diff --git a/packages/db/scripts/migrate-block-api-keys-to-byok.ts b/packages/db/scripts/migrate-block-api-keys-to-byok.ts
new file mode 100644
index 00000000000..bca9bb581f9
--- /dev/null
+++ b/packages/db/scripts/migrate-block-api-keys-to-byok.ts
@@ -0,0 +1,737 @@
+#!/usr/bin/env bun
+
+// Self-contained script for migrating block-level API keys into workspace BYOK keys.
+// Iterates per workspace. Original block-level values are left untouched for safety.
+// Handles both literal keys ("sk-xxx...") and env var references ("{{VAR_NAME}}").
+//
+// Usage:
+//   # Step 1 — Dry run: audit for conflicts + preview inserts (no DB writes)
+//   #   Outputs migrate-byok-workspace-ids.txt for the live run.
+//   bun run packages/db/scripts/migrate-block-api-keys-to-byok.ts --dry-run \
+//     --map jina=jina --map perplexity=perplexity --map google_books=google_cloud
+//
+//   # Step 2 — Live run: insert BYOK keys (--from-file is required)
+//   bun run packages/db/scripts/migrate-block-api-keys-to-byok.ts \
+//     --map jina=jina --map perplexity=perplexity --map google_books=google_cloud \
+//     --from-file migrate-byok-workspace-ids.txt
+//
+//   # Optionally scope dry run to specific users (repeatable)
+//   bun run packages/db/scripts/migrate-block-api-keys-to-byok.ts --dry-run \
+//     --map jina=jina --user user_abc123 --user user_def456
+
+import { createCipheriv, createDecipheriv, randomBytes } from 'crypto'
+import { appendFileSync, readFileSync, writeFileSync } from 'fs'
+import { resolve } from 'path'
+import { eq, sql } from 'drizzle-orm'
+import { index, json, jsonb, pgTable, text, timestamp, uniqueIndex } from 'drizzle-orm/pg-core'
+import { drizzle } from 'drizzle-orm/postgres-js'
+import postgres from 'postgres'
+import { v4 as uuidv4 } from 'uuid'
+
+// ---------- CLI ----------
+const DRY_RUN = process.argv.includes('--dry-run')
+
+function parseMapArgs(): Record<string, string> {
+  const mapping: Record<string, string> = {}
+  const args = process.argv.slice(2)
+  for (let i = 0; i < args.length; i++) {
+    if (args[i] === '--map' && args[i + 1]) {
+      const [blockType, providerId] = args[i + 1].split('=')
+      if (blockType && providerId) {
+        mapping[blockType] = providerId
+      } else {
+        console.error(
+          `Invalid --map value: "${args[i + 1]}". Expected format: blockType=providerId`
+        )
+        process.exit(1)
+      }
+      i++
+    }
+  }
+  return mapping
+}
+
+const BLOCK_TYPE_TO_PROVIDER = parseMapArgs()
+if (Object.keys(BLOCK_TYPE_TO_PROVIDER).length === 0) {
+  console.error('No --map arguments provided. Specify at least one: --map blockType=providerId')
+  console.error(
+    'Example: --map jina=jina --map perplexity=perplexity --map google_books=google_cloud'
+  )
+  process.exit(1)
+}
+
+function parseUserArgs(): string[] {
+  const users: string[] = []
+  const args = process.argv.slice(2)
+  for (let i = 0; i < args.length; i++) {
+    if (args[i] === '--user' && args[i + 1]) {
+      users.push(args[i + 1])
+      i++
+    }
+  }
+  return users
+}
+
+const USER_FILTER = parseUserArgs()
+
+function parseFromFileArg(): string | null {
+  const args = process.argv.slice(2)
+  for (let i = 0; i < args.length; i++) {
+    if (args[i] === '--from-file' && args[i + 1]) {
+      return args[i + 1]
+    }
+  }
+  return null
+}
+
+const FROM_FILE = parseFromFileArg()
+
+if (!DRY_RUN && !FROM_FILE) {
+  console.error('Live runs require --from-file. Run with --dry-run first to generate the file.')
