diff --git a/apps/sim/lib/billing/core/billing.ts b/apps/sim/lib/billing/core/billing.ts
index aca33c6e3d..f1b3ae2636 100644
--- a/apps/sim/lib/billing/core/billing.ts
+++ b/apps/sim/lib/billing/core/billing.ts
@@ -22,7 +22,7 @@ import {
   isOrgScopedSubscription,
 } from '@/lib/billing/subscriptions/utils'
 import { Decimal, toDecimal, toNumber } from '@/lib/billing/utils/decimal'
-import type { DbOrTx } from '@/lib/db/types'
+import type { DbClient } from '@/lib/db/types'
 
 export { getPlanPricing }
 
@@ -32,6 +32,8 @@ const logger = createLogger('Billing')
 
 interface GetOrganizationSubscriptionOptions {
   onError?: 'return-null' | 'throw'
+  /** Read-routing client (primary or replica); defaults to the primary. */
+  executor?: DbClient
 }
 
 /**
@@ -42,14 +44,18 @@ interface GetOrganizationSubscriptionOptions {
  * For product-access gating use `getOrganizationSubscriptionUsable`
  * (from `core/subscription.ts`), which excludes `past_due`.
  * Returns `null` when there is no entitled sub.
+ *
+ * `options.executor` exists for replica routing on display/summary read
+ * paths only. Enforcement and webhook callers must read the primary —
+ * omit the executor (or pass `db`).
  */
 export async function getOrganizationSubscription(
   organizationId: string,
   options: GetOrganizationSubscriptionOptions = {}
 ) {
-  const { onError = 'return-null' } = options
+  const { onError = 'return-null', executor = db } = options
   try {
-    const orgSubs = await db
+    const orgSubs = await executor
       .select()
       .from(subscription)
       .where(
@@ -111,13 +117,16 @@ export async function isSubscriptionOrgScoped(sub: { referenceId: string }): Pro
  * column is `NOT NULL DEFAULT '0'` and mixing scopes would break
  * current-period billing math.
  */
-async function aggregateOrgMemberStats(organizationId: string): Promise<{
+async function aggregateOrgMemberStats(
+  organizationId: string,
+  executor: DbClient = db
+): Promise<{
   memberIds: string[]
   currentPeriodCost: number
   currentPeriodCopilotCost: number
   lastPeriodCopilotCost: number
 }> {
-  const rows = await db
+  const rows = await executor
     .select({
       userId: member.userId,
       currentPeriodCost: userStats.currentPeriodCost,
@@ -386,7 +395,7 @@ export async function calculateSubscriptionOverage(sub: {
 export async function getSimplifiedBillingSummary(
   userId: string,
   organizationId?: string,
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<{
   type: 'individual' | 'organization'
   plan: string
@@ -432,8 +441,8 @@ export async function getSimplifiedBillingSummary(
     // Get subscription and usage data upfront
     const [subscription, usageData] = await Promise.all([
       organizationId
-        ? getOrganizationSubscription(organizationId)
-        : getHighestPrioritySubscription(userId),
+        ? getOrganizationSubscription(organizationId, { executor })
+        : getHighestPrioritySubscription(userId, { executor }),
       getUserUsageData(userId, executor),
     ])
 
@@ -455,7 +464,7 @@ export async function getSimplifiedBillingSummary(
       // Pool usage/copilot across all members in one query. Must not use
       // `getUserUsageData` per-member — it now returns the pool itself
       // for org-scoped subs, which would N-times-count.
-      const pooled = await aggregateOrgMemberStats(organizationId)
+      const pooled = await aggregateOrgMemberStats(organizationId, executor)
 
       const rawCurrentUsage = pooled.currentPeriodCost
       const totalLastPeriodCopilotCost = pooled.lastPeriodCopilotCost
@@ -495,7 +504,8 @@ export async function getSimplifiedBillingSummary(
         if (planDollars > 0) {
           const userBounds = await getOrgMemberRefreshBounds(
             organizationId,
-            subscription.periodStart
+            subscription.periodStart,
+            executor
           )
           refreshDeduction = await computeDailyRefreshConsumed(
             {
@@ -516,7 +526,8 @@ export async function getSimplifiedBillingSummary(
       const { limit: orgUsageLimit } = await getOrgUsageLimit(
         organizationId,
         plan,
-        subscription.seats ?? null
+        subscription.seats ?? null,
+        executor
       )
 
       const percentUsed =
@@ -532,7 +543,7 @@ export async function getSimplifiedBillingSummary(
           )
         : 0
 
