Recipient Authentication

Before a recipient can access a ceremony, they must authenticate. SignatureAPI supports three authentication methods that you can use individually or combine for added security.

Authentication methods

Email Link (default)

SignatureAPI sends the recipient an email with a direct link. Clicking the link authenticates the recipient automatically.

• No setup required. Works out of the box.
• Simplest experience for recipients.
• Ceremonies are created and emails sent automatically when you create an envelope.

Learn more about Email Link Authentication

Email Code

SignatureAPI sends the recipient an email with a 9-digit verification code. The recipient enters the code to authenticate.

• You receive the ceremony URL to share through your own channels.
• Confirms the recipient has access to their email account.
• Supports SMS, app notifications, or direct links as delivery channels.

Learn more about Email Code Authentication

Custom

Your application authenticates the recipient. SignatureAPI provides a ceremony URL that you share directly or embed in your application.

• Use your existing authentication systems.
• Supports embedded signing experiences.
• Your authentication details are recorded in the audit log.

Learn more about Custom Authentication

Multiple methods

Combine authentication methods for enhanced security. Recipients complete each method in sequence before accessing the ceremony.

Learn more about Multiple Authentication Methods

How to create a ceremony

You can create a ceremony in two ways: automatically when creating an envelope, or manually using the Create Ceremony endpoint.

On envelope creation (automatic)

Pass a ceremony object on each recipient when creating an envelope. SignatureAPI creates the ceremony immediately.

If you omit ceremony, SignatureAPI uses email link authentication by default.

// POST https://api.signatureapi.com/v1/envelopes
// X-API-Key: key_test_...
// Content-Type: application/json

{
    "title": "Service Agreement",
    "recipients": [
        {
            "type": "signer",
            "key": "client",
            "name": "John Doe",
            "email": "john.doe@example.com"
        }
    ],
    "documents": [ /* ... */ ]
}

Create Ceremony endpoint (manual)

Use the Create Ceremony endpoint after the envelope is created. This lets you change authentication methods or create new access for the same recipient.

Common use cases:

• Switch from custom authentication to email link if the recipient hasn’t signed within a set time.
• Provide a new URL after the original one expires.
• Update ceremony settings like the redirect URL.

// POST https://api.signatureapi.com/v1/recipients/{recipient_id}/ceremonies
// X-API-Key: key_test_...
// Content-Type: application/json

{
    "authentication": [
        {
            "type": "email_link"
        }
    ]
}