+  process.exit(1)
+}
+if (DRY_RUN && FROM_FILE) {
+  console.error(
+    '--from-file cannot be used with --dry-run. Dry runs always discover workspaces from the database.'
+  )
+  process.exit(1)
+}
+
+// ---------- Env ----------
+function getEnv(name: string): string | undefined {
+  if (typeof process !== 'undefined' && process.env && name in process.env) {
+    return process.env[name]
+  }
+  return undefined
+}
+
+const CONNECTION_STRING = getEnv('POSTGRES_URL') ?? getEnv('DATABASE_URL')
+if (!CONNECTION_STRING) {
+  console.error('Missing POSTGRES_URL or DATABASE_URL environment variable')
+  process.exit(1)
+}
+
+const ENCRYPTION_KEY = getEnv('ENCRYPTION_KEY')
+if (!ENCRYPTION_KEY || ENCRYPTION_KEY.length !== 64) {
+  console.error('ENCRYPTION_KEY must be set to a 64-character hex string (32 bytes)')
+  process.exit(1)
+}
+
+// ---------- Encryption (mirrors apps/sim/lib/core/security/encryption.ts) ----------
+function getEncryptionKeyBuffer(): Buffer {
+  return Buffer.from(ENCRYPTION_KEY!, 'hex')
+}
+
+async function encryptSecret(secret: string): Promise<string> {
+  const iv = randomBytes(16)
+  const key = getEncryptionKeyBuffer()
+  const cipher = createCipheriv('aes-256-gcm', key, iv)
+  let encrypted = cipher.update(secret, 'utf8', 'hex')
+  encrypted += cipher.final('hex')
+  const authTag = cipher.getAuthTag()
+  return `${iv.toString('hex')}:${encrypted}:${authTag.toString('hex')}`
+}
+
+async function decryptSecret(encryptedValue: string): Promise<string> {
+  const parts = encryptedValue.split(':')
+  const ivHex = parts[0]
+  const authTagHex = parts[parts.length - 1]
+  const encrypted = parts.slice(1, -1).join(':')
+
+  if (!ivHex || !encrypted || !authTagHex) {
+    throw new Error('Invalid encrypted value format. Expected "iv:encrypted:authTag"')
+  }
+
+  const key = getEncryptionKeyBuffer()
+  const iv = Buffer.from(ivHex, 'hex')
+  const authTag = Buffer.from(authTagHex, 'hex')
+
+  const decipher = createDecipheriv('aes-256-gcm', key, iv)
+  decipher.setAuthTag(authTag)
+
+  let decrypted = decipher.update(encrypted, 'hex', 'utf8')
+  decrypted += decipher.final('utf8')
+  return decrypted
+}
+
+// ---------- Schema ----------
+const workspaceTable = pgTable('workspace', {
+  id: text('id').primaryKey(),
+  ownerId: text('owner_id').notNull(),
+})
+
+const workflow = pgTable('workflow', {
+  id: text('id').primaryKey(),
+  userId: text('user_id').notNull(),
+  workspaceId: text('workspace_id'),
+  name: text('name').notNull(),
+})
+
+const workflowBlocks = pgTable(
+  'workflow_blocks',
+  {
+    id: text('id').primaryKey(),
+    workflowId: text('workflow_id').notNull(),
+    type: text('type').notNull(),
+    name: text('name').notNull(),
+    subBlocks: jsonb('sub_blocks').notNull().default('{}'),
+    createdAt: timestamp('created_at').notNull().defaultNow(),
+    updatedAt: timestamp('updated_at').notNull().defaultNow(),
+  },
+  (table) => ({
+    workflowIdIdx: index('workflow_blocks_workflow_id_idx').on(table.workflowId),
+  })
+)
+
+const workspaceBYOKKeys = pgTable(
+  'workspace_byok_keys',
+  {
+    id: text('id').primaryKey(),
+    workspaceId: text('workspace_id').notNull(),
+    providerId: text('provider_id').notNull(),
+    encryptedApiKey: text('encrypted_api_key').notNull(),
+    createdBy: text('created_by'),
+    createdAt: timestamp('created_at').notNull().defaultNow(),
+    updatedAt: timestamp('updated_at').notNull().defaultNow(),
+  },
+  (table) => ({
+    workspaceProviderUnique: uniqueIndex('workspace_byok_provider_unique').on(
