Can AI build a client proofing and approval tool like Filestage?

Build a personal client proofing and approval web app to replace Filestage for my own freelance use.

Tech rules:
- Plain HTML, CSS, and vanilla JavaScript in one file for the review interface. No framework or build step.
- Files (images, PDFs, videos) are uploaded to an S3-compatible object storage bucket I control; the app generates and reads signed, time-limited URLs, it doesn't handle raw file storage itself.
- Store project, file, and comment metadata in localStorage under one key, with a version number.
- Use the browser's native <video> element with its currentTime property for video timestamp pinning, and a PDF rendering library (like pdf.js) for PDF page annotation.

Data model:
- Project: id, clientName, createdAt.
- FileVersion: id, projectId, versionNumber, fileType (image | pdf | video), storageUrl, uploadedAt, status (pending | approved | changesRequested).
- Comment: id, fileVersionId, authorName (freelancer or client), pinType (timestamp | xy-coordinate | page-number), pinValue, text, createdAt, resolved (boolean).

Features:
- Upload a new file version to a project, generating a shareable review link with a random, hard-to-guess token (no login required to open it).
- Video files: click anywhere on the video to pin a comment at that timestamp; comments list shows timestamps and jumps the video there on click.
- Image and PDF files: click on the image or PDF page to drop a pin and leave a comment at that x/y position or page number.
- Client marks the file version as Approved or Changes Requested, with an optional note.
- Version history: compare which comments belong to which version, and whether older versions are superseded.
- Send an email notification (via a transactional email API I configure) to the freelancer when a client leaves a new comment or changes the approval status.

Edge cases the build must handle correctly:
1. A comment pinned to a timestamp in one video version doesn't carry over to a re-uploaded new version; it stays attached to its original version.
2. Deleting a file version asks for confirmation and keeps its comments visible in a "previous version" read-only view, not deleted.
3. The share link works with no account, but expires after a configurable number of days (default 30) for security, shown clearly to the client before it expires.
4. Resolving a comment doesn't delete it, just marks it resolved with a toggle to show/hide resolved comments.
5. A client leaving multiple comments on the same timestamp in a video creates separate comment entries, not overwriting each other.
6. Large video files show an upload progress indicator, since object storage uploads can take a while on a slow connection.

Backup:
- One-click "Export JSON" (all projects, files, and comments) and "Export CSV" (a flat list of comments with pin location and status).
- "Import JSON" restores after confirmation.

Layout:
- Mobile-first for the client-facing review page, readable at 375px wide, since clients often open the link on a phone. Desktop-first is fine for your own admin/upload view.

Exclusions:
- No publishing, App Store submission, accounts or logins for clients, real-time collaborative editing, or team/internal-comment separation beyond a simple author name field.

Write a short README explaining: where metadata is stored, how to export and restore it, how the object storage bucket needs to be configured (public read via signed URLs, not fully public), and how share links expire.

Keep it under 900 lines. This is a personal tool, not a product.

What is the short answer?

Advanced, not a quick build. AI can build pinned comments on video, image, and PDF files that replace much of what Filestage’s Starter plan costs $199 a month flat for a 10-person workspace. The catch is that this pricing was never aimed at a solo freelancer in the first place, and neither Free (5 files a month) nor $199 a month fits someone reviewing work with one or two clients at a time.

The harder catch is technical. Frame-accurate, timestamp-pinned comments on video need real video-scrubbing code, and click-to-pin annotations on PDFs and images need a real rendering library, not an img tag with a click handler. This is buildable by someone comfortable with code and a bit of API integration, not a first weekend project.

Option	Best for	Upfront cost	Ongoing cost	Main limitation
Build a rough prototype	Developers testing whether pinned comments on one file type work reliably	$0 and 6–8 hours	$1–$10/mo in file storage	Likely works for images or PDFs first; video scrubbing takes longer
Build a daily-use personal version	Freelancers comfortable with code who review a steady stream of client files	$0–$20 and 16–20 hours	$1–$10/mo, scaling with file size and client uploads	No dashboard, team roles, or the polish of a dedicated product
Keep paying for Filestage	Freelancers or small studios who want a polished, no-maintenance review tool	$0	$0 (5 files/mo) or $199+/mo for more	$199/mo minimum paid tier is priced for a team, not one freelancer

The ready-to-paste starter prompt at the end of this page builds the daily-use version.

What should the first version include?

The first version needs one file type working end to end: upload, pin a comment, and get client approval, before adding video or PDF support.

• Upload a file version and generate a shareable link
• Pinned comments on images (x/y coordinates)
• Approve or request changes per file version
• JSON and CSV export of comments
• Deliberate exclusion: no video support in the first pass, no team roles, no internal-vs-external comment separation. Add video scrubbing once image pinning works reliably.

What can AI build reliably?

ChatGPT and Claude build the project and comment data structure reliably, along with pinned comments on static images, since click-to-coordinate mapping is a well-understood pattern.

Concrete things AI gets right:

• A project and file-version list with status tracking
• Click-to-pin comments on an image, storing x/y coordinates
• An approval workflow with Approved and Changes Requested states
• Export buttons for JSON and CSV
• Generating a share link with a random token

Where will AI need human help?

