflows/web-bundle-size.yml'
               - '.github/workflows/style.yml'
               - '.github/actions/setup-web/**'
             ts-common-style:
diff --git a/.github/workflows/style.yml b/.github/workflows/style.yml
index 0ebe9774b90..1a44afe3fb0 100644
--- a/.github/workflows/style.yml
+++ b/.github/workflows/style.yml
@@ -107,8 +107,18 @@ jobs:
         if: inputs.run-python-style
         run: uv run --project api dotenv-linter ./api/.env.example ./web/.env.example
 
-  web-style:
-    name: Web Style
+  web-build:
+    name: Web Build and Bundle Analysis
+    if: ${{ !inputs.skip-checks && inputs.classification-succeeded && inputs.run-web-style }}
+    permissions:
+      contents: read
+      pull-requests: write
+    uses: ./.github/workflows/web-bundle-size.yml
+    with:
+      base-rev: ${{ inputs.base-rev }}
+
+  web-style-checks:
+    name: Web Static Checks
     if: ${{ !inputs.skip-checks && (!inputs.classification-succeeded || inputs.run-web-style) }}
     runs-on: depot-ubuntu-24.04
     defaults:
@@ -146,11 +156,6 @@ jobs:
         working-directory: .
         run: vp run knip
 
-      - name: Web build and unused translations check
-        env:
-          NODE_OPTIONS: --max-old-space-size=8192
-        run: vp run build:vinext
-
       - name: Web dead code check production
         working-directory: .
         run: vp run knip:production
@@ -159,6 +164,24 @@ jobs:
         working-directory: .
         run: vp run knip:production-unused-check
 
+  # Preserve the existing required check while build and static checks run in parallel.
+  web-style:
+    name: Web Style
+    if: ${{ always() && !inputs.skip-checks && (!inputs.classification-succeeded || inputs.run-web-style) }}
+    needs: [web-build, web-style-checks]
+    runs-on: ubuntu-24.04
+    permissions: {}
+    steps:
+      - name: Verify web checks
+        env:
+          BUILD_RESULT: ${{ needs.web-build.result }}
+          STYLE_RESULT: ${{ needs.web-style-checks.result }}
+        run: |
+          if [[ "$BUILD_RESULT" != 'success' || "$STYLE_RESULT" != 'success' ]]; then
+            echo "Web checks failed: build=$BUILD_RESULT, static checks=$STYLE_RESULT" >&2
+            exit 1
+          fi
+
   ts-common-style:
     name: TS Common
     if: ${{ !inputs.skip-checks && (!inputs.classification-succeeded || inputs.run-ts-common-style) }}
diff --git a/.github/workflows/web-bundle-size.yml b/.github/workflows/web-bundle-size.yml
new file mode 100644
index 00000000000..888a520f929
--- /dev/null
+++ b/.github/workflows/web-bundle-size.yml
@@ -0,0 +1,152 @@
+name: Web Bundle Analysis
+
+on:
+  workflow_call:
+    inputs:
+      base-rev:
+        description: Exact base revision selected by the main CI event.
+        required: true
+        type: string
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  measure:
+    name: Measure ${{ matrix.revision }}
+    runs-on: ubuntu-24.04
+    timeout-minutes: 30
+    permissions:
+      contents: read
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - revision: base
+            sha: ${{ inputs.base-rev }}
+          - revision: merge
+            sha: ${{ github.sha }}
+    env:
+      NEXT_TELEMETRY_DISABLED: '1'
+      NODE_OPTIONS: --max-old-space-size=6144
+    steps:
+      # Keep one collector for both revisions, including when it does not exist on base yet.