-      const orgCredits = await getCreditBalance(userId)
+      const orgCredits = await getCreditBalance(userId, executor)
       const orgBillingInterval = getBillingInterval(subscription.metadata as SubscriptionMetadata)
 
       return {
@@ -576,7 +587,7 @@ export async function getSimplifiedBillingSummary(
       }
     }
 
-    const userStatsRows = await db
+    const userStatsRows = await executor
       .select({
         currentPeriodCopilotCost: userStats.currentPeriodCopilotCost,
         lastPeriodCopilotCost: userStats.lastPeriodCopilotCost,
@@ -597,7 +608,7 @@ export async function getSimplifiedBillingSummary(
     let totalCopilotCost = copilotCost
     let totalLastPeriodCopilotCost = lastPeriodCopilotCost
     if (orgScoped && subscription?.referenceId) {
-      const pooled = await aggregateOrgMemberStats(subscription.referenceId)
+      const pooled = await aggregateOrgMemberStats(subscription.referenceId, executor)
       totalCopilotCost = pooled.currentPeriodCopilotCost
       totalLastPeriodCopilotCost = pooled.lastPeriodCopilotCost
     }
@@ -631,7 +642,7 @@ export async function getSimplifiedBillingSummary(
         )
       : 0
 
-    const userCredits = await getCreditBalance(userId)
+    const userCredits = await getCreditBalance(userId, executor)
     const individualBillingInterval = getBillingInterval(
       subscription?.metadata as SubscriptionMetadata
     )
diff --git a/apps/sim/lib/billing/core/organization.ts b/apps/sim/lib/billing/core/organization.ts
index f7240550eb..2000edd898 100644
--- a/apps/sim/lib/billing/core/organization.ts
+++ b/apps/sim/lib/billing/core/organization.ts
@@ -19,7 +19,7 @@ import {
   hasUsableSubscriptionStatus,
 } from '@/lib/billing/subscriptions/utils'
 import { toDecimal, toNumber } from '@/lib/billing/utils/decimal'
-import type { DbOrTx } from '@/lib/db/types'
+import type { DbClient } from '@/lib/db/types'
 
 const logger = createLogger('OrganizationBilling')
 
@@ -66,11 +66,11 @@ interface MemberUsageData {
 export async function getOrgMemberLedgerByUser(
   organizationId: string,
   period?: { start: Date; end: Date } | null,
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<Map<string, number>> {
   let billingPeriod = period ?? null
   if (period === undefined) {
-    const subscription = await getOrganizationSubscription(organizationId)
+    const subscription = await getOrganizationSubscription(organizationId, { executor })
     billingPeriod =
       subscription?.periodStart && subscription?.periodEnd
         ? { start: subscription.periodStart, end: subscription.periodEnd }
@@ -90,11 +90,11 @@ export async function getOrgMemberLedgerByUser(
  */
 export async function getOrganizationBillingData(
   organizationId: string,
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<OrganizationUsageData | null> {
   try {
     // Get organization info
-    const orgRecord = await db
+    const orgRecord = await executor
       .select()
       .from(organization)
       .where(eq(organization.id, organizationId))
@@ -108,7 +108,7 @@ export async function getOrganizationBillingData(
     const organizationData = orgRecord[0]
 
     // Get organization subscription directly (referenceId = organizationId)
-    const subscription = await getOrganizationSubscription(organizationId)
+    const subscription = await getOrganizationSubscription(organizationId, { executor })
 
     if (!subscription) {
       logger.warn('No subscription found for organization', { organizationId })
@@ -116,7 +116,7 @@ export async function getOrganizationBillingData(
     }
 
     // Get all organization members with their usage data
-    const membersWithUsage = await db
+    const membersWithUsage = await executor
       .select({
         userId: member.userId,
         userName: user.name,
@@ -185,7 +185,8 @@ export async function getOrganizationBillingData(
         const memberIds = members.map((m) => m.userId)
         const userBounds = await getOrgMemberRefreshBounds(
           subscription.referenceId,
-          subscription.periodStart
+          subscription.periodStart,
+          executor
         )
         const refreshConsumed = await computeDailyRefreshConsumed(
           {
@@ -233,7 +234,7 @@ export async function getOrganizationBillingData(
 
     const averageUsagePerMember = members.length > 0 ? totalCurrentUsage / members.length : 0
 