Video scrubbing needs your own testing. AI can wire up the browser’s native video element and pin a comment to currentTime, but getting comments to jump the video to the right moment reliably, across different video lengths and playback speeds, takes real iteration. Test with a video longer than 5 minutes before trusting it for real client work.

PDF rendering needs a real library, not a shortcut. Click-to-pin on a specific PDF page requires rendering the PDF in the browser first, typically with a library like pdf.js, which is more setup than an image click handler. Budget extra time here if PDFs are your main file type.

The decision only you can make is whether file storage costs and upload reliability are worth managing yourself. Large video files take real time to upload on a client’s end too, and a stalled upload with no retry logic frustrates non-technical clients fast.

Privacy matters more here than most personal apps, since client files pass through your storage. Use signed, expiring links, not permanently public URLs, so old client work doesn’t stay indefinitely accessible.

Can I get my data out of Filestage?

Only partly, and only on a higher tier. A review report documenting comments, timestamps, and approval decisions is described as a Business-plan feature, at $329 a month and above, not available on Free or the $199 Starter plan.

The trap: no official help-center documentation of this export was found, only a marketing-page mention, so the exact file format is undocumented [VERIFY]. The report also reads as a static audit-trail snapshot of comments and approvals, not a full export of the underlying files themselves.

Since Filestage’s own export is limited and tier-gated, moving to a personal build mostly means starting fresh: re-uploading current project files and manually noting any open feedback threads you still need to resolve, rather than migrating historical comment data.

How long will it take and what will it cost?

Rough prototype: 6–8 hours and $1 to $10 a month in file storage. Pinned comments on one file type, working approval flow.

Dependable daily-use version: 16–20 hours, including video scrubbing, PDF rendering, and tested share-link security. Budget $0 to $20 in AI plan cost plus ongoing storage.

Filestage’s cheapest paid tier costs $199 a month, well above what a solo freelancer needs to spend. Object storage for a moderate volume of client files typically runs a few dollars a month, so the savings are real if you’re past the free plan’s 5-files-a-month cap and the build time is worth it to you.

These are estimates from reviewing the feature set, not measurements from a completed build.

Which AI tool or approach should I use?

Claude or ChatGPT can generate the initial structure and image-pinning logic in a few passes.

Cursor is genuinely useful once you’re debugging video timestamp accuracy or PDF rendering against real files, since that’s iterative fixing better done against a live app than a fresh prompt each time.

Lovable could speed up hosting a real backend for signed upload URLs and email notifications, but that trades a simple static tool for one with ongoing hosting to maintain, worth weighing against how many files you actually review per month.

What will I need to maintain?

More than most apps on this site, since client-facing file storage is real infrastructure.

Recurring work:

• Monitor your object storage bill as client uploads accumulate
• Rotate or clean up expired share links periodically
• Re-test video and PDF rendering after any browser update, since these rely on browser APIs that occasionally change behavior
• Export a JSON backup of comments and approval history regularly

Should I build it, buy it, or reduce scope?

Build it if you’re comfortable with code, review a steady volume of client work, and Filestage’s team-priced tiers clearly don’t fit a solo freelancer’s budget.

Buy it if you want a polished tool with no file-storage maintenance and can either stay under Filestage’s free 5-files-a-month cap or justify the $199-plus monthly cost against your client volume.

Reduce scope to email or a shared folder with manual timestamp notes if you review infrequently and don’t need pinned, threaded comments at all.

Recommendation: check Filestage’s free plan first if you review 5 or fewer files a month. Build your own only if you’re technical, review more than that, and want to avoid team-scale pricing for solo use. For the rest of your freelance workflow, pair this with an invoicing build or a time tracker.

What if I wanted to ship this to other people?

Shipping a proofing tool to other freelancers means real accounts, team permissions, abuse prevention on public share links, and support for far more file types and edge cases than one person’s workflow needs. That’s a competing product, not a natural extension of your own review tool.

Starter build specification

• User: You, for your own use, reviewing client work as a solo freelancer.
• Problem: Filestage’s cheapest paid tier is $199 a month for a 10-person team, far more than a solo freelancer needs, while the free plan caps at 5 files a month.
• Core workflow: Upload a file version, send the client a share link, they pin comments, you address feedback and get approval.
• Required features: File upload with share links, pinned comments per file type, approval status, version history, email notification on new feedback.
• Deliberate exclusions: No team roles, no accounts for clients, no real-time collaborative editing.
• Data ownership: Metadata stored in localStorage. Files stored in your own object storage account. Exported as JSON and CSV.
• Definition of done: A client opens a share link with no login, pins a comment on a video at a specific timestamp, and you receive an email notification and can jump directly to that moment in the video from the comment list.

For scoping help, read can AI build an app for me.

Sources and verification

• Filestage pricing: Free plan (1 project, 5 files/mo), Starter $199/mo, Business $329/mo, flat per-workspace pricing.
• Document version control (Filestage): review report export described as a Business-tier feature.

This app was not built and tested for this page. The verdict is based on Filestage’s own pricing page and marketing documentation, plus a review of what pinned video and PDF commenting requires technically. Filestage’s price was checked on September 24, 2026.

Reviewed on September 24, 2026.