+      - name: Checkout reporting tools
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Preserve collector
+        run: cp web/scripts/bundle-analysis.ts "$RUNNER_TEMP/bundle-analysis.ts"
+
+      - name: Checkout measured revision
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          ref: ${{ matrix.sha }}
+          persist-credentials: false
+
+      - name: Setup web environment
+        uses: ./.github/actions/setup-web
+
+      - name: Instrument selected revision
+        run: node "$RUNNER_TEMP/bundle-analysis.ts" instrument web
+
+      - name: Full Vinext build with official Rolldown analysis
+        working-directory: web
+        shell: bash
+        run: |
+          set -o pipefail
+          started=$SECONDS
+          pnpm exec vinext build 2>&1 | tee "$RUNNER_TEMP/vinext-build.log"
+          printf 'Full Vinext build: **%s seconds**.\n' "$((SECONDS - started))" >> "$GITHUB_STEP_SUMMARY"
+
+      - name: Collect sizes
+        env:
+          COMMIT_SHA: ${{ matrix.sha }}
+        run: node "$RUNNER_TEMP/bundle-analysis.ts" collect web "$COMMIT_SHA" "$RUNNER_TEMP/bundle-size/summary.json"
+
+      - name: Upload size snapshot
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: web-bundle-summary-${{ matrix.revision }}
+          path: ${{ runner.temp }}/bundle-size/summary.json
+          if-no-files-found: error
+          retention-days: 14
+
+      - name: Upload official Rolldown analysis
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+        with:
+          name: web-bundle-analyzer-${{ matrix.revision }}
+          path: |
+            web/dist/client/bundle-analysis.json
+            web/dist/client/bundle-analysis.md
+            ${{ runner.temp }}/vinext-build.log
+          include-hidden-files: true
+          if-no-files-found: error
+          retention-days: 14
+
+  report:
+    name: Compare bundle sizes
+    needs: measure
+    runs-on: ubuntu-24.04
+    timeout-minutes: 5
+    permissions:
+      contents: read
+      pull-requests: write
+    steps:
+      - name: Checkout reporting tools
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+        with:
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: pnpm/setup@703c52620218391530e48b9e8870d5c0082e1b9b # v2.1.0
+        with:
+          install: false
+
+      - name: Download size snapshots
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+        with:
+          pattern: web-bundle-summary-*
+          path: bundle-results
+
+      - name: Compare and summarize
+        env:
+          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+        run: |
+          node web/scripts/bundle-analysis.ts compare \
+            bundle-results/web-bundle-summary-base/summary.json \
+            bundle-results/web-bundle-summary-merge/summary.json \
+            bundle-report.md
+          printf '\n[Download base/merge snapshots and official Rolldown analysis reports](%s#artifacts).\n' "$RUN_URL" >> bundle-report.md
+          printf '\nComparison: event base SHA vs the tested merge commit at GITHUB_SHA (PR or merge queue).\n' >> bundle-report.md
+          cat bundle-report.md >> "$GITHUB_STEP_SUMMARY"
+
+      # Forks still receive the job summary and artifacts, without a privileged PR build.
+      - name: Update PR report
+        if: github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          script: |
+            const fs = require('node:fs');
+            const { owner, repo } = context.repo;
+            const pull_number = context.payload.pull_request.number;
+            const { data: pr } = await github.rest.pulls.get({ owner, repo, pull_number });
+            if (pr.state !== 'open' || pr.head.sha !== context.payload.pull_request.head.sha ||
+                pr.base.sha !== context.payload.pull_request.base.sha) {
+              core.info('Skipping a superseded bundle report.');
+              return;
+            }
+            const body = fs.readFileSync('bundle-report.md', 'utf8');
+            const comments = await github.paginate(github.rest.issues.listComments, {
+              owner, repo, issue_number: pull_number, per_page: 100,
+            });
+            const existing = comments.find(comment =>
+              comment.user?.login === 'github-actions[bot]' &&
+              comment.body?.startsWith('<!-- dify-vinext-bundle-size -->'));
+            if (existing) {
+              await github.rest.issues.updateComment({ owner, repo, comment_id: existing.id, body });
+            } else {
+              await github.rest.issues.createComment({ owner, repo, issue_number: pull_number, body });
+            }
diff --git a/web/docs/bundle-size.md b/web/docs/bundle-size.md
new file mode 100644
index 00000000000..6083abe6dd6
--- /dev/null
+++ b/web/docs/bundle-size.md
@@ -0,0 +1,65 @@
+# Bundle analysis in pull requests
+
+The main CI calls **Web Bundle Analysis** when its Web style checks are required,
+for both pull requests and merge queue entries. It builds the event's exact base
+commit and the tested merge commit from `github.sha` in parallel. Both run the
+complete existing `vinext build` pipeline, including the unused translations check.