+      table.workspaceId,
+      table.providerId
+    ),
+    workspaceIdx: index('workspace_byok_workspace_idx').on(table.workspaceId),
+  })
+)
+
+const environment = pgTable('environment', {
+  id: text('id').primaryKey(),
+  userId: text('user_id').notNull(),
+  variables: json('variables').notNull(),
+})
+
+const workspaceEnvironment = pgTable('workspace_environment', {
+  id: text('id').primaryKey(),
+  workspaceId: text('workspace_id').notNull(),
+  variables: json('variables').notNull().default('{}'),
+})
+
+const WORKSPACE_CONCURRENCY = 100
+const WORKSPACE_BATCH_SIZE = 1000
+const SLEEP_MS = 30_000
+
+// ---------- DB ----------
+const postgresClient = postgres(CONNECTION_STRING, {
+  prepare: false,
+  idle_timeout: 20,
+  connect_timeout: 30,
+  max: 10,
+  onnotice: () => {},
+})
+const db = drizzle(postgresClient)
+
+// ---------- Helpers ----------
+const TOOL_INPUT_SUBBLOCK_IDS: Record<string, string> = {
+  agent: 'tools',
+  human_in_the_loop: 'notification',
+}
+
+const ENV_VAR_PATTERN = /^\{\{([^}]+)\}\}$/
+
+function isEnvVarReference(value: string): boolean {
+  return ENV_VAR_PATTERN.test(value)
+}
+
+function extractEnvVarName(value: string): string | null {
+  const match = ENV_VAR_PATTERN.exec(value)
+  return match ? match[1].trim() : null
+}
+
+function maskKey(key: string): string {
+  if (key.length <= 8) return '•'.repeat(8)
+  return key.slice(0, 4) + '•'.repeat(Math.min(key.length - 8, 12)) + key.slice(-4)
+}
+
+function parseToolInputValue(value: unknown): any[] {
+  if (Array.isArray(value)) return value
+  if (typeof value === 'string') {
+    try {
+      const parsed = JSON.parse(value)
+      if (Array.isArray(parsed)) return parsed
+    } catch {}
+  }
+  return []
+}
+
+type RawKeyRef = {
+  rawValue: string
+  blockName: string
+  workflowId: string
+  workflowName: string
+  userId: string
+}
+
+type EnvLookup = {
+  wsEnvVars: Record<string, string>
+  personalEnvCache: Map<string, Record<string, string>>
+}
+
+type KeySource = 'plaintext' | 'workspace' | 'personal'
+
+const KEY_SOURCE_PRIORITY: Record<KeySource, number> = {
+  plaintext: 0,
+  workspace: 1,
+  personal: 2,
+}
+
+interface ResolveKeyContext {
+  workspaceId: string
+  workspaceOwnerId: string | null
+}
+
+type MigrationStats = {
+  workspacesProcessed: number
+  workspacesSkipped: number
+  conflicts: number
+  inserted: number
+  skippedExisting: number
+  errors: number
+  envVarFailures: number
+}
+
+type WorkspaceResult = {
+  stats: MigrationStats
+  shouldWriteWorkspaceId: boolean
+}
+
+function createEmptyStats(): MigrationStats {
+  return {
+    workspacesProcessed: 0,
+    workspacesSkipped: 0,
+    conflicts: 0,
+    inserted: 0,
+    skippedExisting: 0,
+    errors: 0,
+    envVarFailures: 0,
+  }
+}
+
+function mergeStats(target: MigrationStats, source: MigrationStats) {
+  target.workspacesProcessed += source.workspacesProcessed
+  target.workspacesSkipped += source.workspacesSkipped
+  target.conflicts += source.conflicts
+  target.inserted += source.inserted
+  target.skippedExisting += source.skippedExisting
+  target.errors += source.errors
+  target.envVarFailures += source.envVarFailures
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms))
+}
+
+async function resolveKey(
+  ref: RawKeyRef,
+  env: EnvLookup,
+  ctx: ResolveKeyContext
+): Promise<{ key: string | null; source: KeySource; envVarFailed: boolean }> {
+  if (!isEnvVarReference(ref.rawValue)) {
+    return { key: ref.rawValue, source: 'plaintext', envVarFailed: false }
+  }
+
+  const varName = extractEnvVarName(ref.rawValue)
