From 81809e5f6661e1bb22c4bebc12b132153f58604e Mon Sep 17 00:00:00 2001
From: Reese Herber <herberr@ctxw1k73vf.peninsula.wednet.edu>
Date: Wed, 3 Jun 2026 13:27:16 -0700
Subject: [PATCH] feat: add "download all" zip and scrollable list for envelope
 downloads (do-87)

The envelope download dialog listed each document with its own download
buttons but had no way to fetch them all at once, and the list had no
height constraint so long lists (e.g. 12 documents) overflowed the dialog
with no way to scroll to the clipped entries.

- Add a dependency-free, store-mode ZIP writer (packages/lib/universal/zip.ts)
  used server-side to bundle an envelope's documents into a single archive.
- Add authenticated and recipient-token "download-all" file routes that stream
  the bundled signed (or original) PDFs as a .zip named after the envelope.
- Add a "Download all" action to the envelope download dialog and make the
  document list scrollable (max-height + overflow) so every document is
  reachable regardless of count.

Closes #87
---
 .../dialogs/envelope-download-dialog.tsx      |  52 +++++-
 .../document/document-page-view-button.tsx    |   1 +
 .../document/document-page-view-dropdown.tsx  |   1 +
 .../tables/documents-table-action-button.tsx  |   1 +
 .../documents-table-action-dropdown.tsx       |   1 +
 .../app/components/tables/inbox-table.tsx     |   1 +
 .../_recipient+/sign.$token+/complete.tsx     |   1 +
 apps/remix/server/api/files/files.helpers.ts  | 107 ++++++++++++
 apps/remix/server/api/files/files.ts          | 108 ++++++++++++-
 apps/remix/server/api/files/files.types.ts    |  18 +++
 .../lib/client-only/download-envelope-zip.ts  |  48 ++++++
 packages/lib/universal/zip.ts                 | 153 ++++++++++++++++++
 packages/lib/utils/envelope-download.ts       |  20 +++
 13 files changed, 510 insertions(+), 2 deletions(-)
 create mode 100644 packages/lib/client-only/download-envelope-zip.ts
 create mode 100644 packages/lib/universal/zip.ts

diff --git a/apps/remix/app/components/dialogs/envelope-download-dialog.tsx b/apps/remix/app/components/dialogs/envelope-download-dialog.tsx
index eb046ac446..811827f3f6 100644
--- a/apps/remix/app/components/dialogs/envelope-download-dialog.tsx
+++ b/apps/remix/app/components/dialogs/envelope-download-dialog.tsx
@@ -5,6 +5,7 @@ import { Trans } from '@lingui/react/macro';
 import { DocumentStatus, type EnvelopeItem } from '@prisma/client';
 import { DownloadIcon, FileTextIcon } from 'lucide-react';
 
+import { downloadEnvelopeZip } from '@documenso/lib/client-only/download-envelope-zip';
 import { downloadPDF } from '@documenso/lib/client-only/download-pdf';
 import { trpc } from '@documenso/trpc/react';
 import { Button } from '@documenso/ui/primitives/button';
@@ -28,6 +29,11 @@ type EnvelopeDownloadDialogProps = {
   envelopeStatus: DocumentStatus;
   envelopeItems?: EnvelopeItemToDownload[];
 
+  /**
+   * The envelope title, used to name the "download all" ZIP archive.
+   */
+  envelopeTitle?: string;
+
   /**
    * The recipient token to download the document.
    *
@@ -48,6 +54,7 @@ export const EnvelopeDownloadDialog = ({
   envelopeId,
   envelopeStatus,
   envelopeItems: initialEnvelopeItems,
+  envelopeTitle,
   token,
   canDownloadPartial = false,
   trigger,
@@ -61,6 +68,8 @@ export const EnvelopeDownloadDialog = ({
     [envelopeItemIdAndVersion: string]: boolean;
   }>({});
 
+  const [isDownloadingAll, setIsDownloadingAll] = useState(false);
+
   const generateDownloadKey = (envelopeItemId: string, version: DownloadVersion) =>
     `${envelopeItemId}-${version}`;
 
@@ -121,6 +130,34 @@ export const EnvelopeDownloadDialog = ({
     }
   };
 