+No SSR, reference-analysis, or standalone stage is skipped.
+
+This replaces the separate Vinext build in Web Style. Static checks run alongside
+the analysis workflow, and the existing **Web Style** required check succeeds only
+when both complete successfully. Main CI owns change detection and duplicate-run
+skipping. Target-branch updates alone do not rerun PRs.
+
+The official Rolldown `bundleAnalyzerPlugin` is added only to the client environment
+through a temporary Vite config wrapper. Each revision keeps its own application
+config and lockfile. The plugin is already bundled with the repository's Vite+
+runtime through `vite/rolldown/experimental`; no separate analyzer dependency is
+installed. The experimental schema is validated and unsupported data fails the
+job instead of appearing as savings.
+
+## Reading the report
+
+The comparison appears directly in the Actions summary and in an updated comment
+for same-repository PRs. Merge queue runs receive the summary and artifacts without
+a PR comment. Fork PRs receive the summary and artifacts without a
+privileged build or comment token. Reports are informational: growth does not fail
+the check; build, analysis, and reporting errors do.
+
+- **All client JS:** actual bytes and per-file gzip of the chunks listed in the
+  official analyzer. Includes dynamically imported chunks.
+- **Client CSS:** emitted CSS under `dist/client/_next/static`, excluding copied
+  public assets.
+- **Entry static dependencies:** recursively follows static chunk edges, with
+  shared chunks counted once within an entry. Application source paths identify
+  entries independently of output hashes. Dynamic entries are measured when
+  loaded; these are not full-page first-load measurements. Entries overlap and
+  cannot be summed. The comment shows the 20 largest absolute gzip changes.
+  Added/removed entry boundaries appear separately and are not treated as size
+  changes from zero.
+- **Package attribution:** groups module sizes from the official analyzer by npm
+  package. This is attribution, not compressed output size; the comment shows the
+  15 largest absolute changes.
+
+This measures Vinext/Rolldown output, not Next.js/Turbopack production output or
+browser network timings. Compiler versions are recorded in both snapshots.
+
+Both revisions upload the official JSON and Markdown reports, build logs, and
+size snapshots for 14 days. The summary links to these artifacts; no local viewer
+is required. We do not rely on Vite DevTools' incomplete static Session Compare.
+
+See the [Rolldown analyzer documentation].
+
+## Local collection
+
+The `instrument` command renames `vite.config.ts` and writes a temporary wrapper.
