@@ -0,0 +1,252 @@
+/**
+ * Pins the listing-completeness signals the sync engine relies on to decide whether it may
+ * hard-delete stored documents, plus the Link-header cursor parsing Circleback pagination
+ * depends on. `listingCapped` and a truthful `hasMore` are the only things standing between
+ * a partial listing and reconciliation purging the rest of the knowledge base.
+ *
+ * @vitest-environment node
+ */
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { mockFetchWithRetry } = vi.hoisted(() => ({ mockFetchWithRetry: vi.fn() }))
+
+vi.mock('@/lib/knowledge/documents/utils', () => ({
+  fetchWithRetry: mockFetchWithRetry,
+  VALIDATE_RETRY_OPTIONS: {},
+}))
+vi.mock('@/components/icons', () => ({ CirclebackIcon: () => null }))
+
+import { circlebackConnector } from '@/connectors/circleback/circleback'
+
+function meeting(id: string) {
+  return {
+    id,
+    name: `Meeting ${id}`,
+    createdAt: '2026-01-27T15:30:00Z',
+    updatedAt: '2026-01-27T16:45:00Z',
+    duration: 1800,
+    tags: [{ id: 1, name: 'Customer' }],
+    attendees: [{ profileId: 1, name: 'Oat Benson', email: 'oat@example.com' }],
+    notes: '## Recap\nWe discussed the rollout.',
+    actionItems: [
+      {
+        id: 10,
+        title: 'Send follow-up',
+        description: '',
+        assignee: { name: 'Oat Benson', email: 'oat@example.com' },
+        status: 'PENDING',
+      },
+    ],
+    insights: {},
+  }
+}
+
+/** Queue a single Circleback list response with an optional RFC 8288 next link. */
+function mockListResponse(body: unknown, nextCursor?: string, status = 200) {
+  mockFetchWithRetry.mockResolvedValue({
+    ok: status >= 200 && status < 300,
+    status,
+    headers: {
+      get: (name: string) =>
+        name.toLowerCase() === 'link' && nextCursor
+          ? `<https://circleback.ai/api/meetings?cursor=${nextCursor}>; rel="next"`
+          : null,
+    },
+    json: async () => body,
+    text: async () => JSON.stringify(body),
+  } as unknown as Response)
+}
+
+const list = (sourceConfig: Record<string, unknown>, syncContext: Record<string, unknown>) =>
+  circlebackConnector.listDocuments('tok', sourceConfig, undefined, syncContext, undefined)
+
+describe('circleback connector listing completeness', () => {
+  beforeEach(() => {
+    mockFetchWithRetry.mockReset()
+  })
+
+  it('parses the next cursor from the Link header on a normal page', async () => {
+    mockListResponse([meeting('m1')], 'cur_2')
+
+    const syncContext: Record<string, unknown> = {}
+    const page = await list({}, syncContext)
+
+    expect(page.hasMore).toBe(true)
+    expect(page.nextCursor).toBe('cur_2')
+    expect(syncContext.listingCapped).toBeUndefined()
+  })
+
+  it('reports a complete listing when there is no next link', async () => {
+    mockListResponse([meeting('m1'), meeting('m2')])
+
+    const syncContext: Record<string, unknown> = {}
+    const page = await list({}, syncContext)
+
+    expect(page.hasMore).toBe(false)
+    expect(page.nextCursor).toBeUndefined()
+    expect(syncContext.listingCapped).toBeUndefined()
+    expect(page.documents).toHaveLength(2)
+  })
+
+  it('never caps when no maxMeetings is configured', async () => {
+    mockListResponse([meeting('m1'), meeting('m2')], 'cur_2')
+
+    const syncContext: Record<string, unknown> = {}
+    await list({ maxMeetings: '' }, syncContext)
+
+    expect(syncContext.listingCapped).toBeUndefined()
+  })
+
+  it('caps and flags when maxMeetings slices a page, hiding meetings that still exist', async () => {
+    mockListResponse([meeting('m1'), meeting('m2'), meeting('m3')])
+
+    const syncContext: Record<string, unknown> = {}
+    const page = await list({ maxMeetings: '2' }, syncContext)
+
+    expect(page.documents).toHaveLength(2)
+    expect(syncContext.listingCapped).toBe(true)
+    expect(page.hasMore).toBe(false)
+  })
+
+  it('caps and flags when maxMeetings lands on a page boundary but more pages exist', async () => {
+    mockListResponse([meeting('m1'), meeting('m2')], 'cur_2')
+
+    const syncContext: Record<string, unknown> = {}
+    const page = await list({ maxMeetings: '2' }, syncContext)
+
+    expect(page.documents).toHaveLength(2)
+    expect(syncContext.listingCapped).toBe(true)
+    expect(page.hasMore).toBe(false)
+  })
+
+  it('does NOT flag when the cap lands exactly on the last meeting and the source is exhausted', async () => {
+    mockListResponse([meeting('m1'), meeting('m2')])
+
+    const syncContext: Record<string, unknown> = {}
+    const page = await list({ maxMeetings: '2' }, syncContext)
+
+    expect(page.documents).toHaveLength(2)