-    const [pendingInvitationCount] = await db
+    const [pendingInvitationCount] = await executor
       .select({ count: count() })
       .from(invitation)
       .where(
diff --git a/apps/sim/lib/billing/core/plan.ts b/apps/sim/lib/billing/core/plan.ts
index 8bbd516ee1..b4a56dab13 100644
--- a/apps/sim/lib/billing/core/plan.ts
+++ b/apps/sim/lib/billing/core/plan.ts
@@ -8,6 +8,7 @@ import {
   checkTeamPlan,
   ENTITLED_SUBSCRIPTION_STATUSES,
 } from '@/lib/billing/subscriptions/utils'
+import type { DbClient } from '@/lib/db/types'
 
 const logger = createLogger('PlanLookup')
 
@@ -15,6 +16,8 @@ export type HighestPrioritySubscription = Awaited<ReturnType<typeof getHighestPr
 
 interface GetHighestPrioritySubscriptionOptions {
   onError?: 'return-null' | 'throw'
+  /** Read-routing client (primary or replica); defaults to the primary. */
+  executor?: DbClient
 }
 
 function pickHighestPrioritySubscription<TSubscription>(
@@ -33,9 +36,9 @@ export async function getHighestPriorityPersonalSubscription(
   userId: string,
   options: GetHighestPrioritySubscriptionOptions = {}
 ) {
-  const { onError = 'return-null' } = options
+  const { onError = 'return-null', executor = db } = options
   try {
-    const personalSubs = await db
+    const personalSubs = await executor
       .select()
       .from(subscription)
       .where(
@@ -77,9 +80,9 @@ export async function getHighestPrioritySubscription(
   userId: string,
   options: GetHighestPrioritySubscriptionOptions = {}
 ) {
-  const { onError = 'return-null' } = options
+  const { onError = 'return-null', executor = db } = options
   try {
-    const personalSubs = await db
+    const personalSubs = await executor
       .select()
       .from(subscription)
       .where(
@@ -89,7 +92,7 @@ export async function getHighestPrioritySubscription(
         )
       )
 
-    const memberships = await db
+    const memberships = await executor
       .select({ organizationId: member.organizationId })
       .from(member)
       .where(eq(member.userId, userId))
@@ -99,7 +102,7 @@ export async function getHighestPrioritySubscription(
     let orgSubs: typeof personalSubs = []
     if (orgIds.length > 0) {
       // Verify orgs exist to filter out orphaned subscriptions
-      const existingOrgs = await db
+      const existingOrgs = await executor
         .select({ id: organization.id })
         .from(organization)
         .where(inArray(organization.id, orgIds))
@@ -107,7 +110,7 @@ export async function getHighestPrioritySubscription(
       const validOrgIds = existingOrgs.map((o) => o.id)
 
       if (validOrgIds.length > 0) {
-        orgSubs = await db
+        orgSubs = await executor
           .select()
           .from(subscription)
           .where(
diff --git a/apps/sim/lib/billing/core/usage-log.ts b/apps/sim/lib/billing/core/usage-log.ts
index 985713bebc..034609a65f 100644
--- a/apps/sim/lib/billing/core/usage-log.ts
+++ b/apps/sim/lib/billing/core/usage-log.ts
@@ -8,7 +8,7 @@ import { and, desc, eq, gte, inArray, lt, lte, sql } from 'drizzle-orm'
 import { defaultBillingPeriod } from '@/lib/billing/core/billing-period'
 import { getHighestPrioritySubscription } from '@/lib/billing/core/plan'
 import { isOrgScopedSubscription } from '@/lib/billing/subscriptions/utils'
-import type { DbOrTx } from '@/lib/db/types'
+import type { DbClient, DbOrTx } from '@/lib/db/types'
 
 const logger = createLogger('UsageLog')
 
@@ -184,7 +184,7 @@ export async function getBillingPeriodUsageCost(
   billingEntity: BillingEntity,
   billingPeriod: { start: Date; end: Date },
   source?: UsageLogSource | UsageLogSource[],
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<number> {
   const conditions = [
     eq(usageLog.billingEntityType, billingEntity.type),
@@ -212,7 +212,7 @@ export async function getBillingPeriodUsageCostByUser(
   billingEntity: BillingEntity,
   billingPeriod: { start: Date; end: Date },
   source?: UsageLogSource | UsageLogSource[],
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<Map<string, number>> {
   const conditions = [
     eq(usageLog.billingEntityType, billingEntity.type),
diff --git a/apps/sim/lib/billing/core/usage.ts b/apps/sim/lib/billing/core/usage.ts
index 7845312d31..a39d3d1309 100644
--- a/apps/sim/lib/billing/core/usage.ts
+++ b/apps/sim/lib/billing/core/usage.ts
@@ -34,7 +34,7 @@ import type { BillingData, UsageData, UsageLimitInfo } from '@/lib/billing/types
 import { Decimal, toDecimal, toNumber } from '@/lib/billing/utils/decimal'
 import { isBillingEnabled } from '@/lib/core/config/feature-flags'
 import { getBaseUrl } from '@/lib/core/utils/urls'
-import type { DbOrTx } from '@/lib/db/types'
+import type { DbClient } from '@/lib/db/types'
 import { sendEmail } from '@/lib/messaging/email/mailer'
 import { getEmailPreferences } from '@/lib/messaging/email/unsubscribe'
 
