The Series· No. 25 · Act V — The Studio

By DocuSeller · Published

Signatures
DocuSeller · No. 25

We built our own e-signature

A signature on its own proves nothing. It's a squiggle. Anyone can draw a squiggle.

What makes it evidence is the story around it, and nobody hands you that part.

A signature on a page leaves unanswered questions about identity and consent Signature?Who signed?What did they agree to?
Legally, that is a squiggle. Everything that turns it into proof happens off the page.

So we wrote our own e-signature engine, which in 2026 sounds like a genuinely bad idea.

Here's why. In this business, signing isn't the destination. It's a step in the middle of something longer — the document was built from live association data an hour ago, and things happen to it afterwards.

Renting that step means the workflow stops, walks the document across the road to another company, and waits by the kerb hoping it comes back.

So instead: an envelope goes around the letter or form, and the signers go inside it.

Then you choose how hard to prove they're them. Six ways:

→ a link sent to their email
→ a one-time code by email or text
→ an access code you gave them separately
→ questions only they should be able to answer
→ a scan of their photo ID
→ standing in front of you

Six signer verification choices are presented without implying a universal assurance ranking Choose how to verify the signerEmail linkSent by emailOne-time codeEmail or textAccess codeSeparate codeKnowledgeAnswer questionsPhoto IDDocument scanIn personMeet the signerMatch verification to the signing context
Choose the verification method that fits the document and signing context.
A welcome letter doesn't need a passport. A statement of exactly what a seller owes might.

Consent is recorded under ESIGN and UETA, the two rules that make an electronic signature count. Not just that they agreed — which wording they agreed to.

The document version before signing and the signed version each receive their own recorded fingerprint Record each document versionBefore signingAfter signingEach version has its own fingerprint
Record a fingerprint before and after signing. Check later changes against the recorded version.

Every version of that text is kept and can be pulled back up by its fingerprint.

So the record isn't a vague yes. It's the exact paragraph they read.

The document gets fingerprinted too, before signing and after. Change one comma on page four and the two stop matching.

Then the part nobody thinks about until the day they need it. Every signed document comes with a Certificate of Completion — an audit page clipped to the back.

A signed letter is attached to a completion certificate recording the signer, verification, consent, origin, and events Signed letterCompletion certificateSigner and verificationConsent versionAddress and locationTimed event history
The signature is one line. The certificate is everything that line is standing on.

Who signed. How we proved it was them. From what address, roughly where in the world, which version of the consent text they saw, the signature image, and a timed log of every event from opened to done.

The signature and the story of how it was obtained now travel together, permanently, in one file.

One of them is worthless without the other, and it isn't the story.

Next: the least glamorous AI feature we shipped, and the one that removed the most typing.

#PropTech · #DocumentAutomation