diff --git a/lib/reducers/master-reducer.js b/lib/reducers/master-reducer.js
--- a/lib/reducers/master-reducer.js
+++ b/lib/reducers/master-reducer.js
@@ -37,6 +37,7 @@
   keyserverStoreOpsHandlers,
   type ReplaceKeyserverOperation,
 } from '../ops/keyserver-store-ops.js';
+import { createMessagesToPeersFromAction } from '../shared/dm-ops/dm-op-utils.js';
 import { isStaff } from '../shared/staff-utils.js';
 import type { BaseNavInfo } from '../types/nav-types.js';
 import type { BaseAppState, BaseAction } from '../types/redux-types.js';
@@ -44,6 +45,7 @@
   fullStateSyncActionType,
   incrementalStateSyncActionType,
 } from '../types/socket-types.js';
+import type { OutboundP2PMessage } from '../types/sqlite-types.js';
 import type { StoreOperations } from '../types/store-ops-types.js';
 import { isDev } from '../utils/dev-utils.js';
 
@@ -196,6 +198,11 @@
   const { threadActivityStore, threadActivityStoreOperations } =
     reduceThreadActivity(state.threadActivityStore, action);
 
+  const currentUserInfo = reduceCurrentUserInfo(state.currentUserInfo, action);
+
+  const outboundP2PMessages: $ReadOnlyArray<OutboundP2PMessage> =
+    createMessagesToPeersFromAction(action, auxUserStore, currentUserInfo);
+
   return {
     state: {
       ...state,
@@ -203,7 +210,7 @@
       draftStore,
       entryStore,
       loadingStatuses: reduceLoadingStatuses(state.loadingStatuses, action),
-      currentUserInfo: reduceCurrentUserInfo(state.currentUserInfo, action),
+      currentUserInfo,
       threadStore,
       userStore,
       messageStore,
@@ -246,6 +253,7 @@
       auxUserStoreOperations,
       threadActivityStoreOperations,
       entryStoreOperations,
+      outboundP2PMessages,
     },
   };
 }
diff --git a/lib/shared/dm-ops/create-sidebar-spec.js b/lib/shared/dm-ops/create-sidebar-spec.js
--- a/lib/shared/dm-ops/create-sidebar-spec.js
+++ b/lib/shared/dm-ops/create-sidebar-spec.js
@@ -103,6 +103,7 @@
         updateInfos: [threadJoinUpdateInfo],
       };
     },
+    fromAction: () => null,
   });
 
 export { createSidebarSpec };
diff --git a/lib/shared/dm-ops/create-thread-spec.js b/lib/shared/dm-ops/create-thread-spec.js
--- a/lib/shared/dm-ops/create-thread-spec.js
+++ b/lib/shared/dm-ops/create-thread-spec.js
@@ -157,6 +157,7 @@
         updateInfos: [threadJoinUpdateInfo],
       };
     },
+    fromAction: () => null,
   });
 
 export { createThickRawThreadInfo, createThreadSpec };
diff --git a/lib/shared/dm-ops/dm-op-spec.js b/lib/shared/dm-ops/dm-op-spec.js
--- a/lib/shared/dm-ops/dm-op-spec.js
+++ b/lib/shared/dm-ops/dm-op-spec.js
@@ -2,16 +2,24 @@
 
 import type { DMOperation, DMOperationResult } from '../../types/dm-ops.js';
 import type { RawMessageInfo } from '../../types/message-types.js';
+import type { BaseAction } from '../../types/redux-types.js';
 
 export type ProcessDMOperationUtilities = {
   // Needed to fetch sidebar source messages
   +fetchMessage: (messageID: string) => Promise<?RawMessageInfo>,
 };
 