@@ -58,9 +58,10 @@ export interface OrgUsageLimitResult {
  * downstream refresh / bounds computations.
  */
 export async function getPooledOrgCurrentPeriodCost(
-  organizationId: string
+  organizationId: string,
+  executor: DbClient = db
 ): Promise<{ memberIds: string[]; currentPeriodCost: number; lastPeriodCost: number }> {
-  const rows = await db
+  const rows = await executor
     .select({
       userId: member.userId,
       currentPeriodCost: userStats.currentPeriodCost,
@@ -95,9 +96,10 @@ export async function getPooledOrgCurrentPeriodCost(
 export async function getOrgUsageLimit(
   organizationId: string,
   plan: string,
-  seats: number | null
+  seats: number | null,
+  executor: DbClient = db
 ): Promise<OrgUsageLimitResult> {
-  const orgData = await db
+  const orgData = await executor
     .select({ orgUsageLimit: organization.orgUsageLimit })
     .from(organization)
     .where(eq(organization.id, organizationId))
@@ -164,6 +166,7 @@ export async function handleNewUser(userId: string): Promise<void> {
  * This is a fallback for cases where the user.create.after hook didn't fire
  * (e.g., OAuth account linking to existing users).
  *
+ * Always writes to the primary — never takes a read-routing executor.
  */
 export async function ensureUserStatsExists(userId: string): Promise<void> {
   await db
@@ -180,13 +183,24 @@ export async function ensureUserStatsExists(userId: string): Promise<void> {
 /**
  * Get comprehensive usage data for a user
  */
-export async function getUserUsageData(userId: string, executor: DbOrTx = db): Promise<UsageData> {
+export async function getUserUsageData(
+  userId: string,
+  executor: DbClient = db
+): Promise<UsageData> {
   try {
+    // Write — always on the primary regardless of executor routing.
     await ensureUserStatsExists(userId)
 
     const [userStatsData, subscription] = await Promise.all([
-      db.select().from(userStats).where(eq(userStats.userId, userId)).limit(1),
-      getHighestPrioritySubscription(userId),
+      // Read-your-write: must see the row ensureUserStatsExists may have just
+      // inserted, which a lagging replica can miss (this path throws on a
+      // missing row). Stays on the primary deliberately.
+      db
+        .select()
+        .from(userStats)
+        .where(eq(userStats.userId, userId))
+        .limit(1),
+      getHighestPrioritySubscription(userId, { executor }),
     ])
 
     if (userStatsData.length === 0) {
@@ -239,11 +253,12 @@ export async function getUserUsageData(userId: string, executor: DbOrTx = db): P
       const orgLimit = await getOrgUsageLimit(
         subscription.referenceId,
         subscription.plan,
-        subscription.seats
+        subscription.seats,
+        executor
       )
       limit = orgLimit.limit
 
-      const pooled = await getPooledOrgCurrentPeriodCost(subscription.referenceId)
+      const pooled = await getPooledOrgCurrentPeriodCost(subscription.referenceId, executor)
       orgMemberIds = pooled.memberIds
       lastPeriodCost = pooled.lastPeriodCost
       const ledgerUsage = await getBillingPeriodUsageCost(
@@ -270,7 +285,8 @@ export async function getUserUsageData(userId: string, executor: DbOrTx = db): P
           if (orgMemberIds.length > 0) {
             const userBounds = await getOrgMemberRefreshBounds(
               subscription.referenceId,
-              billingPeriodStart
+              billingPeriodStart,
+              executor
             )
             dailyRefreshConsumed = await computeDailyRefreshConsumed(
               {
@@ -628,16 +644,16 @@ export async function syncUsageLimitsFromSubscription(userId: string): Promise<v
  */
 export async function getEffectiveCurrentPeriodCost(
   userId: string,
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<number> {
-  const subscription = await getHighestPrioritySubscription(userId)
+  const subscription = await getHighestPrioritySubscription(userId, { executor })
   const orgScoped = isOrgScopedSubscription(subscription, userId)
 
   let rawCost: number
   let refreshUserIds: string[] = [userId]
 
