diff --git a/keyserver/.eslintrc.json b/keyserver/.eslintrc.json
--- a/keyserver/.eslintrc.json
+++ b/keyserver/.eslintrc.json
@@ -2,5 +2,8 @@
   "env": {
     "node": true,
     "jest": true
+  },
+  "globals": {
+    "Blob": false
   }
 }
diff --git a/keyserver/src/push/utils.js b/keyserver/src/push/utils.js
--- a/keyserver/src/push/utils.js
+++ b/keyserver/src/push/utils.js
@@ -1,10 +1,15 @@
 // @flow
 
 import type { ResponseFailure } from '@parse/node-apn';
+import crypto from 'crypto';
 import type { FirebaseApp, FirebaseError } from 'firebase-admin';
 import invariant from 'invariant';
+import nodeFetch from 'node-fetch';
+import type { Response } from 'node-fetch';
+import uuid from 'uuid';
 import webpush from 'web-push';
 
+import blobService from 'lib/facts/blob-service.js';
 import type { PlatformDetails } from 'lib/types/device-types.js';
 import type {
   WebNotification,
@@ -12,6 +17,9 @@
 } from 'lib/types/notif-types.js';
 import { threadSubscriptions } from 'lib/types/subscription-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
+import { toBase64URL } from 'lib/utils/base64.js';
+import { makeBlobServiceEndpointURL } from 'lib/utils/blob-service.js';
+import { getMessageForException } from 'lib/utils/errors.js';
 
 import {
   getAPNPushProfileForCodeVersion,
@@ -26,6 +34,7 @@
   TargetedAndroidNotification,
 } from './types.js';
 import { dbQuery, SQL } from '../database/database.js';
+import { generateKey, encrypt } from '../web/media/aes-crypto-utils.js';
 
 const fcmTokenInvalidationErrors = new Set([
   'messaging/registration-token-not-registered',
@@ -352,7 +361,7 @@
   }
 
   try {
-    const result = await fetch(url, {
+    const result = await nodeFetch(url, {
       method: 'POST',
       headers: {
         'Content-Type': 'application/octet-stream',
@@ -375,8 +384,91 @@
   }
 }
 
+async function blobServiceUpload(payload: string): Promise<
+  | {
+      +blobHash: string,
+      +encryptionKey: string,
+    }
+  | { +blobUploadError: string },
+> {
+  const encryptionKey = await generateKey();
+  const encryptedPayloadBuffer = Buffer.from(
+    await encrypt(encryptionKey, new TextEncoder().encode(payload)),
+  );
+
+  const blobHolder = uuid.v4();
+  const blobHashBase64 = await crypto
+    .createHash('sha256')
+    .update(encryptedPayloadBuffer)
+    .digest('base64');
+
+  const blobHash = toBase64URL(blobHashBase64);
+
+  const formData = new FormData();
+  const payloadBlob = new Blob([encryptedPayloadBuffer]);
+
+  formData.append('blob_hash', blobHash);
+  formData.append('blob_data', payloadBlob);
+
+  const assignHolderPromise = fetch(
+    makeBlobServiceEndpointURL(blobService.httpEndpoints.ASSIGN_HOLDER),
+    {
+      method: blobService.httpEndpoints.ASSIGN_HOLDER.method,
+      body: JSON.stringify({
+        holder: blobHolder,
+        blob_hash: blobHash,
+      }),
+      headers: {
+        'content-type': 'application/json',
+      },
+    },
+  );
+
+  const uploadHolderPromise = fetch(
+    makeBlobServiceEndpointURL(blobService.httpEndpoints.UPLOAD_BLOB),
+    {
+      method: blobService.httpEndpoints.UPLOAD_BLOB.method,
+      body: formData,
+    },
+  );
+
+  try {
+    const [assignHolderResponse, uploadBlobResponse] = await Promise.all([
+      assignHolderPromise,
+      uploadHolderPromise,
+    ]);
+
+    if (!assignHolderResponse.ok) {
+      const { status, statusText } = assignHolderResponse;
+      return {
+        blobUploadError: `Holder assignment failed with HTTP ${status}: ${statusText}`,
+      };
+    }
+
+    if (!uploadBlobResponse.ok) {
+      const { status, statusText } = uploadBlobResponse;
+      return {
+        blobUploadError: `Payload upload failed with HTTP ${status}: ${statusText}`,
+      };
+    }
+  } catch (e) {
+    return {
+      blobUploadError: `Payload upload failed with: ${
+        getMessageForException(e) ?? 'unknown error'
+      }`,
+    };
+  }
+
+  const encryptionKeyString = Buffer.from(encryptionKey).toString('base64');
+  return {
+    blobHash,
+    encryptionKey: encryptionKeyString,
+  };
+}
+
 export {
   apnPush,
+  blobServiceUpload,
   fcmPush,
   webPush,
   wnsPush,