DocuSeal

DocuSeal handles document filling and e-signature: build a form over a PDF, send it,
collect signatures.

Listed with a caveat

Like Chatwoot, this is a standalone Rails application, not a mountable engine. It gets
its own deployment and its own database.

It is here because "we need signatures" comes up often enough that knowing the open
option exists is worth the entry — and because it makes the trade-off concrete: a
second deployment is sometimes genuinely the right call, when nothing mountable covers
the job.

Deploying it

docker run --name docuseal -p 3000:3000 docuseal/docuseal