+  const onDownloadAll = async () => {
+    if (isDownloadingAll) {
+      return;
+    }
+
+    setIsDownloadingAll(true);
+
+    try {
+      await downloadEnvelopeZip({
+        envelopeId,
+        token,
+        fileName: envelopeTitle,
+        version: envelopeStatus === DocumentStatus.COMPLETED ? 'signed' : 'original',
+      });
+    } catch (error) {
+      console.error(error);
+
+      toast({
+        title: t`Something went wrong`,
+        description: t`These documents could not be downloaded at this time. Please try again.`,
+        variant: 'destructive',
+        duration: 7500,
+      });
+    } finally {
+      setIsDownloadingAll(false);
+    }
+  };
+
   return (
     <Dialog open={open} onOpenChange={(value) => setOpen(value)}>
       <DialogTrigger asChild>{trigger}</DialogTrigger>
@@ -135,7 +172,20 @@ export const EnvelopeDownloadDialog = ({
           </DialogDescription>
         </DialogHeader>
 
-        <div className="flex w-full flex-col gap-4 overflow-hidden">
+        {!isLoadingEnvelopeItems && envelopeItems.length > 1 && (
+          <div className="flex items-center justify-between gap-2">
+            <p className="text-muted-foreground text-xs">
+              {t`${envelopeItems.length} documents`}
+            </p>
+
+            <Button variant="default" size="sm" onClick={onDownloadAll} loading={isDownloadingAll}>
+              {!isDownloadingAll && <DownloadIcon className="mr-2 h-4 w-4" />}
+              <Trans>Download all</Trans>
+            </Button>
+          </div>
+        )}
+
+        <div className="-mx-1 flex max-h-[60vh] w-full flex-col gap-4 overflow-y-auto px-1">
           {isLoadingEnvelopeItems ? (
             <>
               {Array.from({ length: 1 }).map((_, index) => (
diff --git a/apps/remix/app/components/general/document/document-page-view-button.tsx b/apps/remix/app/components/general/document/document-page-view-button.tsx
index e3e7e0afc2..9864d34a6f 100644
--- a/apps/remix/app/components/general/document/document-page-view-button.tsx
+++ b/apps/remix/app/components/general/document/document-page-view-button.tsx
@@ -74,6 +74,7 @@ export const DocumentPageViewButton = ({ envelope }: DocumentPageViewButtonProps
         envelopeId={envelope.id}
         envelopeStatus={envelope.status}
         envelopeItems={envelope.envelopeItems}
+        envelopeTitle={envelope.title}
         token={recipient?.token}
         trigger={
           <Button className="w-full">
diff --git a/apps/remix/app/components/general/document/document-page-view-dropdown.tsx b/apps/remix/app/components/general/document/document-page-view-dropdown.tsx
index d786545088..bd877b0751 100644
--- a/apps/remix/app/components/general/document/document-page-view-dropdown.tsx
+++ b/apps/remix/app/components/general/document/document-page-view-dropdown.tsx
@@ -106,6 +106,7 @@ export const DocumentPageViewDropdown = ({ envelope }: DocumentPageViewDropdownP
           envelopeStatus={envelope.status}
           token={recipient?.token}
           envelopeItems={envelope.envelopeItems}
+          envelopeTitle={envelope.title}
           canDownloadPartial={canManageDocument}
           trigger={
             <DropdownMenuItem asChild onSelect={(e) => e.preventDefault()}>
