Dropbox Sign

API

eSignature API for signature requests, templates and embedded signing

Price: Paid plans; free test mode
Access: API key (Basic auth)

About

Dropbox's eSignature API (formerly HelloSign) for sending signature requests, reusing templates and embedding signing in your app. Every endpoint works free in test mode, which is watermarked and not legally binding; production sends need a paid API plan.

What you can do with it

Send a PDF for signature by email and download the signed copy
Embed signing or request preparation in your app inside an iFrame
Bulk send signature requests from a saved template

Get started

Create a free API account and generate an API key
Send requests with test_mode=1 until you pick a paid plan

Example

curl -X POST 'https://api.hellosign.com/v3/signature_request/send' \
  -u "$DROPBOX_SIGN_API_KEY:" \
  -F 'files[0]=@contract.pdf' \
  -F 'title=NDA with Acme Co.' \
  -F 'subject=The NDA we talked about' \
  -F 'signers[0][email_address]=jack@example.com' \
  -F 'signers[0][name]=Jack' \
  -F 'test_mode=1'

Details

Hosting: Hosted service
Available in: Worldwide
Official SDKs: Python, JavaScript/TypeScript, PHP, C#, Ruby, Java
MCP server: None