diff --git a/app/server/lib/ActiveDoc.ts b/app/server/lib/ActiveDoc.ts
index 89f4470c..24c38771 100644
--- a/app/server/lib/ActiveDoc.ts
+++ b/app/server/lib/ActiveDoc.ts
@@ -285,8 +285,8 @@ export class ActiveDoc extends EventEmitter {
     return this._actionHistory;
   }
 
-  public handleTriggers(summary: ActionSummary): Promise<void> {
-    return this._triggers.handle(summary);
+  public handleTriggers(localActionBundle: LocalActionBundle): Promise<ActionSummary> {
+    return this._triggers.handle(localActionBundle);
   }
 
   /**
diff --git a/app/server/lib/Sharing.ts b/app/server/lib/Sharing.ts
index 4d083681..6350e28a 100644
--- a/app/server/lib/Sharing.ts
+++ b/app/server/lib/Sharing.ts
@@ -14,8 +14,7 @@ import {shortDesc} from 'app/server/lib/shortDesc';
 import * as assert from 'assert';
 import {Mutex} from 'async-mutex';
 import * as Deque from 'double-ended-queue';
-import { ActionHistory, asActionGroup, getActionUndoInfo} from './ActionHistory';
-import {summarizeAction} from "./ActionSummary";
+import {ActionHistory, asActionGroup, getActionUndoInfo} from './ActionHistory';
 import {ActiveDoc} from './ActiveDoc';
 import {makeExceptionalDocSession, OptDocSession} from './DocSession';
 import {WorkCoordinator} from './WorkCoordinator';
@@ -299,8 +298,7 @@ export class Sharing {
       }
       await this._activeDoc.processActionBundle(ownActionBundle);
 
-      const actionSummary = summarizeAction(localActionBundle);
-      await this._activeDoc.handleTriggers(actionSummary);
+      const actionSummary = await this._activeDoc.handleTriggers(localActionBundle);
 
       // Broadcast the action to connected browsers.
       const actionGroup = asActionGroup(this._actionHistory, localActionBundle, {
diff --git a/app/server/lib/Triggers.ts b/app/server/lib/Triggers.ts
index c8ac18f6..2a4bf3ff 100644
--- a/app/server/lib/Triggers.ts
+++ b/app/server/lib/Triggers.ts
@@ -1,17 +1,19 @@
-import { ActionSummary, TableDelta } from 'app/common/ActionSummary';
-import { delay } from 'app/common/delay';
-import { fromTableDataAction, RowRecord, TableColValues, TableDataAction } from 'app/common/DocActions';
-import { StringUnion } from 'app/common/StringUnion';
-import { MetaRowRecord } from 'app/common/TableData';
-import { CellDelta } from 'app/common/TabularDiff';
-import { ActiveDoc } from 'app/server/lib/ActiveDoc';
-import { makeExceptionalDocSession } from 'app/server/lib/DocSession';
+import {LocalActionBundle} from 'app/common/ActionBundle';
+import {ActionSummary, TableDelta} from 'app/common/ActionSummary';
+import {delay} from 'app/common/delay';
+import {fromTableDataAction, RowRecord, TableColValues, TableDataAction} from 'app/common/DocActions';
+import {StringUnion} from 'app/common/StringUnion';
+import {MetaRowRecord} from 'app/common/TableData';
+import {CellDelta} from 'app/common/TabularDiff';
+import {summarizeAction} from 'app/server/lib/ActionSummary';
+import {ActiveDoc} from 'app/server/lib/ActiveDoc';
+import {makeExceptionalDocSession} from 'app/server/lib/DocSession';
 import * as log from 'app/server/lib/log';
-import { promisifyAll } from 'bluebird';
+import {promisifyAll} from 'bluebird';
 import * as _ from 'lodash';
 import * as LRUCache from 'lru-cache';
 import fetch from 'node-fetch';
-import { createClient, Multi, RedisClient } from 'redis';
+import {createClient, Multi, RedisClient} from 'redis';
 
 promisifyAll(RedisClient.prototype);
 