+Use it only in a disposable checkout, as CI does:
+
+```sh
+node web/scripts/bundle-analysis.ts instrument web
+pnpm --dir web exec vinext build
+node web/scripts/bundle-analysis.ts collect web "$(git rev-parse HEAD)" /tmp/current.json
+node web/scripts/bundle-analysis.ts compare /tmp/base.json /tmp/current.json /tmp/report.md
+```
+
+[Rolldown analyzer documentation]: https://rolldown.rs/builtin-plugins/bundle-analyzer
diff --git a/web/scripts/__tests__/bundle-analysis.spec.ts b/web/scripts/__tests__/bundle-analysis.spec.ts
new file mode 100644
index 00000000000..fc0b5c887b0
--- /dev/null
+++ b/web/scripts/__tests__/bundle-analysis.spec.ts
@@ -0,0 +1,114 @@
+import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { gzipSync } from 'node:zlib'
+import { collect, compare, parseAnalysis, parseSnapshot, staticClosure } from '../bundle-analysis'
+
+const dirs: string[] = []
+const sha = 'a'.repeat(40)
+const graph = () => ({
+  meta: { bundler: 'rolldown', version: '1.2.9' },
+  chunks: [
+    {
+      name: 'entry.js',
+      size: 5,
+      type: 'static-entry',
+      entryModule: 0,
+      imports: [
+        { type: 'static', targetChunkIndex: 1 },
+        { type: 'dynamic', targetChunkIndex: 2 },
+      ],
+    },
+    {
+      name: 'shared.js',
+      size: 6,
+      type: 'common',
+      imports: [{ type: 'static', targetChunkIndex: 0 }],
+    },
+    {
+      name: 'lazy.js',
+      size: 4,
+      type: 'dynamic-entry',
+      entryModule: 1,
+      imports: [{ type: 'static', targetChunkIndex: 1 }],
+    },
+  ],
+  modules: [
+    { path: 'app/view.tsx', size: 5 },
+    { path: 'app/lazy.tsx', size: 4 },
+    { path: '../node_modules/.pnpm/@scope+pkg@1/node_modules/@scope/pkg/index.js', size: 6 },
+  ],
+})
+async function fixture(analysis = graph()) {
+  const root = await mkdtemp(join(tmpdir(), 'vinext-analysis-test-'))
+  dirs.push(root)
+  const client = join(root, 'dist/client')
+  await mkdir(join(client, '_next/static/css'), { recursive: true })
+  await mkdir(join(root, 'node_modules/vinext'), { recursive: true })
+  await writeFile(
+    join(root, 'node_modules/vinext/package.json'),
+    JSON.stringify({ version: '1.0.0' }),
+  )
+  await writeFile(join(client, 'bundle-analysis.json'), JSON.stringify(analysis))
+  for (const [name, data] of Object.entries({
+    'entry.js': 'entry',
+    'shared.js': 'shared',
+    'lazy.js': 'lazy',
+    '_next/static/css/app.css': 'css',
+  }))
+    await writeFile(join(client, name), data)
+  return root
+}
+afterEach(async () => {
+  await Promise.all(dirs.splice(0).map((dir) => rm(dir, { recursive: true, force: true })))
+})
+
+it('deduplicates cycles and shared dependencies without following dynamic edges', () => {
+  expect([...staticClosure(parseAnalysis(JSON.stringify(graph())), 0)]).toEqual([0, 1])
+  expect([...staticClosure(parseAnalysis(JSON.stringify(graph())), 2)]).toEqual([2, 1, 0])
+})
+it('measures emitted files independently of attribution and groups scoped packages', async () => {
+  const result = await collect(await fixture(), sha)
+  expect(result.totals.js).toEqual({
+    raw: 15,
+    gzip: gzipSync('entry').length + gzipSync('shared').length + gzipSync('lazy').length,
+  })
+  expect(result.entries['static-entry: app/view.tsx']?.raw).toBe(11)
+  expect(result.totals.css.raw).toBe(3)
+  expect(result.packages).toEqual({ '@scope/pkg': 6 })
+  expect(parseSnapshot(JSON.stringify(result))).toEqual(result)
+})
+it('fails on missing emitted files instead of reporting false savings', async () => {
+  const root = await fixture()
+  await rm(join(root, 'dist/client/lazy.js'))
+  await expect(collect(root, sha)).rejects.toThrow('ENOENT')
+})
+it('rejects incompatible graph data and dangling references', () => {
+  const invalid = graph()
