---
title: Developers
description: Signing in your product: a REST API, signed webhooks, an embeddable form, SDKs and AI tools.
---

# Signing in your product, in an afternoon

API, webhooks and embedding are included in every plan. Test mode keeps practice runs out of the real thing.

```sh
curl -X POST https://docustay.app/api/v1/documents/send \
  -H "Authorization: Bearer $DOCUSTAY_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
    "templateId": "TEMPLATE_ID",
    "parties": [{ "seat": "signer_1", "name": "Rosa Alvarez", "email": "rosa@example.com" }]
  }'
```

## The shape of an integration

Your system decides a document is needed and calls the API with a template and the names and emails of the people. Docustay emails them, runs reminders, shows the signing page and seals the result. When it is done, a signed webhook tells your system, and your system downloads the signed copy. Most integrations are a few dozen lines.

## Four ways in

The REST API does everything the app does, within the permissions of a key. Webhooks tell you when something happens. The embeddable signing form shows the signature page inside your own site so nobody is emailed. The SDKs and the MCP server wrap those for JavaScript, Python and AI assistants.

## Practise first

Test keys send practice documents that are emailed only to you, are watermarked, and are never counted or billed. Build and check your whole flow with a test key, then swap in a live key.

## Send a document

```
curl -X POST https://docustay.app/api/v1/documents/send \
  -H "Authorization: Bearer $DOCUSTAY_KEY" \
  -H "Idempotency-Key: $(uuidgen)" -H "Content-Type: application/json" \
  -d '{ "templateId": "TEMPLATE_ID", "language": "en", "parties": [{ "seat": "signer_1", "name": "Rosa Alvarez", "email": "rosa@example.com" }] }'
```

## Questions people ask

**Is the API included in every plan?**

Yes, within your monthly allowance, along with webhooks and embedding.

**Is there a sandbox?**

Test keys are the sandbox: same API, practice documents.

**Where is the API described?**

An OpenAPI 3.1 file at /api/openapi.json and a Postman collection.

## Keep reading

- [The API](/developers/api)
- [SDKs](/developers/sdks)
- [AI tools](/developers/ai-tools)
- [Documentation](/docs)
- [Embedding](/product/embedding)
- [Pricing](/pricing)