InkSign

E-signature looks simple from the outside but is fiddly underneath: you have to render an arbitrary uploaded PDF in the browser, let a sender place fields (signature, initials, date, text, checkboxes) at exact coordinates on specific pages, then burn those signatures back into the real PDF at those same coordinates — pixel math that has to survive different page sizes and zoom levels. On top of that, a signature is only worth anything if it's defensible: you need account-free but secure signing links, an enforceable signing order, and a tamper-evident record of who signed what, when, and from where.

InkSign is a complete e-signature workflow with a deliberately minimal legal-tech aesthetic. Field placement: senders upload a PDF (rendered with react-pdf / PDF.js) and drop Signature, Initials, Date, Text, and Checkbox fields onto exact spots; those fields are later written into the output PDF with pdf-lib. Account-free signing: each recipient signs through a unique single-use tokenized URL — no account required — and the sender can enforce a sequential order (Signer 1, then Signer 2) or allow parallel signing. Cryptographic audit certificate: every completed agreement gets an appended certificate page listing PDF SHA-256 hashes, timestamps, IP addresses, and user agents — a tamper-evident record of the whole ceremony. Reusable templates: field layouts with role placeholders ('Signer 1', 'Signer 2') can be saved and reused to spin up future envelopes fast. Built on Next.js 14 (App Router) + TypeScript, Prisma against Neon Postgres, NextAuth for senders, and pdf-lib / react-pdf for the document engine — with browser-only PDF components dynamically loaded for clean builds, and a Docker/Coolify deploy that mounts a persistent volume for stored PDFs.

A finished, deployed e-signature product that handles the genuinely hard parts — coordinate-accurate PDF field placement and a cryptographic audit trail — not just a signature-image upload.