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live#bf13bd8LohnLabgru141ms2025

E-signature platform with its own SDK

A digital signature platform built as a standalone product: Next.js backend, versioned React SDK and legally valid sealing to ETSI CAdES.

SaaS & Platform Build
Next.jsSupabaseReact SDKOpenAPI

CAdES

ETSI-compliant sealing

SDK

published React package

3.1

OpenAPI as source of truth

stage 01

Starting point

The second product we built with LohnLab: for document workflows with legally valid signatures, the team needed its own e-signature solution - flexible enough to be embedded into several products instead of being tied to an external provider.

stage 02

Approach

We built the platform as a monorepo: a Next.js backend for documents, signing flows, templates and webhooks - plus a headless React SDK, typed from an OpenAPI specification and published with versioned releases through CI/CD.

stage 03

Result

PDF upload, field placement, sequential and parallel signing, sealing to ETSI CAdES, audit trails and webhooks - a product any LohnLab frontend can embed through the SDK.

$git log --graph

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LennartDanielChristian
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