Sign

Sign a PDF or DOCX document with a cryptographic signature.

Send a JSON request body with:

• document (required): object containing either base64 or url
• signer (required): signer details — email and name are required; ip and userAgent are optional and, when provided, are recorded in the audit trail certificate. No other signer fields are accepted; use metadata for anything application-specific.
• auditTrail (required): array of signing events. Must include at least one submit event for e-signature compliance.
• eventId (optional): unique identifier for the signing event
• metadata (optional): free-form object for application-specific context (tenantId, contractId, etc.)
• certificate (optional): { enabled: boolean } — controls whether an audit trail certificate page is appended (default: true)

The response returns the signed PDF as base64.

POST /v1/sign

Sign

cURL

curl --request POST \
  --url https://api.superdoc.dev/v1/sign \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "document": {
    "base64": "aSDinaTvuI8gbWludGxpZnk="
  },
  "signer": {
    "email": "[e-mail]",
    "name": "Jane Smith",
    "ip": "203.0.113.42",
    "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36"
  },
  "auditTrail": [
    {
      "timestamp": "2023-11-07T05:31:56Z",
      "data": {}
    }
  ],
  "eventId": "<string>",
  "metadata": {},
  "certificate": {
    "enabled": true
  }
}
'

200

{
  "document": {
    "base64": "<string>",
    "contentType": "<string>"
  }
}

Authorizations

Authorization · string · header · required

API key authentication. Keys start with sd_

Body

application/json

document · base64 · object · required

PDF or DOCX input. Provide exactly one of base64 or url.

base64

url

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signer · object · required

Details of the person applying the signature. email and name are required; ip and userAgent are optional and recorded in the audit trail / certificate page when provided. No other fields are accepted — use metadata for application-specific context.

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auditTrail · object[] · required

Complete event trail of user interactions. Must include at least one submit event for e-signature compliance.

Minimum array length: 1

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eventId · string

Unique identifier for this signing event

metadata · object

Optional application-specific metadata. Free-form object for any context you want to attach to the signing event (e.g. tenantId, contractId, custom audit fields).

certificate · object

Configuration for the audit trail certificate page that is appended to the signed PDF.

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Response

200

application/json

Default Response

document · object · required

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