+  invalid.chunks[0]!.imports![0]!.targetChunkIndex = 99
+  expect(() => parseAnalysis(JSON.stringify(invalid))).toThrow('Invalid')
+  expect(() => parseAnalysis('{}')).toThrow('Invalid')
+})
+it('rejects out-of-output chunk paths', async () => {
+  const invalid = graph()
+  invalid.chunks[0]!.name = '../outside.js'
+  await expect(collect(await fixture(invalid), sha)).rejects.toThrow('outside')
+})
+it('reports additions, removals, gzip differences and package attribution without calling entries pages', async () => {
+  const base = await collect(await fixture(), sha)
+  const merged = {
+    ...base,
+    commit: 'b'.repeat(40),
+    entries: { 'dynamic-entry: app/new|view.tsx': { raw: 4096, gzip: 2048 } },
+    packages: { '@scope/pkg': 1030 },
+  }
+  const report = compare(base, merged)
+  expect(report).toContain('New')
+  expect(report).toContain('Removed')
+  expect(report).toContain('new&#124;view.tsx')
+  expect(report).toContain('New entry')
+  expect(report).not.toContain('+2.00 KiB')
+  expect(report).toContain('+1.00 KiB')
+  expect(report).toContain('not page first-load metrics')
+  expect(() => parseSnapshot(JSON.stringify({ ...base, totals: {} }))).toThrow('Invalid')
+})
diff --git a/web/scripts/bundle-analysis.ts b/web/scripts/bundle-analysis.ts
new file mode 100644
index 00000000000..67037bc364a
--- /dev/null
+++ b/web/scripts/bundle-analysis.ts
@@ -0,0 +1,306 @@
+import { mkdir, readdir, readFile, rename, writeFile } from 'node:fs/promises'
+import { dirname, isAbsolute, join, relative, resolve } from 'node:path'
+import { gzipSync } from 'node:zlib'
+
+type Size = { raw: number; gzip: number }
+type Analysis = {
+  meta: { bundler: string; version: string }
+  chunks: {
+    name: string
+    size: number
+    type: string
+    entryModule?: number
+    imports?: { targetChunkIndex: number; type: string }[]
+  }[]
+  modules: { path: string; size: number }[]
+}
+type Snapshot = {
+  version: 1
+  commit: string
+  vinext: string
+  rolldown: string
+  totals: { js: Size; css: Size }
+  entries: Record<string, Size>
+  packages: Record<string, number>
+}
+const record = (v: unknown): v is Record<string, unknown> =>
+  typeof v === 'object' && v !== null && !Array.isArray(v)
+const bytes = (v: unknown): v is number => Number.isSafeInteger(v) && Number(v) >= 0
+const size = (v: unknown): v is Size => record(v) && bytes(v.raw) && bytes(v.gzip)
+const empty = (): Size => ({ raw: 0, gzip: 0 })
+const add = (a: Size, b: Size): Size => ({ raw: a.raw + b.raw, gzip: a.gzip + b.gzip })
+
+export function parseAnalysis(text: string): Analysis {
+  const v: unknown = JSON.parse(text)
+  if (
+    !record(v) ||
+    !record(v.meta) ||
+    v.meta.bundler !== 'rolldown' ||
+    typeof v.meta.version !== 'string' ||
+    !Array.isArray(v.modules) ||
+    !v.modules.every((m) => record(m) && typeof m.path === 'string' && bytes(m.size)) ||
+    !Array.isArray(v.chunks) ||
+    !v.chunks.length
+  )
+    throw new Error('Invalid Rolldown analysis.')
+  const moduleCount = v.modules.length
+  const chunkCount = v.chunks.length
+  for (const c of v.chunks as unknown[]) {
+    if (
+      !record(c) ||
+      typeof c.name !== 'string' ||
+      !bytes(c.size) ||
+      !['static-entry', 'dynamic-entry', 'common'].includes(String(c.type)) ||
+      (c.entryModule !== undefined && (!bytes(c.entryModule) || c.entryModule >= moduleCount)) ||
+      (c.imports !== undefined &&
+        (!Array.isArray(c.imports) ||
+          !c.imports.every(
+            (i) =>
+              record(i) &&
+              bytes(i.targetChunkIndex) &&
+              i.targetChunkIndex < chunkCount &&
+              ['static', 'dynamic'].includes(String(i.type)),
+          )))
+    )
+      throw new Error('Invalid Rolldown chunk graph.')