+  if (!varName) return { key: null, source: 'personal', envVarFailed: true }
+
+  const personalVars = env.personalEnvCache.get(ref.userId)
+
+  const wsValue = env.wsEnvVars[varName]
+  const personalValue = personalVars?.[varName]
+  const encryptedValue = wsValue ?? personalValue
+  const source: KeySource = wsValue ? 'workspace' : 'personal'
+
+  const logPrefix =
+    `workspace=${ctx.workspaceId} owner=${ctx.workspaceOwnerId ?? 'unknown'}` +
+    ` workflow=${ref.workflowId} user=${ref.userId}`
+
+  if (!encryptedValue) {
+    console.warn(
+      `  [WARN] Env var "${varName}" not found — ${logPrefix} "${ref.blockName}" in "${ref.workflowName}"`
+    )
+    return { key: null, source, envVarFailed: true }
+  }
+
+  try {
+    const decrypted = await decryptSecret(encryptedValue)
+    return { key: decrypted, source, envVarFailed: false }
+  } catch (error) {
+    console.warn(
+      `  [WARN] Failed to decrypt env var "${varName}" — ${logPrefix} "${ref.blockName}" in "${ref.workflowName}": ${error}`
+    )
+    return { key: null, source, envVarFailed: true }
+  }
+}
+
+async function processWorkspace(
+  workspaceId: string,
+  allBlockTypes: string[],
+  userFilter: ReturnType<typeof sql>,
+  total: number,
+  index: number
+): Promise<WorkspaceResult> {
+  const stats = createEmptyStats()
+
+  try {
+    const [blocks, wsRows] = await Promise.all([
+      db
+        .select({
+          blockId: workflowBlocks.id,
+          blockName: workflowBlocks.name,
+          blockType: workflowBlocks.type,
+          subBlocks: workflowBlocks.subBlocks,
+          workflowId: workflow.id,
+          workflowName: workflow.name,
+          userId: workflow.userId,
+        })
+        .from(workflowBlocks)
+        .innerJoin(workflow, eq(workflowBlocks.workflowId, workflow.id))
+        .where(
+          sql`${workflow.workspaceId} = ${workspaceId} AND ${workflowBlocks.type} IN (${sql.join(
+            allBlockTypes.map((t) => sql`${t}`),
+            sql`, `
+          )})${userFilter}`
+        ),
+      db
+        .select({ ownerId: workspaceTable.ownerId })
+        .from(workspaceTable)
+        .where(eq(workspaceTable.id, workspaceId))
+        .limit(1),
+    ])
+
+    const workspaceOwnerId = wsRows[0]?.ownerId ?? null
+
+    console.log(
+      `[${index}/${total}] [Workspace ${workspaceId}] ${blocks.length} blocks, owner=${workspaceOwnerId ?? 'unknown'}`
+    )
+
+    const providerKeys = new Map<string, RawKeyRef[]>()
+
+    for (const block of blocks) {
+      const subBlocks = block.subBlocks as Record<string, { value?: any }>
+
+      const providerId = BLOCK_TYPE_TO_PROVIDER[block.blockType]
+      if (providerId) {
+        const val = subBlocks?.apiKey?.value
+        if (typeof val === 'string' && val.trim()) {
+          const refs = providerKeys.get(providerId) ?? []
+          refs.push({
+            rawValue: val,
+            blockName: block.blockName,
+            workflowId: block.workflowId,
+            workflowName: block.workflowName,
+            userId: block.userId,
+          })
+          providerKeys.set(providerId, refs)
+        }
+      }
+
+      const toolInputId = TOOL_INPUT_SUBBLOCK_IDS[block.blockType]
+      if (toolInputId) {
+        const tools = parseToolInputValue(subBlocks?.[toolInputId]?.value)
+        for (const tool of tools) {
+          const toolType = tool?.type as string | undefined
+          const toolApiKey = tool?.params?.apiKey as string | undefined
+          if (!toolType || !toolApiKey || !toolApiKey.trim()) continue
