Product
Send from your code
Send documents from your own code with a REST API and typed clients for JavaScript and Python. The deeper guide is on the Developers pages.
curl -X POST https://app.docustay.app/api/v1/documents/send \
-H "Authorization: Bearer $DOCUSTAY_KEY" \
-H "Idempotency-Key: lease-2026-0001" \
-H "Content-Type: application/json" \
-d '{ "templateId": "TEMPLATE_ID", "parties": [{ "seat": "signer_1", "name": "Rosa Alvarez", "email": "rosa@example.com" }] }' Sending is one call. Repeating it with the same Idempotency-Key returns the first answer, not a second document.
What is in the box
| Package | What it is | Licence |
|---|---|---|
@docustay/sdk | JavaScript and TypeScript client | MIT |
docustay | Python client | MIT |
@docustay/react, @docustay/vue, @docustay/angular | Wrappers for the signing element | MIT |
@docustay/embed | The <docustay-sign> element | MIT |
@docustay/mcp | MCP server for AI assistants | MIT |
The client packages are MIT, so using them never makes your own software AGPL. Read how the licences fit.

Five lines to send a document
With a key and a template id, sending is one call: the template, the people and their seats. The answer is the document's id and state, and how many signing emails went out. Poll the document, or let a signed webhook tell you when it is signed, then download the sealed PDF.
Clients that do the boring parts
The JavaScript and Python clients retry safely, add an Idempotency-Key for you, walk through pages of results and check webhook signatures in a few lines. They are MIT licensed, so you can put them in any application.
Where to go next
The Developers pages have the quickstart, the full reference generated from the same file the API publishes, the webhook guide, the SDK guides and the AI tools. Keys, scopes and test mode are explained on the authentication page.
What a first integration looks like
Most teams start by creating a test key, sending one practice document to themselves and reading the answer. Next they add the webhook endpoint that tells their system when a document is signed, then switch to a live key. Nothing in that path needs a call with anyone, and the test key never emails the people you name.
Questions people ask
Is the API in every plan?
Yes, within your monthly allowance.
Can I try it without sending real email?
Yes. A test key makes practice documents that are emailed only to you.
Is there a file I can load into other tools?
Yes, the OpenAPI file, and a Postman collection made from it.
Keep reading
Go deeper in Developers
The quickstart, the full reference, webhooks and the SDK guides are on the Developers pages.