@@ -68,7 +70,7 @@ interface Task {
 
 const MAX_QUEUE_SIZE = 1000;
 
-// Processes triggers for records changed as described in ActionSummary objects,
+// Processes triggers for records changed as described in action bundles.
 // initiating webhooks and automations.
 // The interesting stuff starts in the handle() method.
 // Webhooks are placed on an event queue in memory which is replicated on redis as backup.
@@ -122,12 +124,18 @@ export class DocTriggers {
   // Called after applying actions to a document and updating its data.
   // Checks for triggers configured in a meta table,
   // and whether any of those triggers monitor tables which were modified by the actions
-  // described in the given summary.
+  // in the given bundle.
   // If so, generates events which are pushed to the local and redis queues.
-  public async handle(summary: ActionSummary) {
+  //
+  // Returns an ActionSummary generated from the given LocalActionBundle.
+  //
+  // Generating the summary here makes it easy to specify which columns need to
+  // have all their changes included in the summary without truncation
+  // so that we can accurately identify which records are ready for sending.
+  public async handle(localActionBundle: LocalActionBundle): Promise<ActionSummary> {
     const docData = this._activeDoc.docData;
     if (!docData) {
-      return;
+      return summarizeAction(localActionBundle);
     }  // Happens on doc creation while processing InitNewDoc action.
 
     const triggersTable = docData.getMetaTable("_grist_Triggers");
@@ -135,14 +143,31 @@ export class DocTriggers {
     this._getColId = docData.getMetaTable("_grist_Tables_column").getMetaRowPropFunc("colId");
 
     const triggersByTableRef = _.groupBy(triggersTable.getRecords(), "tableRef");
+    const triggersByTableId: Array<[string, Trigger[]]> = [];
+
+    // First we need a list of columns which must be included in full in the action summary
+    const isReadyColIds: string[] = [];
+    for (const tableRef of Object.keys(triggersByTableRef).sort()) {
+      const triggers = triggersByTableRef[tableRef];
+      const tableId = getTableId(Number(tableRef))!;  // groupBy makes tableRef a string
+      triggersByTableId.push([tableId, triggers]);
+      for (const trigger of triggers) {
+        if (trigger.isReadyColRef) {
+          const colId = this._getColId(trigger.isReadyColRef);
+          if (colId) {
+            isReadyColIds.push(colId);
+          }
+        }
+      }
+    }
+
+    const summary = summarizeAction(localActionBundle, {alwaysPreserveColIds: isReadyColIds});
 
     // Work to do after fetching values from the document
     const tasks: Task[] = [];
 
     // For each table in the document which is monitored by one or more triggers...
-    for (const tableRef of Object.keys(triggersByTableRef).sort()) {
-      const triggers = triggersByTableRef[tableRef];
-      const tableId = getTableId(Number(tableRef))!;  // groupBy makes tableRef a string
+    for (const [tableId, triggers] of triggersByTableId) {
       const tableDelta = summary.tableDeltas[tableId];
       // ...if the monitored table was modified by the summarized actions,
       // fetch the modified/created records and note the work that needs to be done.
@@ -165,7 +190,7 @@ export class DocTriggers {
       events.push(...this._handleTask(task, await task.tableDataAction));
     }
     if (!events.length) {
-      return;
+      return summary;
     }
 
     // Only add events to the queue after we finish fetching the backup from redis
@@ -184,6 +209,8 @@ export class DocTriggers {
     while (this._drainingQueue && !this._shuttingDown) {
       await delay(1000);
     }
+
+    return summary;
   }
 
   private get _docId() {
@@ -296,8 +323,7 @@ export class DocTriggers {
         readyBefore = false;
       } else if (!cellDelta ) {
         // Cell wasn't changed, and the record is ready now, so it was ready before.
-        // This assumes that the ActionSummary contains all changes to the isReady column.
-        // TODO ensure ActionSummary actually contains all changes, right now bulk changes are truncated.
+        // This requires that the ActionSummary contains all changes to the isReady column.
         readyBefore = true;
       } else {
         const deltaBefore = cellDelta[0];