+  }
+  return v as Analysis
+}
+
+export function staticClosure(analysis: Analysis, index: number): Set<number> {
+  const seen = new Set<number>()
+  const visit = (i: number) => {
+    if (seen.has(i)) return
+    seen.add(i)
+    const chunk = analysis.chunks[i]
+    if (!chunk) throw new Error(`Missing chunk ${i}`)
+    for (const edge of chunk.imports ?? []) if (edge.type === 'static') visit(edge.targetChunkIndex)
+  }
+  visit(index)
+  return seen
+}
+
+export async function collect(appDirectory: string, commit: string): Promise<Snapshot> {
+  if (!/^[\da-f]{40}$/.test(commit)) throw new Error('Expected a commit SHA.')
+  const app = resolve(appDirectory)
+  const client = join(app, 'dist/client')
+  const analysis = parseAnalysis(await readFile(join(client, 'bundle-analysis.json'), 'utf8'))
+  const cache = new Map<string, Size>()
+  const measure = async (file: string) => {
+    const absolute = resolve(client, file)
+    const local = relative(client, absolute)
+    if (local.startsWith('..') || isAbsolute(local)) throw new Error('Asset outside client output.')
+    const cached = cache.get(absolute)
+    if (cached) return cached
+    const data = await readFile(absolute)
+    const result = { raw: data.length, gzip: gzipSync(data).length }
+    cache.set(absolute, result)
+    return result
+  }
+  const sumFiles = async (files: Iterable<string>) => {
+    let result = empty()
+    for (const file of new Set(files)) result = add(result, await measure(file))
+    return result
+  }
+  const css: string[] = []
+  const visit = async (directory: string): Promise<void> => {
+    for (const item of await readdir(directory, { withFileTypes: true })) {
+      const path = join(directory, item.name)
+      if (item.isDirectory()) await visit(path)
+      else if (item.isFile() && item.name.endsWith('.css')) css.push(path)
+    }
+  }
+  await visit(join(client, '_next/static'))
+  const entries: Record<string, Size> = Object.create(null)
+  for (const [index, chunk] of analysis.chunks.entries()) {
+    if (chunk.entryModule === undefined || chunk.type === 'common') continue
+    const source = analysis.modules[chunk.entryModule]!.path
+    // Application and virtual browser entries are stable across chunk hash changes.
+    if (!source.startsWith('app/') && !source.includes('virtual:vinext-app-browser-entry')) continue
+    const key = `${chunk.type}: ${source}`
+    if (Object.hasOwn(entries, key)) throw new Error(`Duplicate entry: ${key}`)
+    entries[key] = await sumFiles(
+      [...staticClosure(analysis, index)].map((i) => analysis.chunks[i]!.name),
+    )
+  }
+  if (!Object.keys(entries).length) throw new Error('No application entries in Rolldown analysis.')
+  const packages: Record<string, number> = Object.create(null)
+  for (const module of analysis.modules) {
+    const tail = module.path.split('node_modules/').at(-1)!
+    if (tail === module.path) continue
+    const parts = tail.split('/')
+    const name = tail.startsWith('@') ? parts.slice(0, 2).join('/') : parts[0]!
+    packages[name] = (packages[name] ?? 0) + module.size
+  }
+  const pkg: unknown = JSON.parse(
+    await readFile(join(app, 'node_modules/vinext/package.json'), 'utf8'),
+  )
+  if (!record(pkg) || typeof pkg.version !== 'string') throw new Error('Missing Vinext version.')