   if (orgScoped && subscription) {
-    const pooled = await getPooledOrgCurrentPeriodCost(subscription.referenceId)
+    const pooled = await getPooledOrgCurrentPeriodCost(subscription.referenceId, executor)
     if (pooled.memberIds.length === 0) return 0
     refreshUserIds = pooled.memberIds
     const billingPeriod =
@@ -653,7 +669,7 @@ export async function getEffectiveCurrentPeriodCost(
         executor
       ))
   } else {
-    const rows = await db
+    const rows = await executor
       .select({ current: userStats.currentPeriodCost })
       .from(userStats)
       .where(eq(userStats.userId, userId))
@@ -683,7 +699,11 @@ export async function getEffectiveCurrentPeriodCost(
 
   const userBounds =
     orgScoped && subscription.periodStart
-      ? await getOrgMemberRefreshBounds(subscription.referenceId, subscription.periodStart)
+      ? await getOrgMemberRefreshBounds(
+          subscription.referenceId,
+          subscription.periodStart,
+          executor
+        )
       : {}
 
   const refreshConsumed = await computeDailyRefreshConsumed(
diff --git a/apps/sim/lib/billing/credits/balance.ts b/apps/sim/lib/billing/credits/balance.ts
index 7a5bcea061..cdf3dc784f 100644
--- a/apps/sim/lib/billing/credits/balance.ts
+++ b/apps/sim/lib/billing/credits/balance.ts
@@ -10,6 +10,7 @@ import {
   isOrgScopedSubscription,
 } from '@/lib/billing/subscriptions/utils'
 import { Decimal, toDecimal, toFixedString, toNumber } from '@/lib/billing/utils/decimal'
+import type { DbClient } from '@/lib/db/types'
 
 const logger = createLogger('CreditBalance')
 
@@ -28,10 +29,11 @@ export interface CreditBalanceInfo {
  */
 export async function getCreditBalanceForEntity(
   entityType: 'user' | 'organization',
-  entityId: string
+  entityId: string,
+  executor: DbClient = db
 ): Promise<number> {
   if (entityType === 'organization') {
-    const rows = await db
+    const rows = await executor
       .select({ creditBalance: organization.creditBalance })
       .from(organization)
       .where(eq(organization.id, entityId))
@@ -39,7 +41,7 @@ export async function getCreditBalanceForEntity(
     return rows.length > 0 ? toNumber(toDecimal(rows[0].creditBalance)) : 0
   }
 
-  const rows = await db
+  const rows = await executor
     .select({ creditBalance: userStats.creditBalance })
     .from(userStats)
     .where(eq(userStats.userId, entityId))
@@ -47,19 +49,22 @@ export async function getCreditBalanceForEntity(
   return rows.length > 0 ? toNumber(toDecimal(rows[0].creditBalance)) : 0
 }
 
-export async function getCreditBalance(userId: string): Promise<CreditBalanceInfo> {
-  const subscription = await getHighestPrioritySubscription(userId)
+export async function getCreditBalance(
+  userId: string,
+  executor: DbClient = db
+): Promise<CreditBalanceInfo> {
+  const subscription = await getHighestPrioritySubscription(userId, { executor })
 
   if (isOrgScopedSubscription(subscription, userId) && subscription) {
     return {
-      balance: await getCreditBalanceForEntity('organization', subscription.referenceId),
+      balance: await getCreditBalanceForEntity('organization', subscription.referenceId, executor),
       entityType: 'organization',
       entityId: subscription.referenceId,
     }
   }
 
   return {
-    balance: await getCreditBalanceForEntity('user', userId),
+    balance: await getCreditBalanceForEntity('user', userId, executor),
     entityType: 'user',
     entityId: userId,
   }
diff --git a/apps/sim/lib/billing/credits/daily-refresh.ts b/apps/sim/lib/billing/credits/daily-refresh.ts
index 7391c74192..b39351c204 100644
--- a/apps/sim/lib/billing/credits/daily-refresh.ts
+++ b/apps/sim/lib/billing/credits/daily-refresh.ts
@@ -16,7 +16,7 @@ import { member, usageLog, userStats } from '@sim/db/schema'
 import { createLogger } from '@sim/logger'
 import { and, eq, gte, inArray, lt, or, sql, sum } from 'drizzle-orm'
 import { DAILY_REFRESH_RATE } from '@/lib/billing/constants'
-import type { DbOrTx } from '@/lib/db/types'
+import type { DbClient } from '@/lib/db/types'
 
 const logger = createLogger('DailyRefresh')
 