+          const toolProviderId = BLOCK_TYPE_TO_PROVIDER[toolType]
+          if (!toolProviderId) continue
+          const refs = providerKeys.get(toolProviderId) ?? []
+          refs.push({
+            rawValue: toolApiKey,
+            blockName: `${block.blockName} > tool "${tool.title || toolType}"`,
+            workflowId: block.workflowId,
+            workflowName: block.workflowName,
+            userId: block.userId,
+          })
+          providerKeys.set(toolProviderId, refs)
+        }
+      }
+    }
+
+    if (providerKeys.size === 0) {
+      console.log(`  [${index}/${total}] No API keys found, skipping\n`)
+      stats.workspacesSkipped++
+      return { stats, shouldWriteWorkspaceId: false }
+    }
+
+    const needsEnvVars = [...providerKeys.values()]
+      .flat()
+      .some((ref) => isEnvVarReference(ref.rawValue))
+
+    let wsEnvVars: Record<string, string> = {}
+    const personalEnvCache = new Map<string, Record<string, string>>()
+
+    if (needsEnvVars) {
+      const wsEnvRows = await db
+        .select()
+        .from(workspaceEnvironment)
+        .where(sql`${workspaceEnvironment.workspaceId} = ${workspaceId}`)
+        .limit(1)
+      if (wsEnvRows[0]) {
+        wsEnvVars = (wsEnvRows[0].variables as Record<string, string>) || {}
+      }
+
+      const userIds = [...new Set([...providerKeys.values()].flat().map((r) => r.userId))]
+      if (userIds.length > 0) {
+        const personalRows = await db
+          .select()
+          .from(environment)
+          .where(
+            sql`${environment.userId} IN (${sql.join(
+              userIds.map((id) => sql`${id}`),
+              sql`, `
+            )})`
+          )
+        for (const row of personalRows) {
+          personalEnvCache.set(row.userId, (row.variables as Record<string, string>) || {})
+        }
+      }
+    }
+
+    const envLookup: EnvLookup = { wsEnvVars, personalEnvCache }
+
+    stats.workspacesProcessed++
+
+    for (const [providerId, refs] of providerKeys) {
+      const resolved: { ref: RawKeyRef; key: string; source: KeySource }[] = []
+      const resolveCtx: ResolveKeyContext = { workspaceId, workspaceOwnerId }
+      for (const ref of refs) {
+        const { key, source, envVarFailed } = await resolveKey(ref, envLookup, resolveCtx)
+        if (envVarFailed) stats.envVarFailures++
+        if (!key?.trim()) continue
+
+        if (source === 'personal' && ref.userId !== workspaceOwnerId) {
+          console.log(
+            `  [SKIP-PERSONAL] Ignoring non-owner personal key from user=${ref.userId} workflow=${ref.workflowId} "${ref.blockName}" in "${ref.workflowName}"`
+          )
+          continue
+        }
+
+        resolved.push({ ref, key: key.trim(), source })
+      }
+
+      if (resolved.length === 0) continue
+
+      resolved.sort((a, b) => KEY_SOURCE_PRIORITY[a.source] - KEY_SOURCE_PRIORITY[b.source])
+
+      const distinctKeys = new Set(resolved.map((r) => r.key))
+      if (distinctKeys.size > 1) {
+        stats.conflicts++
+        console.log(`  [CONFLICT] provider "${providerId}": ${distinctKeys.size} distinct keys`)
+        for (const { ref, key, source } of resolved) {
+          const isOwner = ref.userId === workspaceOwnerId ? ' (owner)' : ''
+          const display = isEnvVarReference(ref.rawValue)
+            ? `${ref.rawValue} -> ${maskKey(key)}`
+            : maskKey(ref.rawValue)
+          console.log(
+            `    [${source}] user=${ref.userId}${isOwner} workflow=${ref.workflowId} "${ref.blockName}" in "${ref.workflowName}": ${display}`