diff --git a/apps/remix/app/components/tables/documents-table-action-button.tsx b/apps/remix/app/components/tables/documents-table-action-button.tsx
index 506c6afa03..bdcfd2d383 100644
--- a/apps/remix/app/components/tables/documents-table-action-button.tsx
+++ b/apps/remix/app/components/tables/documents-table-action-button.tsx
@@ -103,6 +103,7 @@ export const DocumentsTableActionButton = ({ row }: DocumentsTableActionButtonPr
       <EnvelopeDownloadDialog
         envelopeId={row.envelopeId}
         envelopeStatus={row.status}
+        envelopeTitle={row.title}
         token={recipient?.token}
         trigger={
           <Button className="w-32">
diff --git a/apps/remix/app/components/tables/documents-table-action-dropdown.tsx b/apps/remix/app/components/tables/documents-table-action-dropdown.tsx
index c6f1047820..332b90f84e 100644
--- a/apps/remix/app/components/tables/documents-table-action-dropdown.tsx
+++ b/apps/remix/app/components/tables/documents-table-action-dropdown.tsx
@@ -152,6 +152,7 @@ export const DocumentsTableActionDropdown = ({
         <EnvelopeDownloadDialog
           envelopeId={row.envelopeId}
           envelopeStatus={row.status}
+          envelopeTitle={row.title}
           token={recipient?.token}
           canDownloadPartial={canManageDocument}
           trigger={
diff --git a/apps/remix/app/components/tables/inbox-table.tsx b/apps/remix/app/components/tables/inbox-table.tsx
index a214461650..53437d7938 100644
--- a/apps/remix/app/components/tables/inbox-table.tsx
+++ b/apps/remix/app/components/tables/inbox-table.tsx
@@ -334,6 +334,7 @@ export const InboxTableActionButton = ({ row }: InboxTableActionButtonProps) =>
       <EnvelopeDownloadDialog
         envelopeId={row.envelopeId}
         envelopeStatus={row.status}
+        envelopeTitle={row.title}
         token={recipient?.token}
         trigger={
           <Button className="w-32">
diff --git a/apps/remix/app/routes/_recipient+/sign.$token+/complete.tsx b/apps/remix/app/routes/_recipient+/sign.$token+/complete.tsx
index c64292fdfb..b3ff741701 100644
--- a/apps/remix/app/routes/_recipient+/sign.$token+/complete.tsx
+++ b/apps/remix/app/routes/_recipient+/sign.$token+/complete.tsx
@@ -255,6 +255,7 @@ export default function CompletedSigningPage({ loaderData }: Route.ComponentProp
                 envelopeId={document.envelopeId}
                 envelopeStatus={document.status}
                 envelopeItems={document.envelopeItems}
+                envelopeTitle={document.title}
                 token={recipient?.token}
                 trigger={
                   <Button type="button" variant="outline" className="flex-1 md:flex-initial">
diff --git a/apps/remix/server/api/files/files.helpers.ts b/apps/remix/server/api/files/files.helpers.ts
index 7e50b93a95..729727e874 100644
--- a/apps/remix/server/api/files/files.helpers.ts
+++ b/apps/remix/server/api/files/files.helpers.ts
@@ -12,6 +12,7 @@ import { generatePartialDocumentPdf } from '@documenso/lib/server-only/pdf/gener
 import { getTeamById } from '@documenso/lib/server-only/team/get-team';
 import { sha256 } from '@documenso/lib/universal/crypto';
 import { getFileServerSide } from '@documenso/lib/universal/upload/get-file.server';
+import { type ZipFile, createZip } from '@documenso/lib/universal/zip';
 import { prisma } from '@documenso/prisma';
 