+  return {
+    version: 1,
+    commit,
+    vinext: pkg.version,
+    rolldown: analysis.meta.version,
+    totals: { js: await sumFiles(analysis.chunks.map((c) => c.name)), css: await sumFiles(css) },
+    entries,
+    packages,
+  }
+}
+
+export function parseSnapshot(text: string): Snapshot {
+  const v: unknown = JSON.parse(text)
+  if (
+    !record(v) ||
+    v.version !== 1 ||
+    typeof v.commit !== 'string' ||
+    !/^[\da-f]{40}$/.test(v.commit) ||
+    typeof v.vinext !== 'string' ||
+    typeof v.rolldown !== 'string' ||
+    !record(v.totals) ||
+    !size(v.totals.js) ||
+    !size(v.totals.css) ||
+    !record(v.entries) ||
+    !Object.keys(v.entries).length ||
+    !Object.values(v.entries).every(size) ||
+    !record(v.packages) ||
+    !Object.values(v.packages).every(bytes)
+  )
+    throw new Error('Invalid bundle snapshot.')
+  return v as Snapshot
+}
+const kib = (n: number) => `${(n / 1024).toFixed(2)} KiB`
+const delta = (a: number, b: number) => `${b > a ? '+' : b < a ? '−' : ''}${kib(Math.abs(b - a))}`
+const label = (s: string) =>
+  `<code>${s.replaceAll('&', '&amp;').replaceAll('<', '&lt;').replaceAll('>', '&gt;').replaceAll('|', '&#124;').replaceAll('\n', ' ')}</code>`
+export function compare(a: Snapshot, b: Snapshot): string {
+  const lines = [
+    '<!-- dify-vinext-bundle-size -->',
+    '## Vinext bundle analysis',
+    '',
+    `Base: \`${a.commit}\` · Merge: \`${b.commit}\``,
+    `Vinext: ${a.vinext} → ${b.vinext}; Rolldown: ${a.rolldown} → ${b.rolldown}`,
+    '',
+    '| All client output | Base gzip | Merge gzip | Gzip Δ | Raw Δ |',
+    '| --- | ---: | ---: | ---: | ---: |',
+  ]
+  for (const kind of ['js', 'css'] as const)
+    lines.push(
+      `| ${kind.toUpperCase()} | ${kib(a.totals[kind].gzip)} | ${kib(b.totals[kind].gzip)} | ${delta(a.totals[kind].gzip, b.totals[kind].gzip)} | ${delta(a.totals[kind].raw, b.totals[kind].raw)} |`,
+    )
+  const changed = [...new Set([...Object.keys(a.entries), ...Object.keys(b.entries)])]
+    .filter(
+      (k) =>
+        a.entries[k] &&
+        b.entries[k] &&
+        (a.entries[k].gzip !== b.entries[k].gzip || a.entries[k].raw !== b.entries[k].raw),
+    )
+    .sort(
+      (x, y) =>
+        Math.abs((b.entries[y]?.gzip ?? 0) - (a.entries[y]?.gzip ?? 0)) -
+          Math.abs((b.entries[x]?.gzip ?? 0) - (a.entries[x]?.gzip ?? 0)) || x.localeCompare(y),
+    )
+  lines.push(
+    '',
+    '### Entry static dependencies',
+    '',
+    `Showing ${Math.min(20, changed.length)} of ${changed.length} changed entries, ordered by absolute gzip delta.`,
+    '',
+    '| Source entry | Base gzip | Merge gzip | Gzip Δ |',
+    '| --- | ---: | ---: | ---: |',
+  )
+  if (!changed.length) lines.push('| No entry size changes | — | — | — |')
+  for (const k of changed.slice(0, 20))
+    lines.push(
+      `| ${label(k)} | ${a.entries[k] ? kib(a.entries[k].gzip) : 'New'} | ${b.entries[k] ? kib(b.entries[k].gzip) : 'Removed'} | ${delta(a.entries[k]?.gzip ?? 0, b.entries[k]?.gzip ?? 0)} |`,
+    )
+  const topology = [...new Set([...Object.keys(a.entries), ...Object.keys(b.entries)])]
+    .filter((k) => !a.entries[k] || !b.entries[k])
+    .sort()
+  if (topology.length) {
+    lines.push(
+      '',
+      '### Added or removed entries',
+      '',
+      `Showing ${Math.min(20, topology.length)} of ${topology.length} entry-boundary changes. These are not size deltas from zero.`,
+      '',
+      '| Source entry | Change | Static dependencies (gzip) |',