+          )
+        }
+        const chosenIsOwner = resolved[0].ref.userId === workspaceOwnerId ? ', owner' : ''
+        console.log(
+          `    Using highest-priority key (${resolved[0].source}${chosenIsOwner}, user=${resolved[0].ref.userId})`
+        )
+      }
+
+      const chosen = resolved[0]
+
+      if (DRY_RUN) {
+        console.log(`  [DRY RUN] Would insert BYOK for provider "${providerId}": ${maskKey(chosen.key)}`)
+        continue
+      }
+
+      try {
+        const encrypted = await encryptSecret(chosen.key)
+        const result = await db
+          .insert(workspaceBYOKKeys)
+          .values({
+            id: uuidv4(),
+            workspaceId,
+            providerId,
+            encryptedApiKey: encrypted,
+            createdBy: chosen.ref.userId,
+          })
+          .onConflictDoNothing({
+            target: [workspaceBYOKKeys.workspaceId, workspaceBYOKKeys.providerId],
+          })
+          .returning({ id: workspaceBYOKKeys.id })
+
+        if (result.length === 0) {
+          console.log(`  [SKIP] BYOK already exists for provider "${providerId}"`)
+          stats.skippedExisting++
+        } else {
+          console.log(`  [INSERT] BYOK for provider "${providerId}": ${maskKey(chosen.key)}`)
+          stats.inserted++
+        }
+      } catch (error) {
+        console.error(`  [ERROR] Failed to insert BYOK for provider "${providerId}":`, error)
+        stats.errors++
+      }
+    }
+
+    console.log(`  [${index}/${total}] Done with workspace ${workspaceId}\n`)
+    return { stats, shouldWriteWorkspaceId: DRY_RUN }
+  } catch (error) {
+    console.error(`  [ERROR] Failed workspace ${workspaceId}:`, error)
+    stats.errors++
+    return { stats, shouldWriteWorkspaceId: false }
+  }
+}
+
+// ---------- Main ----------
+async function run() {
+  console.log(`Mode: ${DRY_RUN ? 'DRY RUN (audit + preview)' : 'LIVE'}`)
+  console.log(
+    `Mappings: ${Object.entries(BLOCK_TYPE_TO_PROVIDER)
+      .map(([b, p]) => `${b}=${p}`)
+      .join(', ')}`
+  )
+  console.log(`Users: ${USER_FILTER.length > 0 ? USER_FILTER.join(', ') : 'all'}`)
+  if (FROM_FILE) console.log(`From file: ${FROM_FILE}`)
+  console.log('---\n')
+
+  const stats = createEmptyStats()
+
+  try {
+    // 1. Get distinct workspace IDs that have matching blocks
+    const mappedBlockTypes = Object.keys(BLOCK_TYPE_TO_PROVIDER)
+    const agentTypes = Object.keys(TOOL_INPUT_SUBBLOCK_IDS)
+    const allBlockTypes = [...new Set([...mappedBlockTypes, ...agentTypes])]
+
+    const userFilter =
+      USER_FILTER.length > 0
+        ? sql` AND ${workflow.userId} IN (${sql.join(
+            USER_FILTER.map((id) => sql`${id}`),
+            sql`, `
+          )})`
+        : sql``
+
+    let workspaceIds: string[]
+
+    if (DRY_RUN) {
+      const workspaceIdRows = await db
+        .selectDistinct({ workspaceId: workflow.workspaceId })
+        .from(workflowBlocks)
+        .innerJoin(workflow, eq(workflowBlocks.workflowId, workflow.id))
+        .where(
+          sql`${workflow.workspaceId} IS NOT NULL AND ${workflowBlocks.type} IN (${sql.join(
+            allBlockTypes.map((t) => sql`${t}`),
+            sql`, `
+          )})${userFilter}`
+        )
+
+      workspaceIds = workspaceIdRows
+        .map((r) => r.workspaceId)
+        .filter((id): id is string => id !== null)
+
+      console.log(`Found ${workspaceIds.length} workspaces with candidate blocks\n`)
+
+      const outPath = resolve('migrate-byok-workspace-ids.txt')