 import type { HonoEnv } from '../../router';
@@ -130,6 +131,112 @@ export const handleEnvelopeItemFileRequest = async ({
   return c.body(file);
 };
 
+type EnvelopeZipItem = {
+  title: string;
+  documentData: {
+    type: DocumentDataType;
+    data: string;
+    initialData: string;
+  } | null;
+};
+
+type BuildEnvelopeZipResponseOptions = {
+  envelopeTitle: string;
+  items: EnvelopeZipItem[];
+  version: 'signed' | 'original';
+  context: Context<HonoEnv>;
+};
+
+/**
+ * Ensures every entry in the archive has a unique name. PDF titles within an
+ * envelope are not guaranteed to be unique, so colliding names get a numeric
+ * suffix (e.g. "report (2).pdf") to avoid silently overwriting an entry.
+ */
+const dedupeFileName = (name: string, usedNames: Set<string>): string => {
+  if (!usedNames.has(name)) {
+    usedNames.add(name);
+
+    return name;
+  }
+
+  const extensionMatch = /\.[^.]+$/.exec(name);
+  const extension = extensionMatch ? extensionMatch[0] : '';
+  const base = extension ? name.slice(0, -extension.length) : name;
+
+  let counter = 2;
+  let candidate = `${base} (${counter})${extension}`;
+
+  while (usedNames.has(candidate)) {
+    counter += 1;
+    candidate = `${base} (${counter})${extension}`;
+  }
+
+  usedNames.add(candidate);
+
+  return candidate;
+};
+
+/**
+ * Bundles every document in an envelope into a single ZIP archive and returns
+ * it as a download. Used by the "Download all" action so a user does not have
+ * to download each document in a multi-document envelope individually.
+ */
+export const buildEnvelopeZipResponse = async ({
+  envelopeTitle,
+  items,
+  version,
+  context: c,
+}: BuildEnvelopeZipResponseOptions) => {
+  const usedNames = new Set<string>();
+  const suffix = version === 'signed' ? '_signed.pdf' : '.pdf';
+
+  const files: ZipFile[] = [];
+
+  for (const item of items) {
+    if (!item.documentData) {
+      continue;
+    }
+
+    const documentDataToUse =
+      version === 'signed' ? item.documentData.data : item.documentData.initialData;
+
+    const file = await getFileServerSide({
+      type: item.documentData.type,
+      data: documentDataToUse,
+    }).catch((error) => {
+      console.error(error);
+
+      return null;
+    });
+
+    if (!file) {
+      continue;
+    }
+
+    const baseTitle = item.title.replace(/\.pdf$/, '');
+    const name = dedupeFileName(`${baseTitle}${suffix}`, usedNames);
+
+    files.push({ name, data: file });
+  }
+
+  if (files.length === 0) {
+    return c.json({ error: 'No files available to download' }, 404);
+  }
+
+  const zip = createZip(files);
+
+  const baseZipTitle = envelopeTitle.replace(/\.pdf$/, '') || 'documents';
+  const zipFilename = `${baseZipTitle}.zip`;
+
+  c.header('Content-Type', 'application/zip');
+  c.header('Content-Disposition', contentDisposition(zipFilename));
+  c.header('Cache-Control', 'no-cache, no-store, must-revalidate');
+  c.header('Pragma', 'no-cache');
+  c.header('Expires', '0');
+
+  return c.body(zip);
+};
+
 type CheckEnvelopeFileAccessOptions = {
   userId: number;
   teamId: number;
diff --git a/apps/remix/server/api/files/files.ts b/apps/remix/server/api/files/files.ts
index cb1d0dd31d..40dee4ca8e 100644
--- a/apps/remix/server/api/files/files.ts
+++ b/apps/remix/server/api/files/files.ts
@@ -11,9 +11,15 @@ import { getPresignPostUrl } from '@documenso/lib/universal/upload/server-action
 import { prisma } from '@documenso/prisma';
 
