Browser document engineering · 2026 · Solo — trend research, document architecture, interaction design, test-first implementation, verification, deployment
Final Packet
A local-first document press that adds a cover, indexed contents, numbered dividers, normalized source pages, and packet-wide numbering to the files people actually submit.
The problem
Grant coordinators, paralegals, and operations teams often have the right evidence, exhibits, forms, and images but still need a coherent final packet. Generic merge tools concatenate files; Final Packet completes the submission structure in the browser. A user orders real PDF, JPEG, and PNG sources, names the packet, and receives one newly serialized PDF with a cover, indexed contents, numbered dividers, normalized page placement, and packet page numbers. The workflow is bounded to 12 files, 75 MB, and 100 finished pages and does not claim OCR, signatures, encryption, bookmarks, or filing-rule compliance.
Architecture
Key decisions
Plan the packet before touching output bytes
The pure planner fixes every cover, contents, divider, and source-page index first. That separates document structure from binary adapters and makes numbering deterministic enough to prove with small tests.
Preserve document geometry instead of rasterizing PDFs
PDF pages are embedded in batches with their crop boxes and rotations accounted for, then fitted into bounded packet sheets. Images use their own adapters, so vector source pages remain vector pages while heterogeneous inputs share one output frame.
Fail early at a bounded binary boundary
Declared MIME types must match PDF, JPEG, or PNG signatures before a parser runs. The workflow rejects unsupported input and caps source count, bytes, and finished pages rather than letting a browser tab become an unbounded document service.
Keep source bytes local and lifecycle-explicit
There is no upload endpoint, account, or cloud storage path. React locks concurrent builds and revokes generated object URLs when output changes or the surface unmounts, while the interface states the limits and privacy boundary directly.
Prove the push-driven production release
The private repository is connected to its own Vercel project. GitHub recorded a successful production deployment for exact main SHA 9385e6f0fc0c58e8171ab01902be04415739e375, followed by a real production PDF golden path and responsive, reduced-motion, opposite-scheme, and JavaScript-disabled checks.
Translate PDF reliability demand into completion
Secure radar run 20260804T214612-0700-github-star-radar-9e10c9d4 ranked firecrawl/pdf-inspector first at 2,540 stars that day and 10,295 total on 2026-08-04. Final Packet does not classify PDFs or reuse Firecrawl code or branding; it turns adjacent demand into a new usable document.