+      '| --- | --- | ---: |',
+    )
+    for (const k of topology.slice(0, 20))
+      lines.push(
+        `| ${label(k)} | ${b.entries[k] ? 'New entry' : 'Removed entry'} | ${kib((b.entries[k] ?? a.entries[k])!.gzip)} |`,
+      )
+  }
+  const packages = [...new Set([...Object.keys(a.packages), ...Object.keys(b.packages)])]
+    .filter((k) => a.packages[k] !== b.packages[k])
+    .sort(
+      (x, y) =>
+        Math.abs((b.packages[y] ?? 0) - (a.packages[y] ?? 0)) -
+        Math.abs((b.packages[x] ?? 0) - (a.packages[x] ?? 0)),
+    )
+  lines.push(
+    '',
+    '### Package module attribution',
+    '',
+    '| Package | Base | Merge | Δ |',
+    '| --- | ---: | ---: | ---: |',
+  )
+  if (!packages.length) lines.push('| No package attribution changes | — | — | — |')
+  for (const k of packages.slice(0, 15))
+    lines.push(
+      `| ${label(k)} | ${kib(a.packages[k] ?? 0)} | ${kib(b.packages[k] ?? 0)} | ${delta(a.packages[k] ?? 0, b.packages[k] ?? 0)} |`,
+    )
+  lines.push(
+    '',
+    'Entries follow only static edges in the official Rolldown chunk graph, deduplicating shared files. Dynamic entries are measured when loaded; they are not page first-load metrics. Entry totals overlap and must not be summed.',
+    'Package attribution sums module sizes reported by Rolldown, not compressed emitted bytes. Gzip totals are measured per emitted file. This is Vinext output, not Next.js/Turbopack output.',
+    'Report only: increases do not fail this check. Missing or incompatible analysis data does.',
+  )
+  if (a.vinext !== b.vinext || a.rolldown !== b.rolldown)
+    lines.push('', 'Compiler versions differ; changes may include compiler effects.')
+  return `${lines.join('\n')}\n`
+}
+
+async function instrument(app: string) {
+  await rename(join(app, 'vite.config.ts'), join(app, 'vite.config.bundle-original.ts'))
+  await writeFile(
+    join(app, 'vite.config.ts'),
+    `import { defineConfig, mergeConfig } from 'vite-plus'
+import { bundleAnalyzerPlugin } from 'vite/rolldown/experimental'
+import original from './vite.config.bundle-original.ts'
+export default defineConfig(async env => mergeConfig(await (typeof original === 'function' ? original(env) : original), {
+  plugins: [{ name: 'dify:bundle-analysis', applyToEnvironment(environment) {
+    return environment.name === 'client' ? [
+      bundleAnalyzerPlugin({ fileName: 'bundle-analysis.json' }),
+      bundleAnalyzerPlugin({ fileName: 'bundle-analysis.md', format: 'md' }),
+    ] : false
+  } }],
+}))
+`,
+  )
+}
+async function main() {
+  const [command, first, second, output] = process.argv.slice(2)
+  if (command === 'instrument' && first) return instrument(first)
+  if (!first || !second || !output)
+    throw new Error(
+      'Usage: instrument <web> | collect <web> <sha> <json> | compare <base.json> <merge.json> <report.md>',
+    )
+  const result =
+    command === 'collect'
+      ? `${JSON.stringify(await collect(first, second), null, 2)}\n`
+      : command === 'compare'
+        ? compare(
+            parseSnapshot(await readFile(first, 'utf8')),
+            parseSnapshot(await readFile(second, 'utf8')),
+          )
+        : null
+  if (result === null) throw new Error('Unknown command.')
+  await mkdir(dirname(resolve(output)), { recursive: true })
+  await writeFile(output, result)
+}
+if (import.meta.main)
+  main().catch((error: unknown) => {
+    console.error(error)
+    process.exitCode = 1
+  })