In-house e-signature for a TMS
Challenge
A freight company's TMS needs two document types signed — the Broker-Carrier Agreement during carrier onboarding and a Rate Confirmation for every load. This used to mean printing, signing by hand, scanning and mailing. External services (DocuSign, Dropbox Sign) charge per document and add a third-party dependency. What was needed: an in-house signing engine, legally sufficient under ESIGN/UETA, with a full audit trail.
What was built
An in-house e-signature engine built on top of the existing PDF-generation infrastructure. A single engine serves both document types. The carrier signs via a public token link from their phone — no login, no app install.
One engine, two documents
Broker-Carrier Agreement (Setup) and Rate Confirmation, a shared request table with document type and entity binding.
Stamping over the PDF (FPDI)
the fixed 23-page legal document is never re-typeset; fields and signature are stamped on top at exact coordinates.
Signing page = intake form
the carrier fills in their own data (USDOT, MC, address) which is both stamped into the PDF and used to create the carrier card.
3 signing methods
type (cursive font), draw (signature_pad) or upload an image; all normalized to PNG for stamping.
Split page
full PDF in an iframe on the left (read-only), form with a live preview of the signature block on the right that fills as you type.
Branded link domain
a dedicated signing subdomain (sign.*) instead of the internal one, for carrier trust.
Audit trail
IP, User-Agent, signing method, statuses sent → viewed → signed; the link is valid for 1 hour from generation.
PDF calibrator
an internal tool to align stamp coordinates: drag x/y per field with a live preview of the stamped PDF.
Cross-deployment RateCon
the RateCon is produced in the loadboard system while signing is orchestrated in dispatch; shared DB and server-to-server calls.
Auto-notifications
Telegram and in-app notifications on signing (to admins and the request initiator).
Result
$0 per document instead of paying for DocuSign. A carrier signs the agreement and RateCon from their phone in a minute, with no printing or scans. The signed PDF lands on the card immediately, and data from the signing form auto-populates the carrier card. Legally sufficient for B2B under ESIGN/UETA — capturing IP, signing method and timestamp.
Tech stack
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