+    expect(syncContext.listingCapped).toBeUndefined()
+  })
+
+  it('carries the cap across pages via totalDocsFetched', async () => {
+    mockListResponse([meeting('m3'), meeting('m4')], 'cur_3')
+
+    const syncContext: Record<string, unknown> = { totalDocsFetched: 1 }
+    const page = await list({ maxMeetings: '2' }, syncContext)
+
+    expect(page.documents).toHaveLength(1)
+    expect(syncContext.totalDocsFetched).toBe(2)
+    expect(syncContext.listingCapped).toBe(true)
+  })
+})
+
+describe('circleback connector request shaping and documents', () => {
+  beforeEach(() => {
+    mockFetchWithRetry.mockReset()
+  })
+
+  it('applies only valid scope filters and defaults ownership to Mine', async () => {
+    mockListResponse([])
+
+    await list({ ownership: 'Everything', tagIds: '3, oops, 7' }, {})
+
+    const url = new URL(mockFetchWithRetry.mock.calls[0][0] as string)
+    expect(url.searchParams.get('ownership')).toBe('Mine')
+    expect(url.searchParams.getAll('tagIds')).toEqual(['3', '7'])
+  })
+
+  it('returns deferred plain-text stubs with a metadata-based hash and source URL', async () => {
+    mockListResponse([meeting('m1')])
+
+    const page = await list({}, {})
+    const stub = page.documents[0]
+
+    expect(stub.mimeType).toBe('text/plain')
+    expect(stub.contentDeferred).toBe(true)
+    expect(stub.contentHash).toBe('circleback:m1:2026-01-27T16:45:00Z:notes')
+    expect(stub.sourceUrl).toBe('https://circleback.ai/meetings/m1')
+  })
+
+  it('varies the content hash with the transcript mode so toggling it rehydrates', async () => {
+    mockListResponse([meeting('m1')])
+    const withTranscript = await list({ includeTranscript: 'true' }, {})
+    expect(withTranscript.documents[0].contentHash).toBe(
+      'circleback:m1:2026-01-27T16:45:00Z:transcript'
+    )
+  })
+
+  it('assembles notes and action items into content with an identical hash on getDocument', async () => {
+    mockFetchWithRetry.mockResolvedValue({
+      ok: true,
+      status: 200,
+      headers: { get: () => null },
+      json: async () => meeting('m1'),
+      text: async () => '',
+    } as unknown as Response)
+
+    const doc = await circlebackConnector.getDocument('tok', {}, 'm1')
+
+    expect(doc).not.toBeNull()
+    expect(doc?.contentDeferred).toBe(false)
+    expect(doc?.contentHash).toBe('circleback:m1:2026-01-27T16:45:00Z:notes')
+    expect(doc?.content).toContain('# Meeting m1')
+    expect(doc?.content).toContain('We discussed the rollout.')
+    expect(doc?.content).toContain('- [ ] Send follow-up (Oat Benson)')
+    /* Transcript is opt-in, so only the meeting endpoint is called by default. */
+    expect(mockFetchWithRetry).toHaveBeenCalledTimes(1)
+  })
+
+  it('returns null for a 404 but rethrows other failures so indexed documents survive', async () => {
+    mockFetchWithRetry.mockResolvedValueOnce({
+      ok: false,
+      status: 404,
+      headers: { get: () => null },
+      json: async () => ({}),
+      text: async () => '',
+    } as unknown as Response)
+    expect(await circlebackConnector.getDocument('tok', {}, 'gone')).toBeNull()
+
+    mockFetchWithRetry.mockResolvedValueOnce({
+      ok: false,
+      status: 500,
+      headers: { get: () => null },
+      json: async () => ({}),
+      text: async () => '',
+    } as unknown as Response)
+    await expect(circlebackConnector.getDocument('tok', {}, 'm1')).rejects.toThrow('500')
+  })
+
+  it('rejects caps that the parser would silently treat as unlimited', async () => {
+    for (const bad of ['0', '0.5', 'Infinity', '-1', 'abc']) {
+      const result = await circlebackConnector.validateConfig('tok', { maxMeetings: bad })
+      expect(result.valid).toBe(false)
+    }
+
+    mockFetchWithRetry.mockResolvedValue({
+      ok: true,
+      status: 200,
+      headers: { get: () => null },
+      json: async () => [],
+      text: async () => '',
+    } as unknown as Response)
+    const ok = await circlebackConnector.validateConfig('tok', { maxMeetings: '25' })
+    expect(ok.valid).toBe(true)
+  })
+
+  it('maps metadata to declared tag keys', () => {
+    const tags = circlebackConnector.mapTags?.({
+      title: 'Weekly Sync',
+      attendees: ['Oat Benson', 'Sam Lee'],
+      tags: ['Customer'],
+      meetingDate: '2026-01-27T15:30:00Z',
+      duration: 1800,
+    })
+
+    expect(tags?.title).toBe('Weekly Sync')
+    expect(tags?.attendees).toBe('Oat Benson, Sam Lee')
+    expect(tags?.tags).toBe('Customer')
+    expect(tags?.meetingDate).toBeInstanceOf(Date)
+    expect(tags?.duration).toBe(1800)
+  })
+})