 import type { HonoEnv } from '../../router';
-import { checkEnvelopeFileAccess, handleEnvelopeItemFileRequest } from './files.helpers';
+import {
+  buildEnvelopeZipResponse,
+  checkEnvelopeFileAccess,
+  handleEnvelopeItemFileRequest,
+} from './files.helpers';
 import {
   type TGetPresignedPostUrlResponse,
+  ZDownloadAllEnvelopeFilesRequestParamsSchema,
+  ZDownloadAllEnvelopeFilesTokenRequestParamsSchema,
   ZGetEnvelopeItemFileDownloadRequestParamsSchema,
   ZGetEnvelopeItemFileRequestParamsSchema,
   ZGetEnvelopeItemFileRequestQuerySchema,
@@ -216,6 +222,60 @@ export const filesRoute = new Hono<HonoEnv>()
       });
     },
   )
+  .get(
+    '/envelope/:envelopeId/download-all/:version?',
+    sValidator('param', ZDownloadAllEnvelopeFilesRequestParamsSchema),
+    async (c) => {
+      const { envelopeId, version } = c.req.valid('param');
+
+      const session = await getOptionalSession(c);
+
+      if (!session.user) {
+        return c.json({ error: 'Unauthorized' }, 401);
+      }
+
+      const envelope = await prisma.envelope.findFirst({
+        where: {
+          id: envelopeId,
+        },
+        include: {
+          envelopeItems: {
+            orderBy: {
+              order: 'asc',
+            },
+            include: {
+              documentData: true,
+            },
+          },
+        },
+      });
+
+      if (!envelope) {
+        return c.json({ error: 'Envelope not found' }, 404);
+      }
+
+      const hasDownloadAccess = await checkEnvelopeFileAccess({
+        userId: session.user.id,
+        teamId: envelope.teamId,
+        envelopeType: envelope.type,
+        templateType: envelope.templateType,
+      });
+
+      if (!hasDownloadAccess) {
+        return c.json(
+          { error: 'User does not have access to the team that this envelope is associated with' },
+          403,
+        );
+      }
+
+      return await buildEnvelopeZipResponse({
+        envelopeTitle: envelope.title,
+        items: envelope.envelopeItems,
+        version,
+        context: c,
+      });
+    },
+  )
   .get(
     '/token/:token/envelopeItem/:envelopeItemId',
     sValidator('param', ZGetEnvelopeItemFileTokenRequestParamsSchema),
@@ -323,6 +383,52 @@ export const filesRoute = new Hono<HonoEnv>()
         context: c,
       });
     },
+  )
+  .get(
+    '/token/:token/download-all/:version?',
+    sValidator('param', ZDownloadAllEnvelopeFilesTokenRequestParamsSchema),
+    async (c) => {
+      const { token, version } = c.req.valid('param');
+
+      let envelopeWhereQuery: Prisma.EnvelopeWhereInput = {
+        recipients: {
+          some: {
+            token,
+          },
+        },
+      };
+
+      if (token.startsWith('qr_')) {
+        envelopeWhereQuery = {
+          qrToken: token,
+        };
+      }
+
+      const envelope = await prisma.envelope.findFirst({
+        where: envelopeWhereQuery,
+        include: {
+          envelopeItems: {
+            orderBy: {
+              order: 'asc',
+            },
+            include: {
+              documentData: true,
+            },
+          },
+        },
+      });
+
+      if (!envelope) {
+        return c.json({ error: 'Envelope not found' }, 404);
+      }
+
+      return await buildEnvelopeZipResponse({
+        envelopeTitle: envelope.title,
+        items: envelope.envelopeItems,
+        version,
+        context: c,
+      });
+    },
   );
 