+export type DMOperationSpecification<DMOp: DMOperation> = {
+  +op: DMOp,
+  +supportsAutoRetry: boolean,
+  +recipients: 'all_peer_devices' | 'self_devices',
+};
+
 export type DMOperationSpec<DMOp: DMOperation> = {
   +processDMOperation: (
     dmOp: DMOp,
     viewerID: string,
     utilities: ProcessDMOperationUtilities,
   ) => Promise<DMOperationResult>,
+  +fromAction: (action: BaseAction) => ?DMOperationSpecification<DMOp>,
 };
diff --git a/lib/shared/dm-ops/dm-op-utils.js b/lib/shared/dm-ops/dm-op-utils.js
new file mode 100644
--- /dev/null
+++ b/lib/shared/dm-ops/dm-op-utils.js
@@ -0,0 +1,81 @@
+// @flow
+
+import type { DMOperationSpecification } from './dm-op-spec.js';
+import { dmOpSpecs } from './dm-op-specs.js';
+import type { AuxUserStore } from '../../types/aux-user-types.js';
+import type { DMOperation } from '../../types/dm-ops.js';
+import type { BaseAction } from '../../types/redux-types.js';
+import type { OutboundP2PMessage } from '../../types/sqlite-types.js';
+import { outboundP2PMessageStatuses } from '../../types/sqlite-types.js';
+import type { CurrentUserInfo } from '../../types/user-types.js';
+import { values } from '../../utils/objects.js';
+import { getUUID } from '../../utils/uuid.js';
+
+function generateMessagesToPeers(
+  message: DMOperation,
+  peers: $ReadOnlyArray<string>,
+  userID: string,
+  supportsAutoRetry: boolean,
+): $ReadOnlyArray<OutboundP2PMessage> {
+  const outboundP2PMessages = [];
+  for (const peerID of peers) {
+    const messageToPeer: OutboundP2PMessage = {
+      messageID: getUUID(),
+      deviceID: peerID,
+      userID,
+      timestamp: new Date().getTime().toString(),
+      plaintext: JSON.stringify(message),
+      ciphertext: '',
+      status: outboundP2PMessageStatuses.persisted,
+      supportsAutoRetry: supportsAutoRetry ? '1' : '0',
+    };
+    outboundP2PMessages.push(messageToPeer);
+  }
+  return outboundP2PMessages;
+}
+
+function createOpsFromAction(
+  action: BaseAction,
+): $ReadOnlyArray<DMOperationSpecification<DMOperation>> {
+  const result = [];
+  for (const spec of values(dmOpSpecs)) {
+    const op = spec.fromAction(action);
+    if (op) {
+      result.push(op);
+    }
+  }
+  return result;
+}
+
+function createMessagesToPeersFromAction(
+  action: BaseAction,
+  auxUserStore: AuxUserStore,
+  currentUserInfo: ?CurrentUserInfo,
+): $ReadOnlyArray<OutboundP2PMessage> {
+  if (!currentUserInfo?.id) {
+    return [];
+  }
+  const ops = createOpsFromAction(action);
+  if (ops.length === 0) {
+    return [];
+  }
+  const selfDevices =
+    auxUserStore.auxUserInfos[currentUserInfo.id].deviceList?.devices ?? [];
+  const allPeerDevices = values(auxUserStore.auxUserInfos)
+    .map(info => info.deviceList?.devices ?? [])
+    .flat();
+  const result: Array<OutboundP2PMessage> = [];
+  for (const op of ops) {
+    result.push(
+      ...generateMessagesToPeers(
+        op.op,
+        op.recipients === 'all_peer_devices' ? allPeerDevices : selfDevices,
+        currentUserInfo.id,
+        op.supportsAutoRetry,
+      ),
+    );
+  }
+  return result;
+}
+
+export { createMessagesToPeersFromAction };
diff --git a/lib/shared/dm-ops/send-text-message-spec.js b/lib/shared/dm-ops/send-text-message-spec.js
--- a/lib/shared/dm-ops/send-text-message-spec.js
+++ b/lib/shared/dm-ops/send-text-message-spec.js
@@ -37,6 +37,7 @@
         updateInfos,
       };
     },
+    fromAction: () => null,
   });
 
 export { sendTextMessageSpec };
diff --git a/lib/types/sqlite-types.js b/lib/types/sqlite-types.js
--- a/lib/types/sqlite-types.js
+++ b/lib/types/sqlite-types.js
@@ -26,6 +26,7 @@
   +status: string,
 };
 
+// How to get it from a DMOperation?
 export type OutboundP2PMessage = {
   +messageID: string,
   +deviceID: string,