+      writeFileSync(outPath, '')
+      console.log(`[DRY RUN] Will write workspace IDs with keys to ${outPath}\n`)
+    } else {
+      const raw = readFileSync(resolve(FROM_FILE!), 'utf-8')
+      workspaceIds = raw
+        .split('\n')
+        .map((l) => l.trim())
+        .filter(Boolean)
+      console.log(`Loaded ${workspaceIds.length} workspace IDs from ${FROM_FILE}\n`)
+    }
+
+    // 2. Process workspaces in parallel groups of 100, pausing for 60s after each 1000
+    for (let batchStart = 0; batchStart < workspaceIds.length; batchStart += WORKSPACE_BATCH_SIZE) {
+      const batch = workspaceIds.slice(batchStart, batchStart + WORKSPACE_BATCH_SIZE)
+      console.log(
+        `[BATCH] Processing workspaces ${batchStart + 1}-${batchStart + batch.length} of ${workspaceIds.length}`
+      )
+
+      for (
+        let concurrencyStart = 0;
+        concurrencyStart < batch.length;
+        concurrencyStart += WORKSPACE_CONCURRENCY
+      ) {
+        const workspaceChunk = batch.slice(
+          concurrencyStart,
+          concurrencyStart + WORKSPACE_CONCURRENCY
+        )
+        const results = await Promise.all(
+          workspaceChunk.map((workspaceId, chunkIndex) =>
+            processWorkspace(
+              workspaceId,
+              allBlockTypes,
+              userFilter,
+              workspaceIds.length,
+              batchStart + concurrencyStart + chunkIndex + 1
+            )
+          )
+        )
+
+        if (DRY_RUN) {
+          const workspaceIdsWithKeys = results
+            .map((result, resultIndex) => (result.shouldWriteWorkspaceId ? workspaceChunk[resultIndex] : null))
+            .filter((id): id is string => id !== null)
+
+          if (workspaceIdsWithKeys.length > 0) {
+            appendFileSync(resolve('migrate-byok-workspace-ids.txt'), `${workspaceIdsWithKeys.join('\n')}\n`)
+          }
+        }
+
+        for (const result of results) {
+          mergeStats(stats, result.stats)
+        }
+      }
+
+      if (batchStart + batch.length < workspaceIds.length) {
+        console.log(
+          `  [THROTTLE] ${batchStart + batch.length}/${workspaceIds.length} workspaces — sleeping ${SLEEP_MS / 1000}s`
+        )
+        await sleep(SLEEP_MS)
+      }
+    }
+
+    // 3. Summary
+    console.log('---')
+    console.log('Summary:')
+    console.log(`  Workspaces processed: ${stats.workspacesProcessed}`)
+    console.log(`  Workspaces skipped (no keys): ${stats.workspacesSkipped}`)
+    console.log(`  BYOK keys inserted: ${stats.inserted}`)
+    console.log(`  BYOK keys skipped (already existed): ${stats.skippedExisting}`)
+    console.log(`  Conflicts (multiple distinct keys): ${stats.conflicts}`)
+    console.log(`  Insert errors: ${stats.errors}`)
+    console.log(`  Env var resolution failures: ${stats.envVarFailures}`)
+
+    if (DRY_RUN) {
+      console.log(
+        `\n[DRY RUN] Wrote ${stats.workspacesProcessed} workspace IDs (with keys) to migrate-byok-workspace-ids.txt`
+      )
+      console.log('[DRY RUN] No changes were made to the database.')
+      console.log('Run without --dry-run to apply changes.')
+    } else {
+      console.log('\nMigration completed successfully!')
+    }
+  } catch (error) {
+    console.error('Fatal error:', error)
+    process.exit(1)
+  } finally {
+    try {
+      await postgresClient.end({ timeout: 5 })
+    } catch {}
+  }
+}
+
+run()
+  .then(() => {
+    console.log('\nDone!')
+    process.exit(0)
+  })
+  .catch((error) => {
+    console.error('Unexpected error:', error)
+    process.exit(1)
+  })