 // PDF routes for both tokens and auth based
diff --git a/apps/remix/server/api/files/files.types.ts b/apps/remix/server/api/files/files.types.ts
index 4d581729c6..437e742138 100644
--- a/apps/remix/server/api/files/files.types.ts
+++ b/apps/remix/server/api/files/files.types.ts
@@ -72,3 +72,21 @@ export const ZGetEnvelopeItemFileTokenDownloadRequestParamsSchema = z.object({
 export type TGetEnvelopeItemFileTokenDownloadRequestParams = z.infer<
   typeof ZGetEnvelopeItemFileTokenDownloadRequestParamsSchema
 >;
+
+export const ZDownloadAllEnvelopeFilesRequestParamsSchema = z.object({
+  envelopeId: z.string().min(1),
+  version: z.enum(['signed', 'original']).default('signed'),
+});
+
+export type TDownloadAllEnvelopeFilesRequestParams = z.infer<
+  typeof ZDownloadAllEnvelopeFilesRequestParamsSchema
+>;
+
+export const ZDownloadAllEnvelopeFilesTokenRequestParamsSchema = z.object({
+  token: z.string().min(1),
+  version: z.enum(['signed', 'original']).default('signed'),
+});
+
+export type TDownloadAllEnvelopeFilesTokenRequestParams = z.infer<
+  typeof ZDownloadAllEnvelopeFilesTokenRequestParamsSchema
+>;
diff --git a/packages/lib/client-only/download-envelope-zip.ts b/packages/lib/client-only/download-envelope-zip.ts
new file mode 100644
index 0000000000..aaeda160ef
--- /dev/null
+++ b/packages/lib/client-only/download-envelope-zip.ts
@@ -0,0 +1,48 @@
+import { getEnvelopeDownloadAllUrl } from '../utils/envelope-download';
+import { downloadFile } from './download-file';
+
+type DownloadEnvelopeZipProps = {
+  envelopeId: string;
+  token: string | undefined;
+
+  /**
+   * Specifies which version of each document to include in the archive.
+   * 'signed': The signed version (default).
+   * 'original': The original (unsigned) version.
+   */
+  version?: 'original' | 'signed';
+
+  /** The base name to use for the downloaded archive (the envelope title). */
+  fileName?: string;
+};
+
+/**
+ * Downloads every document in an envelope as a single ZIP archive.
+ */
+export const downloadEnvelopeZip = async ({
+  envelopeId,
+  token,
+  version = 'signed',
+  fileName,
+}: DownloadEnvelopeZipProps) => {
+  const downloadUrl = getEnvelopeDownloadAllUrl({
+    envelopeId,
+    token,
+    version,
+  });
+
+  const response = await fetch(downloadUrl);
+
+  if (!response.ok) {
+    throw new Error(`Failed to download archive (${response.status})`);
+  }
+
+  const blob = await response.blob();
+
+  const baseTitle = (fileName ?? 'documents').replace(/\.zip$/, '');
+
+  downloadFile({
+    filename: `${baseTitle}.zip`,
+    data: blob,
+  });
+};
diff --git a/packages/lib/universal/zip.ts b/packages/lib/universal/zip.ts
new file mode 100644
index 0000000000..16957035d4
--- /dev/null
+++ b/packages/lib/universal/zip.ts
@@ -0,0 +1,153 @@
+/**
+ * A tiny, dependency-free ZIP archive writer.
+ *
+ * Files are stored uncompressed (the "store" method). This is intentional:
+ * the only consumer bundles already-compressed PDFs, where deflate would add
+ * CPU cost for virtually no size benefit. Keeping this dependency-free avoids
+ * pulling a zip library into the server bundle.
+ *
+ * Limitations: no ZIP64, so the archive and each individual entry must be
+ * smaller than 4GB. This is well within the bounds of bundling signed PDFs.
+ */
+
+export type ZipFile = {
+  /** The name (including any directory path) the file should have inside the archive. */
+  name: string;
+  /** The raw file contents. */
+  data: Uint8Array;
+};
+
+const CRC_TABLE = (() => {
+  const table = new Uint32Array(256);
+
+  for (let n = 0; n < 256; n++) {
+    let c = n;
+
+    for (let k = 0; k < 8; k++) {
+      c = c & 1 ? 0xedb88320 ^ (c >>> 1) : c >>> 1;
+    }
+
+    table[n] = c >>> 0;
+  }
+
+  return table;
+})();
+
+const crc32 = (data: Uint8Array): number => {
+  let crc = 0xffffffff;
+
+  for (let i = 0; i < data.length; i++) {
+    crc = (crc >>> 8) ^ CRC_TABLE[(crc ^ data[i]) & 0xff];
+  }
+
+  return (crc ^ 0xffffffff) >>> 0;
+};
+
+// Fixed DOS timestamp (1980-01-01 00:00:00). The modification time is not
+// meaningful for these archives, so a constant keeps the output deterministic.
+const DOS_TIME = 0;
+const DOS_DATE = 0x0021;
+
+// General purpose bit 11 flags that file names are UTF-8 encoded.
+const FLAG_UTF8 = 0x0800;
+
+type ZipEntry = {
+  nameBytes: Uint8Array;
+  data: Uint8Array;
+  crc: number;
+  offset: number;
+};
+
+/**
+ * Builds a ZIP archive (store method) from the provided files and returns the
+ * raw bytes.
+ */
+export const createZip = (files: ZipFile[]): Uint8Array => {
+  const encoder = new TextEncoder();
+  const entries: ZipEntry[] = [];
+
+  const localParts: Uint8Array[] = [];