@@ -52,7 +52,7 @@ export async function computeDailyRefreshConsumed(
     userBounds?: Record<string, PerUserBounds>
     billingEntity?: { type: 'user' | 'organization'; id: string }
   },
-  executor: DbOrTx = db
+  executor: DbClient = db
 ): Promise<number> {
   const {
     userIds,
@@ -157,9 +157,10 @@ export function getDailyRefreshDollars(planDollars: number): number {
 
 export async function getOrgMemberRefreshBounds(
   organizationId: string,
-  periodStart: Date
+  periodStart: Date,
+  executor: DbClient = db
 ): Promise<Record<string, { userStart: Date }>> {
-  const rows = await db
+  const rows = await executor
     .select({
       userId: member.userId,
       snapshotAt: userStats.proPeriodCostSnapshotAt,
diff --git a/apps/sim/lib/db/types.ts b/apps/sim/lib/db/types.ts
index 8039e2b78b..8b1129deaf 100644
--- a/apps/sim/lib/db/types.ts
+++ b/apps/sim/lib/db/types.ts
@@ -15,3 +15,15 @@ export type DbOrTx =
       typeof schema,
       ExtractTablesWithRelations<typeof schema>
     >
+
+/**
+ * Read-routing client: the primary `db` or the read replica `dbReplica`.
+ *
+ * For read-path helpers (billing summaries, dashboard aggregations) whose
+ * executor param exists to route SELECT fan-outs to a replica. Deliberately
+ * excludes transaction handles — these helpers issue multi-step query fans
+ * that must never run while a transaction holds a pooled connection. Use
+ * `DbOrTx` only for helpers genuinely designed to join a caller's
+ * transaction.
+ */
+export type DbClient = typeof db
diff --git a/apps/sim/lib/mcp/workflow-mcp-sync.ts b/apps/sim/lib/mcp/workflow-mcp-sync.ts
index 7a6a25d4eb..8c5d42a67d 100644
--- a/apps/sim/lib/mcp/workflow-mcp-sync.ts
+++ b/apps/sim/lib/mcp/workflow-mcp-sync.ts
@@ -143,7 +143,6 @@ interface SyncOptionsBase {
   requestId: string
   /** Context for logging (e.g., 'deploy', 'revert', 'activate') */
   context?: string
-  notify?: boolean
   throwOnError?: boolean
 }
 
@@ -151,11 +150,17 @@ interface SyncOptionsBase {
  * Callers running inside a transaction must preload the workflow state:
  * loading it lazily would issue queries on the global pool while the
  * transaction already holds a pooled connection.
+ *
+ * Server notification is strictly post-commit. The standalone arm notifies
+ * after its own transaction commits (`notify` defaults to true); the `tx` arm
+ * never notifies — publishing before the caller's transaction commits would
+ * announce state that may still roll back, so the transaction owner notifies
+ * after commit (see deployment-outbox).
  */
 type SyncOptions = SyncOptionsBase &
   (
-    | { tx: DbOrTx; state: { blocks?: Record<string, unknown> } }
-    | { tx?: undefined; state?: { blocks?: Record<string, unknown> } }
+    | { tx: DbOrTx; state: { blocks?: Record<string, unknown> }; notify?: false }
+    | { tx?: undefined; state?: { blocks?: Record<string, unknown> }; notify?: boolean }
   )
 
 /**
@@ -193,21 +198,11 @@ export async function syncMcpToolsForWorkflow(
     return tools
   }
 
-  const {
-    workflowId,
-    requestId,
-    state,
-    context = 'sync',
-    tx,
-    notify = true,
-    throwOnError = false,
-  } = options
+  const { workflowId, requestId, state, context = 'sync', tx, throwOnError = false } = options
 
   try {
     if (!hasValidStartBlockInState(state as WorkflowState | null)) {
-      const affectedTools = await removeMcpToolsForWorkflow(workflowId, requestId, tx, false, true)
-      if (notify) notifyMcpToolServers(affectedTools)
-      return affectedTools
+      return await removeMcpToolsForWorkflow(workflowId, requestId, tx, true)
     }
 
     const generatedParameterSchema = state.blocks
@@ -324,9 +319,7 @@ export async function syncMcpToolsForWorkflow(
       `[${requestId}] Synced ${syncedToolCount} MCP tool(s) for workflow (${context}): ${workflowId}`
     )
 
-    const affectedTools = [...affectedServerIds].map((serverId) => ({ serverId }))
-    if (notify) notifyMcpToolServers(affectedTools)
-    return affectedTools
+    return [...affectedServerIds].map((serverId) => ({ serverId }))
   } catch (error) {
     logger.error(`[${requestId}] Error syncing MCP tools (${context}):`, error)
     if (throwOnError) throw error
@@ -336,20 +329,23 @@ export async function syncMcpToolsForWorkflow(
 
