# How to send an envelope

You send an envelope by making a POST request to `/v1/envelopes`. The request includes your document, the parties who need to sign, and the fields where they enter information.

## Add a document to your envelope

The API supports two methods for providing documents:

- **Upload a document** – Send the file directly in your request
- **Use a template** – Reference a pre-configured template by its fingerprint


The two methods differ in how you configure and send documents:

|  | Upload a document | Use a template |
|  --- | --- | --- |
| Document source | File sent in request | Template fingerprint |
| Field placement | Tags in document | Pre-configured in web app |
| Party assignment | Defined in request | Assigned to template roles |
| Setup required | None | Create template first |


Before you begin, ensure you have authenticated with the API. For instructions on using your API key, see the [Authentication documentation](/authentication).

Upload a document
Upload a document when you send files that vary between recipients or when you generate documents programmatically.

You define signature fields using tags — special markers such as `{signature:signer1}` or `{date:signer1}` that you place in your document before uploading. Signable detects these tags and creates interactive fields at those locations.

**Use this method for:**

- One-off contracts or agreements
- Documents generated from your application
- Situations where content or field placement changes each time


For more information, see [Send an envelope with an uploaded document](/guides/send-envelope/send-envelope-uploaded-document).

Use a template
Use a template when you send the same document structure repeatedly with different signers.

Templates store your document, field positions, and party roles. You create templates in the Signable web app, then reference them by fingerprint when sending envelopes using the API. You can prefill fields with recipient-specific data at send time.

**Use this method for:**

- Standardised forms you send frequently
- Workflows with defined party roles (such as "Employee" and "Manager")
- High-volume sending where consistency matters


For more information, see [Send an envelope using a template](/guides/send-envelope/send-envelope-template).

You can only use one document input method per request. You cannot upload a document and provide a template fingerprint in the same API call.

## Related documentation

- [Signable concepts](/concepts) – Understand envelopes, parties, and fields
- [Tags](/tags) – Place fields automatically using text markers
- [Webhooks](/webhooks) – Receive notifications when envelopes are signed