+  let offset = 0;
+
+  for (const file of files) {
+    const nameBytes = encoder.encode(file.name);
+    const crc = crc32(file.data);
+
+    const header = new Uint8Array(30 + nameBytes.length);
+    const view = new DataView(header.buffer);
+
+    view.setUint32(0, 0x04034b50, true); // Local file header signature
+    view.setUint16(4, 20, true); // Version needed to extract
+    view.setUint16(6, FLAG_UTF8, true); // General purpose bit flag
+    view.setUint16(8, 0, true); // Compression method (0 = store)
+    view.setUint16(10, DOS_TIME, true); // Last mod file time
+    view.setUint16(12, DOS_DATE, true); // Last mod file date
+    view.setUint32(14, crc, true); // CRC-32
+    view.setUint32(18, file.data.length, true); // Compressed size
+    view.setUint32(22, file.data.length, true); // Uncompressed size
+    view.setUint16(26, nameBytes.length, true); // File name length
+    view.setUint16(28, 0, true); // Extra field length
+    header.set(nameBytes, 30);
+
+    entries.push({ nameBytes, data: file.data, crc, offset });
+
+    localParts.push(header, file.data);
+    offset += header.length + file.data.length;
+  }
+
+  const centralStart = offset;
+  const centralParts: Uint8Array[] = [];
+
+  for (const entry of entries) {
+    const header = new Uint8Array(46 + entry.nameBytes.length);
+    const view = new DataView(header.buffer);
+
+    view.setUint32(0, 0x02014b50, true); // Central directory file header signature
+    view.setUint16(4, 20, true); // Version made by
+    view.setUint16(6, 20, true); // Version needed to extract
+    view.setUint16(8, FLAG_UTF8, true); // General purpose bit flag
+    view.setUint16(10, 0, true); // Compression method
+    view.setUint16(12, DOS_TIME, true); // Last mod file time
+    view.setUint16(14, DOS_DATE, true); // Last mod file date
+    view.setUint32(16, entry.crc, true); // CRC-32
+    view.setUint32(20, entry.data.length, true); // Compressed size
+    view.setUint32(24, entry.data.length, true); // Uncompressed size
+    view.setUint16(28, entry.nameBytes.length, true); // File name length
+    view.setUint16(30, 0, true); // Extra field length
+    view.setUint16(32, 0, true); // File comment length
+    view.setUint16(34, 0, true); // Disk number start
+    view.setUint16(36, 0, true); // Internal file attributes
+    view.setUint32(38, 0, true); // External file attributes
+    view.setUint32(42, entry.offset, true); // Relative offset of local header
+    header.set(entry.nameBytes, 46);
+
+    centralParts.push(header);
+    offset += header.length;
+  }
+
+  const centralSize = offset - centralStart;
+
+  const eocd = new Uint8Array(22);
+  const eocdView = new DataView(eocd.buffer);
+
+  eocdView.setUint32(0, 0x06054b50, true); // End of central directory signature
+  eocdView.setUint16(4, 0, true); // Number of this disk
+  eocdView.setUint16(6, 0, true); // Disk where central directory starts
+  eocdView.setUint16(8, entries.length, true); // Number of entries on this disk
+  eocdView.setUint16(10, entries.length, true); // Total number of entries
+  eocdView.setUint32(12, centralSize, true); // Size of central directory
+  eocdView.setUint32(16, centralStart, true); // Offset of central directory
+  eocdView.setUint16(20, 0, true); // Comment length
+
+  const totalSize = offset + eocd.length;
+  const output = new Uint8Array(totalSize);
+
+  let cursor = 0;
+
+  for (const part of [...localParts, ...centralParts, eocd]) {
+    output.set(part, cursor);
+    cursor += part.length;
+  }
+
+  return output;
+};
diff --git a/packages/lib/utils/envelope-download.ts b/packages/lib/utils/envelope-download.ts
index 82b1ed3eba..e8a5a62ad2 100644
--- a/packages/lib/utils/envelope-download.ts
+++ b/packages/lib/utils/envelope-download.ts
@@ -37,6 +37,26 @@ export const getEnvelopeItemPdfUrl = (options: EnvelopeItemPdfUrlOptions) => {
     : `${NEXT_PUBLIC_WEBAPP_URL()}/api/files/envelope/${envelopeId}/envelopeItem/${id}${presignToken ? `?token=${presignToken}` : ''}`;
 };
 
+export type EnvelopeDownloadAllUrlOptions = {
+  envelopeId: string;
+  token: string | undefined;
+  version: 'original' | 'signed';
+};
+
+/**
+ * Builds the URL that returns every document in an envelope bundled into a
+ * single ZIP archive.
+ */
+export const getEnvelopeDownloadAllUrl = ({
+  envelopeId,
+  token,
+  version,
+}: EnvelopeDownloadAllUrlOptions) => {
+  return token
+    ? `${NEXT_PUBLIC_WEBAPP_URL()}/api/files/token/${token}/download-all/${version}`
+    : `${NEXT_PUBLIC_WEBAPP_URL()}/api/files/envelope/${envelopeId}/download-all/${version}`;
+};
+
 export type DocumentDataUrlOptions = {
   envelopeId: string;
   envelopeItemId: string;