 /**
  * Remove all MCP tools for a workflow (used when undeploying).
- * Queries affected tools before deleting so we can notify their servers.
+ * Queries affected tools before deleting so their servers can be notified.
+ *
+ * Server notification is strictly post-commit: the standalone path notifies
+ * after the transaction opened here commits; when `tx` is provided the
+ * transaction owner notifies after commit using the returned server ids.
  */
 export async function removeMcpToolsForWorkflow(
   workflowId: string,
   requestId: string,
   tx?: DbOrTx,
-  notify = true,
   throwOnError = false
 ): Promise<Array<{ serverId: string }>> {
   if (!tx) {
     const tools = await db.transaction((transaction) =>
-      removeMcpToolsForWorkflow(workflowId, requestId, transaction, false, throwOnError)
+      removeMcpToolsForWorkflow(workflowId, requestId, transaction, throwOnError)
     )
-    if (notify) notifyMcpToolServers(tools)
+    notifyMcpToolServers(tools)
     return tools
   }
 
@@ -365,7 +361,6 @@ export async function removeMcpToolsForWorkflow(
     await tx.delete(workflowMcpTool).where(eq(workflowMcpTool.workflowId, workflowId))
     logger.info(`[${requestId}] Removed MCP tools for workflow: ${workflowId}`)
 
-    if (notify) notifyMcpToolServers(tools)
     return tools
   } catch (error) {
     logger.error(`[${requestId}] Error removing MCP tools:`, error)
diff --git a/apps/sim/lib/workflows/deployment-outbox.ts b/apps/sim/lib/workflows/deployment-outbox.ts
index b33003f7a4..468e621f10 100644
--- a/apps/sim/lib/workflows/deployment-outbox.ts
+++ b/apps/sim/lib/workflows/deployment-outbox.ts
@@ -461,7 +461,7 @@ async function removeMcpToolsIfStillUndeployed(
       .limit(1)
 
     if (!workflowRecord || workflowRecord.isDeployed) return []
-    return removeMcpToolsForWorkflow(workflowId, requestId, tx, false, true)
+    return removeMcpToolsForWorkflow(workflowId, requestId, tx, true)
   })
   notifyMcpToolServers(tools)
 }
diff --git a/apps/sim/lib/workflows/schedules/deploy.test.ts b/apps/sim/lib/workflows/schedules/deploy.test.ts
index 8e6e5a3318..9bbac181f7 100644
--- a/apps/sim/lib/workflows/schedules/deploy.test.ts
+++ b/apps/sim/lib/workflows/schedules/deploy.test.ts
@@ -721,7 +721,7 @@ describe('Schedule Deploy Utilities', () => {
 
       setupMockTransaction()
 
-      const result = await createSchedulesForDeploy('workflow-1', blocks, {} as any)
+      const result = await createSchedulesForDeploy('workflow-1', blocks)
 
       expect(result.success).toBe(true)
       expect(mockTransaction).not.toHaveBeenCalled()
@@ -742,7 +742,7 @@ describe('Schedule Deploy Utilities', () => {
 
       setupMockTransaction()
 
-      const result = await createSchedulesForDeploy('workflow-1', blocks, {} as any)
+      const result = await createSchedulesForDeploy('workflow-1', blocks)
 
       expect(result.success).toBe(true)
       expect(result.scheduleId).toBe('test-uuid')
@@ -767,13 +767,37 @@ describe('Schedule Deploy Utilities', () => {
 
       setupMockTransaction()
 
-      const result = await createSchedulesForDeploy('workflow-1', blocks, {} as any)
+      const result = await createSchedulesForDeploy('workflow-1', blocks)
 
       expect(result.success).toBe(false)
       expect(result.error).toBe('Time is required for daily schedules')
       expect(mockTransaction).not.toHaveBeenCalled()
     })
 
+    it('should write through a provided transaction without opening a new one', async () => {
+      const blocks: Record<string, BlockState> = {
+        'block-1': {
+          id: 'block-1',
+          type: 'schedule',
+          subBlocks: {
+            scheduleType: { value: 'daily' },
+            dailyTime: { value: '09:00' },
+            timezone: { value: 'UTC' },
+          },
+        } as BlockState,
+      }
+
+      setupMockTransaction()
+      const callerTx = { insert: mockInsert, delete: mockDelete, select: mockSelect } as any
+
+      const result = await createSchedulesForDeploy('workflow-1', blocks, callerTx)
+
+      expect(result.success).toBe(true)
+      expect(mockTransaction).not.toHaveBeenCalled()
+      expect(mockInsert).toHaveBeenCalled()
+      expect(mockOnConflictDoUpdate).toHaveBeenCalled()
+    })
+
     it('should use onConflictDoUpdate for existing schedules', async () => {
       const blocks: Record<string, BlockState> = {
         'block-1': {
@@ -789,7 +813,7 @@ describe('Schedule Deploy Utilities', () => {
 
       setupMockTransaction()
 
