Unity package
SignArgs for Unity
Show a PDF, take a signature and finalize the signed document, all on the device.
- #unity
- #signatures
- #offline
- Engine
- Unity 6000.0 or newer
- Platforms
- Android, Windows, macOS, iOS preview
- PDF engine
- PDFium, included
- Network
- None: it runs on the device
SignArgs for Unity lets your application show a PDF, take a handwritten signature and finalize the signed document where the signer stands: the signature stamped in place, an audit page appended, the file hashed, and a set of records written that anyone can check later. It needs no server, no account for the signer and no network, so it works on a site, in a van or in a basement.
How it works
- The signature is bound to what was shown. Every signature record ties together the exact bytes of the document, a hash of every page as it was drawn on screen, every input event of the stroke with the device’s timestamp, and the sentence the signer agreed to.
- Confirm, then finalize. Confirming records one signature and grows the audit chain. Finalizing then does everything that changes the document once, for all signatures together.
- A bundle anyone can verify. Each finished session leaves the signed PDF, the original, the signature records, the strokes, a hash-linked audit chain and a manifest of SHA-256 hashes. Checking one needs a SHA-256 tool, not SignArgs.
- Evidence, honestly labelled. What can be proven is recorded as fact; what cannot, such as the device’s clock or what your application reports, is labelled as reported. Nothing is presented as more certain than it is.
Features
- Showing documents Pages drawn on a
RawImagewith form field values filled in, rendered off the main thread so the frame keeps its budget. - Signature capture Touch, pen or mouse recorded at event rate with the device’s timestamps and pen pressure, drawn as ink.
- Templates One record that says where each signature goes, what each signer agrees to, how sure you must be of them and in which order they sign.
- Several signers One document, several fields, several people signing in turn on one device, each with their own consent sentence.
- Audit page and bundle An appended page that explains the document to whoever reads it, plus the records that back it up.
- Pseudonymous records Names and contact details stay out of the records, in one deletable file per signer. Deleting one breaks no hash.
Simple electronic signatures
SignArgs for Unity produces simple electronic signatures: there is no certificate, no cryptographic signature over the PDF and no trusted timestamp. What it gives you is evidence — a signature bound to the pages that were shown, in records anyone can check. Times are device times, and the audit page says so. Limitations lists the rest before you build on it.
Documentation
Guides for every feature, the bundle format and what has been run on which platform are in the SignArgs documentation. The quick start builds a signed document from an empty scene, and two samples ship with the package.