-      await createSchedulesForDeploy('workflow-1', blocks, {} as any)
+      await createSchedulesForDeploy('workflow-1', blocks)
 
       expect(mockOnConflictDoUpdate).toHaveBeenCalledWith({
         target: expect.any(Array),
@@ -818,7 +842,7 @@ describe('Schedule Deploy Utilities', () => {
 
       mockTransaction.mockRejectedValueOnce(new Error('Database error'))
 
-      const result = await createSchedulesForDeploy('workflow-1', blocks, {} as any)
+      const result = await createSchedulesForDeploy('workflow-1', blocks)
 
       expect(result.success).toBe(false)
       expect(result.error).toBe('Database error')
diff --git a/apps/sim/lib/workflows/schedules/deploy.ts b/apps/sim/lib/workflows/schedules/deploy.ts
index 1973a2cb8b..4a6d7893d9 100644
--- a/apps/sim/lib/workflows/schedules/deploy.ts
+++ b/apps/sim/lib/workflows/schedules/deploy.ts
@@ -24,12 +24,13 @@ export interface ScheduleDeployResult {
 
 /**
  * Create or update schedule records for a workflow during deployment.
- * Uses a transaction to ensure atomicity - all schedules are created or none are.
+ * Atomic either way: writes run inside the caller's transaction when `tx`
+ * is provided, otherwise inside a transaction opened here.
  */
 export async function createSchedulesForDeploy(
   workflowId: string,
   blocks: Record<string, BlockState>,
-  dbCtx: DbOrTx,
+  tx?: DbOrTx,
   deploymentVersionId?: string
 ): Promise<ScheduleDeployResult> {
   const scheduleBlocks = findScheduleBlocks(blocks)
@@ -73,10 +74,10 @@ export async function createSchedulesForDeploy(
   } | null = null
 
   try {
-    const writeSchedules = async (tx: DbOrTx) => {
+    const writeSchedules = async (trx: DbOrTx) => {
       const currentBlockIds = new Set(validatedBlocks.map((b) => b.blockId))
 
-      const existingSchedules = await tx
+      const existingSchedules = await trx
         .select({ id: workflowSchedule.id, blockId: workflowSchedule.blockId })
         .from(workflowSchedule)
         .where(
@@ -97,7 +98,7 @@ export async function createSchedulesForDeploy(
         logger.info(
           `Deleting ${orphanedScheduleIds.length} orphaned schedule(s) for workflow ${workflowId}`
         )
-        await tx.delete(workflowSchedule).where(inArray(workflowSchedule.id, orphanedScheduleIds))
+        await trx.delete(workflowSchedule).where(inArray(workflowSchedule.id, orphanedScheduleIds))
       }
 
       for (const validated of validatedBlocks) {
@@ -133,7 +134,7 @@ export async function createSchedulesForDeploy(
           infraRetryCount: 0,
         }
 
-        await tx
+        await trx
           .insert(workflowSchedule)
           .values(values)
           .onConflictDoUpdate({
@@ -156,11 +157,9 @@ export async function createSchedulesForDeploy(
       }
     }
 
-    if (dbCtx === db || !hasScheduleWriteMethods(dbCtx)) {
-      await db.transaction(writeSchedules)
-    } else {
-      await writeSchedules(dbCtx)
-    }
+    // The global client is not a transaction — wrap it so the atomicity
+    // contract holds even if a caller passes `db` explicitly.
+    await (tx && tx !== db ? writeSchedules(tx) : db.transaction(writeSchedules))
   } catch (error) {
     logger.error(`Failed to create schedules for workflow ${workflowId}`, error)
     return {
@@ -175,15 +174,6 @@ export async function createSchedulesForDeploy(
   }
 }
 
-function hasScheduleWriteMethods(value: DbOrTx): boolean {
-  const candidate = value as Partial<Pick<DbOrTx, 'select' | 'insert' | 'delete'>>
-  return (
-    typeof candidate.select === 'function' &&
-    typeof candidate.insert === 'function' &&
-    typeof candidate.delete === 'function'
-  )
-}
-
 /**
  * Delete all schedules for a workflow
  * This should be called within a database transaction during undeploy